HCW Biologics announces results from ongoing Phase 1 trial of HCW9218

HCW Biologics 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 38th Annual Meeting of the Society for Immunotherapy of Cancer, SITC. 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, 0.5 mg/kg, 0.8 mg/kg or 1.2 mg/kg. The median number of cycles was three. 87% had greater than4 lines of prior therapy. 53% patients treated with HCW9218 were evaluated in a post-treatment assessment, including biopsies and scanning. 50% 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% 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 cell and CD8+ T cell activation, proliferation, and infiltration into the tumor microenvironment which correlated with disease stabilization. Repeated HCW9218 administration at up to the highest planned dose level was well tolerated by patients with chemotherapy-refractory advanced solid tumors, which has provided support for the Recommended Phase 2 Dose level for future Phase 2 studies of HCW9218. HCW9218 significantly reduced blood levels of TGF-beta in cancer patients in a dose-dependent manner, without causing treatment-emergent skin lesions and bleeding events previously reported with TGF-beta antagonists in clinic. HCW9218 strongly promotes proliferation and activation of NK and T cells in patients’ blood after dosing without causing cytokine release syndrome. No liver enzyme elevation was observed. HCW9218 also showed a substantial increase in blood NK cell counts three weeks after a single dosing.