EQ Equillium Inc

As filed with the Securities and Exchange Commission on January 6, 2023

Registration No. 333-        

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

2018 Equity Incentive Plan

2018 Employee Stock Purchase Plan

(Full titles of the plans)

Bruce D. Steel

President and Chief Executive Officer

Equillium, Inc.

2223 Avenida de la Playa, Suite 105

La Jolla, California 92037

(Name and Address of agent for service)

(858) 412-5302

(Telephone number, including area code, of agent for service)

With a copy to:

Thomas A. Coll

Cooley LLP

4401 Eastgate Mall

San Diego, California 92121

(858) 550-6000

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

REGISTRATION OF ADDITIONAL SECURITIES

PURSUANT TO GENERAL INSTRUCTION E

This Registration Statement is being filed for the purpose of increasing the number of securities of the same class as other securities for which a Registration Statement of the Registrant on Form S-8 relating to the same employee benefit plans is effective.

The Registrant previously registered shares of its Common Stock for issuance under the Equillium, Inc. 2018 Equity Incentive Plan and Equillium, Inc. 2018 Employee Stock Purchase Plan under Registration Statements on Form S-8 filed with the Securities and Exchange Commission on October  16, 2018 (File No. 333-227859), March 27, 2019 (File No. 333-230536), as amended, March 26, 2020 (File No. 333-237407), March 24, 2021 (File No. 333-254656) and March 23, 2022 (File No. 333-263790). Pursuant to General Instruction E to Form S-8, this Registration Statement hereby incorporates by reference the contents of the Registration Statements referenced above.