X0508 4 2025-11-03 0 0001104506 INSMED Inc INSM 0001870278 Smith Michael Alexander 700 US HIGHWAY 202/206 BRIDGEWATER NJ 08807 0 1 0 0 Chief Legal Officer 1 Common Stock 2025-11-03 4 M 0 27130 23.75 A 82032 D Common Stock 2025-11-03 4 S 0 1342 181.01 D 80690 D Common Stock 2025-11-03 4 S 0 7619 181.88 D 73071 D Common Stock 2025-11-03 4 S 0 4286 182.60 D 68785 D Common Stock 2025-11-03 4 S 0 4032 183.92 D 64753 D Common Stock 2025-11-03 4 S 0 3243 184.91 D 61510 D Common Stock 2025-11-03 4 S 0 3636 185.93 D 57874 D Common Stock 2025-11-03 4 S 0 1572 187.15 D 56302 D Common Stock 2025-11-03 4 S 0 1400 187.97 D 54902 D Stock Option (right to buy) 23.75 2025-11-03 4 M 0 27130 0 D 2030-01-03 Common Stock 27130 0 D This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on February 27, 2025, in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. This is the weighted average sales price representing 1,342 shares sold at prices ranging from $180.29 to $181.19 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 7,619 shares sold at prices ranging from $181.30 to $182.29 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 4,286 shares sold at prices ranging from $182.30 to $183.03 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 4,032 shares sold at prices ranging from $183.49 to $184.48 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 3,243 shares sold at prices ranging from $184.50 to $185.48 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 3,636 shares sold at prices ranging from $185.51 to $186.45 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 1,572 shares sold at prices ranging from $186.61 to $187.53 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. This is the weighted average sales price representing 1,400 shares sold at prices ranging from $187.88 to $188.13 per share. The Reporting Person undertakes to provide to the SEC staff, the issuer, or a security holder of the issuer the number of shares sold at each price within the price range upon request. The options became exercisable based on the following vesting schedule: 25% vested on the first anniversary of the grant date and an additional 12.5% vested on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant. All options are currently exercisable. /s/ Michael A. Smith 2025-11-05