On October 5, 2017 Syndax Pharmaceuticals, Inc. (“Syndax,” the “Company” or “we”) (Nasdaq: SNDX), a clinical stage biopharmaceutical company developing entinostat and SNDX-6352 in multiple cancer indications, reported that Kyowa Hakko Kirin Co., Ltd (Kyowa Hakko Kirin), its Japan and Korea sublicensee, has now dosed the first patient in a randomized, double-blind, placebo-controlled, pivotal Phase 2 trial of entinostat (designated KHK2375 by Kyowa Hakko Kirin), Syndax’s oral Class-I histone deacetylase inhibitor, in combination with exemestane versus exemestane plus placebo in Japanese patients with advanced or recurrent hormone receptor-positive (HR+), human epidermal growth factor receptor two-negative (HER2-) breast cancer (Press release, Syndax, OCT 5, 2017, View Source [SID1234520800]). Enrollment of the first patient in this trial triggers a $5 million milestone payment to Syndax from Kyowa Hakko Kirin.

“Dosing of the first patient in this pivotal trial marks another important milestone in the entinostat development program,” said Briggs W. Morrison, M.D., Chief Executive Officer of Syndax. “We are nearing completion of enrollment of our Phase 3 trial, E2112, comparing entinostat plus exemestane to exemestane monotherapy in advanced HR+, HER2- breast cancer. We currently anticipate completion of enrollment in this Phase 3 trial, and release of the progression free survival analysis to be available in the first half of 2018. Through our partnership with Kyowa Hakko Kirin, we are also working to make this promising breast cancer therapy available to patients globally.”

The Phase 2 trial is expected to enroll approximately 124 patients in Japan. The primary endpoint of the trial will be progression free survival, with secondary endpoints including overall survival, overall response rate, and safety.

In January 2015, Syndax announced completion of a license agreement with Kyowa Hakko Kirin for the exclusive rights to develop and commercialize entinostat in Japan and Korea.