---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-319981"
form_type: "8-K"
ticker: "GLUE"
cik: "0001826457"
company_name: "Monte Rosa Therapeutics, Inc."
filed_at: "2025-12-16T23:59:59+00:00"
generated_at: "2026-05-16T13:05:22.359235+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# MRT-2359 + enzalutamide shows 100% PSA response in AR-mutant mCRPC; Phase 2 planned 2026

## Summary
- In 14 evaluable mCRPC patients, overall DCR 64% (9/14); in AR-mutant subset (n=4), 100% PSA response rate and 100% DCR, with 2 RECIST partial responses.
- Combination well tolerated with primarily Grade 1-2 GI adverse events; no new safety signals.
- Company plans to initiate Phase 2 study of MRT-2359 + AR inhibitor targeting AR-mutant mCRPC patients in 2026.
- Breast cancer cohort (n=6) discontinued due to insufficient activity; MRT-8102 interim Phase 1 data expected early 2026.
- Updated MRT-2359 data to be presented at ASCO GU Symposium in February 2026.

## SEC filing metadata
- accession: 0001193125-25-319981
- form_type: 8-K
- ticker: GLUE
- cik: 0001826457
- company_name: Monte Rosa Therapeutics, Inc.
- filed_at: 2025-12-16T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1826457/000119312525319981/0001193125-25-319981-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1826457/000119312525319981/glue-20251216.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-319981
- JSON: https://secwatch.observer/filing/0001193125-25-319981.json
- Plain text: https://secwatch.observer/filing/0001193125-25-319981.txt

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