---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-221527"
form_type: "8-K"
ticker: "ENTA"
cik: "0001177648"
company_name: "ENANTA PHARMACEUTICALS INC"
filed_at: "2025-09-29T23:59:59+00:00"
generated_at: "2026-05-17T05:22:10.183795+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Zelicapavir shows 6.7-day symptom resolution improvement in high-risk RSV adults

## Summary
- 6.7-day faster complete resolution of all 13 RSV symptoms in HR3 population (COPD/CHF/age≥75); 7.2-day improvement in total RiiQ.
- Hospitalization rate 1.7% for zelicapavir vs 5.0% placebo; 2-day faster PGI-S improvement (p<0.05).
- Robust antiviral effect: 4–5 day faster undetectable viral load; 23.5% vs 10.0% undetectable at end of treatment (p=0.0198).
- Favorable safety: no treatment discontinuations; most common AEs diarrhea (3.3%) and asthma (2.5%).
- Primary endpoint (time to mild LRTD symptoms) not met; data inform Phase 3 design and registrational endpoints.

## SEC filing metadata
- accession: 0001193125-25-221527
- form_type: 8-K
- ticker: ENTA
- cik: 0001177648
- company_name: ENANTA PHARMACEUTICALS INC
- filed_at: 2025-09-29T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1177648/000119312525221527/0001193125-25-221527-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1177648/000119312525221527/d16388d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-221527
- JSON: https://secwatch.observer/filing/0001193125-25-221527.json
- Plain text: https://secwatch.observer/filing/0001193125-25-221527.txt

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