The possibility of a 2025 approval looks to be off the table for Actinium Pharmaceuticals Inc.’s Iomab-B, at least in the U.S. In a move that H.C. Wainwright analyst Joseph Pantginis dubbed “a major surprise,” the FDA has requested a head-to-head study demonstrating overall survival before it will consider approving the radiotherapy candidate for use in patients with active relapsed or refractory acute myeloid leukemia.