SIRPA and acute myeloid leukemia: In a recent phase 1b clinical trial including 87 previously untreated AML patients, the median OS was 9.8 months for TP53-mutant patients and 18.9 months for wild-type patients.1046 TTI-621, a fully human recombinant protein that blocks the CD47-SIRPα axis, has enhanced macrophage-mediated phagocytosis of tumor cells in aggressive AML and B-cell lymphoma.