Rein Therapeutics announces publication of data on LTI-03 in IPF

Rein Therapeutics (RNTX) announced the publication of novel data on its lead drug candidate, LTI-03, in iScience, a peer-reviewed, open-access journal published by Cell Press. The paper, titled “LTI-03 peptide demonstrates anti-fibrotic activity in ex vivo lung slices from IPF patients,” reports how LTI-03 was tested directly on lung tissue donated by patients with idiopathic pulmonary fibrosis who underwent lung transplant. In this model, LTI-03 showed signs of reducing scarring and protecting lung cells, reinforcing its potential as an important new therapy. The study used real lung tissue donated by IPF patients. These samples continued to show scarring activity for several days, making them a highly relevant way to test new therapies. LTI-03 reduced multiple scarring pathways, while also lowering collagen production and inflammatory signals in diseased lung tissue. Unlike nintedanib, the FDA-approved standard-of-care drug, LTI-03 achieved these effects without causing cell damage or death in patient samples, reinforcing the drug’s strong safety profile. The findings add to the growing body of evidence that LTI-03 has the potential to become a meaningful new therapy for IPF. Rein recently announced regulatory approval from the U.K.’s MHRA to initiate the Phase 2 RENEW trial of LTI-03. The trial will evaluate safety, tolerability, and changes in lung function in up to 120 patients, with initial data expected in 2026.