---
schema_version: "secwatch.filing_event.v1"
accession: "0001370053-25-000091"
form_type: "8-K"
ticker: "ANAB"
cik: "0001370053"
company_name: "ANAPTYSBIO, INC"
filed_at: "2025-11-10T23:59:59+00:00"
generated_at: "2026-05-16T22:18:48.644138+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# AnaptysBio's rosnilimab fails Phase 2 UC trial; trial discontinued

## Summary
- Rosnilimab did not meet primary (mMS change) or key secondary endpoints at Week 12 in moderate-to-severe UC.
- Clinical remission 7% for both doses vs 5% and 4% endoscopic remission; placebo rates within historical ranges.
- Trial discontinued saving at least $10M; update on rosnilimab in RA expected H1 2026 via strategic capital.
- Reaffirms 2026 separation of biopharma from royalty assets; Jemperli royalties >$390M/yr at peak sales >$2.7B.
- Expects ~$300M cash end-2025 including $75M milestone from GSK for Jemperli reaching $1B global net sales.

## SEC filing metadata
- accession: 0001370053-25-000091
- form_type: 8-K
- ticker: ANAB
- cik: 0001370053
- company_name: ANAPTYSBIO, INC
- filed_at: 2025-11-10T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1370053/000137005325000091/0001370053-25-000091-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1370053/000137005325000091/anab-20251110.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001370053-25-000091
- JSON: https://secwatch.observer/filing/0001370053-25-000091.json
- Plain text: https://secwatch.observer/filing/0001370053-25-000091.txt

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