NEW YORK – Hutchmed said on Wednesday that it has begun a US-based Phase Ib/II study of fits VEGFR inhibitor fruquintinib combined with BeiGene's PD-1 inhibitor tislelizumab for patients with advanced triple-negative breast cancer (TNBC) or endometrial cancer.
Specifically, Hong Kong-based Hutchmed and Beijing-based BeiGene will evaluate the combination in a two-part trial. During the first part, the firms will assess the safety, tolerability, and recommended Phase II dose of fruquintinib and tislelizumab, and in the second part they will evaluate patients' objective response rates among multiple cohorts. One cohort will consist of TNBC patients who have been previously treated with an immune checkpoint inhibitor and one cohort will consist of patients who have not. The firm anticipates opening a third cohort in the third quarter of this year evaluating the combination as a second-line treatment for endometrial cancer patients.
Additionally, the trial will collect fresh or archival tumor tissue samples from enrolled patients to conduct a retrospective biomarker analysis. The firm plans to measure patients' PD-L1 expression levels as well as other exploratory biomarkers that may play into their response or resistance to the therapy.
Hutchmed's VEGFR inhibitor fruquintinib is believed to improve BeiGene's immune checkpoint inhibitor's activity while minimizing toxicities. The firm owns rights to the agent outside of China but shares development and marketing rights for the agent with Eli Lilly in China.