Phio Pharmaceuticals Corp. 8-K

What Happened
On December 23, 2025, Phio Pharmaceuticals Corp. (PHIO) filed a Form 8-K and issued a press release stating the U.S. Food and Drug Administration (FDA) accepted the company’s nonclinical protocol study design for its investigational candidate PH-762. The company said the planned toxicology study will commence in the first quarter of 2026. The press release is attached to the filing as Exhibit 99.1.

Key Details

• Filing date and announcement: December 23, 2025 (Form 8-K, Item 8.01).
• FDA action: Acceptance of Phio’s nonclinical protocol study design for PH-762.
• Next step/timeline: Toxicology study scheduled to begin in Q1 2026.
• The 8-K did not report financial results or management changes.

Why It Matters
FDA acceptance of a nonclinical study protocol is a regulatory step that enables the company to proceed with the planned toxicology work, a standard preclinical requirement that supports future regulatory filings and potential clinical development. For investors, this is a development-stage milestone that advances PH-762’s program timeline; it may affect the company’s near-term operational focus and upcoming news flow. Monitor Phio for toxicology study start notices, results, and any updates about subsequent regulatory or clinical milestones.