CAMBRIDGE, Mass.--(BUSINESS WIRE)--Xanthus Pharmaceuticals, Inc., today announced that it has reached an agreement with the U.S. Food and Drug Administration (FDA) under the FDA’s Special Protocol Assessment (SPA) process for the design of its planned Phase 3 registration trial of Xanafide® (amonafide malate) for the treatment of patients with secondary acute myeloid leukemia (sAML). Under the SPA agreement with the FDA, a statistically significant, positive result for the Phase 3 trial would support an efficacy claim for Xanafide in secondary AML in a New Drug Application (NDA).