Syndax, Genentech pair up for clinical trial deal

WALTHAM, Mass.—Biopharmaceutical company Syndax Pharmaceuticals Inc. has announced the beginning of a clinical collaboration with Genentech, a member of the Roche Group, to determine the safety, tolerability and preliminary efficacy of Syndax's entinostat combined with Genentech's atezolizumab. The compounds will be tested in patients with triple-negative breast cancer.

Syndax will assume responsibility for conducting the Phase 1b/2 clinical trial, and under the agreement, there is a provision by which Genentech and Syndax can extend the collaboration to include a Phase 3 trial, as well as other trials in different indications of interest. No financial details were shared.

"Clinical development collaborations with industry leaders are an essential element of our strategy to realize the full potential of entinostat and position Syndax at the forefront of next-generation immuno-oncology therapy,” Dr. Briggs W. Morrison, CEO of Syndax, said in a press release. “This collaboration expands our emerging immuno-oncology program into an important new indication. We are looking forward to collaborating with Genentech to study atezolizumab and entinostat in a breast cancer population with few treatment options."

Entinostat is an oral small-molecule histone deacetylase inhibitor that targets immune regulatory cells (specifically, myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs)), and is being evaluated in non-small cell lung cancer (NSCLC), melanoma and advanced breast cancer. It received Breakthrough Therapy Designation from the U.S. Food and Drug Administration (FDA) in combination with hormone therapy in patients with advance hormone receptor-positive breast cancer. Atezolizumab (MPDL3280A) is a fully humanized monoclonal antibody that targets protein programmed cell death ligand 1 (PD-L1). In a recent Phase 2 study, atezolizumab met its primary endpoint and shrank tumors in patients with locally advanced or metastatic NSCLC presenting with PD-L1, an indication for which it was granted a Breakthrough Therapy Designation earlier this year from the FDA.

This is the second clinical trial collaboration for Syndax involving entinostat so far this year. The end of March saw the company announcing a deal with Merck & Co. Inc., known as MSD outside of the United States and Canada, to evaluate the safety and efficacy of combining entinostat with Merck's KEYTRUDA. The study, which is expected to begin enrolling patients in the second half of this year, will be a Phase 1b/2 study in patients with either advanced NSCLC or melanoma, with the Phase 1b portion to evaluate the safety and tolerability of the combination and the Phase 2 portion to evaluate the efficacy of entinostat together with KEYTRUDA in advanced NSCLC and melanoma patients. Merck and Syndax can elect to extend the collaboration to include a Phase 3 trial as well.