Phio Pharmaceuticals Announces Positive Safety Monitoring Committee Recommendation to Advance INTASYL PH-762 Skin Cancer Study to Fourth Dose Escalation Cohort

Associated Press

09-04-2025

-Phio's lead clinical siRNA compound PH-762 demonstrates supportive safety profile in third cohort, permitting escalation in next dose concentration
Marlborough, Massachusetts--(Newsfile Corp. - April 9, 2025) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage siRNA biopharmaceutical company developing therapeutics using its proprietary INTASYL ® siRNA gene silencing technology to eliminate cancer. Phio announced today that the Safety Monitoring Committee (SMC) recommended dose escalation in Phio's Phase 1b clinical trial (NCT 06014086) for Phio's lead product candidate, PH-762.
Phio's Phase 1b clinical trial is a multi-center, dose-escalating trial designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in cutaneous squamous cell carcinoma, melanoma, or Merkel cell carcinoma. This trial assesses the tumor response and determines the recommended dose for further study of PH-762. In the third cohort of this trial, three patients with cutaneous squamous cell carcinoma were enrolled. For these patients, injections were well tolerated with no serious adverse events and there were no dose-limiting toxicities. Pathology results related to efficacy of PH-762 in the third cohort are forthcoming.
'We are impressed with the continuing safety profile of PH-762 having now progressed through the first 3 escalating doses,' said Mary Spellman, MD, Phio's acting Chief Medical Officer.
Previously, seven patients diagnosed with cutaneous carcinomas were treated in dose cohorts 1 and 2. The second cohort enrolled a total of 4 patients who were diagnosed with cutaneous squamous cell carcinoma. At Day 36 (tumor excision) in the second cohort, two patients had a complete response (100% tumor clearance), and one patient had a partial response (90% clearance). All three patients in cohort 1 and one patient in cohort 2 maintained stable disease.
'We are optimistic that the clinical trial will continue to demonstrate that PH-762 may present a viable non-surgical alternative to existing modes of therapy for skin cancer,' said Robert Bitterman, President and CEO of Phio Pharmaceuticals.
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 program is an INTASYL compound, PH-762, that silences the PD-1 gene implicated in various forms of skin cancer. The on-going 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.
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