LIXTE Biotechnology Announces a Supported Collaborative Trial to Study LIXTE’s First-in-Class PP2A Inhibitor, Plus GSK’s Immunotherapy in Clear-Cell Ovarian Cancer

LIXTE Biotechnology Holdings, Inc. recently announced a Phase 1b collaborative clinical trial to assess whether adding Lixte’s LB-100 to GSK’s programmed death receptor-1 (PD-1)-blocking monoclonal antibody, dostarlimab, may enhance the effectiveness of immunotherapy in the treatment of ovarian clear cell carcinoma (OCCC). The clinical trial is sponsored by The University of Texas – MD Anderson Cancer Center and will be conducted at MD Anderson and will also be open at Northwestern University’s Robert H. Lurie Comprehensive Cancer Center. LIXTE will provide LB-100; GSK will provide dostarlimab and financial support for the clinical trial.

The clinical trial is based on the observation of longer survival of patients with OCCC treated with immunotherapy whose cancer cells have an acquired gene mutation resulting in a reduction in PP2A. This finding was reported by the lead clinical investigators of this new trial: Amir Jazaeri MD, Professor of Gynecologic Oncology at MD Anderson, and Emily Hinchcliff, MD, MPH, Assistant Professor of Obstetrics and Gynecology at Northwestern University Feinberg School of Medicine. The observation by Drs. Jazaeri and Hinchcliff, that a genetically acquired reduction in PP2A enhances sensitivity to immunotherapy, raises the possibility that reducing PP2A pharmacologically with LB-100 will enhance the anti-tumor effect of the PD-1 blocking monoclonal antibody dostarlimab in patients with OCCC lacking the genetic reduction in PP2A.

John S. Kovach, M.D., LIXTE’s founder and Chief Executive Officer, said “Preclinical data supports the idea that LB-100 enhances the efficacy of PD-1 therapy. Clinical data also supports this idea, in that patients with ovarian clear cell carcinoma with dysfunctional PP2A due to somatic mutations in PPP2R1A have shown dramatically longer survival after treatment with immune checkpoint blockers.”

Dr. Hinchcliff added “OCCC is a comparatively chemotherapy resistant disease and therefore has very limited options for treatment. This clinical trial is an exciting alternative approach that leverages the potential synergy between these two agents and is aiming to improve the impact immunotherapy may have for these patients.”

LIXTE Biotechnology Holdings, Inc. is a clinical-stage pharmaceutical company focused on new targets for cancer drug development and developing and commercializing cancer therapies. LIXTE has achieved a breakthrough demonstrating that its first-in-class lead clinical PP2A inhibitor, LB-100, is well-tolerated in cancer patients at doses associated with anti-cancer activity. Based on extensive published preclinical data (see, LB-100 has the potential to significantly improve outcomes for patients undergoing various chemotherapies or immunotherapies. LIXTE’s new approach has no known competitors and is covered by a comprehensive patent portfolio. Initial proof-of-concept clinical trials are in progress.