Kronos Bio reports ‘positive’ preliminary data from Phase 1/2 KB-0742 study

Kronos Bio announced “positive” preliminary data from the Phase 1 dose escalation portion of the ongoing Phase 1/2 clinical trial of KB-0742 at the AACR-NCI-EORTC International Conference in Boston, Mass. KB-0742 is the company’s internally discovered, highly selective, orally bioavailable cyclin dependent kinase 9, or CDK9, inhibitor being developed to treat transcriptionally addicted solid tumors. These tumors include transcription factor fusion driven cancers such as sarcomas, as well as MYC-dependent tumors, such as triple negative breast, ovarian, and lung cancer. The preliminary analysis included 28 patients enrolled in a dose escalation study who received doses from 10 mg up to 60 mg, with data cut-off September 1, 2023. KB-0742 demonstrated on-mechanism single agent anti-tumor activity in heavily pre-treated patients with transcriptionally addicted tumor types and exhibited a manageable safety profile, with no grade 3/4 neutropenia observed. KB-0742 also demonstrated dose proportional exposure and target engagement and a 24-hour plasma half-life, enabling intermittent dosing. “These positive preliminary efficacy and safety data underscore the promise of KB-0742 to treat patients with transcriptionally addicted tumors. The observed anti-tumor activity and absence of grade 3/4 neutropenia are particularly encouraging as we continue to enroll patients and explore a maximum tolerated dose. We look forward to advancing the study and reporting additional results, including data from the dose expansion portion of the study, mid next year,” said Jorge DiMartino, M.D., Ph.D., Chief Medical Officer and Executive Vice President, Clinical Development.