Company: IMRX
Filing Date: 2025-09-25
Form Type: 424B5
Source: 0001104659-25-093438
Chunk: 9

Company: Immuneering Corp
Filing Date: 2025-09-25
Form: 424B5
Chunk 9
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 a qualified public offering), and is expected to close concurrent with the completion of the qualified public offering. The purchase price per share of Class A common stock (or per share of Class B common stock in lieu of Class A common stock) shall be the public offering price per share at which our Class A common stock is sold to the public in the qualified public offering. We intend that this offering shall constitute the qualified public offering. The sale of the shares in the concurrent private placement will not be registered under the Securities Act of 1933, as amended, or the Act. The closing of this offering is not conditioned upon the closing of the concurrent private placement.

#### Corporate Information
The mailing address for our principal executive office is 245 Main Street, Second Floor, Cambridge, MA 02142 and our telephone number is (617) 500-8080. Our website address is www.immuneering.com . The information contained in or accessible from our website is not incorporated into this prospectus supplement, and you should not consider it part of this prospectus supplement. We have included our website address in this prospectus supplement solely as an inactive textual reference.

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TABLE OF CONTENTS

### THE OFFERING
Class A common stock offered by us

18,959,914 shares of our Class A common stock.

Underwriters’ option to purchase additional Class A common stock

We have granted the underwriters an option to purchase up to 2,843,987 additional shares of our Class A common stock. This option is exercisable, in whole or in part, for a period of 30 days from the date of this prospectus supplement.

Concurrent private placement

We have entered into a securities purchase agreement with the Investor, pursuant to which the Investor agreed to purchase, subject to certain conditions, up to $25.0 million of our Class A common stock, or in certain situations in lieu of shares of Class A common stock, shares of our non-voting Class B common stock, in a private placement. Under the terms of the securities purchase agreement, the private placement is subject to and contingent upon the closing of a qualified public offering, and is expected to close concurrent with the completion of the qualified public offering. The purchase price per share of Class A common stock (or per share of Class B common stock in lieu of Class A common stock) shall be the public offering price per share at which our Class A common stock is sold to the public in the qualified public offering. Under