UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 5, 2026

INSMED INCORPORATED

(Exact name of registrant as specified in its charter)

Virginia	000-30739	54-1972729
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

700 US Highway 202/206 Bridgewater, New Jersey		08807 (Zip Code)
(Address of principal executive offices)

Registrant’s telephone number, including area code: (908) 977-9900

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.01 per share	INSM	Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR 230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR 240.12b-2).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

ITEM 5.02

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On October 5, 2026, Insmed Incorporated (the “Company”) announced that Sara Bonstein, the Company’s Chief Financial Officer, would be separating from the Company, effective October 30, 2026, and the Company has a search underway to identify a successor. The separation is not related to any disagreement between Ms. Bonstein and the Company on any matter relating to the Company’s accounting practices, financial statements, internal controls or operations. Ms. Bonstein will receive the benefits set forth in Section 6.e of the Amended and Restated Employment Agreement between the Company and Ms. Bonstein dated April 1, 2022.

ITEM 7.01

Regulation FD Disclosure.

On October 5, 2026, the Company issued a press release announcing the separation of Ms. Bonstein and providing certain guidance information for the third quarter of 2026. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated herein by reference.

The information contained in this Item 7.01, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

ITEM 9.01

Financial Statements and Exhibits.

(d)

Exhibits

Exhibit No.		Description
99.1		Press release issued by Insmed Incorporated on October 5, 2026.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Dated: October 5, 2026	INSMED INCORPORATED

	By:	/s/ Michael A. Smith
	Name:	Michael A. Smith
	Title:	Chief Legal Officer and Secretary