Phio Pharmaceuticals (PHIO) investor relations material

Market opportunity and technology platform

• INTASYL platform enables precise gene silencing to enhance immune cell effectiveness against cancer, targeting cutaneous squamous cell carcinoma, the second most common solid tumor, with a growing patient population due to aging and immunocompromised subgroups.

• INTASYL is a patented, intratumoral, non-biologic drug with demonstrated safety and efficacy in a phase I-B trial (PH-762), with patent protection through 2044.

• The platform's specificity, safety, and stability are supported by a robust intellectual property portfolio and a lean, experienced team.

Clinical development and trial results

• PH-762 targets the PD-1 gene, validated by prior large pharma studies, but INTASYL acts at the T-cell source rather than the tumor surface.

• Phase I-B trial in cutaneous squamous cell carcinoma showed no immune-related or treatment-related toxicities across escalating doses, with an 85% response rate at the highest dose and 65% overall response.

• Treatment is administered in-office, offering convenience, tissue-sparing benefits, and reduced need for reconstructive surgery.

• Next clinical trial design is underway, with FDA submission planned early next quarter and trial commencement expected in Q1 next year.

Pipeline, strategy, and business development

• PH-894, targeting the BRD4 gene, has completed IND-enabling studies and shows a clean safety profile; final indication selection and IND filing are pending.

• Non-strategic programs are being positioned for out-licensing, targeting oncology and infectious diseases, leveraging a broad gene-silencing compound portfolio.

• Commercial-scale API production for PH-762 has begun, supporting upcoming clinical trials and de-risking manufacturing scalability.