University of Iowa Holden Comprehensive Cancer Center Presents Preliminary Data from Clinical Trial of Vidutolimod at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting

May 26, 2022

CAMBRIDGE, Mass., May 26, 2022 (GLOBE NEWSWIRE) -- Checkmate Pharmaceuticals, Inc. (NASDAQ: CMPI) (“Checkmate”), a clinical stage biotechnology company focused on developing its proprietary technology to harness the power of the immune system to combat cancer, today announced the University of Iowa Holden Comprehensive Cancer Center’s presentation of preliminary data from an investigator-sponsored phase 1/2 trial evaluating vidutolimod, a first-in-class, immunostimulatory, noninfectious virus-like particle (VLP) containing a CpG-A Toll-like receptor 9 (TLR9) agonist. The early phase trial is investigating intratumoral vidutolimod therapy in combination with intravenous pembrolizumab in patients with relapsed lymphoma. The objective of this study is to determine the dose of vidutolimod that, in combination with pembrolizumab, has optimal clinical efficacy and acceptable toxicity in patients with relapsed lymphoma who have failed at least one line of therapy. In addition to the funding provided by Checkmate, the ongoing study is supported by NCI grant P50 CA97274 to the University of Iowa/Mayo Clinic (UI/MC) Lymphoma SPORE (specialized program of research excellence).

Preliminary results from an early-phase trial of in situ immunization of lymphoma with a virus-like particle containing a TLR9 agonist combined with anti–PD-1 therapy (Abstract #: 2639: NCT03983668)

During the 2022 ASCO Developmental Therapeutics—Immunotherapy Poster Session on Sunday, June 5 at 9:00am ET, Umar Farooq, M.D., Clinical Associate Professor of Internal Medicine at University of Iowa Hospitals & Clinics, principal investigator, and study sponsor, will present preliminary safety, response and translational laboratory data from 7 enrolled patients with relapsed lymphoma.
Key highlights from the presentation include:

  • Preliminary results suggest that in situ immunization with vidutolimod plus systemic pembrolizumab had clinical activity in a variety of lymphomas in 5 of 7 patients studied
  • No significant adverse effects (AEs) were reported after the 4-hour observation period other than mild headache or fatigue lasting only through day 1
  • Consistent with preclinical data, generation of anti-Qβ antibodies after the initial subcutaneous (SC) vidutolimod dose correlated with response to study treatment; further evaluation in additional patients is needed to confirm these initial observations
  • Additional evaluation of complex interactions between cells in the tumor microenvironment in response to vidutolimod will be needed to understand these findings

Study enrollment is ongoing and given the common use of B cell depleting therapies for the treatment of certain lymphomas, the study was modified to require generation of anti-Qβ antibodies after the initial SC dose of vidutolimod before patients receive IT therapy.

“Our understanding of the immune and therapeutic responses to intratumoral vidutolimod with checkpoint inhibitors continues to grow stronger based on these data,” said Art Krieg, M.D., Founder and Chief Scientific Officer of Checkmate. “These initial observations provide valuable insights into the mechanism of action of vidutolimod and reinforce earlier preclinical data from the Iowa team that suggest the activity of vidutolimod requires the generation of anti-Qβ antibodies. We look forward to the continued investigation of vidutolimod in combination with immune checkpoint inhibitors to improve available treatment options for people with lymphoma and other difficult to treat cancers.”

About Checkmate Pharmaceuticals 
 
Checkmate Pharmaceuticals is a clinical stage biotechnology company focused on developing its proprietary technology to harness the power of the immune system to combat cancer. Checkmate Pharmaceuticals’ product candidate, vidutolimod (CMP-001), is an advanced generation Toll-like receptor 9 (TLR9) agonist, delivered as a biologic virus-like particle utilizing a CpG-A oligodeoxynucleotide as a key component, designed to trigger the body’s innate immune system to attack tumors in combination with other therapies. Information regarding Checkmate Pharmaceuticals is available at www.checkmatepharma.com.

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Forward-Looking Statements
Various statements in this release are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including words such as, but not limited to, “anticipate,” “believe,” “can,” “could,” “expect,” “estimate,” “design,” “goal,” “intend,” “may,” “might,” “objective,” “plan,” “predict,” “project,” “target,” “likely,” “should,” “will,” and “would,” or the negative of these terms and similar expressions or words, identify forward-looking statements. Forward-looking statements are based upon current expectations that involve risks, changes in circumstances, assumptions, and uncertainties. These statements include those regarding our ability to consummate the proposed merger with Regeneron, the timing of the closing of such merger, including the satisfaction to conditions to closing of the proposed merger within the expected timeframe or at all, the expected benefits of the proposed merger, vidutolimod (CMP-001), including its development, efficacy and therapeutic potential and the advancement of our clinical and preclinical pipeline, and the timing of our ongoing clinical trials, including the potential benefit of acceleration in development following the consummation of the proposed merger. Forward-looking statements should not be read as a guarantee of future performance or results and may not be accurate indications of when such performance or results will be achieved. These forward-looking statements are subject to risks and uncertainties, including those related to the development of vidutolimod, including any delays in our ongoing or planned preclinical or clinical trials, the results from clinical trials, including the fact that positive results from a trial may not necessarily be predictive of the results of future or ongoing clinical trials, the impact of the ongoing COVID-19 pandemic on our business, operations, clinical supply , clinical enrollment and plans, the risks inherent in the drug development process, including related to regulatory approval, the risks regarding the accuracy of our estimates of expenses and timing of development, our capital requirements, and obtaining, maintaining and protecting our intellectual property, risks associated with our ability to consummate the proposed merger and the timing of the closing of the proposed merger, including the risks that a condition to closing would not be satisfied within the expected timeframe or at all or that the closing of the proposed merger will not occur, the outcome of any legal proceedings that may be instituted against the parties and others related to the definitive agreement entered into with Regeneron, the occurrence of any event, change or other circumstance or condition that could give rise to the termination of the merger agreement, unanticipated difficulties or expenditures relating to the proposed merger, the response of business partners and competitors to the announcement of the proposed merger, and/or potential difficulties in employee retention as a result of the announcement and pendency of the proposed merger, and the response of our stockholders to the merger agreement, and ongoing actions taken and any future actions that may be taken by activist stockholders. These and additional risks are discussed in the sections titled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Quarterly Report on Form 10-Q for the three months ended March 31, 2022 and Annual Report on Form 10-K for the year ending December 31, 2021, filed with the Securities and Exchange Commission, which are available on the Securities and Exchange Commission’s website at www.sec.gov, and as well as discussions of potential risks, uncertainties and other important factors in our subsequent filings with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and Checkmate undertakes no duty to update this information unless required by law.


Investor Contact  Rob Dolski Chief Financial Officer  rdolski@checkmatepharma.com Media Contact  Karen Sharma  MacDougall Advisors 781-235-3060  ksharma@macdougall.bio