UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

(Rule 13d-102) 

Information Statement Pursuant to Rules 13d-1 and 13d-2

Under the Securities Exchange Act of 1934

(Amendment No.     )*

Replimune Group, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

76029N 106

(CUSIP Number)

July 24, 2018

(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 (“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).

The name of the issuer to which this filing on Schedule 13G relates is Replimune Group, Inc. (the “Company”).

The principal executive offices of the Company are located at 18 Commerce Way, Woburn, MA 01801.

This Schedule 13G is being filed jointly by Bain Capital Life Sciences Fund, L.P., a Cayman exempted limited partnership (“BC LS”), and BCIP Life Sciences Associates, LP, a Delaware limited partnership (“BCIP LS” and, together with BC LS, the “Reporting Persons”).

Bain Capital Life Sciences Investors, LLC, a Delaware limited liability company (“BCI LS”), is the general partner of Bain Capital Life Sciences Partners, LP, a Cayman exempted limited partnership (“BC LS P”), which is the general partner of BC LS.

Boylston Coinvestors, LLC, a Delaware limited liability company (“Boylston”), is the general partner of BCIP LS.

The governance, investment strategy and decision-making process with respect to the investments held by all of the Reporting Persons is directed by BCI LS, whose managers are Jeffrey Schwartz and Adam Koppel. As a result, each of BCI LS, Mr. Schwartz and Dr. Koppel may be deemed to share voting and dispositive power with respect to the securities held by the Reporting Persons.

The Reporting Persons have entered into a Joint Filing Agreement, dated August 1, 2018, pursuant to which the Reporting Persons have agreed to file this Schedule 13G jointly in accordance with the provisions of Rule 13d-1(k)(1) promulgated under the Act.

The principal business address of each of the Reporting Persons, BCI LS, BC LS P, Boylston, Mr. Schwartz and Dr. Koppel is 200 Clarendon Street, Boston, MA 02116.

BC LS and BC LS P are organized under the laws of the Cayman Islands. BCIP LS, BCI LS and Boylston are organized under the laws of the State of Delaware. Mr. Schwartz and Dr. Koppel are citizens of the United States.

The class of equity securities of the Company to which this filing on Schedule 13G relates is Common Stock, par value $0.001 per share (“Common Stock”).

The CUSIP number of the Company’s Common Stock is 76029N 106.

Not applicable.

As of the date hereof, BC LS held 2,575,360 shares of Common Stock, representing approximately 8.2% of the Company’s outstanding shares of Common Stock, and BCIP LS held 263,608 shares of Common Stock, representing approximately 0.8% of the Company’s outstanding shares of Common Stock. As a result of the foregoing and the relationships described in Item 2(a), the Reporting Persons may be deemed to beneficially own in the aggregate 2,838,968 shares of Common Stock, representing approximately 9.0% of the Company’s outstanding shares of Common Stock. The percentage of the Company’s outstanding shares of Common Stock held by the Reporting Persons is based on 31,546,523 shares of Common Stock outstanding as reported by the Company in the prospectus relating to its initial public offering, filed with the Securities and Exchange Commission pursuant to Rule 424(b) under the Securities Act of 1933, as amended, on July 23, 2018, after giving effect to the partial exercise of the underwriters’ option to purchase additional shares of Common Stock in connection with the initial public offering, as disclosed by the Company in its Form 8-K, filed with the Securities and Exchange Commission on July 30, 2018.

See Item 4(a) hereof.

Not applicable.

Not applicable.

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.

SIGNATURES

After reasonable inquiry and to the best of my knowledge and belief, the undersigned certifies that the information set forth in this Statement is true, complete and correct.

Dated: August 1, 2018

Exhibit A

Agreement Regarding the Joint Filing of Schedule 13G

The undersigned hereby agree as follows:

(i) Each of them is individually eligible to use the Schedule 13G to which this Exhibit is attached, and such Schedule 13G is filed on behalf of each of them; and

(ii) Each of them is responsible for the timely filing of such Schedule 13G and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate.

Dated: August 1, 2018