KING OF PRUSSIA, PENNSYLVANIA, March 23, 2026
Phio Pharmaceuticals Corp. has announced the presentation of positive clinical study results from its Phase 1b trial of PH-762, a novel PD-1 directed immunotherapy, at the American Academy of Dermatology (AAD) 2026 Annual Meeting in Denver. The late-breaking presentation highlights encouraging efficacy and safety outcomes in patients with cutaneous carcinomas, reinforcing the company’s progress in advancing its RNAi-based immuno-oncology pipeline.
Promising Phase 1b Results in Cutaneous Carcinoma
The Phase 1b clinical study evaluated the safety, tolerability, and preliminary efficacy of PH-762, administered as an intratumoral therapy in patients with cutaneous squamous cell carcinoma (cSCC), melanoma, and Merkel cell carcinoma. The study enrolled 22 patients across multiple dose-escalation cohorts, with results demonstrating no dose-limiting toxicities or serious adverse events, underscoring a favorable safety profile.
Importantly, the trial reported a pathological response rate of approximately 65% across all cohorts, with an impressive 85% response rate in the highest-dose group, indicating strong anti-tumor activity. Additionally, patients experienced modest reductions in tumor burden, suggesting meaningful clinical benefit. These findings position PH-762 as a potential non-surgical treatment option for skin cancers, addressing a significant unmet need in dermatologic oncology.
Innovative RNAi Technology Targeting PD-1 Pathway
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PH-762 is developed using Phio’s proprietary INTASYL® gene silencing platform, a self-delivering RNA interference (RNAi) technology designed to enhance immune cell activity against cancer cells. By targeting the PD-1 immune checkpoint pathway, PH-762 aims to boost the body’s natural immune response, enabling more effective tumor destruction without the need for complex delivery systems.
This next-generation immunotherapy approach represents a significant advancement over traditional therapies, offering localized treatment with reduced systemic exposure. The ability to directly silence immune inhibitory signals within the tumor microenvironment highlights the precision and versatility of RNAi-based therapeutics, positioning PH-762 as a promising candidate in the evolving immuno-oncology landscape.
Advancing Clinical Development and Regulatory Pathway
The presentation of these results at a prestigious dermatology conference underscores the growing recognition of PH-762 within the scientific and clinical community. Phio Pharmaceuticals has indicated plans for continued clinical development, with regulatory engagement with the FDA expected in the second quarter of 2026 to define next steps in trial design and advancement.
The company’s strategic focus on clinical-stage development and regulatory alignment reflects adherence to Good Clinical Practice (GCP) standards, ensuring that future studies will support potential regulatory submissions and commercialization pathways. With sufficient financial resources projected to sustain operations into 2027, Phio is well-positioned to accelerate its clinical pipeline and expand its immuno-oncology portfolio.
As the demand for innovative, targeted cancer therapies continues to grow, PH-762’s early clinical success highlights the transformative potential of RNAi-based treatments. The ongoing development of this therapy could significantly impact the management of cutaneous carcinomas, offering patients a less invasive and highly targeted therapeutic alternative.
Source: Phio Pharmaceuticals press release
