PHIO Phio Pharmaceuticals Corporation

Phio Pharmaceuticals Corp. (Nasdaq: PHIO), a clinical stage biotechnology company whose proprietary INTASYL™ siRNA gene silencing technology is designed to make immune cells more effective in killing tumor cells, today announced it is presenting new data about its lead clinical product candidate, PH-762, an INTASYL compound.

Preclinical studies demonstrate:

• PH-762 is rapidly taken up by cells and robustly silences PD-1 mRNA and protein in lymphocytes within the tumor microenvironment (TME)
• Intratumoral injection of murine PH-762 (mPH-762) significantly inhibits tumor growth in murine tumor models and is well tolerated
• mPH-762-mediated silencing of PH-762 within the TME may generate memory-specific T cells, promoting IFN-γ release in the TME
• Studies in non-human primates demonstrate that PH-762 is well-tolerated and does not induce release of cytokines associated with cytokine release syndrome (CRS)
• These finding support the ongoing clinical trial of PH-762’s safety and efficacy as a neoadjuvant therapy for treatment of cSCC, melanoma, or Merkel cell carcinoma

The data, authored by Melissa Maxwell, Linda Mahoney, and Dr. Mary Spellman, will be presented at the American Society of Gene and Cell Therapy (ASGCT) on May 8th in Baltimore, Maryland.

Presentation Details are as follows:
Title:	INTASYL PH-762: PD-1 Intratumoral Immunotherapy
Abstract Number:	774
Session Title:	Cancer-Immunotherapy and Cancer Vaccines
Authors:	Melissa Maxwell, Linda Mahoney, Mary Spellman, M.D.
Date and Time:	May 8, 2024     12:00 PM
Location:	Exhibit Hall

About Phio Pharmaceuticals Corp.

Phio Pharmaceuticals Corp. (Nasdaq: PHIO) is a clinical stage biotechnology company whose proprietary INTASYL™ siRNA gene silencing technology is designed to make immune cells more effective in killing tumor cells. INTASYL is the only self-delivering RNAi technology focused on immuno-oncology therapeutics. INTASYL drugs precisely target specific proteins that reduce the body’s ability to fight cancer, without the need for specialized formulations or drug delivery systems.

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. 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.ir@phiopharma.com

PR ContactMichael AdamsBridge View Mediaadams@bridgeviewmedia.com