Insmed CMO exercises options, sells 27,173 shares

Insmed Inc’s Chief Medical Officer, Martina Flammer, exercised stock options for 27,173 shares of common stock on August 6, 2026 and sold the same number of shares, in transactions effected under a Rule 10b5-1 trading plan adopted on February 27, 2025.

Rhea-AI Filing Summary

Insmed Inc’s Chief Medical Officer, Martina Flammer, exercised stock options for 27,173 shares of common stock on August 6, 2026 and sold the same number of shares, in transactions effected under a Rule 10b5-1 trading plan adopted on February 27, 2025.

The options covered 18,278 shares at $18.95 and 8,895 shares at $25.83. Related sales were 8,895 shares at $127.00 and 18,278 shares at a weighted average $129.40 within a $129.40–$129.41 range.

Insider Trade Summary 10b5-1

Exercise and Sale: 27,173 shares ($2.92M approx. pre-tax spread)

Exercise and Sale 6 txns

Insider Flammer Martina M.D.

Role Chief Medical Officer

Sold 27,173 shs ($3.49M)

Approx. gross sale proceeds $3.49M

Approx. exercise cost $576K

Approx. pre-tax spread $2.92M

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy) F1, F3	18,278	$0.00	$0.00
Exercise	Stock Option (right to buy) F1, F4	8,895	$0.00	$0.00
Exercise	Common Stock F1	18,278	$18.95	$346K
Exercise	Common Stock F1	8,895	$25.83	$230K
Sale	Common Stock F1	8,895	$127.00	$1.13M
Sale	Common Stock F1, F2	18,278	$129.40	$2.37M

Holdings After Transaction: Stock Option (right to buy) — 72,135 contracts (Direct); Common Stock — 60,486 shares (Direct)

Footnotes (4)

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 18,278 shares sold at prices ranging from $129.40 to $129.41 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. 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.
4. F4. 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.

Key Figures

Options exercised: 27,173 shares Exercise price for 18,278 options: $18.95 per share Exercise price for 8,895 options: $25.83 per share +2 more

5 metrics

Options exercised 27,173 shares Total shares underlying options exercised on August 6, 2026

Exercise price for 18,278 options $18.95 per share Conversion price for 18,278 option shares exercised into common stock

Exercise price for 8,895 options $25.83 per share Conversion price for 8,895 option shares exercised into common stock

Shares sold at $127.00 8,895 shares Common shares sold at $127.00 per share on August 6, 2026

Shares sold at weighted avg $129.40 18,278 shares Shares sold at weighted average $129.40 within a $129.40–$129.41 range

Key Terms

Rule 10b5-1 trading plan, weighted average sales price, vesting schedule, Stock Option (right to buy)

4 terms

Rule 10b5-1 trading plan regulatory

"This transaction was effected pursuant to a 10b5-1 trading plan adopted..."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average sales price financial

"This is the weighted average sales price representing 18,278 shares sold..."

vesting schedule financial

"The options become exercisable based on the following vesting schedule..."

A vesting schedule is a timeline that determines when someone gains full ownership of certain benefits, such as company stock or retirement contributions. Think of it like earning the right to own a gift gradually over time, rather than receiving it all at once. It matters to investors because it affects when they can fully access or sell these benefits, influencing their financial planning and decision-making.

Stock Option (right to buy) financial

"security_title: Stock Option (right to buy) for derivative entries"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did Insmed (INSM) disclose in Martina Flammer’s latest insider transaction?

Insmed reported that CMO Martina Flammer exercised options for 27,173 shares and sold 27,173 common shares on August 6, 2026. All of these transactions were carried out under a pre-arranged Rule 10b5-1 trading plan adopted on February 27, 2025.

How many Insmed (INSM) stock options did Martina Flammer exercise and at what prices?

Martina Flammer exercised options covering 27,173 shares of Insmed common stock. This included 18,278 shares at an exercise price of $18.95 per share and 8,895 shares at $25.83 per share, all on August 6, 2026.

At what prices did Insmed’s CMO sell INSM common stock in this Form 4?

Flammer sold 8,895 shares at $127.00 per share and 18,278 shares at a weighted average price of $129.40, within a $129.40–$129.41 range. These sales matched the shares received from option exercises on August 6, 2026.

Was the INSM insider transaction executed under a Rule 10b5-1 trading plan?

Yes. The filing states the trades were effected under a Rule 10b5-1 trading plan adopted by Martina Flammer on February 27, 2025. The document’s 10b5-1 checkbox is also affirmed, indicating all reported transactions followed that pre-arranged plan.

What vesting terms applied to the Insmed stock options in this insider filing for INSM?

The options referenced vest in stages: one grant vests 25% on the first anniversary of grant, then 12.5% every six months through year four. Another grant vests 25% after an initial vesting date, then 12.5% every six months through its fourth anniversary.

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

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Available on EDGAR 08/07/2026 - 04:39 PM Accepted by SEC EDGAR 08/07/2026 - 04:39 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 NEW JERSEY 08807

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/06/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	08/06/2026		M(1)		18,278	A	$18.95	78,764	D
Common Stock	08/06/2026		M(1)		8,895	A	$25.83	87,659	D
Common Stock	08/06/2026		S(1)		8,895	D	$127	78,764	D
Common Stock	08/06/2026		S(1)		18,278	D	$129.4(2)	60,486	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)	$18.95	08/06/2026		M(1)			18,278	(3)	05/11/2033	Common Stock	18,278	$0	36,555	D
Stock Option (right to buy)	$25.83	08/06/2026		M(1)			8,895	(4)	05/13/2034	Common Stock	8,895	$0	35,580	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 18,278 shares sold at prices ranging from $129.40 to $129.41 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. 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.

4. 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:

	/s/ Martina Flammer, M.D., by Michael A. Smith as Attorney-in-fact	08/07/2026
	** 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).
** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)