Abstract: The present invention is directed to stable aqueous pharmaceutical formulations that comprise a bispecific monovalent diabody (“Diabody formulation”), and to aqueous stabilizer solutions for stabilizing and administering said diabody. The invention particularly concerns such pharmaceutical formulations that comprise a diabody drug product (DART-A DP formulations) that comprise a sequence-optimized CD 123×CDS bispecific diabody (DART-A) that is capable of simultaneously binding to CD 123 and CDS. The invention further concerns the use of such DART-A DP formulations in the treatment of hematologic malignancies such as acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) in patients.

Abstract: The present invention is directed to a dosing regimen for administering a CD 123×CDS bispecific diabody to patients with a hematologic malignancy such as acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). The present invention is also directed to a dosing regimen for administering a CD 123×CDS bispecific diabody in combination with a molecule capable of binding PD-1 or a natural ligand of PD-1 (a “PD-1 or PD-1 ligand binding molecule”) to patients with a hematologic malignancy such as acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). The invention particularly concerns the use of such regimens for administering the sequence-optimized CD 123×CDS bispecific diabody, “DART-A,” which is capable of simultaneous binding to CD 123 and CDS.