Syndax Pharmaceuticals announced a new clinical collaboration with Genentech, a member of the Roche Group. As part of the collaboration, the two companies will evaluate the combination of Syndax’s entinostat, an oral, small molecule, class I HDAC inhibitor, and Genentech’s programmed cell death ligand 1 (PD-L1) blocking antibody, atezolizumab (TECENTRIQ), in patients with second-line hormone receptor positive, human epidermal growth factor receptor 2 negative (HR+, HER2-) metastatic breast cancer.

The planned Phase Ib/II, open-label, multicenter, randomized trial will enroll patients with metastatic HR+, HER2- breast cancer who have experienced disease progression during or following first-line therapy. Genentech will be responsible for conducting the trial. 

“This collaboration represents further validation of the ongoing interest to test the potential ability of Syndax’s entinostat to enhance the effectiveness of an immuno-oncology therapy in an area of unmet medical need,” said Briggs W. Morrison, M.D., chief executive officer of Syndax. “While checkpoint inhibitors have shown initial promise in triple-negative breast cancer, there is a clear need to augment the effectiveness of such therapies in the setting of HR+, HER2- breast cancer.”