Syndax Pharmaceuticals, a clinical stage biopharmaceutical company developing entinostat and SNDX-6352 in multiple cancer indications, 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. The trial will be conducted as part of MORPHEUS, Roche's novel cancer immunotherapy development platform. MORPHEUS is a phase Ib/II adaptive platform to develop combinations of cancer immunotherapies more rapidly and efficiently.

"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."

In August 2015, Syndax announced a separate collaboration with Genentech for ENCORE 602, a Phase Ib/II trial to examine the safety, tolerability and clinical activity of entinostat in combination with TECENTRIQ in triple-negative breast cancer. ENCORE 602 is expected to complete enrollment in the phase II portion of the trial in the first half of 2018.