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

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Investor Contact  Rob Dolski Chief Financial Officer Media Contact  Karen Sharma  MacDougall Advisors 781-235-3060