---
schema_version: "secwatch.filing_event.v1"
accession: "0001437749-26-003575"
form_type: "8-K"
ticker: "PHIO"
cik: "0001533040"
company_name: "Phio Pharmaceuticals Corp."
filed_at: "2026-02-10T23:59:59+00:00"
generated_at: "2026-05-16T03:34:42.283960+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Phio reports 85% pathological response in highest dose cohort of PH-762 Phase 1b trial; no serious adverse events

## Summary
- No serious adverse events or dose-limiting toxicities across all 22 patients in five dose cohorts.
- 85% pathological response (6/7 patients) in final cohort; 4 of 6 responders had complete tumor clearance.
- Overall response rate of 65% for squamous cell carcinomas (13/20 pathologic responders, including 9 complete).
- FDA submission for next-step guidance targeted for Q2 2026; cGMP manufacturing expected in H2 2026.

## SEC filing metadata
- accession: 0001437749-26-003575
- form_type: 8-K
- ticker: PHIO
- cik: 0001533040
- company_name: Phio Pharmaceuticals Corp.
- filed_at: 2026-02-10T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1533040/000143774926003575/0001437749-26-003575-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1533040/000143774926003575/phio20260206_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001437749-26-003575
- JSON: https://secwatch.observer/filing/0001437749-26-003575.json
- Plain text: https://secwatch.observer/filing/0001437749-26-003575.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.