Pharmacokinetics (PK) of blinatumomab and its clinical implications.

3048 Background: Blinatumomab is an investigational, bispecific, single-chain T cell engaging (BiTE) antibody of 55 kD that targets CD19 on B cells and CD3 on T cells. Blinatumomab induces polyclonal T cell activation and proliferation, resulting in redirected lysis of CD19+target cells. Comprehensive analysis of its PK and the clinical implications is presented. Methods: PK data from 131 patients enrolled in 3 phase 1 or 2 studies of non-Hodgkin lymphoma (NHL; N=76), relapsed/refractory acute lymphoblastic leukemia (r/r ALL; N=36), and ALL with minimal residual disease (MRD; N=19) were analyzed. Blinatumomab was given by constant IV (cIV) infusion at 0.5, 1.5, 3, 5, 10, 15, 30, 60 and 90 μg/m2/d over 4 weeks/cycle. Serum blinatumomab concentrations were assessed using a validated bioassay. PK parameters, including volume of distribution (V), half-life (t1/2) and clearance (CL), were analyzed with noncompartmental methods. CL was derived by dividing infusion rate by blinatumomab concentration at steady st...