Back/Insmed Discontinues Brensocatib Study, Shifts Focus to Promising INS1148 Therapy
pharma·December 19, 2025·insm

Insmed Discontinues Brensocatib Study, Shifts Focus to Promising INS1148 Therapy

ED
Editorial
Cashu Markets·2 min read
TL;DR
  • Insmed discontinues Phase 2b study of brensocatib for chronic rhinosinusitis due to ineffective results compared to placebo.
  • Brensocatib showed a favorable safety profile, with no new safety signals emerging during the trial.
  • Insmed acquires INS1148, a monoclonal antibody targeting respiratory diseases, ready for Phase 2 trials.

Insmed Discontinues Phase 2b Study of Brensocatib for Chronic Rhinosinusitis, Shifts Focus to New Therapy

Insmed Incorporated, a biopharmaceutical company renowned for its innovative treatment approaches for serious diseases, announces the cessation of its Phase 2b BiRCh study of brensocatib in chronic rhinosinusitis without nasal polyps (CRSsNP). This decision follows the study's failure to achieve both primary and secondary efficacy endpoints, as the treatment arms administered 10 mg and 40 mg of brensocatib demonstrated minimal improvement compared to placebo. With the placebo group showing a least squares mean change from baseline on the Sinus Total Symptom Score (sTSS) of -2.44, the brensocatib doses presented changes of -2.21 and -2.33, respectively, indicating no significant therapeutic advantage.

Despite the disappointing efficacy outcomes, brensocatib exhibited a favorable safety profile, with no new safety signals emerging during the trial. The treatment-emergent adverse event (TEAE) rates were comparable across all groups, with 63.6% for the 10 mg arm, 69.9% for the 40 mg arm, and 65.3% for the placebo. Dr. Martina Flammer, Insmed's Chief Medical Officer, expressed disappointment regarding the results but acknowledged the clarity they provide for the company moving forward. This development reflects the ongoing challenges faced in the area of treating chronic rhinosinusitis, a condition that significantly impacts patients' quality of life.

In a strategic pivot following the BiRCh study’s conclusion, Insmed announces the acquisition of INS1148, a promising monoclonal antibody that is ready for Phase 2 trials. This new therapy is designed to target respiratory and inflammatory diseases by selectively engaging a specific isoform of Stem Cell Factor SCF248. Insmed positions INS1148 as a potential first-in-class treatment that could preserve critical healing pathways, thus addressing significant unmet medical needs in respiratory health. The company is committed to advancing INS1148 through clinical trials, aiming to provide innovative solutions for patients suffering from these conditions.

In summary, while the discontinuation of the brensocatib study marks a setback for Insmed, the acquisition of INS1148 signifies a forward-looking approach. The company continues to prioritize research and development in areas with high unmet needs, underscoring its dedication to advancing therapies that can profoundly improve patient outcomes in respiratory and inflammatory diseases.