Syndax Announces Presentation of Entinostat Data in Two Posters at the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting

WALTHAM, Mass. - May 27, 2014 - Syndax Pharmaceuticals, Inc., today announced that clinical trial data on entinostat will be presented in two posters during the 50th Annual Meeting of the American Society of Clinical Oncology (ASCO) being held May 30 - June 3, 2014, in Chicago.

The first poster, titled "Phase 2 study investigating the safety, efficacy, and surrogate biomarkers of response to 5-azacitidine (5-AZA) and entinostat in advanced breast cancer," is being presented by Roisin M. Connolly, M.D, assistant professor of oncology at the Kimmel Comprehensive Cancer Center at Johns Hopkins University. The second, being presented by Denise A. Yardley, M.D, an oncologist at the Sarah Cannon Research Institute, is titled "A phase 1 study to assess the food effect on the pharmacokinetics (PK) of entinostat."

Presentations are as follows:

Abstract #:     569
Title:                Phase 2 study investigating the safety, efficacy, and surrogate biomarkers of response to 5-azacitidine (5-AZA) and entinostat in advanced breast cancer
Presenter:       Roisin M. Connolly, M.D.
When:              Monday, June 2, 8:00 a.m.-11:45 a.m. CDT
Session Title:   Breast Cancer - HER2/ER
Location:         S Hall A2, Board 33

Abstract #:     591
Title:                A phase 1 study to assess the food effect on the pharmacokinetics (PK) of entinostat
Presenter:       Denise A. Yardley, M.D.
When:              Monday, June 2, 8:00 a.m.-11:45 a.m. CDT
Session Title:   Breast Cancer - HER2/ER
Location:         S Hall A2, Board 55

About Syndax Pharmaceuticals
Syndax is developing entinostat for the treatment of patients with therapy-resistant cancers. Entinostat is designed to prolong the effectiveness of current cancer treatments through an epigenetic mechanism and has been designated a Breakthrough Therapy by the FDA when used in combination with exemestane in estrogen receptor positive metastatic breast cancer. Entinostat is an oral, selective HDAC inhibitor that is being evaluated in combination with exemestane in a pivotal Phase 3 clinical study for the treatment of hormone receptor positive metastatic breast cancer. Syndax holds rights to entinostat in all major markets.

Corporate Contact:
Bob Goodenow
Chief Business Officer
Syndax Pharmaceuticals
(781) 419-1418
BGoodenow@Syndax.com

Investor Contact:
Robert Flamm, Ph.D.
Russo Partners
(212) 845-4226
robert.flamm@russopartnersllc.com

Media Contacts:
David Schull or Matt Middleman, M.D.
Russo Partners
(212) 845-4271
(212) 845-4272
david.schull@russopartnersllc.com
matt.middleman@russopartnersllc.com