1010P - Phase I dose-escalation study of HBM1020: A novel anti-B7H7 antibody in patients with advanced solid tumors

Background

B7H7, a novel immune checkpoint, is a promising target in solid tumors due to its overexpression and correlation with poor prognosis. HBM1020 is a first-in-class anti-B7H7 antibody designed to augment T cell anti-tumor response.

Methods

This objective of this phase 1 study is to assess the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of HBM1020 in patients (pts) with advanced solid tumors. In Part 1 (dose escalation), HBM1020 was administered at dose levels between 0.3mg/kg and 30mg/kg every 3 weeks (Q3W) by intravenous infusion. Enrollment is ongoing in Part 2 (dose expansion).

Results

As of 01-April-2024, 17 pts with have received HBM1020 from 0.3mg/kg to 30 mg/kg Q3W. Median age was 62 years (34-80). All pts completed dose limiting toxicity (DLT) observation periods (21 days) and no DLT events were observed and MTD has not yet been reached. A total of 6 (35.3%) pts had a treatment related adverse event (TRAE) and all TRAEs were Grade 1-2. Eleven (64.7%) pts had reported serious adverse events (SAEs) and all SAEs were deemed unrelated to study treatment by both investigator and study sponsor. Nine (9) pts had post baseline tumor evaluation, and 6 out of 9 (66.7%) pts had stable disease (SD) as best response (including 1 pt with SD, tumor shrinkage of 25%). PK analysis of HBM1020 demonstrated a typical IgG behavior with elimination half-life of ∼two weeks in the dose range of 3 to 20 mg/kg. Drug exposure increased in a nearly dose-proportional manner. The expression of B7H7 was assessed by validated immunohistochemistry (IHC) assay for patients with available archived samples.

Conclusions

HBM1020, as a first-in-class anti-B7H7 antibody, demonstrated promising safety and tolerability profiles in patients with advanced solid tumors. Further studies are warranted to explore the therapeutic potential of HBM1020 in solid tumors.

Clinical trial identification

NCT05824663.

Editorial acknowledgement

Legal entity responsible for the study

Harbour Biomed US.

Funding

Harbour Biomed US.

Disclosure

X. Tao: Financial Interests, Personal, Full or part-time Employment: Harbour Biomed Ltd; Financial Interests, Personal, Stocks/Shares: Harbour Biomed Ltd. All authors have declared no conflicts of interest.