INSMED Inc — Director's Dealing 2025

May 19, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: INSMED Inc (INSM)
CIK: 0001104506
Period of Report: 2025-05-15

Reporting Person: Flammer Martina M.D. (Chief Medical Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-05-15	Common Stock	A	6508	—	Acquired	96521	Direct
2025-05-15	Common Stock	S	9925	$65.47	Disposed	86596	Direct
2025-05-16	Common Stock	S	1799	$67.53	Disposed	84797	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-05-15	Stock Option (right to buy)	$67.22	A	31610	Acquired	2035-05-15	Common Stock (31610)	Direct

Footnotes

F1: Represents Restricted Stock Units (RSUs), each representing a contingent right to receive one share of Common Stock, granted pursuant to the Company's Amended and Restated 2019 Incentive Plan, as amended. The RSUs vest as follows: 25% on the first day of the first month following the first anniversary of the date of grant (the Initial Vesting Date) and 25% on each anniversary of the Initial Vesting Date until fully vested.

F2: Each RSU was granted on May 15, 2025 for no consideration.

F3: This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended.

F4: This is the weighted average sales price representing 9,925 shares sold at prices ranging from $65.32 to $65.99 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.

F5: These stock options were granted under the Company's Amended and Restated 2019 Incentive Plan, as amended. The options become exercisable based on the following vesting schedule: 25% vest on the Initial Vesting Date and an additional 12.5% vest every six months thereafter until fully vested.