Amendment: SEC Form S-1/A filed by HCW Biologics Inc.

As filed with the Securities and Exchange Commission on June 18, 2026

Registration No. 333-296577

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

Amendment No. 1

to

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

HCW BIOLOGICS INC.

(Exact name of Registrant as specified in its charter)

2929 N Commerce Parkway

Miramar, FL 33025

(954) 842-2024

Address, including zip code, and telephone number, including area code, of Registrant’s principal executive offices

Hing C. Wong, Ph.D.

Chief Executive Officer

HCW Biologics Inc.

2929 N Commerce Parkway

Miramar, FL 33025

(954) 842-2024

Name, Address Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service

With a copy to:

Approximate Date of Commencement of Proposed Sale to the Public: From time to time after the effective date of this registration statement, as determined by market conditions.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

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. ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to Section 8(a) of the Securities Act, may determine.

EXPLANATORY NOTE

HCW Biologics Inc. is filing this Amendment No. 1 to its Registration Statement on Form S-1 (File No. 333-296577) as an exhibits-only filing. Accordingly, this Amendment consists only of the facing page, this explanatory note, Item 16(a) of Part II of the Registration Statement, the signature page to the Registration Statement and the filed exhibits. The remainder of the Registration Statement is unchanged and has therefore been omitted.

PART II

Item 16. Exhibits.

EXHIBIT INDEX

+ Indicates a management contract or compensatory plan or arrangement.

†† Certain information in this document has been excluded pursuant to Item 601(b)(10) of Regulation S-K. Such excluded information is not material and is the type of information the Registrant treats as private and confidential. The Registrant agrees to furnish supplementally such information to the SEC upon request.

# Certain information in this document has been excluded pursuant to Item 601(a)(5) or (a)(6) of Regulation S-K. The Registrant agrees to furnish supplementally such information to the SEC upon request.

* Previously filed.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this registration statement on Form S-1 to be signed on its behalf by the undersigned, in the city of Miramar, State of Florida, on June 18, 2026.

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this registration statement on Form S-1 to be signed on its behalf by the undersigned, thereunto duly authorized.