Kronos Bio Doses First Patient with KB-0742 for Platinum-Resistant Ovarian Cancer

Kronos Bio, Inc. (Nasdaq: KRON), a biopharmaceutical company focused on developing small molecule treatments for cancers and other diseases driven by deregulated transcription, has initiated dosing the first patient in an expansion cohort with KB-0742. The dosing regimen consists of 80mg administered on a four-days-on, three-days-off schedule. This expansion cohort is specifically targeting patients with platinum-resistant high-grade serous ovarian cancer (HGSOC), a type of tumor that is particularly responsive to CDK9 inhibition due to MYC amplification or overexpression and deficiencies in homologous recombination (HRD+).

Kronos Bio has accumulated a safety database of over 100 patients for KB-0742, which has shown preliminary anti-tumor activity without causing grade 3 or 4 neutropenia at the 60mg dose on a three-days-on, four-days-off schedule. According to Norbert Bischofberger, Ph.D., president and chief executive officer of Kronos Bio, pharmacokinetic modeling indicates that the 80mg four-days-on, three-days-off schedule results in a 1.8-fold increase in the area under the curve (AUC) over seven days compared to the previous regimen. Dr. Bischofberger expressed optimism that this new dosing schedule will produce therapeutic responses in patients with high unmet needs. The company aims to provide an efficacy update on this cohort in the first half of 2025.

In the United States, there are approximately 22,000 new cases of ovarian cancer annually, with a five-year survival rate of less than 50%. Of these cases, about 85% exhibit MYC amplification or overexpression, and 50% are HRD+. Howard “Skip” A. Burris M.D., president of the Sarah Cannon Research Institute (SCRI), shared his enthusiasm for the focused expansion of KB-0742 in platinum-resistant HGSOC, noting that one of his patients experienced prolonged stable disease for over 300 days on this treatment. Dr. Burris emphasized the limited treatment options available for HGSOC patients who have progressed after platinum therapy and highlighted the potential of KB-0742 to offer new possibilities for these patients.

Kronos Bio, Inc. is a clinical-stage company committed to developing small molecule therapeutics targeting deregulated transcription, a key factor in many cancers and other diseases. Their proprietary discovery engine helps decode complex transcription factor regulatory networks to identify druggable cofactors. The company then screens and optimizes small molecules to target these cofactors in a tumor-specific context. This approach has led to a preclinical pipeline and the development of two drug candidates. KB-0742 is designed to inhibit CDK9 to address MYC deregulation in solid tumors, while KB-9558 targets p300 to address IRF4 dependence in multiple myeloma.

KB-0742 is a selective oral inhibitor of CDK9, a crucial cofactor in the activity of the oncogenic MYC transcription factor. The KB-0742-1001 study (NCT04718675) is a Phase 1/2 open-label trial exploring the dose escalation and cohort expansion of KB-0742 for treating MYC-amplified and other transcriptionally dependent relapsed or refractory solid tumors. This expansion cohort particularly focuses on patients with platinum-resistant high-grade serous ovarian cancer.

Kronos Bio has its headquarters in San Mateo, California, and a research facility in Cambridge, Massachusetts.