Phase III trial of entinostat + exemestane in HER+, HER2- breast cancer fails to meet primary endpoint.- Syndax Pharmaceuticals, Inc.

Syndax Pharmaceuticals, Inc. announced receipt of the final results of E2112 the Phase III clinical trial conducted by ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) and sponsored by the National Cancer Institute (NCI), that evaluated the investigational compound entinostat, Syndax’s class I HDAC inhibitor, plus exemestane in patients with advanced hormone receptor positive, human epidermal growth factor receptor 2 negative (HR+, HER2-) breast cancer who have progressed on a non-steroidal aromatase inhibitor.

The trial did not achieve the primary endpoint of demonstrating a statistically significant overall survival (OS) benefit over hormone therapy alone . The E2112 trial was designed and conducted independently by ECOG-ACRIN under the sponsorship of the NCI, which is part of the National Institutes of Health. The double-blind, placebo-controlled trial randomized a total of 608 patients with HR+, HER2- advanced breast cancer to receive exemestane in combination with entinostat or placebo.