Insmed Inc

BRINSUPRI launch performance is exceptionally strong and fundamentals look durable - 44% sequential revenue growth in calendar Q1 (notably strong given Q1 launch slowdowns typically caused by plan changes, out-of-pocket resets, and reauthorization dynamics). - Management argues BRINSUPRI is outpacing past specialty respiratory analogs in early Q1 sequential growth (those averaged ~9%, and even when including post-coverage-gap analogs, BRINSUPRI’s rate is still higher than WINREVAIR / Rezdiffra which showed ~30–40% in comparable first calendar Q1 periods). - No price increase at start of 2026; inventory stocking impact negligible → suggests performance is driven by true demand/acceptance. - Guidance reiterated: BRINSUPRI expected ≥ $1B global net revenue in 2026; if achieved, management frames it as among the industry’s biggest launches.

Demand is transitioning from “ready-and-waiting” into true organic growth (key investor watch-point) - “Ready and waiting” patients: nearly all those poised at approval were treated quickly due to pre-launch disease awareness and EMR readiness at major institutions. - Estimated contribution: ~3,500 of ~9,000 new patient starts in Q4, and ~1,500 of ~7,800 new starts in Q1. - Management expects that ready-and-waiting surge is now complete, so Q2 should be the first quarter less boosted by that effect. - Despite that, company expects organic new patient demand to grow sequentially from Q2 through the rest of 2026 (no quarterly guidance provided, but direction is positive).

Launch “engine” metrics are very favorable (access, adherence, continuation, payer friction) - Payer access: specialty pharmacy approval rate ~90% since launch; payer approval time < 1 week for most patients. - Patient support uptake: >80% enrolled in inLighten. - Refill/compliance: prescriptions being refilled nearly every 30 days vs an industry benchmark ~every 37 days (implies better persistence). - Continuation rates: tracking slightly above real-world oral-medicine analogs (e.g., generic statins ~70% remaining at 6 months). - Prescriber reach: cumulative writers >5,000 (~1/4 of US pulmonologists). - Depth opportunity: of ~1,800 physicians who prescribed to only one patient as of Dec, roughly half have expanded to 2+ patients by end of Q1. - Surprising/important: management sees depth growth as the biggest incremental driver (they caution uptake is slower in bronchiectasis due to historical lack of novel options).