According to the company, 60 percent of evaluable patients exhibited a clinical response in the study. Activity was observed at all levels.
PDS Biotechnology (NASDAQ:PDSB) has reviewed additional data from its previously reported Phase 1 study.
As quoted in the press release:
In the study, 60% of evaluable patients had a clinical response (as defined below). The primary focus of the study was safety and evaluation of immune biomarkers resulting from administration of Versamune®-based PDS0101 in patients with cervical intraepithelial neoplasia (CIN) infected with multiple high-risk, cancer-causing types of human papillomavirus (HPV). These newly-available clinical data are the result of a post-hoc follow up which was not part of the protocol design. The novel Versamune® mechanisms of action and the resulting unique regression of advanced preclinical tumors were recently published (Journal of Immunology, Vol. 202, Issue 1215 June 2019).
The Phase 1 clinical trial was an open-label, dose-escalating study that included 12 patients; 3 receiving a 1mg dose, 3 receiving a 3 mg dose, and 6 receiving a 10mg dose. All 12 patients completed three doses of PDS0101. As previously reported, no dose-limiting toxicities or long-term safety concerns were observed.
PDS0101 was immunologically active at all three doses and resulted in a strong increase (5 to 73-fold) in circulating HPV disease-attacking T-cells in 10/12 subjects, quantified by either INF-γ or granzyme-b ELISPOT studies of blood drawn approximately 14 days after subcutaneous injection. The potentially unique ability of PDS0101 to safely generate high levels of circulating, granzyme-b inducing (cytolytically active) CD8+ (killer) T-cells prompted a retrospective evaluation of clinical outcomes.
PDS received limited follow-up clinical data from eleven out of the twelve patients and was able to review the source data reported for all but two of these patients (both in the 10mg dose group and whose data were reported by correspondence from the investigator). The clinical results were evaluated and reported by the respective physicians/principal investigators outside the scope of the Phase 1 trial protocol and were not evaluated at specific predetermined times after treatment. Clinical response (regression/ elimination of CIN) was determined by cytology or colposcopy as available from individual investigators.