Phio Pharmaceuticals Announces Positive Safety Monitoring Committee Recommendation to Advance INTASYL PH-762 Skin Cancer Study to Fourth Dose Escalation Cohort
Phio Pharmaceuticals (NASDAQ: PHIO) announced positive safety results for the third cohort in its Phase 1b clinical trial of PH-762, their lead INTASYL® siRNA compound for skin cancer treatment. The Safety Monitoring Committee recommended advancing to the fourth dose escalation cohort following successful results in three cutaneous squamous cell carcinoma patients, who showed no serious adverse events or dose-limiting toxicities.
The multi-center trial (NCT 06014086) evaluates PH-762's safety and tolerability in cutaneous squamous cell carcinoma, melanoma, and Merkel cell carcinoma. Prior results from cohorts 1 and 2, comprising seven patients, showed promising outcomes. In the second cohort, two patients achieved complete response (100% tumor clearance) and one patient showed partial response (90% clearance) by Day 36. All three patients in cohort 1 and one patient in cohort 2 maintained stable disease.
Phio Pharmaceuticals (NASDAQ: PHIO) ha annunciato risultati di sicurezza positivi per la terza coorte nel suo studio clinico di fase 1b per PH-762, il loro principale composto siRNA INTASYL® per il trattamento del cancro della pelle. Il Comitato di Monitoraggio della Sicurezza ha raccomandato di passare alla quarta coorte di escalation della dose dopo risultati favorevoli in tre pazienti con carcinoma squamoso cutaneo, che non hanno mostrato eventi avversi gravi o tossicità limitanti la dose.
Lo studio multicentrico (NCT 06014086) valuta la sicurezza e la tollerabilità di PH-762 nel carcinoma squamoso cutaneo, nel melanoma e nel carcinoma a cellule di Merkel. I risultati precedenti delle coorti 1 e 2, che comprendevano sette pazienti, hanno mostrato esiti promettenti. Nella seconda coorte, due pazienti hanno raggiunto una risposta completa (100% di eliminazione del tumore) e un paziente ha mostrato una risposta parziale (90% di eliminazione) entro il giorno 36. Tutti e tre i pazienti nella coorte 1 e un paziente nella coorte 2 hanno mantenuto una malattia stabile.
Phio Pharmaceuticals (NASDAQ: PHIO) anunció resultados positivos de seguridad para la tercera cohorte en su ensayo clínico de fase 1b de PH-762, su compuesto principal de siRNA INTASYL® para el tratamiento del cáncer de piel. El Comité de Monitoreo de Seguridad recomendó avanzar a la cuarta cohorte de escalada de dosis tras los resultados exitosos en tres pacientes con carcinoma de células escamosas cutáneas, quienes no mostraron eventos adversos graves ni toxicidades limitantes de dosis.
El ensayo multicéntrico (NCT 06014086) evalúa la seguridad y tolerabilidad de PH-762 en carcinoma de células escamosas cutáneas, melanoma y carcinoma de células de Merkel. Resultados anteriores de las cohortes 1 y 2, que incluyeron a siete pacientes, mostraron resultados prometedores. En la segunda cohorte, dos pacientes lograron respuesta completa (100% de eliminación del tumor) y un paciente mostró respuesta parcial (90% de eliminación) para el día 36. Los tres pacientes de la cohorte 1 y un paciente de la cohorte 2 mantuvieron enfermedad estable.
Phio Pharmaceuticals (NASDAQ: PHIO)는 피부암 치료를 위한 주요 INTASYL® siRNA 화합물인 PH-762의 1b상 임상시험 세 번째 코호트에 대한 긍정적인 안전성 결과를 발표했습니다. 안전성 모니터링 위원회는 세 명의 피부 편평세포 암 환자에서 성공적인 결과를 바탕으로 네 번째 용량 증량 코호트로 진행할 것을 권장했습니다. 이들 환자는 심각한 부작용이나 용량 제한 독성을 보이지 않았습니다.
이 다기관 시험(NCT 06014086)은 피부 편평세포 암, 멜라노마 및 메르켈 세포 암에서 PH-762의 안전성과 내약성을 평가합니다. 1코호트와 2코호트에서 7명의 환자로부터 얻은 이전 결과는 유망한 결과를 보여주었습니다. 두 번째 코호트에서 두 명의 환자가 완전 반응(100% 종양 제거)을 달성했으며, 한 환자는 부분 반응(90% 제거)을 보였습니다. 1코호트의 세 환자와 2코호트의 한 환자는 모두 안정된 질병을 유지했습니다.
Phio Pharmaceuticals (NASDAQ: PHIO) a annoncé des résultats de sécurité positifs pour la troisième cohorte de son essai clinique de phase 1b concernant PH-762, leur principal composé siRNA INTASYL® pour le traitement du cancer de la peau. Le Comité de Surveillance de la Sécurité a recommandé de passer à la quatrième cohorte d'escalade de dose après des résultats réussis chez trois patients atteints de carcinome épidermoïde cutané, qui n'ont présenté aucun événement indésirable grave ni toxicité limitante de dose.
L'essai multicentrique (NCT 06014086) évalue la sécurité et la tolérance de PH-762 dans le carcinome épidermoïde cutané, le mélanome et le carcinome à cellules de Merkel. Les résultats précédents des cohortes 1 et 2, comprenant sept patients, ont montré des résultats prometteurs. Dans la deuxième cohorte, deux patients ont atteint une réponse complète (100 % d'élimination de la tumeur) et un patient a montré une réponse partielle (90 % d'élimination) au jour 36. Tous les trois patients de la cohorte 1 et un patient de la cohorte 2 ont maintenu une maladie stable.
Phio Pharmaceuticals (NASDAQ: PHIO) gab positive Sicherheitsresultate für die dritte Kohorte seiner Phase 1b-Studie zu PH-762, ihrem führenden INTASYL® siRNA-Verbindung zur Behandlung von Hautkrebs, bekannt. Der Sicherheitsüberwachungsausschuss empfahl, zur vierten Dosissteigerungskohorte überzugehen, nachdem in drei Patienten mit kutanem Plattenepithelkarzinom erfolgreiche Ergebnisse erzielt wurden, die keine schwerwiegenden unerwünschten Ereignisse oder dosislimitierende Toxizitäten zeigten.
Die multizentrische Studie (NCT 06014086) bewertet die Sicherheit und Verträglichkeit von PH-762 bei kutanem Plattenepithelkarzinom, Melanom und Merkelzellkarzinom. Frühere Ergebnisse aus den Kohorten 1 und 2, die sieben Patienten umfassten, zeigten vielversprechende Ergebnisse. In der zweiten Kohorte erreichten zwei Patienten eine komplette Ansprechrate (100% Tumorentfernung) und ein Patient zeigte eine partielle Ansprechrate (90% Entfernung) bis Tag 36. Alle drei Patienten in Kohorte 1 und ein Patient in Kohorte 2 hatten eine stabile Erkrankung.
- Phase 1b trial's second cohort showed strong efficacy with 2 complete responses (100% tumor clearance) and 1 partial response (90% clearance)
- Safety profile continues to be favorable with no serious adverse events in third cohort
- Trial advancing to fourth dose escalation cohort following positive safety review
- Efficacy results for third cohort still pending
Insights
The progression of Phio's PH-762 to a fourth dose cohort represents a significant clinical milestone in the development of this siRNA therapeutic. The absence of serious adverse events or dose-limiting toxicities across three escalating dose cohorts suggests a favorable safety profile for intratumoral administration in skin cancers.
The preliminary efficacy signals from earlier cohorts are particularly noteworthy. In the second cohort, two patients achieved complete response (100% tumor clearance) and one patient demonstrated 90% clearance. This level of response in a Phase 1b trial is encouraging, especially considering these were likely sub-optimal doses.
The trial design merits attention - using a neoadjuvant approach allows for direct assessment of tumor response before surgical removal, providing clear endpoints for efficacy evaluation. While the sample size remains small (only 10 patients treated across three cohorts), the consistent safety profile supports continued dose escalation.
The INTASYL® platform's mechanism - direct siRNA delivery for gene silencing within the tumor microenvironment - represents a differentiated approach in immuno-oncology. PH-762 targets PD-1 expression locally, potentially offering advantages over systemic antibody approaches including reduced systemic toxicity.
While safety data from cohort 3 is positive, we should await the forthcoming pathology results to assess efficacy at this dose level. The progressive increase in response rates across cohorts would further validate the dose-response relationship critical for determining optimal dosing.
For a micro-cap company with
The early efficacy signals in previous cohorts - including complete responses in 2 of 4 patients in cohort 2 - suggest potential clinical utility that could differentiate PH-762 in the competitive skin cancer landscape. The non-surgical alternative positioning addresses a clear market need, as many patients with skin cancers are elderly and may have comorbidities complicating surgical intervention.
The INTASYL platform's broader potential beyond this lead program represents underappreciated value. As a proprietary technology for local siRNA delivery, successful clinical validation with PH-762 could unlock applications across multiple tumor types and target genes.
Investor focus should remain on several key upcoming catalysts: efficacy data from cohort 3, completion of cohort 4 enrollment, and the determination of a recommended Phase 2 dose. These milestones will be critical in establishing proof-of-concept for both PH-762 specifically and the INTASYL platform more broadly.
The disconnect between emerging clinical signals and current market valuation suggests significant re-rating potential if development continues positively. However, this remains a high-risk investment given the early clinical stage, patient numbers, and typical challenges facing micro-cap biotechs including potential financing needs to advance beyond Phase 1.
-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 (
"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.
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
Corporate Affairs
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FAQ
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