Insmed CMO exercises options and sells INSM stock

Insmed Inc.’s Chief Medical Officer Martina Flammer reported a series of stock transactions.

Rhea-AI Filing Summary

Insmed Inc.’s Chief Medical Officer Martina Flammer reported a series of stock transactions. On February 2, 2026, she exercised a stock option for 7,982 shares of common stock at $65.72 per share and sold multiple blocks of common stock under a Rule 10b5-1 trading plan, at weighted average prices including $152.06, $153.16, $154.56, $155.46 and $156.86 per share. On February 3, 2026, she sold 795 shares at $155.77 per share to satisfy tax withholding and related broker fees upon RSU vesting. After these transactions, she directly owned 84,112 shares of common stock and held 23,948 stock options.

Insider Trade Summary

Exercise and sale activity reported; no spread calculated

Exercise and Sale 8 txns

Insider Flammer Martina M.D.

Role Chief Medical Officer

Sold 8,777 shs ($1.36M)

Approx. gross sale proceeds $1.36M

Approx. exercise cost $525K

Type	Security	Shares	Price	Value
Sale	Common Stock	795	$155.77	$124K
Exercise	Stock Option (right to buy)	7,982	$0.00	$0.00
Exercise	Common Stock	7,982	$65.72	$525K
Sale	Common Stock	563	$152.06	$86K
Sale	Common Stock	928	$153.16	$142K
Sale	Common Stock	3,349	$154.56	$518K
Sale	Common Stock	3,042	$155.46	$473K
Sale	Common Stock	100	$156.86	$16K

Holdings After Transaction: Stock Option (right to buy) — 23,948 contracts (Direct); Common Stock — 84,112 shares (Direct)

Footnotes (7)

1. 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.
2. F2. This is the weighted average sales price representing 563 shares sold at prices ranging from $151.76 to $152.74 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. F3. This is the weighted average sales price representing 928 shares sold at prices ranging from $152.77 to $153.31 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. F4. This is the weighted average sales price representing 3,349 shares sold at prices ranging from $154.10 to $155.09 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. F5. This is the weighted average sales price representing 3,042 shares sold at prices ranging from $155.10 to $155.96 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. F6. Shares sold to satisfy tax withholding obligations upon the vesting of Restricted Stock Units and to cover related broker fees.
7. F7. 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 first day of the first month following the first anniversary of the date of grant and an additional 12.5% vest every six months thereafter until fully vested.

FAQ

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What insider transactions did INSM Chief Medical Officer Martina Flammer report?

Martina Flammer reported exercising stock options for 7,982 Insmed (INSM) shares and selling several blocks of common stock. Sales occurred at various weighted average prices above $150 per share on February 2–3, 2026, as disclosed in her Form 4 filing.

How many Insmed (INSM) shares does Martina Flammer own after these Form 4 trades?

After the reported transactions, Martina Flammer directly owned 84,112 shares of Insmed common stock. She also held 23,948 stock options granted under the company’s Amended and Restated 2019 Incentive Plan, according to the Form 4 ownership tables.

What stock option exercise did the Insmed (INSM) Form 4 disclose?

The Form 4 shows Martina Flammer exercised a stock option for 7,982 shares of Insmed common stock at an exercise price of $65.72 per share on February 2, 2026. These options were part of the company’s 2019 Incentive Plan and followed a defined vesting schedule.

At what prices did Martina Flammer sell Insmed (INSM) shares in this filing?

She sold Insmed common shares at several weighted average prices, including $152.06, $153.16, $154.56, $155.46 and $156.86 per share. One additional sale of 795 shares at $155.77 per share on February 3, 2026, was to cover tax withholding and broker fees.

Was the Insmed (INSM) insider trading under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effected under a Rule 10b5-1 trading plan that Martina Flammer adopted on February 27, 2025. Such plans pre-schedule trades, allowing insiders to systematically sell shares according to predetermined instructions.

Why were some Insmed (INSM) shares sold to cover tax withholding?

The Form 4 explains that 795 shares were sold to satisfy tax withholding obligations from the vesting of Restricted Stock Units and to pay related broker fees. This type of sale is administrative and commonly used to meet tax requirements on equity compensation.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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Accepted by SEC EDGAR 02/04/2026 - 04:15 PM Learn about SEC filing dates

SEC Form 4

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a 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). See Instruction 10.

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)
02/02/2026

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	02/02/2026		M(1)		7,982	A	$65.72	92,889	D
Common Stock	02/02/2026		S(1)		563	D	$152.06(2)	92,326	D
Common Stock	02/02/2026		S(1)		928	D	$153.16(3)	91,398	D
Common Stock	02/02/2026		S(1)		3,349	D	$154.56(4)	88,049	D
Common Stock	02/02/2026		S(1)		3,042	D	$155.46(5)	85,007	D
Common Stock	02/02/2026		S(1)		100	D	$156.86	84,907	D
Common Stock	02/03/2026		S(6)		795	D	$155.77	84,112	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)	$65.72	02/02/2026		M(1)			7,982	(7)	01/08/2035	Common Stock	7,982	$0	23,948	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 563 shares sold at prices ranging from $151.76 to $152.74 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 928 shares sold at prices ranging from $152.77 to $153.31 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 3,349 shares sold at prices ranging from $154.10 to $155.09 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 3,042 shares sold at prices ranging from $155.10 to $155.96 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. Shares sold to satisfy tax withholding obligations upon the vesting of Restricted Stock Units and to cover related broker fees.

7. 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 first day of the first month following the first anniversary of the date of grant and an additional 12.5% vest every six months thereafter until fully vested.

Remarks:

	/s/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact	02/04/2026
	** 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).
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