Boehringer drops inhaled gene therapy for cystic fibrosis

Boehringer Ingelheim has discontinued an inhaled gene therapy for cystic fibrosis after halting its phase 1/2 Lenticlair 1 trial. The candidate, BI 3720931, a lentiviral vector designed for inhalation, failed to generate clinical data supporting further development. The study, launched in late 2024, enrolled five patients and assessed safety and lung function. According to the company, the safety profile was in line with expectations for an innovative inhaled genetic therapy, but efficacy data did not justify continuation. The decision does not affect other research programmes. Boehringer continues to evaluate verducatib, a DPP1/Cathepsin C inhibitor, in a phase 3 trial in cystic fibrosis-associated and non-CF bronchiectasis.

Setback, but still on a wave of approvals

Despite this setback, the privately owned group remains optimistic about its broader late-stage pipeline and is awaiting key regulatory decisions in the United States. The FDA is expected to rule on the full approval of zongertinib, a HER2-selective tyrosine kinase inhibitor for previously treated HER2-mutated non-small cell lung cancer, which is the first oral targeted therapy in this setting and has won accelerated approval late in 2025. A decision in favor of nerandomilast, a PDE4B inhibitor for idiopathic pulmonary fibrosis, was another success for Boehringer a few months ago, where phase 3 data have suggested a potential advance over existing treatments and convinced the FDA.

Beyond respiratory disease and oncology, Boehringer is advancing survodutide, a dual glucagon/GLP-1 receptor agonist partnered with Zealand Pharma, in late-stage trials for obesity and metabolic dysfunction-associated steatohepatitis. With more than ten late-stage trials expected to read out within the next 12 to 18 months, the company describes its pipeline as entering a more mature phase, even as individual projects fall away.