Boehringer axes inhaled gene therapy after viewing cystic fibrosis data

 Boehringer Ingelheim is discarding an inhaled gene therapy designed to treat cystic fibrosis (CF) after terminating a phase 1/2 trial.

The shuttered study, dubbed Lenticlair 1, failed to produce clinical data supporting further development, a Boehringer spokesperson told Fierce Biotech. The trial was assessing BI 3720931, a lentiviral vector gene therapy designed to be inhaled.

The study launched in late 2024 and enrolled five patients with CF, a genetic disease that damages the lungs and other organs. The first portion of the study was an open-label study of three different dose levels, while the second part was a double-blind, placebo-controlled, dose-expansion assessment. 

Phase 1 of the study measured adverse events related to treatment, while the second part looked at how much air an individual could forcefully exhale during a single breath compared to baseline at Week 8.

The termination follows the study’s primary readout on Feb. 3.

“The safety profile of BI 3720931 was consistent with expectations for an innovative, inhaled genetic therapy,” the spokesperson told Fierce. 

The discontinuation of BI 3720931 doesn’t impact Boehringer’s other gene therapy programs, the spokesperson said, though the company doesn’t list any other clinical gene therapies on its website.

The pharma is also evaluating another CF treatment—an investigative DPP1/Cathepsin C inhibitor called verducatib—in a phase 3 study for patients with CF-associated bronchiectasis and non-CF bronchiectasis.

Cystic fibrosis has proven to be a tricky indication for novel treatment developers. In October, Arcturus Therapeutics revealed a lack of efficacy for its investigational inhaled mRNA therapy in a phase 2 CF trial.  

Earlier in May, Vertex Pharmaceuticals paused a phase 1/2 CF trial over a tolerability issue related to VX-522, a Moderna-partnered mRNA therapy. The company now aims to finish dosing in the multiple ascending dose portion of the study and to reveal data in the second half of 2026.

Elsewhere, Sionna Therapeutics is moving ahead with several cystic fibrosis prospects, three of which were picked up from AbbVie. The biotech is being propelled forward by its recent $135 million IPO.

https://www.fiercebiotech.com/biotech/boehringer-axes-inhaled-gene-therapy-after-viewing-cystic-fibrosis-data