Checkpoint Therapeutics Reports First Quarter Financial Results and Recent Corporate Updates

UNLOXCYT™(cosibelimab-ipdl) approved by U.S. FDA in December 2024 as first and only anti-PD-L1 treatment for advanced cutaneous squamous cell carcinoma

Special meeting of stockholders to vote on Merger to take place on May 28, 2025

WALTHAM, Mass., May 13, 2025 (GLOBE NEWSWIRE) -- Checkpoint Therapeutics, Inc. (“Checkpoint”) (Nasdaq: CKPT), a commercial-stage immunotherapy and targeted oncology company, today announced financial results for the first quarter ended March 31, 2025, and recent corporate updates.

About UNLOXCYT™(cosibelimab-ipdl)UNLOXCYT is a human immunoglobulin G1 monoclonal antibody that binds PD-L1 and blocks the interaction between PD-L1 and its T cell receptors, PD-1 and B7.1. This interaction releases the inhibitory effects of PD-L1 on the anti-tumor immune response. UNLOXCYT has also been shown to induce antibody-dependent cell-mediated cytotoxicity.

UNLOXCYT (cosibelimab-ipdl) is indicated for the treatment of adults with metastatic cSCC or locally advanced cSCC who are not candidates for curative surgery or curative radiation.

Immune-Mediated Pneumonitis

Immune-Mediated Colitis

Immune-Mediated Hepatitis

Immune-Mediated EndocrinopathiesAdrenal Insufficiency

Hypophysitis

Thyroid Disorders

Type 1 Diabetes Mellitus, Which Can Present with Diabetic Ketoacidosis

Immune-Mediated Nephritis with Renal Dysfunction

Immune-Mediated Dermatologic Adverse Reactions

Other Immune-Mediated Adverse Reactions

Common Adverse ReactionsThe most common adverse reactions (≥10%) were fatigue, musculoskeletal pain, rash, diarrhea, hypothyroidism, constipation, nausea, headache, pruritus, edema, localized infection, and urinary tract infection.

Please see fullPrescribing Information.

About Checkpoint TherapeuticsCheckpoint Therapeutics, Inc. is a commercial-stage immunotherapy and targeted oncology company focused on the acquisition, development and commercialization of novel treatments for patients with solid tumor cancers. Checkpoint has received approval from the FDA for UNLOXCYT™ (cosibelimab-ipdl) for the treatment of adults with metastatic cSCC or locally advanced cSCC who are not candidates for curative surgery or curative radiation. Additionally, Checkpoint is evaluating its lead investigational small-molecule, targeted anti-cancer agent, olafertinib (formerly CK-101), a third-generation epidermal growth factor receptor (“EGFR”) inhibitor, as a potential new treatment for patients with EGFR mutation-positive non-small cell lung cancer. Checkpoint is headquartered in Waltham, MA and was founded by Fortress Biotech, Inc. (Nasdaq: FBIO). For more information, visitwww.checkpointtx.com.

Forward‐Looking StatementsThis press release contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, each as amended, that involve a number of risks and uncertainties. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, express or implied, statements regarding the Merger and related matters, including the benefits of and timeline for closing the Merger, any payments under the CVRs, prospective performance and opportunities, post-closing operations and the outlook for the companies’ businesses; projections of or targets for revenues, costs, income (or loss), earnings per share, capital expenditures, dividends, capital structure, net financials and other financial measures; expectations for the timing and commercial launch and availability of UNLOXCYT™ (cosibelimab-ipdl) for the treatment of adults with metastatic cSCC or locally advanced cSCC who are not candidates for curative surgery or curative radiation; the commercial potential of UNLOXCYT; anticipated healthcare professional and patient acceptance and use of UNLOXCYT for the FDA-approved indication; and assumptions underlying or relating to such statements.

Factors that may affect future results and may cause these forward-looking statements to be inaccurate include, but are not limited to: uncertainties as to the timing of completion of the Merger; uncertainties as to whether Checkpoint’s stockholders will vote to approve the transaction; the possibility that competing offers will be made; the possibility that various closing conditions for the transaction may not be satisfied or waived, including that a governmental entity may prohibit, delay or refuse to grant approval for the consummation of the transaction (or only grant approval subject to adverse conditions or limitations); the possibility that the proposed transaction may not be completed in the time frame expected by Checkpoint, or at all; failure to realize the anticipated benefits of the proposed transaction in the time frame expected, or at all; the effects of the transaction on relationships with employees, other business partners or governmental entities; potential adverse reactions or changes to business relationships resulting from the announcement or completion of the proposed transaction; significant or unexpected costs, charges or expenses resulting from the proposed transaction; negative effects of this announcement or the consummation of the proposed acquisition on Checkpoint’s common stock and/or Checkpoint’s operating results; the difficulty of predicting the timing or outcome of regulatory approvals or actions; the risks related to non-achievement of the CVR milestone and that holders of the CVRs will not receive payments in respect of the CVRs; other business effects, including the effects of industry, economic or political conditions outside of the companies’ control; transaction costs; actual or contingent liabilities; risk of litigation and/or regulatory actions related to the proposed acquisition; adverse impacts on business, operating results or financial condition in the future due to pandemics, epidemics or outbreaks, and their impact on Checkpoint’s business, operations, supply chain, patient enrollment and retention, clinical trials, strategy, goals and anticipated milestones; government-mandated or market-driven price decreases for Checkpoint’s products; the existence or introduction of competing products; reliance on information technology; Checkpoint’s ability to successfully market current and new products; Checkpoint’s and its collaborators’ ability to continue to conduct research and clinical programs; and exposure to product liability and legal proceedings and investigations. Further risks and uncertainties that could cause actual results to differ materially from the results anticipated by the forward-looking statements are detailed from time to time in Checkpoint’s periodic reports filed with the SEC, including the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and the definitive proxy statement to be filed by Checkpoint with the SEC in connection with the proposed transaction. These filings, when available, are available on the investor relations section of Checkpoint’s website athttps://ir.checkpointtx.comor on the SEC’s website athttps://www.sec.gov.

Any forward-looking statements set forth in this press release speak only as of the date of this press release, are made based on current beliefs and judgments, and are not predictions of actual performance. New risks and uncertainties arise from time to time, and it is impossible for us to predict these events or how they may affect us. We caution that a number of important factors, including those described in this document, could cause actual results to differ materially from those contemplated in any forward-looking statements. Unlisted factors may present significant additional obstacles to the realization of forward-looking statements. We expressly disclaim any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in our expectations or any changes in events, conditions or circumstances on which any such statement is based, except as required by law. This press release and prior releases are available at www.checkpointtx.com. The information found on our website is not incorporated by reference into this press release and is included for reference purposes only.