Treprostinil Palmitil Inhalation Powder (TPIP)

July 16, 2026: Insmed Incorporated (NASDAQ: INSM) announced positive 12-month data from an ongoing 24-month open-label extension (OLE) study of once-daily treprostinil palmitil inhalation powder (TPIP) in pulmonary arterial hypertension (PAH; WHO Group 1) patients who completed prior TPIP PAH studies. At Month 12, secondary efficacy measures showed sustained improvements in six-minute walk distance (6MWD), NT-proBNP, WHO Functional Class, and REVEAL Lite 2.0 risk score; patients who crossed over from placebo (N=31) achieved similar outcomes to those continuing TPIP (N=60).

Key Month 12 results: mean 6MWD improvement +55.7 m (TPIP Continued) and +54.1 m (Placebo Crossed); NT-proBNP reduced ~60% (GMR 0.40 and 0.41); WHO Functional Class I/II in 78.3% and 80.6% (with >25% achieving Class I across groups); mean REVEAL Lite 2.0 improved by 2.0 and 1.4 points, with ~65% reaching “Refined Low Risk” status.

Safety/tolerability: doses up to 1,280 µg once daily were permitted; TEAEs occurred in 89.0%, serious TEAEs in 18.7%, severe TEAEs in 16.5%, and discontinuations due to TEAEs in 7.7%. Four deaths occurred, none considered related to TPIP.

The OLE findings support continued development and the recent initiation of the Phase 3 PALM-PAH trial (24 weeks; primary endpoint change in 6MWD). Insmed also scheduled an investor call for July 16, 2026 at 8:00 a.m. ET.