Phio Pharmaceuticals Announces Key Tumor Response Data from all Cohorts in Intratumoral PH-762 Dose Escalation Cutaneous Carcinoma Trial

Core Insights - Phio Pharmaceuticals Corp. reported a 70% overall response rate in its Phase 1b clinical trial for the treatment of cutaneous squamous cell carcinoma (cSCC) using the INTASYL compound PH-762, with 100% clearance observed in 10 out of 14 responders [1][4] - The trial demonstrated favorable safety and tolerability, with no dose-limiting toxicities or clinically relevant adverse effects reported across all dose escalation cohorts [3][4] Summary by Sections Clinical Trial Results - A total of 22 patients with cutaneous carcinomas completed treatment in the Phase 1b trial, with 20 patients having cSCC. Among these, 14 were pathologic responders, including 10 with complete response (100% clearance), 2 with major/near clear response (greater than 90% clearance), and 2 with partial response (greater than 50% clearance) [2] - One patient with metastatic Merkel cell carcinoma also showed a partial response with greater than 50% clearance, while six cSCC patients and one melanoma patient had responses of less than 50%, but none experienced disease progression [2] Safety and Tolerability - PH-762 was well tolerated in all patients across five dose escalation cohorts, with drug concentration increased 20-fold from the first to the final cohort [3] - Safety data from an extended follow-up period is expected to be reported in the second quarter of 2026 [3] Company Overview - Phio Pharmaceuticals Corp. is a clinical-stage siRNA biopharmaceutical company focused on developing therapeutics using its proprietary INTASYL® gene silencing technology aimed at treating various forms of skin cancer [6] - The lead clinical program, PH-762, targets the PD-1 gene and is being evaluated for its potential as a non-surgical treatment for skin cancers [6]