Demonstrating its deep interest in the future of rare diseases, Pfizer ($PFE) has signed on to partner with Gaithersburg, MD-based GlycoMimetics on its lead drug program for sickle cell disease, promising up to $340 million in a broad array of milestones and an unspecified upfront payment. The partnership will bring in Pfizer on the development of GMI-1070, an inflammation inhibitor that researchers have been studying in a Phase II trial for the painful vaso-occlusive crises that threaten the organs of sickle cell patients.