Horizon Quantum Computing to Establish First-of-a-Kind…

WALTHAM, Mass., August 24, 2015 – Syndax Pharmaceuticals, Inc., a clinical stage biopharmaceutical company developing entinostat as a combination therapy in multiple cancer
indications, announced today that it has completed an $80 million Series C financing. The financing was led by Fidelity Management & Research Company and Delos Capital Fund LP
with participation from EcoR1 Capital, OrbiMed, Jennison Associates (on behalf of certain clients), Tavistock Life Sciences, Arrowpoint Partners, Cormorant Asset Management, BioMed
Ventures and undisclosed top-tier mutual funds, as well as existing investors Domain Associates, MPM Capital, RusnanoMedInvest (RMI) and Forward Ventures.