SEATTLEPreliminary phase II data show that CMA-676, an
engineered human anti-CD33 antibody linked to calicheamicin, a potent
cytotoxic agent, produced an objective response in 10 of 23 patients
(43%) with acute myelogenous leukemia in first relapse after initial
chemotherapy. Six responders went on to allogeneic bone marrow transplant.
The side effects are mild compared to standard
chemotherapy, Eric Sievers, MD, of Fred Hutchinson Cancer
Research Center, said at ASH. The antibody was given as a single
agent intravenously at a dose of 9 mg/m² every 2 weeks for two
doses. The agent, from Wyeth-Ayerst Research (Radnor, PA), is being
tested at 13 leading US leukemia centers.