About CUDC-427 (previously referred to as GDC-0917)CUDC-427 is an oral, synthetic, small molecule that triggers tumor cell apoptosis by selectively antagonizing inhibitor of apoptosis (IAP) proteins, which are frequently over-expressed in cancer cells. CUDC-427 was designed to mimic the endogenous IAP antagonist, second mitochondria-derived activator of caspases/direct IAP-binding protein (Smac/DIABLO) that is released into the cytoplasm in response to pro-apoptotic stimuli and binds to the IAPs. CUDC-427 has demonstrated single-agent and combination therapy anti-tumor activity in mouse xenograft tumor models when administered orally. IND-enabling safety studies have shown CUDC-427 to be well tolerated when dosed daily by oral administration, potentially enabling sustained target inhibition. In a single-agent Phase 1 clinical trial in patients with advanced malignancies, CUDC-427 demonstrated a favorable safety profile and exhibited anti-tumor activity in some patients when it was administered at once daily dosing regimen with 14 days "on" and 7 days "off" for a 21-day cycle. CUDC-427 was exclusively licensed from Genentech in November 2012. About Curis, Inc. Curis is an oncology-focused drug development company seeking to develop novel drug candidates for the treatment of human cancers. Erivedge is the first and only FDA-approved medicine for the treatment of advanced basal cell carcinoma and is being commercialized and developed by Roche and Genentech, a member of the Roche Group, under a collaboration agreement between Curis and Genentech. Curis is also seeking to further the development of its pipeline of proprietary targeted cancer drug candidates, including CUDC-427, a small molecule antagonist of IAP proteins, and CUDC-907, a dual PI3K and HDAC inhibitor. For more information, visit Curis' website at www.curis.com . Cautionary Statement This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including without limitation statements regarding Curis' expectations for the timing of conducting additional clinical studies with CUDC-427 as well as the potential benefits and safety of this drug candidate. Forward-looking statements used in this press release may contain the words "believes," "expects," "anticipates," "plans," "seeks," "estimates," "assumes," "will," "may," "could" or similar expressions. These forward-looking statements are not guarantees of future performance and involve risks, uncertainties, assumptions and other important factors that may cause actual results to be materially different from those indicated by such forward-looking statements. For example, Curis and its collaborators may experience adverse results, delays and/or failures in their drug development programs. Curis' drug candidates, including CUDC-427, are unproven and may cause unexpected toxicities and/or fail to demonstrate sufficient safety and efficacy in clinical trials and may never achieve the requisite regulatory approval needed for commercialization. Curis will require substantial additional capital to fund the research and development of its drug development programs, and such capital may be difficult to obtain. Curis may not obtain or maintain necessary patent protection for its programs and could become involved in expensive and time consuming patent litigation and interference proceedings. Curis faces substantial competition from other companies developing cancer therapeutics. Unstable market and economic conditions may adversely affect Curis' financial conditions and its ability to access capital to fund the growth of its business. Curis also faces other important risks relating to its business, operations, financial condition and future prospects that are discussed in its Quarterly Report on Form 10-Q for the quarter ended March 31, 2013 and other filings that it periodically makes with the Securities and Exchange Commission.