Rein Therapeutics Gains FDA Fast Track for LTI-03 in IPF

Rein Therapeutics has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for LTI-03, an investigational therapy being developed to treat idiopathic pulmonary fibrosis (IPF).

The FDA Fast Track programme supports the development and review of medicines intended for serious conditions with significant unmet medical needs. 

The designation can provide opportunities for closer communication with the FDA and may enable rolling submissions of a marketing application. 

Eligible medicines may also receive consideration for Accelerated Approval or Priority Review if regulatory requirements are met.

LTI-03 has previously received Orphan Drug designation from the FDA for IPF. The inhaled peptide therapy is derived from Caveolin-1 biology, which is involved in regulating fibrotic signalling. 

It is designed to reduce lung scarring while supporting alveolar progenitor cells that contribute to lung tissue repair and regeneration.

IPF is a progressive and potentially fatal lung disease characterised by the build-up of scar tissue in the lungs. Current therapies can slow progression but do not reverse established lung damage.

LTI-03 is being evaluated in the Phase 2 RENEW trial, a randomised, placebo-controlled study involving approximately 120 patients across the US, UK, Australia, Poland and Germany. 

The study is assessing two dose levels against placebo, with safety through Week 24 and change in forced vital capacity (FVC) as key endpoints. Interim data is expected in the second half of 2026.