(Mark One)☒ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934For the fiscal year ended December 31, 2025OR☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934FOR THE TRANSITION PERIOD FROMTOCommission File Number 001-40591HCW Biologics Inc.(Exact name of registrant as specified in its Charter)Delaware82-5024477(State or other jurisdiction ofincorporation or organization)(I.R.S. EmployerIdentification No.)2929 N. Commerce ParkwayMiramar, Florida33025(Address of principal executive offices)(Zip Code)Registrant’s telephone number, including area code: (954) 842–2024Securities registered pursuant to Section 12(b) of the Act:Trading Common Stock, par value $0.0001 per share Securities registered pursuant to Section 12(g) of the Act:NoneIndicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. YES☐NO☒ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. YES☐NO☒ Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (orfor such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. YES☒NO☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). YES☒NO☐Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, 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 accountingstandards provided pursuant to Section 13(a) of the Exchange Act.☒Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). YES☐NO☒ The aggregate market value of the common stock held by non-affiliates of the registrant as of June 30, 2025, the last business day of the registrant’s most recently completed second fiscalquarter, was approximately $6.2 million based on the closing price of the shares of $3.9650 per share as reported on the Nasdaq Capital Market on such date. This calculation does not reflecta determination that certain persons are affiliates of the registrant for any other purpose. The number of shares of the registrant’s common stock outstanding as of March 25, 2026 is 6,734,104. DOCUMENTS INCORPORATED BY REFERENCEPart III incorporates by reference certain information from the registrant’s definitive proxy statement (the “Proxy Statement”) relating to its 2025 Annual Meeting of Stockholders. The Proxy Statement will be filed with the United States Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates. Table of Contents Part I Item 1BusinessItem 1ARisk FactorsItem 1BUnresolved Staff CommentsItem 1CCybersecurityItem 2PropertiesItem 3Legal ProceedingsItem 4Mine Safety Disclosures Part IIItem 5 Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of EquitySecurities76Item 6[Reserved]79Item 7Management’s Discussion and Analysis of Financial Condition and Results of Operations80Item 7AQuantitative and Qualitative Disclosures About Market Risk100Item 8Financial Statements and Supplementary Data101Item 9Changes in and Disagreements with Accountants on Accounting and Financial Disclosure141Item 9AControls and Procedures