SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)/1/ UNITED THERAPEUTICS CORPORATION (Name of Issuer) COMMON STOCK, $ .01 PAR VALUE (Title of Class of Securities) 91307C102 (CUSIP Number) DECEMBER 31, 2001 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: |_| Rule 13d-1(b) |_| Rule 13d-1(c) [X] Rule 13d-1(d) -------- /1/ The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G Page 2 of 4 Pages ------ ----- -------------------------------------------------------------------------------- 1 NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Noah A. Samara -------------------------------------------------------------------------------- 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) |_| (b) |_| -------------------------------------------------------------------------------- 3 SEC USE ONLY -------------------------------------------------------------------------------- 4 CITIZENSHIP OR PLACE OF ORGANIZATION United States -------------------------------------------------------------------------------- 5 SOLE VOTING POWER NUMBER 2,205,574 OF SHARES ---------------------------------------------------- 6 SHARED VOTING POWER BENEFICIALLY None OWNED BY ---------------------------------------------------- 7 SOLE DISPOSITIVE POWER EACH 2,205,574 REPORTING ---------------------------------------------------- 8 SHARED DISPOSITIVE POWER PERSON WITH None -------------------------------------------------------------------------------- 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,205,574 -------------------------------------------------------------------------------- 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES* [ ] -------------------------------------------------------------------------------- 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 10.9% -------------------------------------------------------------------------------- 12 TYPE OF REPORTING PERSON* IN -------------------------------------------------------------------------------- *SEE INSTRUCTIONS BEFORE FILLING OUT! -------------------------------------------------------------------------------- -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G Page 3 of 4 Pages ------ ----- -------------------------------------------------------------------------------- Item 1(a). Name of Issuer: United Therapeutics Corporation Item 1(b) Address of Issuer's Principal Executive Offices: 1110 Spring Street Silver Spring, MD 20910 Item 2(a) Name of Person Filing: Noah A. Samara Item 2(b) Address of Principal Business Office or, if None, Residence: 2400 N Street, N.W. Washington, DC 20037 Item 2(c) Citizenship: United States of America Item 2(d) Title of Class of Securities: Common Stock, $.01 par value Item 2(e) CUSIP Number: 91307C102 Item 3. If This Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a: Not applicable Item 4. Ownership. Provide the following information regarding the aggregate number and percentage of the ` class of securities of the issuer identified in Item 1. (a) Amount beneficially owned: 2,205,574 (b) Percent of Class: 10.9% (c) Number of shares as to which such person has: (i) Sole power to vote or to direct the vote 2,205,574 -------------------------------------------------------------------------------- CUSIP No. 91307C102 13G Page 4 of 4 Pages ------ ----- -------------------------------------------------------------------------------- (ii) Shared power to vote or to direct the vote None (iii) Sole power to dispose or to direct the disposition of 2,205,574 (iv) Shared power to dispose or to direct the disposition of None Item 5. Ownership of Five Percent or Less of a Class. Not applicable Item 6. Ownership of More than Five Percent on Behalf of Another Person. Not applicable Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company. Not applicable Item 8. Identification and Classification of Members of the Group. Not applicable. Item 9. Notice of Dissolution of Group. Not applicable. Item 10. Certifications. Not applicable. SIGNATURE After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. February 14, 2002 ------------------ (Date) /s/ Noah A. Samara ------------------ (Signature) Noah A. Samara ------------------ (Name/Title)