As filed with the Securities and Exchange Commission on January 28, 2019

Registration No. 333-          

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

OPKO Health, Inc.

(Exact name of registrant as specified in its charter)

4400 Biscayne Blvd.

Miami, FL 33137

(305) 575-4100

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Kate Inman, Esq.

General Counsel and Secretary

OPKO Health, Inc.

4400 Biscayne Blvd.

Miami, Florida 33137

(305) 575-4100

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this registration statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☒

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

CALCULATION OF REGISTRATION FEE

PROSPECTUS

Common Stock

Preferred Stock

Debt Securities

Depositary Shares

Warrants

Purchase Contracts

Units

We or any selling stockholder may offer and sell from time to time, in one or more series or issuances and on terms that we will determine at the time of the offering, any combination of the securities described in this prospectus.

This prospectus provides you with a general description of the securities we or any selling stockholder may offer and sell. We will provide specific terms of any offering in a supplement to this prospectus. Any prospectus supplement may also add, update, or change information contained in this prospectus. You should carefully read this prospectus and the applicable prospectus supplement as well as the documents incorporated or deemed to be incorporated by reference in this prospectus before you invest in any of our securities.

We or any selling stockholder may offer and sell in the same offering or in separate offerings; to or through underwriters, dealers and agents; or directly to purchasers. The names of any underwriters, dealers, or agents involved in the sale of our securities and any applicable fees, commissions, or discounts will be described in the applicable prospectus supplement. Our net proceeds from the sale of securities will also be set forth in the applicable prospectus supplement. We will not receive any proceeds from the sale of securities by selling stockholders.

This prospectus may not be used to consummate a sale of our securities unless accompanied by the applicable prospectus supplement.

Our common stock is listed on the Nasdaq Global Select Market of The Nasdaq Stock Market LLC under the symbol “OPK.”

Investing in our securities involves a high degree of risk. See the “Risk Factors” section beginning on page 1 of this prospectus for a discussion of information that should be considered in connection with an investment in our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is January 28, 2019.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we and/or selling stockholders may sell, from time to time, any combination of the securities described in this prospectus in one or more offerings. This prospectus provides you with general information regarding the securities we and/or selling stockholders may offer. We will provide a prospectus supplement that contains specific information about any offering by us and/or selling stockholders.

The prospectus supplement also may add, update, or change information contained in the prospectus. You should read both this prospectus and the prospectus supplement related to any offering as well as additional information described under the headings “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.”

Neither we nor any selling stockholder has authorized anyone to provide you with information different from that contained or incorporated by reference in this prospectus or any accompanying prospectus supplement or any “free writing prospectus.” We and/or selling stockholders are offering to sell, and seeking offers to buy, securities only in jurisdictions where offers and sales are permitted. The information contained in this prospectus and in any accompanying prospectus supplement is accurate only as of the dates of their covers, regardless of the time of delivery of this prospectus or any prospectus supplement or of any sale of our securities. Our business, financial condition, results of operations, and prospects may have changed since those dates. You should rely only on the information contained or incorporated by reference in this prospectus or any accompanying prospectus supplement. To the extent there is a conflict between the information contained in this prospectus and the prospectus supplement, you should rely on the information in the prospectus supplement, provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference into this prospectus or any prospectus supplement — the statement in the document having the later date modifies or supersedes the earlier statement.

Unless the context otherwise requires, the terms “OPKO,” “Company,” “we,” “us,”, “our”, or “ours” refer to OPKO Health, Inc., a Delaware corporation, including its wholly-owned subsidiaries.

RISK FACTORS

Investing in our securities involves a high degree of risk. Before making an investment decision, you should carefully consider the discussion of risks and uncertainties under the heading “Risk Factors” contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, which is incorporated by reference in this prospectus, and under similar headings in our subsequently filed Quarterly Reports on Form 10-Q, any Current Reports on Form 8-K that are filed with the SEC and Annual Reports on Form 10-K, as well as the other risks and uncertainties described in any applicable prospectus supplement or free writing prospectus and in the other documents incorporated by reference in this prospectus. See the sections entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus. The risks and uncertainties we discuss in this prospectus, in any applicable prospectus supplement or free writing prospectus and in the other documents incorporated by reference in this prospectus are not the only ones facing our company. Additional risks and uncertainties not presently known to us or that we currently believe are immaterial also may materially and adversely affect our business, financial condition and results of operations. Please also refer to the section of this prospectus titled “Cautionary Statement About Forward Looking Statements.”

CAUTIONARY STATEMENT ABOUT FORWARD-LOOKING STATEMENTS

This prospectus, any applicable prospectus supplement and the documents and information incorporated by reference herein and therein may contain “forward-looking statements” within the meaning of Section 27A of the

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Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Forward-looking statements may include, but are not limited to, statements relating to our objectives, plans and strategies as well as statements, other than historical facts, that address activities, events, or developments that we intend, expect, project, believe or anticipate will or may occur in the future. These statements are often characterized by terminology such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “potential,” or “continue” or the negative of these terms or other similar expressions.

Forward-looking statements are based on assumptions and assessments made in light of our experience and perception of historical trends, current conditions, expected future developments and other factors believed to be appropriate. Forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties, many of which are outside of our control. You should not place undue reliance on these forward-looking statements, which reflect our view only as of the date of this prospectus, and we undertake no obligation to update these forward-looking statements in the future, except as required by applicable law.

A number of important factors could cause actual results to differ materially from those indicated by the forward-looking statements, including, without limitation, those factors described under the heading “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2017, which is incorporated by reference in this prospectus, and under similar headings in our subsequently filed Quarterly Reports on Form 10-Q, any Current Reports on Form 8-K that are filed with the SEC and Annual Reports on Form 10-K, as well as the other risks and uncertainties described in any applicable prospectus supplement or free writing prospectus and in the other documents incorporated by reference in this prospectus. Some of the key factors that could cause actual results to differ from our expectations include the following:

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OUR COMPANY

We are a diversified healthcare company that seeks to establish industry-leading positions in large and rapidly growing medical markets. Our diagnostics business includes BioReference Laboratories, the nation’s third-largest clinical laboratory with a core genetic testing business and an almost 400-person sales and marketing team to drive growth and leverage new products, including the 4Kscore prostate cancer test and the Claros 1 in-

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office immunoassay platform (in development). Our pharmaceutical business features Rayaldee, a U.S. Food and Drug Administration (“FDA”)- approved treatment for secondary hyperparathyroidism in adults with stage 3 or 4 chronic kidney disease and vitamin D insufficiency (launched in November 2016), OPK88004, a selective androgen receptor modulator currently being studied for benign prostatic hyperplasia but for which we are exploring other potential indications, and OPK88003, a once or twice weekly oxyntomodulin for type 2 diabetes and obesity which is a clinically advanced drug candidate among the new class of GLP-1 glucagon receptor dual agonists (phase 2b). Our pharmaceutical business also features hGH-CTP, a once-weekly human growth hormone injection (in phase 3 and partnered with Pfizer Inc. (“Pfizer”)).

We operate established pharmaceutical platforms in Spain, Ireland, Chile and Mexico, which are generating revenue and from which we expect to generate positive cash flow and facilitate future market entry for our products currently in development. We have a development and commercial supply pharmaceutical company, as well as a global supply chain operation and holding company in Ireland, which we expect will play an important role in the development, manufacturing, distribution and approval of a wide variety of drugs with an emphasis on high potency products. We also own a specialty active pharmaceutical ingredients manufacturer in Israel, which we expect will facilitate the development of our pipeline of molecules and compounds for our proprietary molecular diagnostic and therapeutic products.

We are a Delaware corporation. We maintain our principal executive offices at 4400 Biscayne Blvd., Miami, FL 33137. Our telephone number is (305) 575-4100. We maintain a website at www.opko.com. The information contained on our websites or that can be accessed through our website does not constitute part of this prospectus or the accompanying prospectus supplement.

USE OF PROCEEDS

Except as may be otherwise set forth in any prospectus supplement accompanying this prospectus, we will use the net proceeds we receive from sales of securities offered hereby to fund research and development to further develop and commercialize our portfolio of proprietary pharmaceutical and diagnostic products and for working capital, capital expenditures, acquisitions and other general corporate purposes, which may include the repayment or repurchase of indebtedness or debt securities outstanding from time to time. Pending these uses, the net proceeds may also be temporarily invested in cash equivalents or short-term securities. When specific securities are offered, the prospectus supplement relating thereto will set forth our intended use of the net proceeds that we receive from the sale of such securities.

SELLING STOCKHOLDERS

Selling stockholders are persons or entities that, directly or indirectly, have acquired or will from time to time acquire from us, our securities. Such selling stockholders may be parties to registration rights agreements with us, or we otherwise may have agreed or will agree to register their securities for resale. The initial purchasers of our securities, as well as their transferees, pledges, donees or successors, all of whom we refer to as “selling stockholders,” may from time to time offer and sell our securities pursuant to this prospectus and any applicable prospectus supplement.

The applicable prospectus supplement will set forth the name of each of the selling stockholders and the number of securities beneficially owned by such selling stockholder that are covered by such prospectus supplement. The applicable prospectus supplement will also disclose whether any of the selling stockholders has held any position or office with, has been employed by or otherwise has had a material relationship with us during the three years prior to the date of the applicable prospectus supplement.

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DILUTION

We will set forth in a prospectus supplement the following information regarding any material dilution of the equity interests of investors purchasing securities in an offering under this prospectus:

DESCRIPTION OF CAPITAL STOCK

General

This section describes the general terms of our capital stock. A prospectus supplement may provide information that is different from this prospectus. If the information in the prospectus supplement with respect to our stock being offered differs from this prospectus, you should rely on the information in the prospectus supplement. A copy of our amended and restated certificate of incorporation, as amended, which we refer to as our Amended and Restated Certificate of Incorporation, and our amended and restated bylaws, which we refer to as our Amended and Restated Bylaws, have been incorporated by reference from our filings with the SEC as an exhibit to the registration statement of which this prospectus forms a part. Our stock and the rights of the holders of our stock are subject to the applicable provisions of the General Corporation Law of the State of Delaware, which we refer to as the DGCL, our Amended and Restated Certificate of Incorporation, our Amended and Restated Bylaws, as well as some of the terms of our outstanding indebtedness.

The description below of our stock and provisions of our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws are summaries and are qualified by reference to the Amended and Restated Certificate of Incorporation and our Amended and Restated Bylaws, and by the applicable provisions of the DGCL.

Our authorized capital stock consists of 760,000,000 shares of capital stock, of which: (i) 750,000,000 shares are designated as common stock, par value $0.01 per share; and (ii) 10,000,000 shares are designated as preferred stock, par value $0.01 per share. As of December 31, 2018, there were 586,331,543 shares of common stock issued and outstanding and no shares of preferred stock issued and outstanding.

Common Stock

Voting Rights

The holders of shares of our common stock are entitled to one vote per share in connection with the election of directors and all other matters submitted to a vote of stockholders. The holders of shares of our common stock do not have cumulative voting rights.

Dividend Rights

Subject to any preferential dividend rights of holders of any then outstanding shares of our preferred stock and our Amended and Restated Certificate of Incorporation, the holders of shares of our common stock shall be entitled to receive, on a pro rata basis, such dividends and other distributions in cash, stock or property when, as and if declared thereon by our board of directors from time to time out of our assets or funds legally available therefor. No dividends have been paid to holders of shares of our common stock since our incorporation, and no dividends are anticipated to be declared or paid in the reasonably foreseeable future.

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Liquidation Rights

After payments to creditors and subject to any preferential liquidation, dissolution or winding up rights of holders of any then outstanding shares of our preferred stock, the holders of shares of our common stock are entitled to share ratably in all of our remaining assets and funds available for distribution to holders of shares of our common stock upon the liquidation, dissolution or winding-up of our affairs.

Other Matters

Holders of shares of our common stock do not have any preemptive, subscription, redemption or conversion rights. All of the shares of our common stock currently issued and outstanding are fully-paid and nonassessable.

Preferred Stock

Under our Amended and Restated Certificate of Incorporation, our board of directors has the authority, without further action by stockholders, to divide shares of our preferred stock into such number of series as our board of directors may determine and to determine and alter, from time to time, the designations, rights, preferences, privileges and restrictions granted to and imposed upon any wholly unissued series of our preferred stock, including dividend rights, dividend rate, conversion rights, voting rights, rights and terms of redemption (including sinking fund provisions), redemption price or prices, and the liquidation preference of any wholly unissued series of our preferred stock, any or all of which may be greater than the rights of our common stock, and to establish the number of shares constituting any such series. The issuance of preferred stock with voting rights or conversion rights may adversely affect the voting power of our common stock, including the loss of voting control to others. The issuance of preferred stock may also have the effect of delaying, deferring or preventing a change in control of our company without stockholder approval.

Series A Convertible Preferred Stock

Of the authorized preferred stock, 4,000,000 shares are designated “Series A Convertible Preferred Stock”. We redeemed all previously issued and outstanding shares of our Series A Convertible Preferred Stock.

Voting Rights

The holders of record of our Series A Convertible Preferred Stock were and would be entitled to notice of, and to vote on or consent to, all actions on which holders of shares of our common stock are required or permitted to act upon. On all matters requiring or permitting a vote or consent of the holders of common stock, each share of Series A Convertible Preferred Stock was and would be equivalent to one share of common stock and all shares of Series A Convertible Preferred Stock were and would be voted together with the shares of common stock as a single class, except as otherwise provided by our Amended and Restated Certificate of Incorporation or our Amended and Restated Bylaws or by law. So long as shares of Series A Convertible Preferred Stock were and would be outstanding, without the approval of the holders of record of at least a majority of the then outstanding shares of Series A Convertible Preferred Stock, voting separately as a class, we were not and would not be permitted to (i) alter or change the rights, preferences, privileges or restrictions of shares of Series A Preferred so as to affect them adversely; or (ii) increase the authorized number of shares of Series A Convertible Preferred Stock.

Dividend Rights

Holders of record of our Series A Convertible Preferred Stock were and would be entitled to receive dividends in the amount of $0.25 per share, payable annually in arrears. At the option of our board of directors, dividends were and would be payable to the extent lawfully permitted either (i) wholly or partially in cash or (ii) in newly issued shares of Series A Convertible Preferred Stock valued as set forth in our Amended and Restated Certificate of Incorporation.

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Liquidation Rights

In the event of a liquidation, dissolution or winding-up, the holders of record of our Series A Convertible Preferred Stock were and would be entitled to receive ratably in full, out of our lawfully available assets, an amount in cash per outstanding share of Series A Convertible Preferred Stock equal to the sum of $2.50 and all dividends (whether or not declared) accrued and unpaid thereon as of the date of final distribution to such holders, without interest, before any payment shall be made or any assets distributed to the holders of common stock or any other class or series of our capital stock ranking junior as to liquidation rights to the Series A Convertible Preferred Stock; provided, however, that such rights would accrue to the holders of Series A Convertible Preferred Stock only in the event our payments with respect to the liquidation preferences of any holders of capital stock ranking senior as to liquidation rights to our Series A Convertible Preferred Stock (the “Senior Liquidation Stock”) are fully met. If, upon any liquidation, dissolution and winding-up, the amount available for such payment to the holders of Series A Convertible Preferred Stock would not be sufficient to pay in full the amounts payable on the Series A Convertible Preferred Stock, the holders of the Series A Convertible Preferred Stock and any other class or series of the our capital stock which may be created having parity as to liquidation rights with the Series A Convertible Preferred Stock would share in the distribution of the amount available in proportion to the respective preferential amounts to which each is entitled.

The liquidation preference of our Series A Convertible Preferred Stock is subject to proportional adjustment as set forth in our Amended and Restated Certificate of Incorporation.

Conversion Rights

Each share of Series A Convertible Preferred Stock was and would be convertible, at the option of the holder of record, into fully paid and nonassessable shares of our common stock. Shares of Series A Convertible Preferred Stock were and would be convertible into the number of shares of our common stock determined by dividing (i) the number of shares of Series A Convertible Preferred Stock (including additional shares) held by a holder by (ii) a divisor equal to $2.50, subject to certain adjustments set forth in our Amended and Restated Certificate of Incorporation.

Optional Redemption

Shares of Series A Convertible Preferred Stock were and would be redeemable, at our option, in whole or in part, at any time and from time to time, if the average closing bid price of our common stock was at least $3.75 per share for any 30 consecutive trading days ending within 15 days prior to the date on which we give notice of redemption of shares of Series A Convertible Preferred Stock. The redemption price was and would be $2.50 per share plus a sum equal to the accrued but unpaid dividends on the Series A Convertible Preferred Stock.

Series C Convertible Preferred Stock

Of the authorized preferred stock, 500,000 shares are designated “Series C Convertible Preferred Stock”. All previously issued and outstanding shares of Series C Convertible Preferred Stock automatically converted into shares of our common stock, on a one–hundred–for–one basis.

Voting Rights

Except as otherwise expressly provided in our Amended and Restated Certificate of Incorporation or as otherwise required by law, (i) each holder of Series C Convertible Preferred Stock was and would be entitled to vote on all matters submitted to a vote of our stockholders and was and would be entitled to that number of votes equal to the largest number of whole shares of common stock into which such holder’s shares of Series C Convertible Preferred Stock could be converted, at the record date for the determination of stockholders entitled to vote on such matters or, if no such record date is established, at the date such vote is taken or any written consent of stockholders is solicited, and (ii) the holders of shares of preferred stock and common stock would vote together (or tender written consents in lieu of a vote) as a single class on all matters submitted to our stockholders.

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Dividend Rights

The holders of shares of Series C Convertible Preferred Stock were and would be entitled to receive, when, as and if declared by our board of directors, out of our assets legally available therefor, prior and in preference to any declaration or payment of any dividend on our common stock or any other class or series of our capital stock ranking junior to the Series C Convertible Preferred Stock with respect to the payment of dividends, and subject to the rights to dividends of any class or series of our preferred stock ranking senior or on parity with our Series C Convertible Preferred Stock with respect to dividends, cumulative cash dividends at the rate per share as set forth in our Amended and Restated Certificate of Incorporation. Whenever we would declare a dividend on our common stock, the holders of the Series C Convertible Preferred Stock were and would be also entitled to receive dividends in an amount equal per share (on an as-if-converted to common stock basis) to the amount paid or set aside for each share of our common stock.

Liquidation Rights

In the event of any liquidation, dissolution or winding up, or in the event of our insolvency, distributions to our stockholders would be made in the following manner:

(i) First, before any distribution or payment is made to any holders of common stock or any other class or series of capital stock, the holders of Series C Convertible Preferred Stock would be entitled to be paid first out of the assets of the Company available for distribution to holders of capital stock of all classes and series, whether such assets are capital, surplus or earnings (collectively, “Available Assets”), an amount per share equal to the Series C Preferential Amount (as defined in our Amended and Restated Certificate of Incorporation).

(ii) After payment of the Series C Preferential Amount to all holders of the Series C Convertible Preferred Stock and payment of any other preference amounts to the holders of any other class or series of preferred stock entitled to a liquidation preference, the entire remaining Available Assets, if any, would be distributed among the holders of common stock, Series C Convertible Preferred Stock and any other class or series of preferred stock entitled to participate with the common stock in a liquidating distribution, pro rata in proportion to the shares of common stock then held by them and the shares of common stock which they then have the right to acquire upon conversion of such shares of preferred stock held by them.

Conversion Rights

The Series C Convertible Preferred Stock was and would be subject to conversion into shares of common stock at the option of the holder and upon certain specified events, in each case as set forth in our Amended and Restated Certificate of Incorporation.

8% Series D Cumulative Convertible Preferred Stock

Of the authorized preferred stock, 2,000,000 shares are designated “8% Series D Cumulative Convertible Preferred Stock” (“Series D Preferred Stock”). All previously issued and outstanding shares of our Series D Preferred Stock were converted into shares of our common stock.

Voting Rights

The holders of Series D Preferred Stock had and would have the right to receive notice of any meeting of holders of our common stock or Series D Preferred Stock and to vote (on an as–converted into common stock basis) upon any matter submitted to a vote of the holders of common stock or Series D Preferred Stock. Except as otherwise expressly set forth in our Amended and Restated Certificate of Incorporation, the holders of Series D Preferred Stock would vote on each matter submitted to them with the holders of common stock and all other classes and series of our capital stock entitled to vote on such matter, taken together as a single class.

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Dividend Rights

Holders of shares of the Series D Preferred Stock were and would be entitled to receive, when, as and if declared by our board of directors, out of funds legally available therefor, dividends on each share of Series D Preferred Stock at a rate per annum equal to 8.0% of the sum of (i) $24.80 as adjusted in accordance with our Amended and Restated Certificate of Incorporation for each stock combination, stock split, recapitalization, or similar corporate action that is the functional equivalent of any of the foregoing, plus (ii) any and all declared and unpaid and accrued dividends thereon. All dividends described in the foregoing sentence were and would be cumulative, whether or not earned or declared, and accrued on an annual basis from the issue date of the Series D Preferred Stock. Whenever we would declare and pay or make a dividend or any other distribution on or with respect to shares of any class of our common stock, holders of shares of the Series D Preferred Stock were and would also be entitled to receive in respect of each share of Series D Preferred Stock, a dividend or distribution in an amount equal to the amount of such dividend or distribution received by a holder of the number of shares of our common stock for which such share of Series D Preferred Stock is convertible on the date of the payment of such dividend or distribution to holders of our common stock.

Rank and Liquidation Rights

With respect to dividend distributions (other than required dividends to the holders of our Series A Convertible Preferred Stock) and distributions upon liquidation, winding up or our dissolution, the Series D Preferred Stock ranked and would rank senior to all classes of our common stock, our Series A Convertible Preferred Stock, our Series C Convertible Preferred Stock and to each other class of our capital stock that is not specifically designated as ranking senior to or pari passu with our Series D Preferred Stock.

Conversion Rights

The Series D Preferred Stock was and would be subject to conversion into shares of common stock at the option of the holder and upon certain specified events, in each case as set forth in the certificate of designation with respect to the Series D Preferred Stock.

Certain Amended and Restated Certificate of Incorporation and Bylaws Provisions

Requirements for Advance Notification of Stockholder Nominations and Proposals

Our Amended and Restated Bylaws establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the board of directors or one of its committees or other matters properly brought by a stockholder under Rule 14a-8 promulgated under the Exchange Act.

Special Meetings

Our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws provide that, except as otherwise required by law, special meetings of the stockholders may only be called by the chairman of the board of directors, the Chief Executive Officer, or by the board of directors acting pursuant to a resolution approved by the affirmative vote of a majority of the whole board. Only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders.

No Cumulative Voting

Section 214 of the DGCL provides that the certificate of incorporation of any corporation may provide stockholders with the right to cumulate votes in the election of directors. Our Amended and Restated Certificate of Incorporation does not provide for cumulative voting of shares of our stock.

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Delaware Anti-Takeover Law

We are a Delaware corporation subject to Section 203 of the DGCL. Under Section 203, certain “business combinations” between a Delaware corporation whose stock is listed on a national securities exchange or held of record by more than 2,000 stockholders and an “interested stockholder” are prohibited for a three-year period following the date that such stockholder became an interested stockholder, unless:

The three-year prohibition also does not apply to some business combinations proposed by an interested stockholder following the announcement or notification of an extraordinary transaction involving the corporation and a person who had not been an interested stockholder during the previous three years or who became an interested stockholder with the approval of a majority of the corporation’s directors. The term “business combination” is defined generally to include mergers or consolidations between a Delaware corporation and an interested stockholder, transactions with an interested stockholder involving the assets or stock of the corporation or its majority-owned subsidiaries and transactions which increase an interested stockholder’s percentage ownership of stock, or other transaction resulting in a financial benefit to the interested stockholder. The term “interested stockholder” is defined generally as those stockholders who become beneficial owners of 15% or more of a Delaware corporation’s voting stock, together with the affiliates or associates of that stockholder.

Listing

Our common stock is listed on the NASDAQ Global Select Market under the trading symbol “OPK.”

Transfer Agent and Registrar

The Transfer Agent and Registrar for our common stock is American Stock Transfer & Trust Company. The registrar and transfer agent for our preferred stock will be set forth in the applicable prospectus supplement.

DESCRIPTION OF DEBT SECURITIES

This prospectus describes certain general terms and provisions of the debt securities that we may offer under this prospectus and one or more prospectus supplements. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a prospectus supplement. The following description of debt securities will apply to the debt securities offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of debt securities may specify different or additional terms.

We may issue “senior,” “senior subordinated,” or “subordinated” debt securities. “Senior securities” will be direct obligations of ours and will rank equally and ratably in right of payment with other indebtedness of ours

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that is not subordinated. “Senior subordinated securities” will be subordinated in right of payment to the prior payment in full of senior indebtedness, as defined in the applicable prospectus supplement, and may rank equally and ratably with any other senior subordinated indebtedness. “Subordinated securities” will be subordinated in right of payment to senior subordinated securities.

We need not issue all debt securities of one series at the same time. Unless we provide otherwise, we may reopen a series, without the consent of the holders of such series, for issuances of additional securities of that series.

We will issue the senior debt securities and senior subordinated debt securities under a senior indenture, which we will enter into with a trustee to be named in the senior indenture, and we will issue the subordinated debt securities under a subordinated indenture, which we will enter into with a trustee to be named in the subordinated indenture. We use the term “indenture” or “indentures” to refer to both the senior indenture and the subordinated indenture. Each indenture will be subject to and governed by the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act, and we may supplement the indenture from time to time. Any trustee under any indenture may resign or be removed with respect to one or more series of debt securities, and we may appoint a successor trustee to act with respect to that series. We have filed a form of indenture as an exhibit to this registration statement, of which this prospectus forms a part. The terms of the senior indenture and subordinated indenture will be substantially similar, except that the subordinated indenture will include provisions pertaining to the subordination of the subordinated debt securities and senior subordinated debt securities to the senior debt securities and any other of our senior securities. The following statements relating to the debt securities and the indenture are summaries only, are subject to change, and are qualified in their entirety to the detailed provisions of the indenture, any supplemental indenture, and the discussion contained in any prospectus supplements.

General

The debt securities will be our direct obligations. We may issue debt securities from time to time and in one or more series as our board of directors may establish by resolution or as we may establish in one or more supplemental indentures. The particular terms of each series of debt securities will be described in a prospectus supplement relating to the series. We may issue debt securities with terms different from those of debt securities that we previously issued.

We may issue debt securities from time to time and in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will set forth in a prospectus supplement, relating to any series of debt securities being offered, the initial offering price, and the following terms of the debt securities:

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We may issue debt securities that are exchangeable for or convertible into shares of our common stock or other securities or property. The terms, if any, on which the debt securities may be exchanged for or converted into shares of our common stock or other securities or property will be set forth in the applicable prospectus supplement. Such terms may include provisions for conversion, either mandatory, at the option of the holder or at our option, in which case the number of shares of common stock or other securities or property to be received by the holders of debt securities would be calculated as of a time and in the manner stated in the prospectus supplement.

We may issue debt securities at less than the principal amount payable upon maturity. We refer to these securities as “original issue discount securities.” If material or applicable, we will describe in the applicable prospectus supplement special U.S. federal income tax, accounting, and other considerations applicable to original issue discount securities.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and interest and any additional amounts on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will describe the restrictions, elections, general tax considerations, specific terms, and provide other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Except as may be set forth in any prospectus supplement relating to the debt securities, no indenture will contain any other provisions that would limit our ability to incur indebtedness or that would afford holders of the debt securities protection in the event of a highly leveraged or similar transaction involving us or in the event of a change in control. You should review carefully the applicable prospectus supplement for information with respect to events of default and any covenants applicable to the debt securities being offered.

Payments and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

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We will pay principal of, and interest and any additional amounts on, the debt securities of a particular series at the office of the paying agents designated by us, except that, unless we otherwise indicate in the applicable prospectus supplement, we may make interest payments by check, which we will mail to the holder, or by wire transfer to certain holders. Unless we otherwise indicate in a prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series.

Form, Transfer, and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, as depositary, or a nominee of the depositary (as a “book-entry debt security”), or a certificate issued in definitive registered form (as a “certificated debt security”), as described in the applicable prospectus supplement. Except as described under “Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities

A holder of our debt securities may transfer or exchange certificated debt securities at the trustee’s office or paying agencies in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

A holder of our debt securities may transfer certificated debt securities and the right to receive the principal of, and interest and any additional amounts on, certificated debt securities only by surrendering the old certificate representing those certificated debt securities and either we or the trustee will reissue the old certificate to the new holder, or we or the trustee will issue a new certificate to the new holder.

Global Debt Securities and Book-Entry System

Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the depositary, and registered in the name of the depositary or a nominee of the depositary. Ownership of beneficial interests in book-entry debt securities will be limited to persons that have accounts with the depositary for the related global debt security, whom we refer to as participants, or persons that may hold interests through participants.

Except as described in this prospectus or any applicable prospectus supplement, beneficial owners of book-entry debt securities will not be entitled to have securities registered in their names, will not receive or be entitled to receive physical delivery of a certificate in definitive form representing securities, and will not be considered the owners or holders of those securities under the indenture. Accordingly, to exercise any rights of a holder under the indenture, each person beneficially owning book-entry debt securities must rely on the procedures of the depositary for the related global debt security and, if that person is not a participant, on the procedures of the participant through which that person owns its interest.

We understand, however, that under existing industry practice, the depositary will authorize the persons on whose behalf it holds a global debt security to exercise certain rights of holders of debt securities, and the indenture provides that we, the trustee, and our respective agents will treat as the holder of a debt security the persons specified in a written statement of the depositary with respect to that global debt security for purposes of obtaining any consents or directions required to be given by holders of the debt securities pursuant to the indenture.

We will make payments of principal of, and interest and any additional amounts on, book-entry debt securities to the depositary or its nominee, as the case may be, as the registered holder of the related global debt security. We,

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the trustee, and any other agent of ours or agent of the trustee will not have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising, or reviewing any records relating to such beneficial ownership interests.

Any certificated debt securities issued in exchange for a global debt security will be registered in such name or names as the depositary shall instruct the trustee. We expect that such instructions will be based upon directions received by the depositary from participants with respect to ownership of book-entry debt securities relating to such global debt security.

For additional discussion of book entry and certificated securities, see the section entitled “Legal Ownership of Securities” included in this prospectus. We have obtained the foregoing information in this section and the “Legal Ownership of Securities” section concerning the depositary and the depositary’s book-entry system from sources we believe to be reliable. We take no responsibility for the depositary’s performance of its obligations under the rules and regulations governing its operations.

No Protection in the Event of a Change in Control

Unless we provide otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control).

Covenants

Unless we provide otherwise in the applicable prospectus supplement, the debt securities will not contain any restrictive covenants, including covenants restricting us or any of our subsidiaries from incurring, issuing, assuming, or guaranteeing any indebtedness secured by a lien on any of our or our subsidiaries’ property or capital stock or restricting us or any of our subsidiaries from entering into any sale and leaseback transactions.

Merger, Consolidation, and Sale of Assets

Unless we provide otherwise in the applicable prospectus supplement, we may not merge with or into or consolidate with, or convey, transfer, or lease all or substantially all of our properties and assets to, any person (a “successor person”), unless the following applies:

This covenant would not apply to any recapitalization transaction, a change in control of us, or a transaction in which we incur a large amount of additional debt unless the transactions or change in control included a merger, consolidation, or transfer or lease of substantially all of our assets. Except as may be described in the applicable prospectus supplement, there are no covenants or other provisions in the indenture providing for a “put” right or increased interest or that would otherwise afford holders of debt securities additional protection in the event of a recapitalization transaction, a change in control of us, or a transaction in which we incur a large amount of additional debt.

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Events of Default Under the Indenture

Unless we provide otherwise in the applicable prospectus supplement, an “event of default” will mean, with respect to any series of debt securities, any of the following:

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency, or reorganization) necessarily will constitute an event of default with respect to any other series of debt securities. An event of default may also be an event of default under our bank credit agreements or other debt securities in existence from time to time and under certain guaranties by us of any subsidiary indebtedness. In addition, certain events of default or an acceleration under the indenture may also be an event of default under some of our other indebtedness outstanding from time to time.

Unless we provide otherwise in the applicable prospectus supplement, if an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing (other than certain events of our bankruptcy, insolvency, or reorganization), then the trustee or the holders of not less than a majority in principal amount of the outstanding debt securities of that series may, by written notice to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and accrued and unpaid interest, if any, of all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency, or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, of all outstanding debt securities will become and be immediately due and payable without any declaration or other act by the trustee or any holder of outstanding debt securities.

At any time after an acceleration with respect to debt securities of a series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of not less than a majority

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in principal amount of the outstanding debt securities of that series may cancel the acceleration and annul its consequences if the rescission would not conflict with any judgment or decree and if all existing events of default with respect to that series have been cured or waived except nonpayment of principal (or such lesser amount) or interest that has become due solely because of the acceleration.

The indenture also provides that the holders of not less than a majority in principal amount of the outstanding debt securities of any series may waive any past default with respect to that series and its consequences, except a default involving the following:

The trustee is generally required to give notice to the holders of debt securities of each affected series within 90 days of a default actually known to a responsible officer of the trustee unless the default has been cured or waived. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Unless we provide otherwise in the applicable prospectus supplement, the indenture will provide that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request or discretion of any holder of any such outstanding debt securities unless the trustee receives indemnity satisfactory to it against any loss, liability, or expense. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method, and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series. The trustee may, however, refuse to follow any discretion that conflicts with the indenture or any law or which may be unduly prejudicial to the holders of the debt securities of the applicable series not joining in the discretion.

Unless we provide otherwise in the applicable prospectus supplement, no holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding the foregoing, except as provided in the subordination provisions, if any, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, and any interest or additional amounts on, that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a certificate as to compliance with the indenture, or, in the event of noncompliance, specify the noncompliance and the nature and status of the noncompliance.

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Modification of Indenture and Waiver

Except as specified below, modifications and amendments to the indenture require the approval of not less than a majority in principal amount of our outstanding debt securities.

Changes Requiring the Unanimous Approval

We and the trustee may not make any modification or amendment to the indenture without the consent of the holder of each affected debt security then outstanding if that amendment will have any of the following results:

Changes Not Requiring Approval of Debt Holders

We and the trustee may modify or amend an indenture, without the consent of any holder of debt securities, for any of the following purposes:

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A vote by holders of debt securities will not be required for clarifications and certain other changes that would not adversely affect holders of the debt securities.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance

Unless the terms of the applicable series of debt securities provide otherwise, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities of the series; to replace stolen, lost, or mutilated debt securities of the series; and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, foreign government obligations (as described at the end of this section), that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient to pay and discharge each installment of principal, interest, and any additional amounts on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of such payments in accordance with the terms of the indenture and those debt securities.

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This discharge may occur only if, among other things, we have delivered to the trustee an officers’ certificate and an opinion of counsel stating that we have received from, or there has been published by, the U.S. Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable U.S. federal income tax law, in either case to the effect that holders of the debt securities of such series will not recognize income, gain, or loss for U.S. federal income tax purposes as a result of the deposit, defeasance, and discharge and will be subject to U.S. federal income tax on the same amount and in the same manner and at the same times as would have been the case if the deposit, defeasance, and discharge had not occurred.

Defeasance of Certain Covenants

Unless the terms of the applicable series of debt securities provide otherwise, upon compliance with certain conditions, we may omit to comply with the restrictive covenants contained in the indenture (except for certain obligations to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents), as well as any additional covenants contained in the applicable prospectus supplement.

The conditions include, among others, the following:

Covenant Defeasance and Events of Default

If we exercise our option, as described above, not to comply with certain covenants of the indenture with respect to any series of debt securities, and the debt securities of that series are declared due and payable because of the occurrence of any event of default, the amount of money and/or U.S. government obligations or foreign government obligations on deposit with the trustee will be sufficient to pay amounts due on the debt securities of that series at the time of their stated maturity but may not be sufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. However, we will remain liable for those payments.

“Foreign government obligations” means, with respect to debt securities of any series that are denominated in a currency other than U.S. dollars:

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Guarantees

Our payment obligations under any series of debt securities may be guaranteed by us or one or more of our subsidiaries. The terms of any such guarantee will be set forth in the applicable prospectus supplement.

Subordination

We will set forth in the applicable prospectus supplement the terms and conditions, if any, upon which any series of senior subordinated securities or subordinated securities is subordinated to debt securities of another series or to other indebtedness of ours. The terms will include a description of the following:

Conversion and Exchange Rights

The terms on which debt securities of any series may be convertible into or exchangeable for our common stock, preferred stock, or other securities or property of our company will be described in the applicable prospectus supplement. These terms will include the following:

The conversion or exchange price of any debt securities of any series that are convertible into our common stock or preferred stock may be adjusted for any stock dividends, stock splits, reclassification, combinations, or similar transactions, as set forth in the applicable prospectus supplement.

Redemption of Debt Securities

The debt securities may be subject to optional or mandatory redemption on terms and conditions described in the applicable prospectus supplement. Subject to such terms, we may opt at any time to redeem the debt securities in whole or in part.

If less than all the debt securities of any series are to be redeemed or purchased in an offer to purchase at any time, the trustee will select the debt securities of that series to be redeemed or purchased as follows: (1) if the securities of such series are listed on any national securities exchange, in compliance with the requirements of the principal national securities exchange on which the debt securities of that series are listed, or, (2) if the debt securities of that series are not listed on a national securities exchange, on a pro rata basis, by lot, or by such other method as the trustee deems fair and appropriate.

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Except as otherwise provided as to any particular series of debt securities, at least 30 days but not more than 60 days before a redemption date, we or the trustee will mail a notice of redemption to each holder whose debt securities are to be redeemed. From and after notice has been given as provided in the applicable indenture, if funds for the redemption of any debt securities called for redemption shall have been made available on the redemption date, the debt securities will cease to bear interest on the date fixed for the redemption specified in the notice, and the only right of the holders of the debt securities will be to receive payment of the redemption price.

Governing Law

The indentures and the debt securities will be governed by and construed in accordance with the laws of the state of New York, except to the extent that the Trust Indenture Act is applicable.

DESCRIPTION OF DEPOSITARY SHARES

We may issue receipts for depositary shares representing fractional shares of preferred stock. The fractional share of the applicable series of preferred stock represented by each depositary share will be set forth in the applicable prospectus supplement.

The shares of any series of preferred stock underlying any depositary shares that we may sell under this prospectus will be deposited under a deposit agreement between us and a depositary selected by us. Subject to the terms of the deposit agreement, each holder of a depositary share will be entitled, in proportion to the applicable fraction of a share of the preferred stock underlying the depositary share, to all of the rights, preferences, and privileges, and will be subject to the qualifications and restrictions, of the preferred stock underlying that depositary share.

The depositary shares will be evidenced by depositary receipts issued under the deposit agreement. Depositary receipts will be distributed to the holders of the depositary shares that are sold in the applicable offering. We will incorporate by reference into the registration statement of which this prospectus forms a part the form of any deposit agreement, including a form of depositary receipt, that describes the terms of any depositary shares we are offering before the issuance of the related depositary shares. The following summaries of material provisions of the deposit agreement, the depositary shares and the depositary receipts are subject to, and qualified in their entirety by reference to, all of the provisions of the deposit agreement applicable to a particular offering of depositary shares. We urge you to read the prospectus supplements relating to any depositary shares that are sold under this prospectus, as well as the complete deposit agreement and depositary receipt.

Form

Pending the preparation of definitive depositary receipts, the depositary may, upon our written order, issue temporary depositary receipts substantially identical to the definitive depositary receipts but not in definitive form. These temporary depositary receipts will entitle their holders to all of the rights of definitive depositary receipts. Temporary depositary receipts will then be exchangeable for definitive depositary receipts at our expense.

Dividends and Other Distributions

The depositary will distribute all cash dividends or other cash distributions received with respect to the underlying preferred stock to the record holders of depositary shares in proportion to the number of depositary shares owned by those holders.

If there is a distribution other than in cash, the depositary will distribute property received by it to the record holders of depositary shares in proportion to the number of depositary shares owned by those holders, unless the

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depositary determines that it is not feasible to do so. If this occurs, the depositary may, with our approval, sell the property and distribute the net proceeds from the sale to those holders in proportion to the number of depositary shares owned by them.

The amount distributed to holders of depositary shares will be reduced by any amounts required to be withheld by us or the preferred stock depositary on account of taxes or other governmental charges.

Liquidation Preference

If a series of preferred stock underlying the depositary shares has a liquidation preference, in the event of our voluntary or involuntary liquidation, dissolution, or winding up, holders of depositary shares will be entitled to receive the fraction of the liquidation preference accorded each share of the applicable series of preferred stock, as set forth in the applicable prospectus supplement.

Withdrawal of Underlying Preferred Stock

Except as otherwise provided in a prospectus supplement, holders may surrender depositary receipts at the principal office of the depositary and, upon payment of any unpaid amount due to the depositary, be entitled to receive the number of whole shares of underlying preferred stock and all money and other property represented by the related depositary shares. We will not issue any partial shares of preferred stock. If the holder delivers depositary receipts evidencing a number of depositary shares that represent more than a whole number of shares of preferred stock, the depositary will issue a new depositary receipt evidencing the excess number of depositary shares to the holder.

Redemption of Depositary Shares

If the preferred stock underlying any depositary shares we may sell under this prospectus is subject to redemption, the depositary shares will be redeemed from the proceeds received by the depositary resulting from any such redemption, in whole or in part, of that underlying preferred stock. The redemption price per depositary share will be equal to the applicable fraction of the redemption price per share payable with respect to the underlying preferred stock. Whenever we redeem shares of underlying preferred stock that are held by the depositary, the depositary will redeem, as of the same redemption date, the number of depositary shares representing the shares of underlying preferred stock so redeemed. If fewer than all of the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot or proportionately, as may be determined by the depositary.

After the date fixed for redemption, the depositary shares called for redemption will no longer be deemed to be outstanding, and all rights of the holders of the depositary shares will cease, except the right to receive the monies payable and any other property to which the holders were entitled upon the redemption upon surrender to the preferred stock depositary of the depositary receipts evidencing the depositary shares. Any funds deposited by us with the preferred stock depositary for any depositary shares that the holders fail to redeem will be returned to us after a period of two years from the date the funds are deposited.

Voting

Upon receipt of notice of any meeting at which holders of the preferred stock underlying any depositary shares that we may sell under this prospectus are entitled to vote, the depositary will mail the information contained in the notice to the record holders of the depositary shares. Each record holder of the depositary shares on the record date, which will be the same date as the record date for the underlying preferred stock, will be entitled to instruct the depositary as to the exercise of the voting rights pertaining to the amount of the underlying preferred stock represented by the holder’s depositary shares. The depositary will then try, as far as practicable, to vote the number of shares of preferred stock underlying those depositary shares in accordance with those instructions, and

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we will agree to take all reasonable actions which may be deemed necessary by the depositary to enable the depositary to do so. The depositary will not vote the underlying preferred stock to the extent it does not receive specific instructions with respect to the depositary shares representing such preferred stock.

Conversion of Preferred Stock

If the prospectus supplement relating to any depositary shares that we may sell under this prospectus states that the underlying preferred stock is convertible into our common stock or other securities, the following will apply. The depositary shares, as such, will not be convertible into any of our securities. Rather, any holder of the depositary shares may surrender the related depositary receipts to the depositary with written instructions that direct us to cause conversion of the preferred stock represented by the depositary shares into or for whole shares of our common stock or other securities, as applicable. Upon receipt of those instructions and any amounts payable by the holder in connection with the conversion, we will cause the conversion using the same procedures as those provided for conversion of the underlying preferred stock. If only some of a holder’s depositary shares are converted, a new depositary receipt or receipts will be issued to the holder for any depositary shares not converted.

Amendment and Termination of the Deposit Agreement

The form of depositary receipt evidencing the depositary shares and any provision of the deposit agreement may at any time be amended by agreement between us and the depositary. However, any amendment which materially and adversely alters the rights of the holders of depositary shares will not be effective until 90 days after notice of that amendment has been given to the holders. Each holder of depositary shares at the time any amendment becomes effective shall be deemed to consent and agree to that amendment and to be bound by the deposit agreement as so amended. The deposit agreement may be terminated by us or by the depositary only if all outstanding depositary shares have been redeemed or converted into any other securities into which the underlying preferred stock is convertible or there has been a final distribution, including to holders of depositary receipts, of the underlying preferred stock in connection with our liquidation, dissolution, or winding up.

Charges of Depositary

We will pay all transfer and other taxes and governmental charges arising solely from the existence of the depositary arrangement. We will also pay charges of the depositary in connection with the initial deposit of the preferred stock, the initial issuance of the depositary shares, any redemption of the preferred stock, and all withdrawals of preferred stock by owners of depositary shares. Holders of depositary receipts will pay transfer, income, and other taxes and governmental charges and other specified charges as provided in the deposit arrangement for their accounts. If these charges have not been paid, the depositary may refuse to transfer depositary shares, withhold dividends and distributions, and sell the depositary shares evidenced by the depositary receipt.

Limitation on Liability

Neither we nor the depositary will be liable if either of us is prevented or delayed by law or any circumstance beyond our control in performing our respective obligations under the deposit agreement. Our obligations and those of the depositary will be limited to performance of our respective duties under the deposit agreement without, in our case, negligence or bad faith or, in the case of the depositary, negligence or willful misconduct. We and the depositary may rely upon advice of counsel or accountants, or upon information provided by persons presenting the underlying preferred stock for deposit, holders of depositary receipts, or other persons believed by us in good faith to be competent and on documents believed to be genuine.

Corporate Trust Office of Preferred Stock Depositary

The preferred stock depositary’s corporate trust office will be set forth in the applicable prospectus supplement relating to a series of depositary shares. The preferred stock depositary will act as transfer agent and registrar for

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depositary receipts, and, if shares of a series of preferred stock are redeemable, the preferred stock depositary will act as redemption agent for the corresponding depositary receipts.

Resignation and Removal of Depositary

The depositary may resign at any time by delivering notice to us of its election to resign. We may remove the depositary at any time. Any resignation or removal will take effect upon the appointment of a successor depositary and its acceptance of the appointment. The successor depositary must be appointed within 60 days after delivery of the notice of resignation or removal and must be a bank or trust company having its principal office in the United States and having a combined capital and surplus of at least $50,000,000.

Reports to Holders

We will deliver all required reports and communications to holders of the preferred stock to the preferred stock depositary, and it will forward those reports and communications to the holders of depositary shares. Upon request, the preferred stock depositary will provide for inspection to the holders of depositary shares the transfer books of the depositary and the list of holders of receipts; provided that any requesting holder certifies to the preferred stock depositary that such inspection is for a proper purpose reasonably related to such person’s interest as an owner of depositary shares evidenced by the receipts.

DESCRIPTION OF WARRANTS

General

We may issue warrants to purchase common stock, which we refer to as common stock warrants, preferred stock, which we refer to as preferred stock warrants, debt securities, which we refer to as debt security warrants, or depositary shares, which we refer to as depositary share warrants. Any of these warrants may be issued independently or together with any other securities offered by this prospectus and may be attached to or separate from those securities.

While the terms we have summarized below will generally apply to any future warrants we may offer under this prospectus, we will describe the particular terms of any warrants that we may offer in more detail in the applicable prospectus supplement. The terms of any warrants we offer under a prospectus supplement may differ from the terms we describe below.

We may issue the warrants under a warrant agreement, which we will enter into with a warrant agent to be selected by us. Each warrant agent will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

We will incorporate by reference into the registration statement of which this prospectus forms a part the form of warrant agreement, including a form of warrant certificate, that describes the terms of the series of warrants we are offering before the issuance of the related series of warrants. The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement applicable to a particular series of warrants. We urge you to read the applicable prospectus supplements related to the warrants that we sell under this prospectus, as well as the complete warrant agreements that contain the terms of the warrants.

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We will set forth in the applicable prospectus supplement the terms of the warrants in respect of which this prospectus is being delivered, including, when applicable, the following:

Unless specified in an applicable prospectus supplement, common stock warrants, preferred stock warrants, debt security warrants, or depositary shares warrants will be in registered form only.

A holder of warrant certificates may exchange them for new certificates of different denominations, present them for registration of transfer, and exercise them at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Until any common stock warrants, preferred stock warrants, debt security warrants, or depositary shares warrants are exercised, holders of the warrants will not have any rights of holders of the underlying common stock, preferred stock, debt securities, or depositary shares, including any rights to receive dividends or to exercise any voting rights, except to the extent set forth under the heading “Warrant Adjustments” below.

Exercise of Warrants

Each warrant will entitle the holder to purchase for cash shares of common stock, preferred stock, debt securities, or depositary shares at the applicable exercise price set forth in, or determined as described in, the applicable prospectus supplement. Warrants may be exercised at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

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Warrants may be exercised by delivering to the corporation trust office of the warrant agent or any other officer indicated in the applicable prospectus supplement (a) the warrant certificate properly completed and duly executed and (b) payment of the amount due upon exercise. As soon as practicable following exercise, we will forward the shares of common stock, preferred stock, debt securities, or depositary shares. If less than all of the warrants represented by a warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants. If we so indicate in the applicable prospectus supplement, holders of the warrants may surrender securities as all or a part of the exercise price for the warrants.

Amendments and Supplements to the Warrant Agreements

We may amend or supplement a warrant agreement without the consent of the holders of the applicable warrants to cure ambiguities in the warrant agreement, to cure or correct a defective provision in the warrant agreement, or to provide for other matters under the warrant agreement that we and the warrant agent deem necessary or desirable, so long as, in each case, such amendments or supplements do not materially and adversely affect the interests of the holders of the warrants.

Warrant Adjustments

Unless the applicable prospectus supplement states otherwise, the exercise price of, and the number of securities covered by, a common stock warrant, preferred stock warrant, debt security warrant, or depositary share warrant will be adjusted proportionately if we subdivide or combine our common stock, preferred stock, debt securities, or depositary shares, as applicable. In addition, unless the prospectus supplement states otherwise, if we, without payment:

then the holders of common stock warrants, preferred stock warrants, debt security warrants, and depositary share warrants, as applicable, will be entitled to receive upon exercise of the warrants, in addition to the securities otherwise receivable upon exercise of the warrants and without paying any additional consideration, the amount of stock and other securities and property such holders would have been entitled to receive had they held our common stock, preferred stock, debt securities, or depositary shares, as applicable, issuable under the warrants on the dates on which holders of those securities received or became entitled to receive such additional stock and other securities and property.

Except as stated above, the exercise price and number of securities covered by a common stock warrant, preferred stock warrant, debt security warrant, and depositary share warrant, and the amounts of other securities or property to be received, if any, upon exercise of those warrants, will not be adjusted or provided for if we issue those securities or any securities convertible into or exchangeable for those securities, or securities carrying the right to purchase those securities or securities convertible into or exchangeable for those securities.

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Holders of common stock warrants, preferred stock warrants, debt security warrants, and depositary share warrants may have additional rights under the following circumstances:

If one of the above transactions occurs and holders of our common stock, preferred stock, debt securities, or depositary shares are entitled to receive stock, securities, or other property with respect to or in exchange for their securities, the holders of our common stock warrants, preferred stock warrants, debt security warrants, and depositary share warrants then outstanding, as applicable, will be entitled to receive upon exercise of their warrants the kind and amount of shares of stock and other securities or property that they would have received upon the applicable transaction if they had exercised their warrants immediately before the transaction.

DESCRIPTION OF PURCHASE CONTRACTS

We may issue purchase contracts, including contracts obligating holders to purchase from us, and for us to sell to holders, a specific or varying number of debt securities, shares of common stock or preferred stock, depositary shares, warrants, or any combination of the above, at a future date or dates. Alternatively, the purchase contracts may obligate us to purchase from holders, and obligate holders to sell to us, a specific or varying number of debt securities, shares of common stock or preferred stock, depositary shares, warrants, or any combination of the above. The price of the securities subject to the purchase contracts may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula described in the purchase contracts. We may issue purchase contracts separately or as a part of units each consisting of a purchase contract and one or more of the other securities described in this prospectus or securities of third parties, including U.S. Treasury securities, securing the holder’s obligations under the purchase contract. If we issue a purchase contract as part of a unit, the applicable prospectus supplement will state whether the purchase contract will be separable from the other securities in the unit before the purchase contract settlement date. The purchase contracts may require us to make periodic payments to holders or vice versa and the payments may be unsecured or pre-funded on some basis. The purchase contracts may require holders to secure the holder’s obligations in a manner specified in the applicable prospectus supplement, and in certain circumstances, we may deliver newly issued prepaid purchase contracts, often known as prepaid securities, upon release to a holder of any collateral securing such holder’s obligations under the original purchase contract.

We will incorporate by reference into the registration statement of which this prospectus forms a part the form of purchase contract we are offering before the issuance of the purchase contract. The following summaries of material provisions of the purchase contract are subject to, and qualified in their entirety by reference to, all the provisions of the purchase contract. We urge you to read the applicable prospectus supplements related to the purchase contracts that we sell under this prospectus, as well as the complete purchase contract.

The applicable prospectus supplement will describe the terms of any purchase contracts in respect of which this prospectus is being delivered, including, to the extent applicable, the following:

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Material U.S. federal income tax consideration applicable to the purchase contracts and the purchase units will also be discussed in the applicable prospectus supplement.

DESCRIPTION OF UNITS

The following description, together with the additional information we include in any applicable prospectus supplement, summarizes the material terms and provisions of the units that we may offer under this prospectus. Units may be offered independently or together with common stock, preferred stock, debt securities, depositary shares, and warrants offered by any prospectus supplement, and may be attached to or separate from those securities. While the terms we have summarized below will generally apply to any future units that we may offer under this prospectus, we will describe the particular terms of any series of units that we may offer in more detail in the applicable prospectus supplement. The terms of any units offered under a prospectus supplement may differ from the terms described below.

We will incorporate by reference into the registration statement of which this prospectus forms a part the form of unit agreement, including a form of unit certificate, if any, that describes the terms of the series of units we are offering before the issuance of the related series of units. The following summaries of material provisions of the units and the unit agreements are subject to, and qualified in their entirety by reference to, all the provisions of the unit agreement applicable to a particular series of units. We urge you to read the applicable prospectus supplements related to the units that we sell under this prospectus, as well as the complete unit agreements that contain the terms of the units.

General

We may issue units consisting of common stock, preferred stock, debt securities, depositary shares, and warrants in any combination. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time, or at any time before a specified date.

We will describe in the applicable prospectus supplement the terms of the series of units, including the following:

The provisions described in this section, as well as those described under “Description of Capital Stock,” “Description of Debt Securities,” “Description of Depositary Shares,” and “Description of Warrants,” will apply to each unit and to any common stock, preferred stock, debt security, depositary share, or warrant included in each unit, respectively.

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Issuance in Series

We may issue units in such amounts and in such numerous distinct series as we determine.

Enforceability of Rights by Holders of Units

Each unit agent will act solely as our agent under the applicable unit agreement and will not assume any obligation or relationship of agency or trust with any holder of any unit. A single bank or trust company may act as unit agent for more than one series of units. A unit agent will have no duty or responsibility in case of any default by us under the applicable unit agreement or unit, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a unit, without the consent of the related unit agent or the holder of any other unit, may enforce by appropriate legal action its rights as holder under any security included in the unit.

Title

We, the unit agent, and any of their agents may treat the registered holder of any unit certificate as an absolute owner of the units evidenced by that certificate for any purposes and as the person entitled to exercise the rights attaching to the units so requested, despite any notice to the contrary.

LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

See also the section entitled “Description of Debt Securities — Form, Transfer, and Exchange” above for additional discussion of book entry and certificated form of ownership as such forms of ownership impact the rights and obligations of purchasers of debt securities to be issued under this prospectus.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers. Upon the issuance of a global security, the depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal amounts of the book-entry securities represented by the global security beneficially owned by such participants. The accounts to be credited will be designated by any dealers, underwriters, or agents participating in the distribution of the book-entry securities. Ownership of book-entry securities will be shown on, and the transfer of the ownership interests will be effected only through, records maintained by the depositary for the related global security (with respect to interests of participants) and on the records of participants (with respect to interests of persons holding through participants). The laws of some states may require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to own, transfer, or pledge beneficial interests in book-entry securities.

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Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a book-entry security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker, or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker, or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he, she, or it maintains at that institution.

For securities held in street name, we will recognize only the intermediary banks, brokers, and other financial institutions in whose names the securities are registered as the holders of those securities, and we will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee and of any third parties employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name, or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the holder, we have no further responsibility for the payment or notice even if that holder is required, under agreements with depositary participants or customers or by law, to pass it along to the indirect holders but does not do so. Whether and how the holders contact the indirect holders is up to the holders.

Special Considerations For Indirect Holders

If you hold securities through a bank, broker, or other financial institution, either in book-entry form or in street name, you should check with your own institution to determine the following:

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Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms. Each security issued in book-entry form will be represented by a global security that we deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee, or a successor depositary, unless special termination situations arise. We describe those situations below under “Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank, or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

We may at any time and in our sole discretion determine not to have any of the book-entry securities of any series represented by one or more global securities and, in that event, we will issue certificated securities in exchange for the global securities of that series.

Special Considerations For Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

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There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, the global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, the global security will terminate when the following special situations occur:

The prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular types and series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and not we or any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

PLAN OF DISTRIBUTION

We and/or any selling stockholder may sell the securities described in this prospectus from time to time in one or more of the following ways:

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The prospectus supplement with respect to the offered securities will describe the terms of the offering, including the following:

We and/or any selling stockholder may distribute the securities from time to time in one or more of the following ways:

Unless otherwise indicated in the applicable prospectus supplement, if we and/or any selling stockholder use underwriters for a sale of securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities in one or more transactions, including negotiated transactions, at a fixed public offering price, or at varying prices determined at the time of sale. The obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. Unless otherwise indicated in a prospectus supplement, the underwriters will be obligated to purchase all the securities of the series offered if they purchase any of the securities of that series. We and/or any selling stockholder may change from time to time any initial public offering price and any discounts or concessions the underwriters allow or reallow or pay to dealers. We and/or any selling stockholder may use underwriters with whom we or they have a material relationship. We will describe in the prospectus supplement naming the underwriter the nature of any such relationship. We and/or any selling stockholder may designate agents who agree to use their reasonable efforts to solicit purchases for the period of their appointment or to sell securities on a continuing basis. We and/or any selling stockholder may also sell securities directly to one or more purchasers without using underwriters or agents.

Underwriters, dealers, or agents may receive compensation in the form of discounts, concessions, or commissions from us and/or any selling stockholder or from purchasers of the securities as their agents in connection with the sale of the securities. These underwriters, dealers, or agents may be considered to be underwriters under the Securities Act. As a result, discounts, commissions, or profits on resale received by underwriters, dealers, or agents may be treated as underwriting discounts and commissions. Each prospectus supplement will identify any underwriter, dealer, or agent and describe any compensation received by them from us and/or any selling stockholder. Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

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Unless otherwise specified in the applicable prospectus supplement, each class or series of securities will be a new issue with no established trading market, other than our common stock, which is listed on the Nasdaq Global Select Market. We may elect to apply for listing of our common stock on another securities exchange or to list any other class or series of securities on any exchange, but we are not obligated to do so. It is possible that one or more underwriters may make a market in a class or series of securities, but the underwriters will not be obligated to do so and may discontinue any market making at any time without notice. We cannot give any assurance as to the liquidity of the trading market for any of the securities.

In connection with any offering, the underwriters may engage in stabilizing transactions, over-allotment transactions, syndicate covering transactions, and penalty bids in accordance with Regulation M under the Exchange Act.

These stabilizing transactions, over-allotments, syndicate covering transactions, and penalty bids may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. These transactions may be effected on the Nasdaq Global Select Market or otherwise and, if commenced, may be discontinued at any time.

We and/or any selling stockholder may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we and/or any selling stockholder may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us and/or any selling stockholder or borrowed from us and/or any selling stockholder or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be named in the applicable prospectus supplement.

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In addition, we and/or any selling stockholder may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

Underwriters, dealers, and agents may be entitled under agreements entered into with us to indemnification against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments they may be required to make in respect of these liabilities thereof. Underwriters, dealers, and agents and their affiliates may be customers of, may engage in transactions with, or perform services for us in the ordinary course of business for which they receive compensation.

LEGAL MATTERS

The validity of the securities offered hereby will be passed upon by Greenberg Traurig, LLP.

EXPERTS

The consolidated financial statements of OPKO Health, Inc. and subsidiaries as of December 31, 2017 and 2016, and for each of the three years in the period ended December 31, 2017, and the effectiveness of internal control over financial reporting as of December 31, 2017, included in the OPKO Health, Inc. Current Report on Form 8-K dated January 28, 2019, have been audited by Ernst & Young LLP, independent registered certified public accounting firm, as set forth in their reports thereon (which contain an explanatory paragraph describing the adoption of Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers (Topic 606), as described in Note 1 to the consolidated financial statements), and are incorporated herein by reference. Such consolidated financial statements are incorporated by reference herein in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Through our website at www.opko.com, you may access, free of charge, our filings, as soon as reasonably practical after we electronically file them with or furnish them to the SEC. The information contained in our website is not incorporated by reference in, and should not be considered a part of, this prospectus or any accompanying prospectus supplement. Our SEC filings are also available to the public at the SEC’s website at www.sec.gov.

This prospectus is part of a registration statement on Form S-3 that we filed with the SEC to register the securities to be offered hereby. This prospectus does not contain all of the information included in the registration statement, including certain exhibits and schedules. You may obtain the registration statement and exhibits to the registration statement from the SEC at the address listed above or from the SEC’s website listed above.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to incorporate by reference the information we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information that we incorporate by reference is considered to be part of this prospectus. Information that we file with the SEC in the future and incorporate by reference in this prospectus automatically updates and supersedes previously filed information as applicable.

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We incorporate by reference into this prospectus the following documents filed by us with the SEC, other than any portion of any such documents that is not deemed “filed” under the Exchange Act in accordance with the Exchange Act and applicable SEC rules:

In addition, all documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (not including any information furnished under Item 2.02, 7.01 or 9.01 of Form 8-K and any other information that is identified as “furnished” rather than filed, which information is not incorporated by reference herein), including those filings made after the date of the initial filing of the registration statement of which this prospectus forms a part, prior to the termination of the offering, will be deemed to be incorporated herein by reference and to be a part of this prospectus from the date of filing of such documents. Any statement contained in a document incorporated herein by reference will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained herein, or in a subsequently filed document incorporated herein by reference, modifies or supersedes the statement. Any statement modified or superseded will not be deemed, except as modified or superseded, to constitute a part of this prospectus.

We will provide without charge to each person, including any beneficial owner, to whom a prospectus is delivered, upon written or oral request of that person, a copy of any and all of the information that has been incorporated by reference in this prospectus but not delivered with this prospectus (excluding exhibits unless specifically incorporated by reference into those documents). Please direct requests to us at the following address:

OPKO Health, Inc.

4400 Biscayne Blvd.

Miami, Florida 33137

Attention: Secretary

Telephone: (305) 575-4100

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PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

The following table sets forth the costs and expenses payable by the registrant in connection with the offerings described in this registration statement. In addition to the costs and expenses set forth below, the registrant will pay any selling commissions and brokerage fees and any applicable taxes, fees and disbursements with respect to securities registered hereby sold by the registrant. All of the amounts shown are estimates:

The following is a summary of the statutes, certificate of incorporation, and bylaw provisions or other arrangements under which the registrant’s directors and officers are insured or indemnified against liability in their capacities as such. All the directors and officers of the registrants are covered by insurance policies maintained and held in effect by OPKO against certain liabilities for actions taken in their capacities as such, including liabilities under the Securities Act.

Section 145 of Delaware General Corporation Law.

OPKO is incorporated under the laws of the State of Delaware. Section 145 of the General Corporation Law of the State of Delaware, or DGCL, provides that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that the person is or was a director, officer, employee, or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit, or proceeding if the person acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe the person’s conduct was unlawful.

Section 145 further provides that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending, or completed action or suit by or in the right of the corporation to procure a judgment in its favor by reason of the fact that such person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against expenses (including

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attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if the person acted in good faith and in a manner the person reasonably believed to be in or not opposed to the best interests of the corporation. However, no indemnification shall be made in respect of any claim, issue or matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery of the State of Delaware or the court in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery of the State of Delaware or such other court shall deem proper.

Section 145 further provides that to the extent that a present or former director or officer of a corporation has been successful on the merits or otherwise in defense of any action, suit, or proceeding referred to above, or in defense of any claim, issue, or matter therein, such person shall be indemnified against expenses (including attorneys’ fees) actually and reasonably incurred by such person in connection therewith.; provided that indemnification provided for by Section 145 or granted pursuant thereto shall not be deemed exclusive of any other rights to which the indemnified party may be entitled.

Section 145 also provides that a Delaware corporation shall have the power to purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity or arising out of such person’s status as such whether or not the corporation would have the power to indemnify such person against such liabilities under Section 145.

Certificate of Incorporation Provisions on Exculpation and Indemnification.

As permitted by Section 102(b)(7) of the DGCL, our Amended and Restated Certificate of Incorporation provides that a director of the Company shall not be personally liable to either the Company or any of its stockholders for monetary damages for a breach of fiduciary duty as a director except for: (i) breaches of the duty of loyalty to the corporation or its stockholders; (ii) acts or omissions not in good faith or involving intentional misconduct or knowing violation of the law; (iii) as required by Section 174 of the DGCL; or (iv) a transaction resulting in an improper personal benefit.

Our Amended and Restated Certificate of Incorporation provides that we will indemnify, in the manner and to the fullest extent permitted by the DGCL, any person (or the estate of any person) who is or was a party to, or is threatened to be made a party to, any threatened, pending or completed action, suit or proceeding, whether or not by or in the right of the Company, and whether civil, criminal, administrative, investigative or otherwise, by reason of the fact that such person is or was a director or officer of the Company, or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust or other enterprise.

Our Amended and Restated Certificate of Incorporation further provides that we may indemnify, in the manner and to the fullest extent permitted by the DGCL, any person (or the estate of any person) who is or was a party to, or is threatened to be made a party to, any threatened, pending or completed action, suit or proceeding, whether or not by or in the right of the Company and whether civil, criminal, administrative, investigative or otherwise, by reason of the fact that such person is or was an employee or agent of the Company, or is or was serving at our request as an employee or agent of another corporation, partnership, joint venture, trust or other enterprise.

Our Amended and Restated Certificate of Incorporation further provides that expenses incurred by any director, officer, employee or agent in defending any action, suit or proceeding may be advanced by us prior to the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of such director, officer, employee or agent to repay such amount if it shall ultimately be determined that he or she is not entitled to be indemnified as authorized by the DGCL and our Amended and Restated Certificate of Incorporation.

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Bylaws Provisions on Indemnification.

Our Amended and Restated Bylaws provide generally that the Company shall indemnify its directors, officers, employees, and agents who are or were a party, or threatened to be made a party, to any threatened, pending, or contemplated action, suit or proceeding, whether civil, criminal, administrative, or investigative (other than an action by or in the right of the corporation), by reason of the fact that such person is or was the director, officer, employee, or agent of the corporation, or is or was serving in such a position at its request of any other corporation, partnership, joint venture, trust, or other enterprise, against expenses including attorneys’ fees, judgments, fines and amounts paid in settlement actually and reasonably incurred by him or her in connection with such action, suit or proceeding if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the Corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Our Amended and Restated Bylaws further provide that the Company shall indemnify any person who was or is a party, or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the Company to procure a judgment in its favor by reason of the fact that he or she is or was a director, officer, employee or agent of the Company, or is or was serving at the request of the Company as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against expenses (including attorneys’ fees) actually and reasonably incurred by him or her in connection with the defense or settlement of such action or suit if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the Company and except that no indemnification shall be made in respect of any claim, issue or matter as to which such person shall have been adjudged to be liable to the Company unless and only to the extent that the Court of Chancery of the State of Delaware or the court in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery of the State of Delaware or such other court shall deem proper.

Our Amended and Restated Bylaws further provide that expenses (including attorneys’ fees) incurred by an officer or director in defending a civil, criminal, administrative or investigative action, suit or proceeding may be paid by the Company in advance of the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of such director or officer to repay such amount if it shall ultimately be determined that he or she is not entitled to be indemnified by the Company as authorized in our Amended and Restated Bylaws. Such expenses (including attorneys’ fees) incurred by other employees and agents may be so paid upon such terms and conditions, if any, as our board of directors deems appropriate.

Other Provisions on Indemnification.

The Company is also a party to indemnification agreements with each of the Company’s directors and certain officers of Company. The indemnification agreements require the Company, among other things, to (i) maintain directors’ and officers’ liability insurance for each indemnitee, and (ii) indemnify each indemnitee to the fullest extent permitted by law for certain expenses incurred in a proceeding arising out of indemnitee’s service to the Company or its subsidiaries. The indemnification agreements also provide for the advancement of such expenses to the indemnitee by the Company.

The above discussion of the Amended and Restated Certificate of incorporation and Amended and Restated Bylaws of the registrant and the indemnification agreements is not intended to be exhaustive and is qualified in its entirety by such certificate of incorporation, bylaws, and indemnification agreements.

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(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by section 10(a)(3) of the Securities Act of 1933;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement;

(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

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provided, however, that paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the registrant pursuant to section 13 or section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act of 1933 to any purchaser:

(A) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(B) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by section 10(a) of the Securities Act of 1933 shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for the purpose of determining liability of the registrant under the Securities Act of 1933 to any purchaser in the initial distribution of the securities: The undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

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(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act of 1933, each filing of the registrant’s annual report pursuant to section 13(a) or section 15(d) of the Securities Exchange Act of 1934 (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to section 15(d) of the Securities Exchange Act of 1934) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

(d) The undersigned registrant hereby undertakes to file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of section 310 of the Trust Indenture Act (“Act”) in accordance with the rules and regulations prescribed by the Commission under section 305(b)(2) of the Act.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Miami, State of Florida, on the 28^th day of January, 2019.

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Steven D. Rubin and Adam Logal, and each one of them acting alone, as his true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him and in his name, place, and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement, and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them acting alone, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them, or his or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.