Insmed (INSM) Stock After Hours on Dec. 19, 2025: Friday Rebound Holds, Analyst Targets Reset, and What to Watch Before the Next Market Open
Insmed shares closed Friday, Dec. 19, 2025, at $174.84, up nearly 5%, after a volatile week triggered by a failed Phase 2b trial for brensocatib in CRSsNP. The company said it would discontinue that program. Shares held steady in after-hours trading. Insmed also announced the acquisition of INS1148, a Phase 2–ready monoclonal antibody.