Syndax Announces Initiation Of Entinostat Clinical Program In Japan By Partner Kyowa Hakko Kirin

December 1, 2015

WALTHAM, Mass., Dec. 1, 2015 /PRNewswire/ -- Syndax Pharmaceuticals, Inc., a clinical stage biopharmaceutical company focused on developing entinostat as a combination therapy in multiple cancer indications, announced today the initiation of the entinostat clinical program in Japan by its partner Kyowa Hakko Kirin, Co., Ltd. Entinostat, an oral, small molecule drug candidate that targets both cancer cells and immune regulatory cells, is being developed by Syndax as an immuno-oncology therapeutic and evaluated as a treatment for advanced hormone receptor positive (HR+) breast cancer in an ongoing Phase 3 clinical trial (designated E2112) in the United States. In September 2013, entinostat was granted breakthrough therapy designation by the U.S. Food and Drug Administration in advanced HR+ breast cancer following positive results from the Phase 2b clinical trial, ENCORE-301.

"In addition to the entinostat immuno-oncology combination regimens entering clinical development in the U.S., we are pleased to see continued clinical progress for entinostat in advanced breast cancer both in the U.S. and Japan," said Briggs Morrison, M.D., Chief Executive Officer of Syndax. "We view this milestone as an important step towards potentially providing new treatment options to breast cancer patients globally and look forward to continuing our collaboration with our valued partner Kyowa Hakko Kirin."

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. Kyowa Hakko Kirin has now dosed the first patient in Japan in a Phase 1 clinical trial investigating the safety of entinostat (designated KHK2375 by Kyowa Hakko Kirin) as a monotherapy and in combination with exemestane in advanced or metastatic HR+ breast cancer patients previously treated with a nonsteroidal aromatase inhibitor. Secondary endpoints include pharmacokinetic parameters and preliminary efficacy.

About Syndax Pharmaceuticals, Inc.
Syndax is a clinical stage biopharmaceutical company developing entinostat as a combination therapy in multiple cancer indications with an initial focus on tumors that have shown sensitivity to immunotherapy, including lung cancer, melanoma and triple-negative breast cancer (TNBC). Entinostat is an oral, small molecule drug candidate that has direct effects on both cancer cells and immune regulatory cells, potentially enhancing the body's immune response to tumors. Entinostat is being evaluated as a combination therapeutic in Phase 1b/2 clinical trials with Merck & Co., Inc. for non-small cell lung cancer and melanoma and with Genentech, Inc. for TNBC, as well as a Phase 3 clinical trial with ECOG-ACRIN for advanced hormone receptor positive breast cancer. For more information on Syndax please visit

About Kyowa Hakko Kirin
Kyowa Hakko Kirin is a leading biopharmaceutical company in Japan focusing on its core business area of oncology, nephrology and immunology/allergy. Kyowa Hakko Kirin leverages antibody-related leading-edge technologies to discover and develop innovative new drugs aiming to become a global specialty pharmaceutical company which contributes to the health and well-being of people around the world. For more information, visit

Syndax's Cautionary Note on Forward-Looking Statements
This press release contains forward-looking statements. Forward-looking statements contained in this press release include, without limitation, statements regarding Syndax's expectations regarding the clinical progress of entinostat in and the potential for new treatments for advanced breast cancer. Words such as "may," "believe," "will," "expect," "plan," "anticipate," "estimate," "intend" and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are not guarantees of future performance and involve a number of unknown risks, assumptions, uncertainties and factors that are beyond Syndax's control. All forward-looking statements are based on Syndax's expectations and assumptions as of the date of this press release. Actual results may differ materially from these forward-looking statements. Except as required by law, Syndax expressly disclaims any responsibility to update any forward-looking statements contained herein, whether as a result of new information, future events or otherwise.

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