Syndax Pharmaceuticals, Inc. (Nasdaq: SNDX), a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies, today announced that it plans to offer and sell, subject to market and other conditions, shares of its common stock in an underwritten public offering. There can be no assurance as to whether or when the offering may be completed, or the actual size or terms of the offering. Syndax also expects to grant the underwriters a 30-day option to purchase up to an additional 15% of the number of shares sold in the public offering. All of the shares in the proposed offering are to be sold by Syndax.

Goldman Sachs & Co. LLC, Citigroup and Cowen are acting as joint book-running managers for the offering. BTIG is acting as lead manager for the offering. Baird is acting as co-manager for the offering.

About Syndax Pharmaceuticals, Inc.

Syndax Pharmaceuticals is a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies. The Company's pipeline includes SNDX-5613, a highly selective inhibitor of the Menin–MLL binding interaction, axatilimab, a monoclonal antibody that blocks the colony stimulating factor 1 (CSF-1) receptor, and entinostat, a class I HDAC inhibitor.