SUNESIS LAUNCHES TRIAL OF DRUG FOR B-CELL MALIGNANCIES

Sunesis Pharmaceuticals has begun dosing in a Phase I clinical trial of SNS-032 in patients with advanced B-cell malignancies. SNS-032, a novel, selective and potent small-molecule inhibitor of cyclin-dependent kinases (CDK) 2, 7 and 9, has been shown in preclinical and clinical studies to deplete cells of myeloid cell leukemia sequence 1 (MCL-1), a protein associated with cell survival, particularly in lymphomas and other B-lymphoid malignancies.

This Phase I trial is designed to examine the safety and tolerability, as well as the preliminary antitumor activity, of SNS-032 in patients with B-cell malignancies. The trial is a dose-escalation study to establish a maximum-tolerated dose in this setting. The clinical trial will enroll approximately 40 patients at three centers in the U.S. Sunesis hopes to obtain initial safety results from this study by the end of the year.

CDKs 2, 7 and 9 are critical in the communication and relay of signals to promote cellular growth and function, according to Sunesis. CDK2 is involved in cellular proliferation by regulating the initiation of and progression through the DNA-synthesis phase of the cell cycle. CDK7 and CDK9 are involved in transcriptional regulation of certain proteins involved in cell survival. Inappropriate activity by these CDKs can lead to unregulated proliferation, avoidance of apoptosis and increased cell survival, all of which are hallmarks of cancer. By selectively targeting these CDKs, SNS-032 may halt both aberrant cell proliferation and induce apoptosis.