Martina Flammer - 01 Dec 2025 Form 4 Insider Report for INSMED Inc (INSM)

Signature
/s/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact
Issuer symbol
INSM
Transactions as of
01 Dec 2025
Transactions value $
-$1,611,343
Form type
4
Filing time
03 Dec 2025, 16:01:49 UTC
Previous filing
13 Nov 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Flammer Martina M.D. Chief Medical Officer 700 US HIGHWAY 202/206, BRIDGEWATER /s/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact 03 Dec 2025 0001796960

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction INSM Common Stock Options Exercise $230K +8.9K +10.7% $25.83 92K 01 Dec 2025 Direct F1
transaction INSM Common Stock Sale -$299K -1.45K -1.58% $205.98 90.6K 01 Dec 2025 Direct F1, F2
transaction INSM Common Stock Sale -$1.22M -5.89K -6.5% $207.03 84.7K 01 Dec 2025 Direct F1, F3
transaction INSM Common Stock Sale -$324K -1.56K -1.84% $207.73 83.1K 01 Dec 2025 Direct F1, F4

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction INSM Stock Option (right to buy) Options Exercise $0 -8.9K -16.67% $0.00 44.5K 01 Dec 2025 Common Stock 8.9K $25.83 Direct F1, F5
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 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.
F2 This is the weighted average sales price representing 1,450 shares sold at prices ranging from $205.45 to $206.39 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 5,886 shares sold at prices ranging from $206.48 to $207.47 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 1,559 shares sold at prices ranging from $207.49 to $208.17 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 The options become exercisable based on the following vesting schedule: 25% vest on the first day of the first month following the first anniversary of the date of grant (the Initial Vesting Date) and 12.5% vest on each sixth month anniversary date thereafter through the fourth anniversary of the Initial Vesting Date.