Kronos Bio, Inc., a company dedicated to transforming the lives of those affected by cancer, announced U.S. Food and Drug Administration (FDA) clearance of the company’s Investigational New Drug (IND) application for KB-0742, a highly selective, orally bioavailable inhibitor of cyclin dependent kinase 9 (CDK9). The company plans to begin a Phase 1/2 clinical trial of KB-0742 in patients with advanced solid tumours in the first quarter of 2021.

“CDK9 is an important transcriptional co-factor of MYC, a well-known driver of cancer that is amplified in approximately 30 percent of solid tumours,” said Norbert Bischofberger, Ph.D., president and CEO. “FDA clearance of the IND for KB-0742 marks an important milestone for this program, which was generated using our proprietary drug discovery platform. In the next few months, we look forward to initiating a first-in-human clinical trial designed to define a dose and schedule which affords appropriate target engagement and acceptable safety, setting the stage for potential further development of this promising investigational therapy.”

The open-label, Phase 1/2 clinical trial for KB-0742 will be conducted over two stages: dose escalation and expansion. The dose-escalation stage will assess the safety, pharmacokinetic (PK) and pharmacodynamic (PD) profile of KB-0742 and seek to establish a pharmacologically active dose and schedule with an acceptable safety profile. This dose and schedule will be further studied in the subsequent expansion stage in patients with MYC-amplified solid tumors and other transcriptionally addicted rare tumours such as sarcomas and chordomas. Kronos Bio expects to report initial safety, PK and PD data from the dose-escalation stage of the study in 2021.

KB-0742 is a highly selective, orally bioavailable inhibitor of cyclin dependent kinase 9 (CDK9) in development for the treatment of MYC-amplified solid tumours. CDK9 is a global regulator of transcription and plays an essential role in the expression and function of MYC, a well-characterized transcription factor and a long-recognized driver of cancer that is amplified in approximately 30 per cent of solid tumours, including those affecting the lungs, ovaries, esophagus, breast, stomach, pancreas and liver. KB-0742 was generated and optimized from a compound that was identified using the company’s proprietary small molecule microarray (SMM) screening platform.