Phio Pharmaceuticals Advances PH-762 Skin Cancer Trial Amid Rising Investor Interest

Introduction

PHIO PHARMACEUTICALS CORP (Nasdaq: PHIO) is a clinical-stage biotechnology company headquartered in Marlborough, Massachusetts, with an additional office in King of Prussia, Pennsylvania. Founded in 2011 as RXi Pharmaceuticals, the company rebranded in November 2018 and focuses on developing immuno-oncology therapeutics using its proprietary INTASYL™ self-delivering siRNA platform. INTASYL compounds are chemically modified to enter target cells without the need for auxiliary delivery systems, with current programs targeting cutaneous squamous cell carcinoma, melanoma, and other solid tumors.

Corporate Structure

Phio employs a lean staffing model, with LinkedIn listing 2–10 employees at its Pennsylvania office. The company was co-founded by Nobel Laureate Craig Mello, who received the 2006 Nobel Prize for the discovery of RNA interference. Robert Bitterman is the Executive Chair and has served as Principal Executive Officer since September 2022. The board includes individuals such as David H. Deming, who was appointed to the board in February 2025. Phio maintains research and development facilities in both Massachusetts and Pennsylvania, supported by partnerships for manufacturing and clinical collaborations.

Immuno-oncology by National Cancer Institute

Recent Developments and News

On June 25, 2025, Phio announced that the Safety Monitoring Committee recommended advancing the INTASYL PH-762 skin cancer trial to its fifth dose-escalation cohort. The following day, June 26, the company reported progress in the PH-762 Phase 1 study for advanced cutaneous squamous cell carcinoma and melanoma, which includes an AgonOx-partnered arm assessing tumor-infiltrating lymphocyte enhancement. On July 7, 2025, Phio filed an 8-K current report concerning arrangements for its 2025 Annual Meeting of Stockholders. Earlier in 2025, Phio reported results from a Phase 1b study of PH-762 (May 7) and provided a business update alongside the first-quarter financial results (May 7).

Financial and Strategic Analysis

On July 25, 2025, PHIO shares closed at USD 3.2997, reflecting a 31.46% increase for the session with 16,570,504 shares traded on the NASDAQ. This trading activity aligns with heightened investor interest following clinical milestones. Comprehensive financial results for 2025 are expected in an upcoming annual report, while the company's recent filings include updates on clinical progress, management appointments, and corporate governance topics rather than detailed earnings figures. Phio is advancing its strategic direction from discovery to development, with PH-762 and PH-894 identified as lead candidates. PH-762 aims to target PD-1 to enhance T-cell activity in solid tumors, while PH-894 focuses on silencing BRD4 to modulate immune and tumor cell gene expression. Additionally, the INTASYL platform is being researched for adoptive cell therapies.

Market Position and Industry Context

Phio operates within the immuno-oncology sector, using self-delivering siRNA to address traditional delivery challenges. Competitors include other RNAi and gene-silencing companies, as well as larger firms focused on checkpoint inhibitors and cell therapies. The global siRNA therapeutics market is growing, influenced by increasing cancer incidence and the demand for targeted treatments. Phio's scientific foundation, bolstered by its Nobel Laureate co-founder and published research demonstrating in vivo efficacy, positions it among emerging industry innovators. However, the company remains reliant on successful clinical outcomes and effective partnerships to proceed toward commercialization.

TL;DR

• On June 25, 2025, the Safety Monitoring Committee approved advancing PH-762 to the fifth dose level in its skin cancer trial.
• On June 26, Phio reported progress in Phase 1 studies of PH-762 for cSCC and melanoma, including an AgonOx-collaboration arm.
• Shares closed at USD 3.2997 on July 25, 2025, with 16.6 million shares traded on NASDAQ.
• Upcoming catalysts include the presentation of detailed 2025 financial results and IND-enabling studies for PH-894.