INSMED Inc

Rule 10b5-1 Trading Plans

Our policy governing transactions in our securities by our directors, officers and employees permits our directors, officers and employees to enter into trading plans complying with Rule 10b5-1 under the Exchange Act. The following table describes the written plans for the sale of our securities adopted orterminated by our officers and directors (each as defined in Rule 16a-1(f) of the Exchange Act) during the third quarter of 2026, each of which was entered into or terminated, as applicable, during an open trading window and is or was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) (each, a Trading Plan).

(1) A Trading Plan may expire on an earlier date if all contemplated transactions are completed before such Trading Plan’s expiration date, upon termination by broker or the holder of the Trading Plan, or as otherwise provided in the Trading Plan.

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

As previously disclosed, Sara Bonstein, the Company’s Chief Financial Officer, is separating from the Company on October 30, 2026, and the Company is conducting a search to identify a successor. The Company has designated William Lewis, the Company’s Chief Executive Officer, as the Company’s interim principal financial officer, and Patrick Kane, the Company’s Vice President, Corporate Controller, as the Company’s interim principal accounting officer, in each case effective as of October 30, 2026.

Mr. Kane, age 52, joined the Company in 2015 and has served as Vice President, Corporate Controller since July 1, 2024. Prior to this role, Mr. Kane served as Executive Director, Corporate Controller since July 1, 2023, and Executive Director, Assistant Corporate Controller prior to that. Mr. Kane received his B.A. in Accountancy from Hofstra University, his M.B.A. from Rutgers University, and obtained his Certified Public Accountant license in the State of New York.

Mr. Kane’s base salary is $406,030, and he is eligible to participate in the Company’s benefit and equity compensation plans. Mr. Kane has an annual target bonus of 35% of his base salary.

Mr. Kane’s employment agreement provides for payment of the following upon Mr. Kane’s death or disability: (i) any accrued obligations; (ii) any earned but unpaid annual bonus in respect to any completed fiscal year that has ended on or prior to the termination; (iii) a pro-rata portion of his annual bonus based on actual performance during the year of the termination; (iv) any insurance benefits to which he and his beneficiaries are entitled as a result of his death or disability; and, solely upon death, (v) accelerated vesting of all time-vested equity awards.

If Mr. Kane’s employment is terminated by the Company without cause or by him for good reason (such a termination, a “Qualifying Termination”) prior to a change in control or more than one year following a change in control, Mr. Kane would be eligible to receive: (i) any accrued obligations; (ii) any earned but unpaid annual bonus in respect to any completed fiscal year that has ended on or prior to the termination; (iii) a pro-rata portion of his annual bonus based on actual performance during the year of the termination; (iv) a severance amount equal to six months of base salary; (v) accelerated vesting of all time-vested equity awards that would have otherwise vested within six months following the termination; and (vi) provided Mr. Kane timely elects coverage under COBRA, for six months, the monthly COBRA cost of continued health and dental coverage of Mr. Kane and his qualified beneficiaries paid by Mr. Kane under the health and dental plans of the Company, less the amount that Mr. Kane would be required to contribute for health and dental coverage if Mr. Kane were an active employee of the Company (collectively, the “Termination Benefits”).

In the event of a Qualifying Termination within one year following a change in control, Mr. Kane would be eligible to receive the Termination Benefits, with the following enhancements: (i) the severance amount would be doubled; (ii) the COBRA benefit would be extended to 12 months; and (iii) all of Mr. Kane’s equity awards would vest in full (other than any performance share units, which would vest in accordance with the applicable award agreement).

There are no arrangements or understandings between Mr. Kane and any other person pursuant to which he was selected as an officer, and there are no family relationships between Mr. Kane and any of the Company’s directors or executive officers. Other than as disclosed herein, there are no transactions involving Mr. Kane that are required to be disclosed pursuant to Item 404(a) of Regulation S-K.

In connection with his appointment, the Company and Mr. Kane will enter into the Company’s standard indemnification agreement for directors and officers.