8-K: Phio Pharma Reports Positive Skin Cancer Trial Data, Extends Cash

Phio Pharmaceuticals announced positive clinical trial results for its lead cancer therapeutic PH-762 and secured $12.1 million in financing, extending its cash runway into H1 2027.

Summary

• Reported financial results for the quarter ended September 30, 2025.
• The PH-762 Phase 1b dose escalation clinical trial has advanced to the fifth and final cohort at the maximum dose.
• Positive pathology results at the maximum dose include 100% tumor clearance (complete response) in one patient, greater than 90% (near complete response) in a second patient, and greater than 50% (partial response) in a third patient.
• The Safety Monitoring Committee issued a favorable review of safety data at the maximum dose of INTASYL PH-762.
• Cumulative pathologic response in 16 patients with cutaneous squamous cell carcinoma (cSCC) includes six with a complete response, two with a near complete response, and two with a partial response.
• No dose-limiting toxicities or clinically relevant treatment-emergent adverse effects have been observed in patients receiving intratumoral PH-762.
• Warrant inducement financing in November 2025 is expected to generate net proceeds totaling approximately $12.1 million, extending the cash runway into the first half of 2027.
• Cash and cash equivalents were approximately $10.7 million at September 30, 2025, and an estimated $21.3 million as of November 13, 2025.
• Research and development expenses for Q3 2025 increased to $1.2 million from $0.6 million in Q3 2024, primarily due to higher clinical trial and CMC costs for PH-762.
• General and administrative expenses for Q3 2025 increased to $1.3 million from $0.9 million in Q3 2024, driven by outsourced professional fees and stock compensation.
• Net loss for Q3 2025 was $2.4 million, compared to $1.5 million for the same period in 2024.

Sentiment

Score: 8

Explanation: The filing presents strong positive clinical data for its lead candidate PH-762, particularly at the maximum dose, coupled with a favorable safety profile. The successful capital raise significantly extends the company's financial runway, providing stability for continued development. While financial losses increased, this is typical for a clinical-stage biotech investing in R&D.

Positives

• PH-762 Phase 1b trial shows strong efficacy at maximum dose, with 100% tumor clearance in one patient, >90% in another, and >50% in a third.
• Favorable safety review by the Safety Monitoring Committee, with no dose-limiting toxicities or clinically relevant adverse effects observed across all dose cohorts.
• Successful warrant inducement financing raised approximately $12.1 million, significantly bolstering the company's financial position.
• Cash runway extended into the first half of 2027, providing stability for ongoing clinical development.
• Cumulative complete response rate of 37.5% (6 out of 16) in cSCC patients treated with PH-762.

Negatives

• Net loss increased to $2.4 million in Q3 2025 from $1.5 million in Q3 2024.
• Research and development expenses increased to $1.2 million in Q3 2025 from $0.6 million in Q3 2024.
• General and administrative expenses increased to $1.3 million in Q3 2025 from $0.9 million in Q3 2024.
• Six cSCC patients and one metastatic melanoma patient had a pathologic non-response (<50% clearance) in the trial.
• The warrant inducement financing involved issuing new unregistered common stock warrants, which could lead to future shareholder dilution.

Risks

• Actual results may differ materially from forward-looking statements due to inherent uncertainties, risks, and changes in circumstances.
• Risks include the outcomes of preclinical and clinical activities, the ability to execute business strategies, and the timing or likelihood of regulatory filings and approvals.
• The ability to manufacture and supply product candidates for clinical activities and for commercial use if approved is a risk.
• The scope of protection the company is able to establish and maintain for intellectual property rights covering its technology platform is a factor.
• The ability to obtain future financing and market conditions are ongoing risks.
• Additional risks are identified in the company's Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q under the caption "Risk Factors".

Future Outlook

The company projects its estimated cash and cash equivalents of approximately $21.3 million (as of November 13, 2025) will sustain operations into the first half of 2027. The company may continue to screen and treat additional patients as part of the fifth cohort of the PH-762 clinical trial.

Management Comments

• PHIO's INTASYL compounds are designed to enhance the body's immune cells to more effectively kill cancer cells.
• PH-762 is a potential non-surgical treatment for skin cancers.

Industry Context

Phio Pharmaceuticals operates in the highly competitive immuno-oncology and gene silencing (siRNA) therapeutic space. Its focus on PD-1 gene silencing for skin cancers positions it against established immunotherapies and traditional surgical treatments. The INTASYL technology aims for a self-delivering siRNA approach, potentially offering advantages in delivery and specificity. The positive early-stage clinical data for PH-762 suggests potential in a market with significant unmet needs for non-surgical options in certain skin cancers.

Comparison to Industry Standards

• The reported complete response rate of 37.5% (6 out of 16 cSCC patients) and overall positive responses (>50% clearance) in the Phase 1b trial for PH-762 are encouraging for an early-stage oncology asset, especially for a non-surgical approach. For comparison, established PD-1 inhibitors in advanced cSCC can show objective response rates (ORR) ranging from 30-50% in later-stage trials, but these are typically systemic treatments for more advanced disease and for different patient populations (neoadjuvant vs. advanced metastatic).
• The safety profile, with no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects, is a strong positive for a novel cancer therapeutic in early development, as safety is a major hurdle for new drugs.
• The cash runway extension into H1 2027 is critical for a clinical-stage biotech, providing stability for ongoing development, which is a common challenge in the industry where many companies face frequent capital needs.

Stakeholder Impact

• Shareholders: Positive impact due to promising clinical data and extended cash runway, reducing immediate financial uncertainty. However, the warrant inducements cause dilution.
• Patients: Potential for a new, non-surgical treatment option for various skin cancers if PH-762 continues to demonstrate efficacy and safety in further trials.
• Employees: Increased job security and continued focus on research and development due to the significantly extended cash runway.
• Creditors/Suppliers: Improved financial stability reduces risk for those doing business with the company.

Next Steps

• Continue to screen and treat additional patients as part of the fifth cohort of the PH-762 Phase 1b trial.
• Further development of PH-762, including cGMP manufacture through the agreement with a U.S. manufacturing company.
• Present an update on the ongoing clinical study for PH-762 at the Society for Immunotherapy of Cancer (SITC) meeting.
• Deliver a podium presentation entitled 'Synthesized INTASYL siRNA Technology Downregulating Gene Expression' at the Advanced Therapies USA conference 2025 in Philadelphia, PA.

Key Dates

Recommendation

The positive clinical data for PH-762, particularly the high rates of tumor clearance and favorable safety profile at the maximum dose, represent a significant de-risking event for a clinical-stage biotech. The successful capital raise, extending the cash runway into H1 2027, provides crucial financial stability for continued development. While the company is still incurring losses, this is expected for a company in this stage. The combination of strong clinical progress and improved financial health makes this an attractive investment opportunity for investors with a higher risk tolerance seeking exposure to innovative oncology therapeutics.

Keywords

Phio Pharmaceuticals, PHIO, INTASYL, siRNA, gene silencing, immuno-oncology, PH-762, skin cancer, cutaneous squamous cell carcinoma, melanoma, Merkel cell carcinoma, clinical trial, Phase 1b, biopharmaceutical, cancer therapy, warrant financing, cash runway, PD-1 gene