PDS Biotechnology Corporation announced updated survival data from the Phase 2 clinical trial investigating the triple combination of PDS0101, PDS0301 (IL-12 antibody- drug conjugate) and an investigational immune checkpoint inhibitor (ICI) in two groups of advanced cancer patients with various types of human papillomavirus (HPV) 16-positive cancers. The ICI naïve group had not responded to standard- of-care treatments but had not yet been treated with an ICI. The ICI resistant group included patients who had not responded to multiple prior treatments, including ICI therapy.

Investigators at the National Cancer Institute (NCI), part of the National Institutes of Health, have completed the primary endpoint analysis of the Phase 2 trial. In the ICI naïve group, final survival data from the trial indicated that 75% (6/8) of these patients were still alive at 36 months, and the median overall survival (OS) has not yet been reached. Published data on standard-of-care ICIs report 30-50% of these patients typically remain alive at 12 months, and less than 30% of the patients remain alive at 24 months.

In the ICI resistant group, the 12-month OS rate was 72% and the triple combination achieved a median OS of approximately 20 months. In addition: For PD10101 plus high doses of ICI and PDS0301, the overall response re (ORR) was 63% (5/8). For PDS010101 plus low doses of ICI and/or PDS0301, the ORR was 5% (1/21).

The historical median survival for ICI therapy in HPV-positive cancer ICI resistant patients is reported to be 3.4 months.