Insmed (INSM) stock sell-off post Q1 results is overdone as underlying metrics appear positive and potential organic patient additions throughout the year should enable Brinsupri for non-cystic fibrosis bronchiectasis to clear the $1 billion floor with cushion, RBC Capital Markets said in a research note emailed Friday.

The stock reaction could be due to investor concerns about a slump in patient additions and compliance, but the brokerage said it maintained its full-year 2026 Brinsupri sales guidance of around $1.3 billion.

RBC concurs with Insmed's view that opportunity to ramp patient count through "doc experience" with Brinsupri could be considerable, while the pulmonary community presents an opportunity for future tailwinds as the company focuses on marketing and diagnostics, according to the note.

There will be a balance between compliance creeping down, tightening of approval rates, future competitors, and the pool of latent patients that can be activated, which could drive $8 billion in US peak sales, analysts wrote.

The brokerage said it reiterated its outperform rating on the stock and cut its price target to $205 per share from $220.

Price: 99.51, Change: -5.29, Percent Change: -5.05