Phio Announces Safety Monitoring Committee's (SMC) Positive Wrap-up on Lead Clinical Candidate PH-762 in Skin Cancer Trial
Rhea-AI Summary
Phio Pharmaceuticals (NASDAQ: PHIO) reported that the Safety Monitoring Committee completed its safety review of PH-762 in a Phase 1b skin cancer trial. No dose-limiting toxicities or serious adverse events were observed among 22 treated patients across five dose-escalation cohorts.
The highest dose cohort (n=7) showed an 85% pathological response (6 of 7), with 4 of 6 responders achieving complete tumor clearance. Overall cSCC response was 65% (13 of 20), including 9 complete responses. An FDA meeting submission is targeted for Q2 2026 and CMC API material is expected in March 2026 ahead of cGMP manufacturing in H2 2026.
Positive
- No dose-limiting toxicities or serious adverse events in 22 patients
- 85% pathological response in final cohort (6 of 7 patients)
- 65% overall cSCC response (13 of 20 patients) including 9 complete responses
- Targeted FDA submission for next-step guidance in Q2 2026
- CMC API material expected in March 2026, supporting non-human primate study
Negative
- Final dose cohort size is small at n=7, limiting statistical power
- Full study results are pending formal analysis and not yet final
- Seven cSCC patients and one melanoma patient had responses of less than 50%
News Market Reaction
On the day this news was published, PHIO gained 24.44%, reflecting a significant positive market reaction. Argus tracked a peak move of +65.8% during that session. Our momentum scanner triggered 34 alerts that day, indicating elevated trading interest and price volatility. This price movement added approximately $3M to the company's valuation, bringing the market cap to $15M at that time. Trading volume was exceptionally heavy at 73.2x the daily average, suggesting very strong buying interest.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
Pre-news, PHIO was down 2.18% while close biotech peers showed mixed moves: PHGE up 19.21%, ADAP down 17.57%, and others modestly positive. With no peers in the momentum scanner and no same-day peer headlines, the setup points to stock-specific factors rather than a coordinated sector move.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Jan 26 | Investor conference | Positive | -4.6% | Discovery conference appearance and completion of PH-762 Phase 1b treatment. |
| Jan 20 | Clinical data update | Positive | -5.3% | Reported key tumor response and safety data from PH-762 cutaneous trial. |
| Jan 15 | Investor conference | Neutral | +0.9% | Sidoti Micro-Cap conference presentation and PH-762 development update. |
| Dec 23 | Regulatory progress | Positive | -6.4% | FDA acceptance of PH-762 nonclinical protocol and interim Phase 1b data. |
| Nov 25 | Trial enrollment | Positive | +3.5% | Completion of enrollment in PH-762 Phase 1b trial with early response data. |
Recent PH-762 updates and events often saw share price weakness despite generally positive clinical and development news, with more divergence than alignment between news tone and next-day moves.
Over the past few months, Phio has repeatedly highlighted progress for PH-762, including enrollment completion on Nov 25, 2025, FDA acceptance of a nonclinical protocol on Dec 23, 2025, and interim/updated Phase 1b data on Jan 20, 2026. Investor conferences in mid‑ and late‑January 2026 reiterated this development story. Price reactions to these largely constructive updates were mixed, with several clinically positive milestones followed by negative next‑day moves, setting a backdrop where strong data have not consistently translated into short‑term gains.
Regulatory & Risk Context
An effective resale registration covers up to 11,763,800 shares issuable on warrant exercise. Existing stockholders, not the company, may resell these shares, while Phio would receive up to $24.5 million in cash only if all warrants are exercised. This structure can add potential supply from selling stockholders over time, alongside possible capital inflows tied to warrant exercises.
Market Pulse Summary
The stock surged +24.4% in the session following this news. A strong positive reaction aligns with the clearly favorable safety and efficacy profile reported for PH-762, including an 85% pathological response at the highest dose and no dose-limiting toxicities across 22 treated patients. Historically, several constructive PH-762 updates saw muted or negative next-day moves, so a large upside move would mark a shift from that pattern. Investors would still need to weigh the overhang from up to 11,763,800 registered warrant shares and potential selling by existing holders.
Key Terms
dose-limiting toxicities medical
pathological response medical
complete response medical
partial response medical
Merkel cell carcinoma medical
non-human primate study medical
Chemistry, Manufacturing and Controls (CMC) technical
cGMP regulatory
AI-generated analysis. Not financial advice.
Maximum Dose Concentration in Final Cohort Yields
No Serious Adverse Events or Dose-Limiting Toxicities Identified Across All 5 Dose Escalation Cohorts
King of Prussia, Pennsylvania--(Newsfile Corp. - February 10, 2026) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage siRNA biopharmaceutical company developing therapeutics using its proprietary INTASYL® gene silencing technology to eliminate cancer. Phio announced today that the Safety Monitoring Committee (SMC) has concluded its planned safety review for all patients treated with the INTASYL compound PH-762 in Phio's Phase 1b clinical trial. No dose-limiting toxicities or serious adverse events have been reported for any of the 22 enrolled patients who completed 4 intratumoral injections of PH-762 and have been followed through at least 4 weeks after the final injection. PH-762 has been evaluated in patients within five dose-escalating cohorts, increasing drug concentration 20-fold from the first to the fifth and final cohort.
"These results support continued evaluation of this highest dose concentration of PH-762 in the next clinical trial," said Robert Bitterman, President and CEO of Phio Pharmaceuticals. "Reported pathological response coupled with a favorable safety-tolerability profile is clinically meaningful."
While final study data is pending formal analysis, an FDA submission intended to propose and seek guidance for next steps in clinical study design for PH-762 is targeted for the second quarter of 2026. A total of 22 patients with cutaneous carcinomas completed treatment in the Phase 1b trial and underwent excision of the treated lesional site. Revised reported data supports an overall response rate of
Concurrently, Chemistry, Manufacturing and Controls (CMC) development for drug substance material (API), is expected to have material available in March 2026 for the non-human primate study, a prerequisite for human pivotal trial commencement. Experimental work and documentation for process and methods development, as well as impurities testing are currently meeting expected timelines to commence manufacturing of cGMP material in the second half of 2026.
About Phio Pharmaceuticals Corp.
Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage biopharmaceutical company advancing its proprietary INTASYL® siRNA gene silencing technology to eliminate cancer. Phio's INTASYL compounds are designed to enhance the body's immune cells to more effectively kill cancer cells. Phio's lead clinical development program is an INTASYL compound, PH-762, that silences the PD-1 gene implicated in various forms of skin cancer. The ongoing Phase 1b trial (NCT# 06014086) is evaluating PH-762 for the treatment of cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. PH-762 is a potential non-surgical treatment for skin cancers.
For additional information, visit the Company's website, www.phiopharma.com.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "intends," "believes," "anticipates," "indicates," "plans," "expects," "suggests," "may," "would," "should," "potential," "designed to," "will," "ongoing," "estimate," "forecast," "target," "predict," "could" and similar references, although not all forward-looking statements contain these words. Examples of forward-looking statements contained in this press release include, among others, the possibility that our INTASYL® siRNA gene silencing technology will make the body's immune cells more effective in killing cancer cells and statements regarding our commercial and clinical strategy, development plans and timelines and other future events.
These statements are based only on our current beliefs, expectations and assumptions and are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict and many of which are outside of our control. Our actual results may differ materially from those indicated in the forward-looking statements as a result of a number of important factors, including, but not limited to, the impact to our business and operations by inflationary pressures, rising interest rates, recession fears, the development of our product candidates, results from our preclinical and clinical activities, our ability to execute on business strategies, our ability to develop our product candidates with collaboration partners, and the success of any such collaborations, the timeline and duration for advancing our product candidates into clinical development, the timing or likelihood of regulatory filings and approvals, the success of our efforts to commercialize our product candidates if approved, our ability to manufacture and supply our product candidates for clinical activities, and for commercial use if approved, the scope of protection we are able to establish and maintain for intellectual property rights covering our technology platform, our ability to obtain future financing, market and other conditions and those identified in our Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q under the caption "Risk Factors" and in other filings the Company periodically makes with the SEC. Readers are urged to review these risk factors and to not act in reliance on any forward-looking statements, as actual results may differ from those contemplated by our forward-looking statements. Phio does not undertake to update forward-looking statements to reflect a change in its views, events or circumstances that occur after the date of this release, except as required by law.
Contact:
Phio Pharmaceuticals Corp.
Jennifer Phillips: jphillips@phiopharma.com
To view the source version of this press release, please visit https://www.newsfilecorp.com/release/283367
FAQ
What safety findings did Phio report for PH-762 in the Phase 1b skin cancer trial (PHIO)?
What were the pathological response results for PH-762 in the highest dose cohort (PHIO)?
What is Phio's overall response rate for cutaneous squamous cell carcinoma (cSCC) in the Phase 1b trial (PHIO)?
When does Phio plan to engage the FDA and proceed with preclinical manufacturing for PH-762 (PHIO)?
How should investors interpret the Phase 1b PH-762 data from Phio (PHIO) for near-term development milestones?
