Press release
Insmed Provides Clinical and Business Update
—Phase 2b BiRCh Study of Brensocatib in CRSsNP Did Not Meet Primary or Secondary Efficacy Endpoints; Safety Consistent with Previous Studies; Insmed
About this update from Insmed Incorporated
[{"type":"text","content":"—Phase 2b BiRCh Study of Brensocatib in CRSsNP Did Not Meet Primary or Secondary Efficacy Endpoints; Safety Consistent with Previous Studies; Insmed Discontinues CRSsNP Program——Company Acquires Phase 2 Ready Monoclonal Antibody for Potential Respiratory and Immunological & Inflammatory Indications—BRIDGEWATER, N.J., Dec. 17, 2025 /PRNewswire/ -- Insmed Incorporated (Nasdaq:INSM), a people-first global biopharmaceutical company striving to deliver first- and best-in-class therapies to transform the lives of patients facing serious diseases, announced today that the Phase 2b BiRCh study of brensocatib in patients with chronic rhinosinusitis without nasal polyps (CRSsNP) did not meet its primary or secondary efficacy endpoints in either the 10 mg or 40 mg treatment arms. Brensocatib was well tolerated, with no new safety signals identified, including in the 40 mg arm, which is the highest dose Insmed has studied to date. Insmed has discontinued its development program of brensocatib in CRSsNP effective immediately and intends to present these data at a future congress.\"Given that there are no animal models in this disease, the purpose of this proof-of-concept study was to determine if brensocatib could provide treatment benefit to patients with CRSsNP,\" said Martina Flammer, M.D., MBA, Chief Medical Officer of Insmed. \"While we are disappointed in the results, they provided us with a clear answer. We extend our sincerest gratitude to the patients and investigators who made the BiRCh study possible.\"In the study, a negative score in the primary endpoint of change from baseline to the 28-day average of daily Sinus Total Symptom Score (sTSS) at Week 24 indicated an improvement. Topline results from each treatment arm were as follows: placebo least squares (LS) mean was -2.44; brensocatib 10 mg LS mean was -2.21; and brensocatib 40 mg LS mean was -2.33. Treatment-emergent adverse event (TEAE) percentages were:Brensocatib 10 mg Once Daily (N=99) Brensocatib 40 mg Once Daily(N=93) Placebo(N=95) Any TEAE, n(%) 63 (63.6)65 (69.9)62 (65.3)Serious TEAE, n(%)2 (2.0)3 (3.2)2 (2.1)Severe TEAE, n(%)003 (3.2)Acquisition of Phase 2 Ready Asset: INS1148Insmed also announced today the acquisition of INS1148, an investigational monoclonal antibody with the potential to be a first-in-class therapy to address respiratory and immunological and infl...