Genocea Biosciences Inc., of Cambridge, Mass., announced a research collaboration with Checkmate Pharmaceuticals Inc., also of Cambridge, to characterize the T cell responses of patients in the ongoing Checkmate phase Ib clinical trial and to identify antigens associated with protective T cell responses. Atlas, Genocea's rapid antigen identification screening system, will be used to profile the T cell responses of approximately 20 patients enrolled in Checkmate's ongoing phase Ib clinical trial of CMP-001 in combination with the checkpoint inhibitor pembrolizumab to a library of tumor-associated antigens common to patients with advanced melanoma.