UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.    )*

Milestone Pharmaceuticals Inc.

(Name of Issuer)

Common Shares

(Title of Class of Securities)

59935V107

(CUSIP Number)

August 3, 2020

(Date of Event which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐ Rule 13d-1(b)

☒ Rule 13d-1(c)

☐ Rule 13d-1(d)

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934, as amended (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications:

Evan K. Hall, Esq.

Haynes and Boone, LLP

2323 Victory Avenue, Suite 700

Dallas, Texas 75219-7673

(214) 651-5000

SCHEDULE 13G

SCHEDULE 13G

SCHEDULE 13G

SCHEDULE 13G

SCHEDULE 13G

Milestone Pharmaceuticals Inc.

1111 Dr. Frederik-Philips Boulevard, Suite 420, Montreal, Quebec, Canada H4M 2X6

This statement is jointly filed by and on behalf of each of Ikarian Capital, LLC, a Delaware limited liability company (“Ikarian Capital”), Ikarian Healthcare Master Fund, L.P, a Cayman Islands exempted limited partnership (the “Fund”), Ikarian Healthcare Fund GP, L.P., a Delaware limited partnership (“Ikarian GP”), Chart Westcott and Neil Shahrestani (collectively referred herein as the “Reporting Persons”). Ikarian Capital is the investment manager of, and may be deemed to indirectly beneficially own securities owned by, the Fund. Ikarian GP is the general partner of, and may be deemed to indirectly beneficially own securities owned by, the Fund. Ikarian Capital is also the general partner of, and may be deemed to indirectly beneficially own, securities beneficially owned by Ikarian GP. Ikarian Capital is a sub-advisor for certain separate managed accounts (collectively, the “Managed Accounts”) and may be deemed to indirectly beneficially own securities owned by the Managed Accounts. Ikarian Capital is ultimately owned and controlled by Chart Westcott Living Trust, of which Mr. Westcott serves as the sole trustee (the “Trust”), and indirectly by Mr. Shahrestani. Accordingly, each of Mr. Westcott, as sole trustee of the Trust, and Mr. Shahrestani may be deemed to indirectly beneficially own securities beneficially owned by, Ikarian Capital. The Fund and the Managed Accounts are the record and direct beneficial owners of the securities covered by this statement. The Fund disclaims beneficial ownership of the shares held by the Managed Accounts.

Each Reporting Person declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purposes of Section 13(d) or 13(g) of the Act or any other purpose, the beneficial owner of any securities covered by this statement.

Each Reporting Person may be deemed to be a member of a group with respect to the issuer or securities of the issuer for the purpose of Section 13(d) or 13(g) of the Act. Each of the Reporting Persons declares that neither the filing of this statement nor anything herein shall be construed as an admission that such person is, for the purpose of Section 13(d) or 13(g) of the Act or any other purpose, (i) acting (or has agreed or is agreeing to act together with any other person) as a partnership, limited partnership, syndicate, or other group for the purpose of acquiring, holding, or disposing of securities of the issuer or otherwise with respect to the issuer or any securities of the issuer or (ii) a member of any group with respect to the issuer or any securities of the issuer.

The address of the principal business office of each of the Reporting Persons is c/o Ikarian Capital, LLC, 100 Crescent Court, Suite 1620, Dallas, Texas 75201.

See Item 4 on the cover page(s) hereto.

Common Shares

59935V107    

If this statement is being filed to report the fact that as of the date hereof the Reporting Persons have ceased to be the beneficial owners of more than five percent of the class of securities, check the following  ☐.

The information set forth in Item 2(a) is incorporated by reference herein.

Not applicable.

Not applicable.

Not applicable.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: January 11, 2021

EXHIBIT INDEX

EXHIBIT 99.1

JOINT FILING AGREEMENT

January 11, 2021

Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended (the “Act”), and the rules and regulations thereunder, each party hereto hereby agrees to the joint filing, on behalf of each of them, of any filing required by such party under Section 13 or Section 16 of the Act or any rule or regulation thereunder (including any amendment, restatement, supplement, and/or exhibit thereto) with the Securities and Exchange Commission (and, if such security is registered on a national securities exchange, also with the exchange), and further agrees to the filing, furnishing, and/or incorporation by reference of this Joint Filing Agreement as an exhibit thereto. This Joint Filing Agreement shall remain in full force and effect until revoked by any party hereto in a signed writing provided to each other party hereto, and then only with respect to such revoking party.

IN WITNESS WHEREOF, each party hereto, being duly authorized, has caused this Joint Filing Agreement to be executed and effective as of the date first written above.