~ New U.S. Patent Extends Protection Through 2042 ~

~ Patent Allowance Secures Highest Level of Intellectual Property Protection for MPAR^® ~

SAN DIEGO, CA / ACCESS Newswire / December 2, 2025 / Ensysce Biosciences, Inc. (NASDAQ: ENSC) ("Ensysce" or the "Company"), a clinical-stage pharmaceutical company pioneering next-generation pain and central nervous system therapeutics designed to minimize abuse and overdose risk, today announced that the U.S. Patent and Trademark Office has issued a Notice of Allowance for a new patent covering Ensysce's MPAR® (Multi-Pill Abuse Resistance) technology. The patent, titled "Compositions Comprising Enzyme-Cleavable Prodrugs and Controlled Release Nafamostat and Methods of Use Thereof", includes both composition-of-matter and method-of-use claims that strengthen Ensysce's intellectual property estate for its unique overdose protection platform. The new protection extends the Company's MPAR^® patent coverage through 2042.

MPAR^®, which earned Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) in January 2025, is designed to limit the effects of opioid exposure in the event of an overdose. In clinical testing, PF614-MPAR demonstrated effective pain relief when taken as prescribed, while preventing excessive opioid delivery when multiple doses were administered. Beyond opioids, Ensysce is applying its MPAR^® technology to additional drug classes, including amphetamines and methadone, to develop safer treatments for pain, ADHD, and opioid use disorder.

"This new patent represents another important milestone in our mission to make vital and proven medicines safer," said Dr. Lynn Kirkpatrick, Chief Executive Officer of Ensysce. "MPAR^® overdose protection, in combination with our TAAP™ abuse-deterrent platform, delivers a dual safety approach which we believe is unlike anything else in the field. We are grateful for support and funding from the National Institute on Drug Abuse¹ that has allowed us to demonstrate clinically that MPAR moderates opioid release when taken in excess. The second clinical trial to further evaluate the potential of this technology is ongoing. We are striving to advance both PF614 and PF614-MPAR through late clinical development to achieve our goal of reducing opioid abuse and overdose."

¹Research supporting this patent was funded by the National Institute on Drug Abuse of the National Institutes of Health under Award Number DA047682.

About Ensysce Biosciences
Ensysce Biosciences is a clinical-stage company with a goal of disrupting the analgesic landscape by introducing a new class of highly novel opioids for the treatment of severe pain. Leveraging its Trypsin-Activated Abuse Protection (TAAP™) and Multi-Pill Abuse Resistance (MPAR®) platforms, the Company is developing unique, tamper-proof treatment options for pain that minimize the risk of both drug abuse and overdose. Ensysce's products are anticipated to provide safer options to treat patients suffering from severe pain and assist in preventing deaths caused by medication abuse. For more information, please visit www.ensysce.com.

Forward-Looking Statements
Statements contained in this press release that are not purely historical may be deemed to be forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995 and other federal securities laws. Without limiting the foregoing, the use of words such as "may," "intends," "can," "might," "will," "expect," "plan," "possible," "believe" and other similar expressions are intended to identify forward-looking statements. The product candidates discussed are in clinic and not approved and there can be no assurance that the clinical programs will be successful in demonstrating safety and/or efficacy, that Ensysce will not encounter problems or delays in clinical development, or that any product candidate will ever receive regulatory approval or be successfully commercialized. All forward-looking statements are based on estimates and assumptions by Ensysce's management that, although Ensysce believes to be reasonable, are inherently uncertain. All forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those that Ensysce expected. In addition, Ensysce's business is subject to additional risks and uncertainties, including among others, possible NASDAQ delisting, the initiation and conduct of preclinical studies and clinical trials; the timing and availability of data from preclinical studies and clinical trials; expectations for regulatory submissions and approvals; potential safety concerns related to, or efficacy of, Ensysce's product candidates; the availability or commercial potential of product candidates; continuation of government funding; the ability of Ensysce to fund its continued operations, including its planned clinical trials; the dilutive effect of stock issuances from our fundraising; and Ensysce's and its partners' ability to perform under their license, collaboration and manufacturing arrangements. These statements are also subject to a number of material risks and uncertainties that are described in Ensysce's most recent quarterly report on Form 10-Q and current reports on Form 8-K, available free of charge at the SEC's website at www.sec.gov. Any forward-looking statement speaks only as of the date on which it was made. Ensysce undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise, except as required under applicable law.

Ensysce Biosciences Company Contact:
Lynn Kirkpatrick, Ph.D.
Chief Executive Officer
(858) 263-4196

Ensysce Biosciences Investor Relations Contact:
Shannon Devine
MZ North America
Main: 203-741-8811
ENSC@mzgroup.us

SOURCE: Ensysce Biosciences