Investigator Sponsor of HCW Biologics’ Phase 1 Clinical Trial Presented Human Data Readout and Anti-Cancer Mechanism of Action of HCW9218 at 38th SITC Annual Meeting

Showed HCW9218 clinical safety and tumor response endpoints
for 15 patients with heavily pretreated advanced solid tumors

Results in ovarian cancer patients outpace other indications, with 66% stable disease

MIRAMAR, Fla., Nov. 08, 2023 (GLOBE NEWSWIRE) -- HCW Biologics Inc. (the “Company” or “HCW Biologics”) (NASDAQ: HCWB), a clinical-stage biopharmaceutical company focused on discovering and developing novel immunotherapies to lengthen healthspan by disrupting the link between inflammation and age-related diseases, announced results from a preliminary human data readout from an ongoing Phase 1 clinical trial sponsored by the University of Minnesota to evaluate HCW9218, the lead drug candidate of HCW Biologics, in patients with solid tumors who failed at least two prior lines of therapy. Data from this study was presented at the 38^th Annual Meeting of the Society for Immunotherapy of Cancer (“SITC”) by Melissa A. Geller, M.D., M.S., Professor and Division Director of Gynecologic Oncology in the Department of Obstetrics, Gynecology and Women’s Health at the University of Minnesota who serves as a Principal Investigator of this trial.

This clinical readout was based on 15 patients who were enrolled in the study as of October 16, 2023, all of whom were patients whose disease had previously progressed after multiple lines of standard-of-care therapy. The trial is now in its final expanded dose level, and the Company expects it to be completed in the fourth quarter of 2023. There has been one dose-limiting toxicity experience in this study, but it did not trigger stopping rules. Highlights of data presented at SITC include:

• HCW9218 was administered subcutaneously once every three weeks for up to six cycles at dose levels 0.25 mg/kg (DL1), 0.5 mg/kg (DL2), 0.8 mg/kg (DL3) or 1.2 mg/kg (DL4). The median number of cycles was three.
  
  
• 87% (13/15) had >4 lines of prior therapy. Tumor types included: Ovarian (n=6), Colorectal (n=4), Rectal (n=3), and Liver (n=2).
  
  
• 53% (8/15) patients treated with HCW9218 were evaluated in a post-treatment assessment, including biopsies and scanning. Tumor types included: Ovarian (n=3), Colorectal (n=3), Rectal (n= 1) and Liver (n=1).
  
  
• 50% (4/8) patients evaluated in post-treatment assessments exhibited stable disease following HCW9218 treatment. Patients showed stable disease lasting over 6 months. Clinical benefit was observed from DL2, DL3 and DL4.
  
  
• 66% (2/3) patients with ovarian cancer who underwent post-treatment assessments showed stable disease.
  
  
• Analysis of patients’ pre- and post-treatment blood and tumor biopsy specimens revealed that HCW9218 induced National Killer (“NK”) cell and CD8⁺ T cell activation, proliferation, and infiltration into the tumor microenvironment which correlated with disease stabilization.