PHIO: In Vivo Data on INTASYL Shows Strong Antitumor Action

MARLBOROUGH, Mass., May 29, 2020 /PRNewswire/ -- Phio Pharmaceuticals Corp. (Nasdaq: PHIO), a biotechnology company developing the next generation of immuno-oncology therapeutics based on its proprietary self-delivering RNAi (INTASYL™) therapeutic platform, today announced positive data from in vivo studies that show strong antitumoral efficacy with several of its INTASYL pipeline programs, including PH-762, PH-894 and PH-804. These results show that intratumoral delivery of INTASYL compounds inhibited tumor growth by overcoming the immunosuppressive tumor microenvironment (TME) as shown by changes in T cell composition and activation. Therefore, the Company believes these pipeline programs show great promise in the treatment of solid tumors. These data were presented during the ASCO 2020 Virtual Scientific Program (Abstract e15206: "Intratumoral use of self-delivering RNAi to reprogram the tumor microenvironment and boost the antitumor response").

The Company's pipeline programs PH-762, PH-894 and PH-804 are INTASYL compounds designed to silence the expression of PD-1, BRD4 and TIGIT, respectively, which are proteins linked to reduced immune cell function in cancer patients. A series of preclinical in vivo studies in tumor models were conducted and the resulting data showed dose-dependent attenuated tumor growth for the INTASYL compounds compared to control groups. Relevant changes in the TME include an increase of tumor-infiltrating lymphocytes, including CD8+ T cells, responsible for tumor cell killing, and an increase of activation markers on these cells. Together, these novel findings support using INTASYL intratumorally as a viable approach to immunotherapy and warrant further investigation in patients.

"These exciting new data show that INTASYL compounds are able to overcome the immunosuppressive TME by reprogramming T cells in order to inhibit tumor growth. These data support our belief that Phio's INTASYL technology can be used to develop powerful immunotherapeutics, which can overcome the shortcomings of currently available systemic immunotherapy," said Dr. Simon Fricker, Phio's VP of Research. "We look forward to continuing our development of INTASYL, including the IND enabling studies which are currently ongoing."

A poster further detailing the data presented at the ASCO 2020 Virtual Scientific Program will be made available under the "Investors – Events and Presentations" section of the Company's website (click here).