Onxeo Announces Promising Results from Preclinical Study of Beleodaq® Combination with Checkpoint Inhibitors

Combination with checkpoint inhibitors decreased tumor growth rate and prolonged survival in syngeneic HCC mouse model

Paris (France), Copenhagen (Denmark) Onxeo S.A. (Euronext Paris, Nasdaq Copenhagen: ONXEO), a biopharmaceutical company specializing in the development of innovative drugs for the treatment of orphan diseases, in particular in oncology, today announced promising results from preclinical studies evaluating the potential of its already PTCL (peripheral T-cell lymphoma)-approved Beleodaq® (belinostat), in combination with checkpoint inhibitors as a potential treatment option for other tumor indications. The studies were conducted as the second step of Onxeo’s ongoing preclinical development program in partnership with leading European research institution the University of Navarra’s University Clinic and Center for Applied Medical Research in Spain under the leadership of Prof. Bruno Sangro and Dr. Pablo Sarobe.

The preclinical studies were performed in an immune-competent mouse syngeneic HCC (hepatocellular carcinoma) model, in which responses to a combination of Beleodaq® and checkpoint inhibitors were compared to responses from treatment with checkpoint inhibitors alone. The studies demonstrated a complete cessation of tumor growth in all mice (100%) treated with the combination of Beleodaq® and checkpoint inhibitors. The tumor cessation effect continued for approximately one week after the final dose of belinostat was administered. By comparison, checkpoint inhibitors alone inhibited tumor growth in only about 30 percent of mice which received the treatment for the same period.

In addition, mechanistic studies performed on the spleens of the mice demonstrated the generation of an underlying immune response that correlated with the observed therapeutic effect of the combination treatment, showing an increase in production of interleukines (signaling proteins for regulating immune responses) by activated T-cells and a decrease in the number of regulatory T-cells, when compared to mice treated only with checkpoint inhibitors.

Graham Dixon, PhD, Chief Scientific Officer of Onxeo, commented, “These data represent promising findings for the continued evaluation of Beleodaq® in cancers beyond peripheral T-cell lymphoma (PTCL) when used as a combination with immuno-oncology agents in various tumor indications such as for example HCC. Approximately 20 percent of cancer patients currently treated with checkpoint inhibitors alone are responding and thus, if translated into the clinic, the positive outcomes from the combination therapy would account for a significant improvement in the number of patients exhibiting high treatment responses. As a next step in our collaboration with Prof. Bruno Sangro and Dr. Pablo Sarobe, we are conducting follow-up studies to fully characterize these preclinical findings demonstrating the potential of Beleodaq® in combination with checkpoint inhibitors in  various  tumor indications, and in particular, are evaluating the immune response in the tumor microenvironment in order to improve the translation of the response into human patients.”

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