INSMED Inc — Director's Dealing 2026

Feb 23, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: INSMED Inc (INSM)
CIK: 0001104506
Period of Report: 2026-02-19

Reporting Person: Lewis William (Director, Chair and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-19	Common Stock	M	6259	$30.46	Acquired	307444	Direct
2026-02-19	Common Stock	M	4440	$17.16	Acquired	311884	Direct
2026-02-19	Common Stock	S	1988	$149.17	Disposed	309896	Direct
2026-02-19	Common Stock	S	1891	$150.10	Disposed	308005	Direct
2026-02-19	Common Stock	S	3413	$151.12	Disposed	304592	Direct
2026-02-19	Common Stock	S	2377	$151.92	Disposed	302215	Direct
2026-02-19	Common Stock	S	1030	$153.38	Disposed	301185	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2026-02-19	Stock Option (right to buy)	$30.46	M	6259	Disposed	2028-01-04	Common Stock (6259)	Direct
2026-02-19	Stock Option (right to buy)	$17.16	M	4440	Disposed	2027-05-17	Common Stock (4440)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	233924	Indirect
Common Stock	50500	Indirect

Footnotes

F1: This transaction was effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on September 4, 2025 in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended.

F2: This is the weighted average sales price representing 1,988 shares sold at prices ranging from $148.51 to $149.50 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.

F3: This is the weighted average sales price representing 1,891 shares sold at prices ranging from $149.53 to $150.50 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.

F4: This is the weighted average sales price representing 3,413 shares sold at prices ranging from $150.54 to $151.51 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: This is the weighted average sales price representing 2,377 shares sold at prices ranging from $151.56 to $152.43 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.

F6: This is the weighted average sales price representing 1,030 shares sold at prices ranging from $153.00 to $153.78 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.

F7: 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.