GlycoMimetics, Inc. (NASDAQ: GLYC) today announced that data showing enhanced effectiveness of an antibody antagonist to a key cancer regulatory ligand, PD-L1, in combination with its drug candidate GMI-1359 will be presented at the Society for Immunotherapy of Cancer (SITC) Annual Meeting & Associated Programs. The SITC meeting will take place November 9 to 13 in National Harbor, Maryland. The poster presentation reviews the results of pre-clinical research on the company's dual E-selectin/CXCR4 antagonist GMI-1359. The data presented will show that GMI-1359 in combination with an antibody against the cancer regulatory programmed death receptor ligand, PD-L1, shortened time to complete tumor regressions in an animal model of colon cancer. The combination therapy also selectively reduced regulatory T cells (a class of lymphocytes that suppress immune responses) in the tumor, and created a more favorable immune-mediated anti-tumor environment. "We are very pleased to announce these results, which show the possible synergy between GMI-1359 and PD-L1 antagonists to treat solid tumors. This is encouraging given PD-L1's key role in inhibiting the immune response and allowing tumor growth," said John Magnani, Vice President and Chief Scientific Officer of GlycoMimetics and co-author of the poster. "The new preclinical data show the scientific rationale for continuing clinical testing of GMI-1359." GMI-1359 is now in a Phase 1 clinical trial. Previous research on GMI-1359 has been shared at annual meetings of the American Association for Cancer Research and the American Society of Hematology. Details of the poster at SITC, including session time and location, are below: Poster (All poster sessions are in the Prince George's Exhibition Hall in the Gaylord Convention Center.) Abstract 209—Combination of a glycomimetic antagonist to E-selectin and CXCR4, GMI-1359, with an anti-PD-L1 antibody attenuates regulatory T cell infiltration and accelerates time to complete response in the murine CT26 tumor model. Friday, Nov. 11, from 12:00-8:00 p.m. The meeting abstracts are available at SITC's website. About GlycoMimetics, Inc. GlycoMimetics is a clinical-stage biotechnology company focused on cancer and sickle cell disease. GlycoMimetics' most advanced drug candidate, rivipansel, a pan-selectin antagonist, is being developed for the treatment of vaso-occlusive crisis in sickle cell disease and is being evaluated in a Phase 3 clinical trial being conducted by its strategic collaborator, Pfizer. GlycoMimetics' wholly-owned drug candidate, GMI-1271, an E-selectin antagonist, is being evaluated in an ongoing Phase 1/2 clinical trial as a potential treatment for AML and in a Phase 1 clinical trial in multiple myeloma. GlycoMimetics has also recently initiated a clinical trial with a third drug candidate, GMI-1359, a combined CXCR4 and E-selectin antagonist. GlycoMimetics is located in Rockville, MD in the BioHealth Capital Region. Learn more at www.glycomimetics.com. Forward-Looking Statements This press release contains forward-looking statements regarding GlycoMimetics' planned activities with respect to the clinical development of its drug candidate GMI-1359. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the availability and timing of data from ongoing clinical trials, the uncertainties inherent in the initiation of future clinical trials, whether interim results from a clinical trial will be predictive of the final results of the trial or results of early clinical trials will be indicative of the results of future trials, expectations for regulatory approvals, availability of funding sufficient for GlycoMimetics' foreseeable and unforeseeable operating expenses and capital expenditure requirements, other matters that could affect the availability or commercial potential of GlycoMimetics' drug candidates and other factors discussed in the "Risk Factors" section of GlycoMimetics' Annual Report on Form 10-K that was filed with the U.S. Securities and Exchange Commission on February 29, 2016, and other filings GlycoMimetics makes with the Securities and Exchange Commission from time to time. In addition, the forward-looking statements included in this press release represent GlycoMimetics' views as of the date hereof. GlycoMimetics anticipates that subsequent events and developments may cause its views to change. However, while GlycoMimetics may elect to update these forward-looking statements at some point in the future, GlycoMimetics specifically disclaims any obligation to do so, except as may be required by law. These forward-looking statements should not be relied upon as representing GlycoMimetics' views as of any date subsequent to the date hereof.