FORM 4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
1. Name and Address of Reporting Person *
Flammer Martina M.D.
(Last) (First) (Middle)
700 US HIGHWAY 202/206
(Street)
BRIDGEWATER NJ 08807
(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
INSMED Inc [ INSM ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
Chief Medical Officer
3. Date of Earliest Transaction (Month/Day/Year)
09/02/2025
4. If Amendment, Date of Original Filed (Month/Day/Year)
 6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 09/02/2025   M (1)   13,680 A $ 34.03 96,791 D  
Common Stock 09/02/2025   M (1)   17,160 A $ 26.46 113,951 D  
Common Stock 09/02/2025   M (1)   25,710 A $ 26.43 139,661 D  
Common Stock 09/02/2025   M (1)   38,846 A $ 17.07 178,507 D  
Common Stock 09/02/2025   M (1)   13,072 A $ 19.74 191,579 D  
Common Stock 09/02/2025   M (1)   36,555 A $ 18.95 228,134 D  
Common Stock 09/02/2025   M (1)   23,835 A $ 29.13 251,969 D  
Common Stock 09/02/2025   M (1)   17,790 A $ 25.83 269,759 D  
Common Stock 09/02/2025   S (1)   19,066 D $ 141.27 (2) 250,693 D  
Common Stock 09/02/2025   S (1)   5,877 D $ 142.03 (3) 244,816 D  
Common Stock 09/02/2025   S (1)   35,245 D $ 143.16 (4) 209,571 D  
Common Stock 09/02/2025   S (1)   28,063 D $ 144.05 (5) 181,508 D  
Common Stock 09/02/2025   S (1)   63,782 D $ 145.33 (6) 117,726 D  
Common Stock 09/02/2025   S (1)   34,615 D $ 146.05 (7) 83,111 D  
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (right to buy) $ 34.03 09/02/2025   M (1)     13,680   (8) 01/07/2031 Common Stock 13,680 $ 0 0 D  
Stock Option (right to buy) $ 26.46 09/02/2025   M (1)     17,160   (8) 05/12/2031 Common Stock 17,160 $ 0 0 D  
Stock Option (right to buy) $ 26.43 09/02/2025   M (1)     25,710   (9) 01/06/2032 Common Stock 25,710 $ 0 8,570 D  
Stock Option (right to buy) $ 17.07 09/02/2025   M (1)     38,846   (9) 05/11/2032 Common Stock 38,846 $ 0 25,898 D  
Stock Option (right to buy) $ 19.74 09/02/2025   M (1)     13,072   (9) 01/05/2033 Common Stock 13,072 $ 0 13,073 D  
Stock Option (right to buy) $ 18.95 09/02/2025   M (1)     36,555   (9) 05/11/2033 Common Stock 36,555 $ 0 73,110 D  
Stock Option (right to buy) $ 29.13 09/02/2025   M (1)     23,835   (9) 01/04/2034 Common Stock 23,835 $ 0 39,725 D  
Stock Option (right to buy) $ 25.83 09/02/2025   M (1)     17,790   (10) 05/13/2034 Common Stock 17,790 $ 0 53,370 D  
Explanation of Responses:
1. 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.
2. This is the weighted average sales price representing 19,066 shares sold at prices ranging from $140.56 to $141.51 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.
3. This is the weighted average sales price representing 5,877 shares sold at prices ranging from $141.61 to $142.55 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.
4. This is the weighted average sales price representing 35,245 shares sold at prices ranging from $142.70 to $143.69 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.
5. This is the weighted average sales price representing 28,063 shares sold at prices ranging from $143.70 to $144.63 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.
6. This is the weighted average sales price representing 63,782 shares sold at prices ranging from $144.70 to $145.69 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.
7. This is the weighted average sales price representing 34,615 shares sold at prices ranging from $145.70 to $146.51 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.
8. 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.
9. The options become exercisable based on the following vesting schedule: 25% vest on the first anniversary of the grant date and an additional 12.5% vest on each sixth month anniversary date thereafter through the fourth anniversary of the date of grant.
10. 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.
Remarks:
Exhibit List - Exhibit 24 - Power of Attorney
/s/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact 09/04/2025
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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ATTACHMENTS / EXHIBITS

ATTACHMENTS / EXHIBITS

EX-24