Percheron Therapeutics (ASX:PER) has announced final results from its Phase I clinical trial of HMBD-002, a novel immunotherapy targeting multiple forms of advanced cancer, showing a strong safety profile and early signs of clinical activity.
The international trial, conducted at six US centres under FDA oversight, enrolled 48 patients with advanced metastatic cancers, including pancreatic, bowel, breast, and lung tumours. Most participants had received four or more prior therapies before joining the study.
HMBD-002, an inhibitor of VISTA (v-domain immunoglobulin suppressor of T-cell activation), was tested both as a monotherapy and in combination with KEYTRUDA (pembrolizumab). The trial confirmed that the drug was well tolerated at doses up to 1,400 mg per week, with fewer than 10 per cent of patients experiencing serious treatment-related adverse events. Importantly, no cases of cytokine release syndrome were observed, and the study was unable to identify a maximum tolerated dose, underscoring its favourable safety profile.
Although the study’s primary focus was safety and dose determination rather than efficacy, several patients experienced encouraging disease stabilisation or tumour reduction. One 49-year-old woman with metastatic triple-negative breast cancer demonstrated a 27 per cent reduction in tumour size after five weeks of treatment with HMBD-002 and KEYTRUDA, approaching the threshold for partial response. Others, including patients with lung, liposarcoma, and head and neck cancers, achieved stable disease for significantly longer than expected, given their advanced condition.
Percheron Therapeutics CEO Dr James Garner described the outcome as a significant step forward for the company’s oncology program.
“These data are very encouraging as we look toward a phase II trial next year,” Dr Garner said. “The study confirms the excellent safety profile of HMBD-002, which has the potential to be best-in-class, and provides tantalising glimpses of possible efficacy. We’re immensely grateful to the clinicians and patients who made this work possible.”
The company plans to publish the whole Phase 1 dataset in a peer-reviewed scientific journal in 2026 and to launch a Phase II efficacy study in the same year. Details of the upcoming trial design will be released in the fourth quarter of 2025.
Initially developed by Hummingbird Bioscience and licensed to Percheron in mid-2025, HMBD-002 has shown preclinical activity across a range of tumour models. The molecule targets a novel immune checkpoint distinct from PD-1 and CTLA-4, offering a potential new mechanism to restore T-cell activity and overcome tumour resistance.
For patients with advanced cancers who have exhausted standard treatment options, the results from this first-in-human study represent a significant step forward in the search for safer, more durable immunotherapies.