Participated · Series C · Aug 2015

Syndax Pharmaceuticals is focused on treating cancer and develops entinostat, an oral small‑molecule drug candidate with direct effects on both cancer cells and immune regulatory cells. Entinostat is intended to potentially enhance the body’s immune response across multiple cancer indications. The company’s initial clinical focus includes tumors that have shown sensitivity to immunotherapy, including lung cancer, melanoma and triple‑negative breast cancer. Entinostat is being evaluated in combination with Merck’s anti‑PD‑1 inhibitor KEYTRUDA (pembrolizumab) in a Phase 1b/2 trial for patients with advanced non‑small cell lung cancer or melanoma. It is also being evaluated in a pivotal Phase 3 trial in combination with Aromasin (exemestane) to treat advanced HR+ breast cancer. Syndax is led by CEO Briggs Morrison, M.D., and Chairman Dennis Podlesak and is based in Waltham, Massachusetts. The company closed an $80M Series C to support continued development of entinostat. Syndax is developing entinostat, an oral, weekly or bi-weekly selective histone deacetylase (HDAC) inhibitor intended to treat treatment-resistant cancers. Entinostat has been described in the S-1 as well-tolerated in clinical trials to date and acts on epigenetic regulation of gene expression. The drug received FDA breakthrough therapy designation based on Phase IIB data in metastatic breast cancer and the company began a Phase III trial in June, expected to complete by mid-2017. Syndax has several other Phase II and Phase I breast cancer trials ongoing and is also testing entinostat in lung cancer. The company is collaborating with the National Cancer Institute on development. Financially, Syndax recently raised about $5 million in debt financing and has refiled for an IPO to raise $60 million. Syndax Pharmaceuticals develops epigenetic-based combination therapies targeting treatment-resistant cancers. It holds worldwide rights to entinostat, an oral, highly selective histone deacetylase (HDAC) inhibitor in late-stage clinical development for advanced breast and lung cancers. The company plans to use the financing to advance its late-stage pipeline and to support activities preparing for an NDA-enabling Phase 3 study of entinostat in metastatic breast cancer. That Phase 3 study is being developed by the ECOG-ACRIN Cancer Research Group under sponsorship of the Division of Cancer Treatment and Diagnosis, National Cancer Institute (NCI). Led by CEO Arlene M. Morris, Syndax is pursuing registration-directed clinical work for entinostat. Founded in 2007 and based in Waltham, MA, the company has raised $81.6M to date. Syndax Pharmaceuticals is a Waltham, MA-based clinical-stage epigenetics oncology company formed in 2005. Its lead program is entinostat, a class I isoform selective HDAC inhibitor being developed for advanced and metastatic breast cancer. The company's intellectual property is based on work from scientific founder Ronald Evans, PhD, a professor at the Salk Institute and a Howard Hughes Medical Institute Investigator. Syndax issued $6m in convertible notes and warrants to its Series A investors in the reported financing. All existing Series A investors—Domain Associates, MPM Capital, Avalon Ventures, Forward Ventures, Pappas Ventures and MC Life Sciences—participated in the securities offering. The financing brings total investment to date to $55m and will be used to complete a randomized Phase 2 study of entinostat.