---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-274950"
form_type: "8-K"
ticker: "ENTA"
cik: "0001177648"
company_name: "ENANTA PHARMACEUTICALS INC"
filed_at: "2026-06-18T11:12:58+00:00"
generated_at: "2026-06-18T11:15:12.687356+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Enanta advances zelicapavir to registrational Phase 2b/3 trial in high-risk adults with RSV; pediatric Phase 2b planned

## Summary
- Registrational Phase 2b/3 trial in high-risk adults (≥75 yrs, COPD, CHF) to start 4Q 2026; Phase 2b topline data expected 2027.
- Phase 2b pediatric trial (28 days-36 months) to start 3Q 2026; topline data expected 2027; conducted with Penta Foundation and Chiang Mai University.
- FDA End-of-Phase 2 meeting successful; trial design includes 800mg oral zelicapavir once daily for 7 days vs placebo.
- Enanta estimates global market opportunity for oral RSV antiviral >$2B; US addressable population >3M patients.
- No available treatment options for RSV; zelicapavir could be first antiviral therapy.

## SEC filing metadata
- accession: 0001193125-26-274950
- form_type: 8-K
- ticker: ENTA
- cik: 0001177648
- company_name: ENANTA PHARMACEUTICALS INC
- filed_at: 2026-06-18T11:12:58+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1177648/000119312526274950/0001193125-26-274950-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1177648/000119312526274950/d159604d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-274950
- JSON: https://secwatch.observer/filing/0001193125-26-274950.json
- Plain text: https://secwatch.observer/filing/0001193125-26-274950.txt

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