Phio Pharmaceuticals to Showcase INTASYL siRNA Platform and PH-762 Skin Cancer Therapy at Renmark Virtual Roadshow on July 28, 2026

Phio's INTASYL Platform: A Novel Gene Silencing Strategy in Cancer Immunotherapy

Phio Pharmaceuticals is advancing therapeutics using its proprietary INTASYL siRNA (small interfering RNA) gene silencing platform. This strategy enhances immune cell function to effectively target and eliminate cancer cells, offering a distinctive mechanism within immuno-oncology. INTASYL compounds are engineered to silence specific genes involved in various cancers, potentially providing non-surgical treatment alternatives.

The company describes the INTASYL platform as a "unique and promising approach to advancing immuno-oncology therapies." CEO Robert Bitterman highlighted its potential to address unmet clinical needs in cancer treatment. The progression of INTASYL compounds from preclinical studies to clinical trials underscores Phio’s commitment to translating this technology into effective human therapies.

PH-762: Leading Clinical Candidate for Treating Skin Cancers

PH-762 is Phio’s lead clinical candidate and most advanced compound, designed to silence the PD-1 gene implicated in skin cancers. It represents a potential non-surgical treatment option, significant given the current reliance on surgical interventions for cutaneous malignancies.

The ongoing Phase 1b trial (Clinical Trial ID: NCT# 06014086) evaluates PH-762 in three skin cancer types: cutaneous squamous cell carcinoma, melanoma, and Merkel cell carcinoma. These cancers account for a large share of skin cancer diagnoses. Testing PH-762 across these indications aims to assess the therapeutic breadth of PD-1 gene silencing in skin cancer immunotherapy.

Investor Engagement via Renmark Virtual Roadshow

The July 28, 2026 presentation at Renmark Financial Communications’ virtual non-deal roadshow will provide both institutional and retail investors direct access to Phio’s management team. Scheduled for 12 PM EDT, CEO Robert Bitterman will present the INTASYL platform overview followed by a live Q&A session. This format facilitates investor interaction and transparency regarding the scientific rationale, clinical progress, and strategic outlook of PH-762 and the broader platform.

Non-deal roadshows are typical for clinical-stage biopharmaceutical companies to communicate with investors outside capital-raising contexts. Phio’s participation highlights its focus on investor relations and transparency about its technology and clinical developments. A replay will be available at https://www.renmarkfinancial.com/vndrs for those unable to attend live.

Registration and Technical Details for Attendees

Investors interested in attending can register via Renmark Financial Communications’ virtual roadshow platform. Phio recommends using the latest Google Chrome browser for optimal connectivity during the event. For technical issues, attendees are advised to copy and paste the registration URL directly into their browser. The replay option ensures flexible access post-event.

Clinical Trial Design and Therapeutic Strategy

The Phase 1b trial for PH-762 follows a standard early-stage development model for novel gene silencing therapies. By simultaneously studying three distinct cutaneous carcinomas, the trial aims to determine if PD-1 gene silencing yields consistent therapeutic effects across diverse skin cancer types. Cutaneous squamous cell carcinoma, melanoma, and Merkel cell carcinoma differ in epidemiology and molecular profiles, making this trial design critical for assessing PH-762’s broad applicability.

Targeting PD-1 gene silencing represents a specific immuno-oncology strategy. PD-1 is a well-known immune checkpoint, with current therapies primarily using antibody-based inhibitors. Phio’s siRNA approach directly silences the PD-1 gene, potentially offering a novel mechanism distinct from existing treatments approved for skin cancers.

Company Overview and Strategic Focus

Phio Pharmaceuticals Corp. is a clinical-stage biopharmaceutical company conducting human trials without yet having regulatory approvals for marketed products. Its exclusive focus on the INTASYL siRNA gene silencing platform for cancer treatment reflects a concentrated pipeline strategy, differing from companies pursuing multiple therapeutic modalities.

Headquartered in King of Prussia, Pennsylvania, and listed on NASDAQ under ticker PHIO, the company operates within the U.S. regulatory and capital markets framework. Additional details about its operations, clinical programs, intellectual property, and financials are available at www.phiopharma.com.

Forward-Looking Statements and Associated Risks

The announcement includes a detailed forward-looking statements disclaimer, noting that projections and expectations involve risks and uncertainties. Terms such as "intends," "believes," "anticipates," "plans," "expects," "potential," "designed to," and "will" indicate forward-looking content. Actual outcomes may differ materially.

Risks include FDA interactions affecting development, inflationary impacts, clinical trial success, regulatory approvals, manufacturing and supply chain challenges, intellectual property protection, and financing needs. Investors are encouraged to review Phio’s latest SEC filings, including the Annual Report on Form 10-K and Quarterly Reports on Form 10-Q, for comprehensive risk disclosures.

Competitive Landscape in Immuno-Oncology and Gene Silencing

Phio’s gene silencing immuno-oncology approach is emerging within a competitive field featuring established therapies like monoclonal antibodies, checkpoint inhibitors, CAR-T cells, and vaccines. The INTASYL platform’s unique siRNA mechanism differentiates it from antibody-based treatments dominating the market.

If PH-762 demonstrates clinical efficacy, it could attract significant interest as a non-surgical skin cancer treatment alternative, potentially complementing or replacing current surgical and topical therapies.

Future Clinical and Regulatory Plans

The announcement does not specify timelines beyond the current Phase 1b trial or regulatory milestones. It notes expectations for FDA submissions to seek guidance on next clinical study steps for PH-762, indicating ongoing regulatory engagement without disclosing exact dates.

Phio also references planned non-clinical toxicology studies supporting ongoing clinical development. The company expects to fund operations and strategic initiatives with existing capital but did not disclose financial specifics in this release. Investors should consult SEC filings for detailed financial information.