PHIO

Completion of Lead Clinical Candidate PH-762 Dose Escalation Trial for Treatment of Skin Cancer with Favorable Safety and Pathology Data Key Development Agreements Secured for Nonclinical Toxicology and U.S. cGMP Clinical Supply Manufacturing King of Prussia, Pennsylvania--(Newsfile Corp. - May 7, 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 today reported its financial results for the quarter ended March 31, 2026, and provided a business update. "We are enthusiastic with the successful completion of our Phase 1b clinical trial which now positions us for upcoming FDA interface which we expect will clarify next steps in advancing the PH-762 development program," said Robert Bitterman, President and Chief Executive Officer. Recent Corporate Updates PH-762 Progress PH-762 was evaluated in a U.S. multi-center Phase 1b dose-escalating clinical trial through the intratumoral injection of PH-762 for the treatment of patients with cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. The trial (NCT 06014086) was designed to evaluate the safety and tolerability of neoadjuvant use of intratumorally injected PH-762, assess the tumor response, and determine the dose or dose range for continued study of PH-762. The study was fully enrolled in November 2025 with a total of 22 patients, 20 with cutaneous squamous cell carcinoma, one with melanoma and one with Merkel cell carcinoma. The clinical phase of the trial is complete, and the final data is currently being analyzed. 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. Capital Sourcing During 2025, Phio strengthened its balance sheet through a series of equity financings and warrant exercises that generated approximately $23.7 million in net proceeds. These transactions extended the Company's cash runway into the first half of 2027 and will support ongoing clinical development, operational requirements and strategic initiatives. Scientific News The Company presented its Phase 1b clinical trial data for PH-762 at the American Academy of Dermatology (AAD) in the Late-Breaking Research Session in...

Prestigious Late-Breaking Research Session Positions PH-762 as a Promising New PD-1 Directed Immunotherapy Candidate on March 28, 2026 at 3 PM (MDT) King of Prussia, Pennsylvania--(Newsfile Corp. - March 23, 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 a podium presentation addressing its lead product candidate, PH-762, will be given in the American Academy of Dermatology's Late-Breaking Research Session S034 on March 28, 2026 in Denver, Colorado. The presentation, entitled "PD-1 Directed Intratumoral Immunotherapy: Results of an Escalating Dose Study of INTASYL PH-762 for Cutaneous Carcinomas", will highlight results of Phio's Phase 1b clinical study (NCT 06014086) which evaluated the safety and tolerability of neoadjuvant use of intratumoral PH-762 in cutaneous squamous cell carcinoma (cSCC), melanoma and Merkel cell carcinoma. "The clinical study results are encouraging and firmly guide Phio to continued clinical development of this immuno-oncology therapy for cutaneous squamous cell carcinoma," said Mary Spellman M.D., Phio's acting Chief Medical Officer. "Preliminary clinical evidence demonstrates that intratumoral PH-762 may provide substantial clinical benefit, with notable pathologic response, and modest mean reductions in tumor burden following treatment." Recent Company Highlights Phio's lead clinical candidate, PH-762, is being evaluated as an intratumoral therapy for cutaneous squamous cell carcinoma (cSCC), melanoma and Merkel cell carcinoma. In its Phase 1b trial, Phio has reported that 22 patients completed treatment across five dose-escalation cohorts, with no dose-limiting toxicities or serious adverse events. The Company has also reported a pathological response rate in cSCC across all dosing cohorts of approximately 65%, including an 85% pathological response (6 of 7 patients) in the highest-dose cohort. Phio has indicated that FDA engagement regarding next-stage clinical development is targeted for the second quarter of 2026 and has reported cash and cash equivalents projected to sustain operations into the first half of 2027. About Phio Pharmaceuticals Corp. Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical-stage siRNA biopharmaceutical company advan...

Treatment Phase for Lead Clinical Candidate PH-762 Dose Escalation Trial is Complete with Favorable Safety, Tolerability and Pathology Data 2025 Financings and Warrant Exercises Strengthen Balance Sheet with $23.7 Million in Net Proceeds, Extending Cash Runway into the First Half of 2027 King of Prussia, Pennsylvania--(Newsfile Corp. - March 5, 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 today reported its financial results for the year ended December 31, 2025, and provided a business update. "Final cohort results mark the culmination of a productive 2025 fiscal year for Phio," said Robert Bitterman, Present and CEO. "Concluding the Phase 1b study with favorable safety, tolerability and pathology data, advancing the CMC and toxicology initiatives while extending our cash runway into 2027 are noteworthy milestones on our continuing pathway to potential approval." Recent Corporate Updates PH-762 Clinical Progress PH-762 is currently being evaluated in a U.S. multi-center Phase 1b dose-escalating clinical trial through the intratumoral injection of PH-762 for the treatment of patients with cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. The trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumorally injected PH-762, assess the tumor response, and determine the dose or dose range for continued study of PH-762. The study was fully enrolled in November 2025 with a total of 22 patients, 20 with cutaneous squamous cell carcinoma, one with melanoma and one with Merkel cell carcinoma. 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. In July 2025, Phio entered into a comprehensive drug substance development services agreement with a US manufacturer. The manufacturer will provide analytical and process development and cGMP manufacture of Phio's lead development compound PH-762. The cGMP material will support future pivotal clinical development of PH-762. In December 2025, Phio entered into a development services agreement with a US laboratory to conduct a non-clinical toxicology study,...

Clinical Trial has Advanced to Fifth and Final Cohort at Maximum Dose of INSTASYL PH-762 in Skin Cancer Trial Positive Pathology Results at Maximum Dose: 100% Tumor Clearance (Complete Response) in One Patient, Greater than 90% (Near Complete Response) in Second Patient, Greater than 50% (Partial Response) in Third Patient Safety Monitoring Committee Issues Favorable Review of Safety Data at Maximum Dose of INTASYL PH-762 Warrant Inducement Financing in November 2025 for Expected Net Proceeds Totaling Approximately $12.1 million, Extending Cash Runway into the First Half of 2027 King of Prussia, Pennsylvania--(Newsfile Corp. - November 13, 2025) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage biopharmaceutical company developing therapeutics using its proprietary INTASYL® siRNA gene silencing technology to eliminate cancer. Phio today reported its financial results for the quarter ended September 30, 2025 and provided a business update. Recent Corporate Updates PH-762 Clinical Progress Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cutaneous squamous cell carcinoma (cSCC), Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. Per the trial's protocol, patients receive four injections of PH-762 at weekly intervals and pathologic response is assessed on day 36 after the initial injection of PH-762. To date, pathologic results for the fifth and final cohort were as follows: 100% tumor clearance in one of three patients, > 90% clearance in the second patient, and > 50% clearance in the third patient at Day 36. To date, a total of 18 patients with cutaneous carcinomas have completed treatment across five dose escalating cohorts in the Phase 1b trial. The cumulative pathologic response in 16 patients with cSCC include six with a complete response (100% clearance), two with a near complete response (> 90% clearance) and two with a partial response (> 50% clearance). A single patient with metastatic Merkel cell carcinoma had a partial response (> 50% clearance). Six patients with cSCC and one patient with metastatic melanoma had a pathologic non-response (< 50% clearance). No patients in the study, however, exhibited clinical progression of disease. To date, there were no dose-limiting toxicities or clinically relev...

Poster Presentation at the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC) King of Prussia, Pennsylvania--(Newsfile Corp. - November 7, 2025) - 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 it will present clinical data from its ongoing Phase 1b clinical trial at the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), which will be held in National Harbor, Maryland from November 7-9, 2025. Phio's poster presentation will highlight the clinical results from the ongoing Phase 1b dose escalation clinical trial. This clinical trial is designed to evaluate the safety and tolerability of intratumoral injection of PH-762 in patients with cutaneous squamous carcinoma, Merkel cell carcinoma, and melanoma. Presentation Details are as follows: About Phio Pharmaceuticals Corp. Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage siRNA biopharmaceutical company advancing its INTASYL® gene silencing technology focused on immuno-oncology therapeutics. 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 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 wil...

Pathologic Clearance: 100% Tumor Clearance (Complete Response) in One Patient, Greater than 90% (Near Complete Response) in Second Patient, Greater than 50% (Partial Response) in Third Patient Pathologic Results Assessed at Approximately 5 Weeks Safety Monitoring Committee Issues Favorable Review of Safety Data at the Maximum Dose King of Prussia, Pennsylvania--(Newsfile Corp. - November 3, 2025) - 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 the pathologic results for three patients with cutaneous squamous cell carcinoma (cSCC) who completed treatment in the fifth and final dose cohort of Phio's on-going Phase 1b dose escalation trial: 100% tumor clearance in one of three patients, > 90% clearance in the second patient, and > 50% clearance in the third patient. To date, a total of 18 patients with cutaneous carcinomas have completed treatment across five dose escalating cohorts in the Phase 1b trial. The cumulative pathologic response in 16 patients with cSCC include six with a complete response (100% clearance), two with a near complete response (> 90% clearance) and two with a partial response (> 50% clearance). A single patient with metastatic Merkel cell carcinoma had a partial response (> 50% clearance). Six patients with cSCC and one patient with metastatic melanoma had a pathologic non-response (< 50% clearance). No patients in the study have exhibited clinical progression of disease. Phio may continue to screen and treat additional patients as part of the fifth cohort. The trial is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cutaneous squamous cell carcinoma (cSCC), Stage 4 melanoma, and Stage 4 Merkel cell carcinoma (NCT# 06014086). Per the trial's protocol, patients receive four injections of PH-762 at weekly intervals and pathologic response is assessed approximately 5 weeks after the initial injection of PH-762. "The encouraging outcomes of intratumoral PH-762 in patients who have received treatment thus far is a significant step in clinical development and highlights the promise of a viable non-surgical alternative treatment for cutaneous carcinomas," said Robert Bitterman, CEO and Chairman of Phio Pharmaceut...

Clinical trial advances for INSTASYL siRNA lead product candidate PH-762 5th cohort enrolling patients in on-going clinical study King of Prussia, Pennsylvania--(Newsfile Corp. - August 14, 2025) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage biopharmaceutical company developing therapeutics using its proprietary INTASYL® siRNA gene silencing technology to eliminate cancer. Phio today reported its financial results for the quarter ended June 30, 2025 and provided a business update. Recent Corporate Updates PH-762 Clinical Progress Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cutaneous squamous cell carcinoma (cSCC), Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. To date, a total of 15 patients with cutaneous carcinomas have been treated across four cohorts in the Phase 1b trial. These cohorts included 13 patients with cSCC, one patient with metastatic melanoma and one patient with metastatic Merkel cell carcinoma. There have been no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients who received intratumoral PH-762 in this trial. Moreover, PH-762 has been well tolerated in all enrolled patients in each escalating dose cohort. No patients exhibited clinical progression of disease during the treatment phase of this trial. The cumulative pathologic responses in the 13 patients with cSCC include five with complete response (100% clearance), one patient with a near complete response (>90% clearance), one with a partial response (>50% clearance) and six patients with a pathologic non-response (< 50% clearance). The Merkel cell carcinoma patient with stage 4 metastatic disease had a pathological partial response (>50% clearance). The melanoma patient was a non-responder (<50% clearance). Phio is now enrolling what is expected to be the 5th and final cohort in the Phase 1b trial. In addition, the Company entered into a comprehensive drug substance development services agreement with a U.S. manufacturing company. The company will provide analytical and process development and cGMP manufacture of Phio's lead development compound PH-762. Scientific News In May 2025, Phio delivered a podium presentation for its INTASYL self-delivering siRNA technology at the Soci...

Complete Pathologic Response in patient with cutaneous squamous cell carcinoma Partial Response in Stage 4 metastatic Merkel cell patient King of Prussia, Pennsylvania--(Newsfile Corp. - July 25, 2025) - 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 pathologic results are available for four of the five patients treated in the fourth cohort. A complete pathologic response (100% tumor clearance) has been reported for one patient with cutaneous squamous cell carcinoma (cSCC). One patient with metastatic Merkel cell carcinoma was reported as a partial response (> 50% clearance). Two patients with cSCC were reported as having a pathologic non-response (<50% tumor clearance). Pathologic results for the remaining patient with cSCC are still pending. Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cSCC, Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. To date, a total of 15 patients with cutaneous carcinomas have been treated across the four cohorts. There were no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients receiving intratumoral PH-762 in this trial. Moreover, PH-762 has been well tolerated in all enrolled patients in each escalating dose cohort. No patients exhibited clinical progression of disease. The cumulative pathologic response in 13 patients with cSCC include five complete response (100% clearance), one patient with a near complete response (>90% clearance) and one with a partial response (>50% clearance) and six patients with a pathologic non-response (< 50% clearance). The one Merkel cell carcinoma patient with stage 4 metastatic disease had a partial response (>50% clearance). The melanoma patient was a non-responder (<50% clearance). Phio is now enrolling what is expected to be the 5th and final cohort in the Phase 1b study. "The positive safety and efficacy outcomes through the fourth cohort continue to indicate that PH-762 may present a viable non-surgical alternative in this large and continually expanding skin cancer market," said Robert Bitterman, CEO and Chairman of Phio Pharmaceuti...

Clinical trial advances for INSTASYL siRNA lead product candidate PH-762 4th Cohort enrolling and treating patients in on-going clinical study Marlborough, Massachusetts--(Newsfile Corp. - May 15, 2025) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage biopharmaceutical company developing therapeutics that use its INTASYL® siRNA gene silencing technology designed to make the body's immune cells more effective in killing cancer cells. Phio today reported its financial results for the quarter ended March 31, 2025 and provided a business update. Recent Corporate Updates PH-762 Clinical Progress Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cutaneous squamous cell carcinoma (cSCC), Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. To date, a total of 10 patients with cutaneous carcinomas have been treated in Cohorts 1, 2 and 3. These cohorts included 9 patients with cSCC and 1 patient with metastatic melanoma. At Day 36 (planned tumor excision), of the 9 patients with cSCC, 4 patients had a pathologic complete response (100% tumor clearance). One patient had a near complete response (>90% clearance) and 1 patient had a partial response (>50% clearance). The other 3 cSCC and one metastatic melanoma patient had a pathologic non-response (< 50% clearance). Patients with a pathologic complete response (100% tumor clearance) may have visual signs of residual scar or subdermal inflammation prior to resection. No patients, however, exhibited clinical progression of disease. To date, there were no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients receiving intratumoral PH-762 in this trial. Moreover, PH-762 has been well tolerated in all enrolled patients in each escalating dose cohort. The fourth cohort is currently enrolling and treating patients; Phio expects to complete enrollment in the trial in the third quarter of 2025. Scientific News During the three months ended March 31, 2025, Phio was awarded podium presentations for its INTASYL self-delivering siRNA technology at the American Academy of Dermatology (AAD) and at the Society of Investigative Dermatology (SID). The Company presented its phase 1b clinical trial results to date. The Company also presented data...

Complete Pathologic Response reported in 2 patients in the Third Cohort with cutaneous squamous cell carcinoma, complementing results in prior cohort Phio to present trial results to date at a podium presentation at Society for Investigative Dermatology (SID) Annual Meeting on May 10th Marlborough, Massachusetts--(Newsfile Corp. - May 7, 2025) - 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 a complete pathologic response (100% tumor clearance) has been reported for 2 of 3 patients with cutaneous squamous cell carcinoma (cSCC) treated in the third dose cohort. The third patient was reported as having a pathologic non-response (<50% tumor clearance). "These positive outcomes continue to indicate that PH-762 may present a viable non-surgical alternative in this large and continually expanding skin cancer market," said Robert Bitterman, President and CEO of Phio Pharmaceuticals. Phio's ongoing Phase 1b dose escalation clinical trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumoral PH-762 in Stages 1, 2 and 4 cSCC, Stage 4 melanoma, and Stage 4 Merkel cell carcinoma. To date, a total of 10 patients with cutaneous carcinomas have been treated in Cohorts 1, 2 and 3. These cohorts included 9 patients with cSCC and 1 patient with metastatic melanoma. At day 36 (planned tumor excision), of the 9 patients with cSCC, 4 patients had a pathologic complete response (100% tumor clearance). One patient had a near complete response (>90% clearance) and 1 patient had a partial response (>50% clearance). The other 3 cSCC and one metastatic melanoma patient had a pathologic non-response (< 50% clearance). Patients with pathologic complete response (100% tumor clearance) may have visual signs of residual scar or subdermal inflammation prior to resection. No patients, however, exhibited clinical progression of disease. To date, there were no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients receiving intratumoral PH-762 in this trial. Moreover, PH-762 has been well tolerated in all enrolled patients in each escalating dose cohort. The fourth cohort is currently enrolling patients; Phio expects to complete en...

Continues advancing clinical trial for INSTASYL siRNA lead product candidate PH-762 3rd Cohort now fully enrolled in on-going clinical study Marlborough, Massachusetts--(Newsfile Corp. - March 31, 2025) - Phio Pharmaceuticals Corp. (NASDAQ: PHIO) is a clinical-stage biotechnology company developing therapeutics that use its INTASYL® siRNA gene silencing technology designed to make the body's immune cells more effective in killing cancer cells. Phio today reported its financial results for the year ended December 31, 2024, and provided a business update. Recent Corporate Updates PH-762 Clinical Progress PH-762 is currently being evaluated in a U.S. multi-center Phase 1b dose-escalating clinical trial through the intratumoral injection of PH-762 for the treatment of patients with cutaneous squamous cell carcinoma, melanoma and Merkel cell carcinoma. The trial (NCT 06014086) is designed to evaluate the safety and tolerability of neoadjuvant use of intratumorally injected PH-762 in up to 30 patients to assess tumor response and determine the dose or dose range for continued study of PH-762 in future trials. In May and December 2024, respectively, a Safety Monitoring Committee (SMC) reviewed data from the first and second dose cohorts treated with PH-762, and in both instances recommended escalation to the next dose concentration. A total of 7 patients with cutaneous carcinomas have been enrolled in dose cohorts 1 and 2. The second cohort enrolled a total of 4 patients, all of whom were diagnosed with cutaneous squamous cell carcinoma. At Day 36 (tumor excision), a complete response (100% tumor clearance) was reported for 2 patients, a partial response (90% tumor clearance) was reported for 1 patient and 1 patient had stable disease, having not progressed. Patients in the first cohort maintained stable disease. To date, intratumoral injection of PH-762 has been well tolerated in all enrolled patients. There were no dose-limiting toxicities or clinically relevant treatment-emergent adverse effects in the patients receiving intratumoral PH-762. The third dose cohort is fully enrolled and patients in this cohort are currently in the treatment or follow-up phase of the study. Phio expects to complete enrollment of all patients in the study in the third quarter of 2025. Capital Sourcing In December 2024 and January 2025, Phio raised an aggregate of approximately $9.2...