Phio Pharmaceuticals Corp. announced the presentation of new preclinical data at the 38th Annual Meeting of the Society for Immunotherapy of Cancer (SITC). The event is scheduled to take place in San Diego, California, from November 1-5, 2023.

Phio?s innovative preclinical study data highlights the benefit of intratumoral injection (IT) of an INTASYL compound targeting CTLA-4 (27790) in conjunction with systemic anti-PD-1 antibody therapy. Preclinical studies have demonstrated: The combination of INTASYL compound 27790 with systemic anti-PD-1 antibody therapy significantly enhanced the efficacy of anti-PD-1 mAb therapy in vivo. The combination of INTASYL compound 27790 and anti-PD-1 elicited complete regression of ~40% of IT treated tumors in a mouse model.

Additionally, INTASYL compound 27790 appeared to improve the efficacy of anti-PD-1 therapy toward those tumors not treated directly with 27790. INTASYL compound 27790 increased the percentage of reactive CD8+ T cells in the tumor while decreasing immunosuppressive/pro-tumor macrophages in the treated tumor micro-environment.