---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-210050"
form_type: "8-K"
ticker: "RNTX"
cik: "0001420565"
company_name: "Rein Therapeutics, Inc."
filed_at: "2025-09-22T23:59:59+00:00"
generated_at: "2026-05-17T05:57:47.306440+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# FDA agrees MCH/H findings not dose-limiting for Rein Therapeutics' LTI-03 Phase 2 trial; CRL submission planned

## Summary
- FDA confirmed MCH/H findings in GLP rat studies are not dose-limiting for proposed 24-week LTI-03 protocol at doses up to 10 mg/day in IPF patients.
- FDA stated Complete Response Letter (CRL) need not include new GLP rat toxicity study; Rein will prepare CRL in coming weeks.
- FDA recommended CRL include updated clinical safety, PK/PD data, augmented safety monitoring with spirometry, and DSMB unblinded reviews.
- Clinical hold on U.S. Phase 2 RENEW trial (LTI-03) remains; company hopeful for timely release after CRL submission.

## SEC filing metadata
- accession: 0001193125-25-210050
- form_type: 8-K
- ticker: RNTX
- cik: 0001420565
- company_name: Rein Therapeutics, Inc.
- filed_at: 2025-09-22T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1420565/000119312525210050/0001193125-25-210050-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1420565/000119312525210050/d902312d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-210050
- JSON: https://secwatch.observer/filing/0001193125-25-210050.json
- Plain text: https://secwatch.observer/filing/0001193125-25-210050.txt

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