A Mutation Spectrum-Selective, Oral, Irreversible TKI

BDTX-189 is designed to be an orally available, irreversible small molecule inhibitor that targets undrugged oncogenic driver mutations of the EGFR and HER2 kinases.

These include extracellular domain allosteric mutations of HER2, as well as EGFR and HER2 kinase domain exon 20 insertions, and additional activating oncogenic drivers of EGFR/HER2. The EGFR/HER2 receptors are a group of receptor tyrosine kinases involved in key cellular functions, including cell growth and survival. These mutations are prevalent across a range of tumor types and cancers including in bladder, breast, colon, endometrial, gastric, and non-small cell lung cancer.

Currently, there are no medicines approved by the U.S. Food and Drug Administration (FDA) to target all of these oncogenic mutations with a single therapy. Black Diamond is enrolling and dosing patients in the MasterKey-01 Phase 1/2 clinical trial. The Phase 1 portion of the trial is evaluating escalating doses of BDTX-189 and is designed to determine the recommended Phase 2 dose and schedule. The Phase 2 portion will determine the objective response rate (ORR) and duration of response in patients with solid tumors that have an allosteric HER2 mutation or EGFR or HER2 exon 20 insertion mutation using next-generation sequencing (NGS).

Initial Phase 1 clinical data support proof-of-concept of BDTX-189: