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

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

HCW BIOLOGICS INC.

(Exact name of Registrant as specified in its charter)

Delaware	2834	82-5024477
(State or Other Jurisdiction of	Primary Standard Industrial	(I.R.S. Employer
Incorporation or Organization)	Classification Code Number	Identification Number)

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:

James Groth

Clark Hill PLC

130 E. Randolph St., Ste. 3900

Chicago, IL 60601

(312) 985-5900

Yevgeniya (Jeny) Zarmon

Clark Hill PLC

210 Carnegie Center, Suite 102

Princeton, NJ 08540

(609) 785-2918

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.

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
		Emerging growth company	☒

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

		Incorporated by reference				Filed or
Exhibit No.	Exhibit title	Form	File No.	Exhibit No.	Filing date	furnished herewith
3.1	Amended and Restated Certificate of Incorporation	8-K	001-40591	3.1	07/26/2021
3.1a	Certificate of Amendment of Certificate of Incorporation, filed March 31, 2025	8-K	001-40591	3.1a	04/01/2025
3.1b	Certificate of Correction of the Certificate of Amendment of Certificate of Incorporation, filed April 1, 2025	8-K	001-40591	3.1b	04/01/2025
3.2	Amended and Restated Bylaws	8-K	001-40591	3.2	07/26/2021
4.1	Specimen Stock Certificate	S-1/A	333-256510	4.1	07/09/2021
4.2	Description of Securities	10-K	001-40591	4.2	03/29/2022
4.3	Form of New Warrant	8-K	001-40591	4.1	11/20/2025
4.4	Form of Common Stock Purchase Warrant	8-K	001-40591	4.1	02/19/2026
4.5	Form of Pre-Funded Common Stock Purchase Warrant	8-K	001-40591	4.2	02/19/2026
4.6	Form of Common Stock Warrant, dated May 7, 2025, between Company and Holder	10-Q	001-40591	10.13	08/18/2025
4.7	Form of Pre-Funded Common Stock Purchase Warrant	8-K	001-40591	4.1	5/21/2026
4.8	Form of Common Stock Purchase Warrant	8-K	001-40591	4.2	5/21/2026
5.1	Opinion of Clark Hill PLC					X
10.1	Form of Inducement Agreement between the Company and Armistice Capital Management LLC	8-K	001-40591	10.1	11/20/2025
10.2	Securities Purchase Agreement, dated February 17, 2026, between Company and Purchaser	8-K	001-40591	10.2	02/19/2026
10.3	Amendment to Existing Warrants Agreement, dated February 17, 2026, between the Company and Purchaser	8-K	001-40591	10.3	02/19/2026
10.4	Form of Lock-up Agreement	S-1	333-393396	10.42	02/11/2026
10.5	Form of Indemnification Agreement between HCW Biologics Inc. and each of its officers and directors.	S-1/A	333-256510	10.1	07/09/2021
10.6+	2019 Equity Incentive Plan, as amended, and forms of agreement thereunder.	S-1/A	333-256510	10.2	07/09/2021
10.7+	First Amendment to 2019 Equity Incentive Plan.	S-1/A	333-256510	10.3	07/09/2021
10.8+	2021 Equity Incentive Plan and forms of agreement thereunder	S-1/A	333-256510	10.4	07/09/2021
10.9+	Employment Agreement, dated July 6, 2021, between Peter Rhode and HCW Biologics Inc.	S-1/A	333-256510	10.6	07/09/2021
10.10+	Employment Agreement, dated October 9, 2019, between Rebecca Byam and HCW Biologics Inc.	S-1/A	333-256510	10.7	07/09/2021

II-1

Incorporated by reference

Filed or

furnished

herewith

Exhibit No.

Exhibit title

Form

File No.

Exhibit No.

Filing date

10.11+

Non-Employee Director Compensation Policy.

S-1/A

333-256510

10.8

07/09/2021

10.12+

Employment Agreement, dated June 18, 2021, between Dr. Hing C. Wong and HCW Biologics Inc.

S-1/A

333-256510

10.13

07/09/2021

10.13+

Executive Incentive Bonus Plan

S-1/A

333-256510

10.11

07/09/2021

10.14†

Exclusive License Agreement, dated December 24, 2020, between HCW Biologics Inc. and Wugen, Inc.

S-1/A

333-256510

10.10

07/09/2021

10.15†

Master Services Agreement, dated March 14, 2019, between HCW Biologics Inc. and EirGenix, Inc.

S-1/A

333-256510

10.12

07/09/2021

10.16†#

Purchase and Sale Agreement, by and between HCW Biologics Inc. and Wai 3300 Corporate Way, LLC, dated May 27, 2022

10-Q

001-40591

10.1

08/12/2022

10.17#

Loan Agreement by and between HCW Biologics Inc. and Cogent Bank, dated August 15, 2022

10-Q

001-40591

10.1

11/07/2022

10.18#

Mortgage and Security Agreement by and between HCW Biologics Inc. and Cogent Bank, dated August 15, 2022

10-Q

001-40591

10.2

11/07/2022

10.19

Form of Subscription Agreement, dated February 20, 2024, by and between the Company and the Subscribers party thereto

8-K

001-40591

10.1

02/22/2024

10.20

Form of Amended and Restated Senior Secured Note Purchase Agreement, dated July 2, 2024, by and between the Company and the Purchase party thereto

10-Q

001-40591

10.1

08/14/2024

10.21

Form of Amended and Restated Pledge Agreement, dated July 2, 2024, by and among the Company, Escrow Agent and Noteholder parties thereto

10-Q

001-40591

10.3

08/14/2024

10.22

Form of Escrow Agreement, dated May 1, 2025, by and between the Company, Escrow Agent and Noteholder party thereto

10-Q

001-40591

10.4

08/14/2024

10.23

Form of First Amendment to Amended and Restated Secured Note Purchase Agreement, dated September 30, 2024, by and between the Company and Purchaser party thereto

10-Q

001-40591

10.5

11/14/2024

10.24

Form of Secured Promissory Note by and between the Company and the Holder party thereof

10-Q

001-40591

10.2

08/14/2024

10.25

Second Amendment to Amended and Restated Senior Secured Note Purchase Agreement and Related Agreements, dated May 1, 2025, between Company and Holder

10-Q

001-40591

10.12

08/18/2025

10.26

Equity Purchase Agreement, dated February 20, 2025, between the Company and Square Gate Master Fund - Series 4.

8-K

001-40591

10.1

2/21/2025

10.27

Registration Rights Agreement, dated February 20, 2025, between the Company and Square Gate Master Fund - Series 4

8-K

001-40591

10.2

2/21/2025

10.28

First Amendment to the Equity Purchase Agreement, dated August 14, 2025, between the Company and Square Gate Master Fund - Series 4.

8-K

001-40591

10.1

08/15/2025

II-2

Incorporated by reference

Filed or

furnished

herewith

Exhibit No.

Exhibit title

Form

File No.

Exhibit No.

Filing date

10.29

Amended and Restated Amended and Restated License, Research and Co-Development Agreement, dated November 17, 2025, between the Company and Beijing Trimmune Biotech Co., Ltd.

S-1

333-293396

10.40

02/11/2026

10.30†#

Amendment 1 to Amended and Restated License, Research and Co-Development Agreement, dated January 27, 2026, between the Company and Beijing Trimmune Biotech Co., Ltd.

S-1

333-293396

10.43

02/11/2026

10.31†#

Shareholder Purchase Agreement, dated October 10, 2025, between co-founders of Beijing Trimmune Biotech Co., Ltd., including the Company

S-1

333-293396

10.44

02/11/2026

10.32

Exclusive License Agreement 12-Month Suspension, dated May 29, 2025, between the Company and Wugen, Inc.

10-Q

001-40591

10.17

08/18/2025

10.33

Settlement Agreement and Release, dated July 13, 2024, by and between the Company and Altor BioScience, LLC, NantCell, Inc., and ImmunityBio, Inc.

10-Q

001-40591

10.6

11/14/2024

10.34

Placement Agency Agreement, dated February 17, 2026, between the Company and Maxim Group LLC

8-K

001-40591

10.1

02/19/2026

10.35

Form of Securities Purchase Agreement

8-K

001-40591

10.1

5/21/2026

10.36

Form of Registration Rights Agreement by and between the Company and the Investors

8-K

001-40591

10.2

5/21/2026

10.37

Form of Placement Agency Agreement, by and between the Company and E.F. Hutton & Co. LLC

8-K

001-40591

10.3

5/21/2026

10.38*

Form of Lock-Up Agreement

23.1*

Consent of Independent Registered Public Accounting Firm

23.2

Opinion of Clark Hill PLC (included in Exhibit 5.1)

101.INS

Inline XBRL Instance Document

101.SCH

Inline XBRL Taxonomy Extension Schema Document

101.CAL

Inline XBRL Taxonomy Extension Calculation Linkbase Document

101.DEF

Inline XBRL Taxonomy Extension Definition Linkbase Document

101.LAB

Inline XBRL Taxonomy Extension Label Linkbase Document

101.PRE

Inline XBRL Taxonomy Extension Presentation Linkbase Document

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

107*

Filing Fee Table

+ 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.

II-3

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.

	HCW BIOLOGICS INC.

	By:	/s/ Hing C. Wong
	Name:	Hing C. Wong
	Title:	Founder & Chief Executive Officer

Signature	Title	Date

* Scott T. Garrett	Chairman of the Board of Directors	June 18, 2026

* Rebecca Byam	Chief Financial Officer	June 18, 2026

* Hing C. Wong	Chief Executive Officer	June 18, 2026

* Rick S. Greene	Director	June 18, 2026

* Lisa M. Giles	Director	June 18, 2026

By:	/s/ Hing C. Wong
	Hing C. Wong, Attorney-in-Fact

II-4