Company: INKT
Filing Date: 2025-08-22
Form Type: 424B5
Source: 0001193125-25-186417
Chunk: 0

Company: MiNK Therapeutics, Inc.
Filing Date: 2025-08-22
Form: 424B5
Chunk 0
---
As Filed Pursuant to Rule 424(b)(5)

Registration No. 333-268143

PROSPECTUS SUPPLEMENT

(To Prospectus dated
November 8, 2022 and

Prospectus Supplement dated July 15, 2025)

Up to $36,585,515

Common Stock

This prospectus supplement (this “Current Prospectus Supplement”) supplements the prospectus dated November 8, 2022 (the “Base
Prospectus”) and the prospectus supplement dated July 15, 2025 (the “Initial Prospectus Supplement”, and together with the Base Prospectus, the “ATM Prospectus”), relating to the offer and sale of shares of our
common stock from time to time pursuant to the terms of the At Market Issuance Sales Agreement, dated July 15, 2025 (the “Agreement”), with B. Riley Securities, Inc. as sales agent. This Current Prospectus Supplement should be read
in conjunction with the ATM Prospectus. This Current Prospectus Supplement is qualified by reference to the ATM Prospectus, except to the extent that the information presented herein supersedes the information contained in the ATM Prospectus. This
Current Prospectus Supplement is not complete without, and may only be delivered or utilized in connection with, the ATM Prospectus and any future amendments or supplements thereto.

As of the date hereof, the aggregate market value of our outstanding common stock held by non-affiliates, calculated
in accordance with General Instruction I.B.6 of Form S-3 under the Securities Act of 1933, as amended (our “public float”), was approximately $98.8 million, based on 1,539,804 outstanding
shares of common stock held by non-affiliates as of August 12, 2025, at a price of $64.17 per share as of July 11, 2025, which was the highest closing sale price of our common stock on the Nasdaq
Capital Market within 60 days of the filing date of this Current Prospectus Supplement.

We are filing this Current Prospectus Supplement to amend the ATM
Prospectus to update our public float and indicate that, since our public float is above $75.0 million, we are no longer subject to the sales limitations of General Instruction I.B.6 of Form S-3 with
respect to the registration statement of which the ATM Prospectus, as amended hereby, forms a part. If we become