Phio Pharmaceuticals Corp. (PHIO) announced that the Safety Monitoring Committee (SMC) has completed its planned safety review of the company's lead clinical candidate, PH-762, in a Phase 1b trial for skin cancer.
The committee reported no dose-limiting toxicities or serious adverse events across all five dose-escalation cohorts, supporting continued evaluation of the highest dose concentration in future studies.
PH-762, an INTASYL siRNA compound designed to silence the PD-1 gene implicated in skin cancers, was administered via four intratumoral injections to 22 patients with cutaneous carcinomas, melanoma, or Merkel cell carcinoma. Patients were followed for at least four weeks after the final injection.
The trial demonstrated encouraging efficacy signals:
•85% pathological response in the final cohort (6 of 7 patients), including complete response (100% tumor clearance) in 4 of 6 responders.
•Among 20 patients with cutaneous squamous cell carcinoma (cSCC), 65% were classified as pathologic responders, including 9 complete responses, 2 near-complete responses (greater than 90% clearance), and 2 partial responses (greater than 50% clearance).
•One patient with metastatic Merkel cell carcinoma achieved a partial response.
•No patients experienced disease progression.
Phio stated that these results, coupled with a favorable safety profile, are clinically meaningful and support advancing PH-762 into the next stage of development. An FDA submission to propose and seek guidance on future clinical study design is targeted for the second quarter of 2026.
In parallel, Chemistry, Manufacturing and Controls (CMC) development is progressing, with drug substance material expected in March 2026 for non-human primate studies. Manufacturing of cGMP material is planned for the second half of 2026, a prerequisite for pivotal human trials.
PHIO has traded between $0.81 and $4.19 over the past year. The stock closed yesterday's trading at $1.12, up 24.44%. In premarket trading today, the stock is up nearly 10% at $1.23.
For comments and feedback contact: editorial@rttnews.com
Business News
May 22, 2026 14:46 ET Minutes of the latest Fed policy session was the highlight of the week along with survey data on the U.S. housing market. In Europe, survey data signaled the trends in the euro area private sector. Further, consumer price inflation data from the U.K. was in focus. In Asia, various economic indicators from China drew attention to the health of the economy.