INSMED Inc — Director's Dealing 2025

Dec 19, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: INSMED Inc (INSM)
CIK: 0001104506
Period of Report: 2025-12-18

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

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-12-18	Common Stock	M	4440	$17.16	Acquired	308351	Direct
2025-12-18	Common Stock	M	6259	$30.46	Acquired	314610	Direct
2025-12-18	Common Stock	S	350	$162.26	Disposed	314260	Direct
2025-12-18	Common Stock	S	1465	$163.19	Disposed	312795	Direct
2025-12-18	Common Stock	S	447	$164.24	Disposed	312348	Direct
2025-12-18	Common Stock	S	697	$165.21	Disposed	311651	Direct
2025-12-18	Common Stock	S	1783	$166.60	Disposed	309868	Direct
2025-12-18	Common Stock	S	1431	$167.29	Disposed	308437	Direct
2025-12-18	Common Stock	S	2175	$168.54	Disposed	306262	Direct
2025-12-18	Common Stock	S	1938	$169.58	Disposed	304324	Direct
2025-12-18	Common Stock	S	362	$170.26	Disposed	303962	Direct
2025-12-18	Common Stock	S	51	$171.20	Disposed	303911	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-12-18	Stock Option (right to buy)	$17.16	M	4440	Disposed	2027-05-17	Common Stock (4440)	Direct
2025-12-18	Stock Option (right to buy)	$30.46	M	6259	Disposed	2028-01-04	Common Stock (6259)	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 350 shares sold at prices ranging from $161.72 to $162.69 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 1,465 shares sold at prices ranging from $162.72 to $163.62 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 447 shares sold at prices ranging from $163.75 to $164.73 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 697 shares sold at prices ranging from $164.83 to $165.67 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 1,783 shares sold at prices ranging from $166.00 to $166.99 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.

F7: This is the weighted average sales price representing 1,431 shares sold at prices ranging from $167.00 to $167.95 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.

F8: This is the weighted average sales price representing 2,175 shares sold at prices ranging from $168.01 to $169.00 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.

F9: This is the weighted average sales price representing 1,938 shares sold at prices ranging from $169.01 to $170.00 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.

F10: This is the weighted average sales price representing 362 shares sold at prices ranging from $170.02 to $170.91 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.

F11: This is the weighted average sales price representing 51 shares sold at prices ranging from $171.09 to $171.35 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.

F12: 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.