Dr. Kreitman on Results of Moxetumomab Pasudotox in Hairy Cell Leukemia

Robert J. Kreitman, MD, chief, Clinical Immunotherapy Section, Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, discusses the findings of moxetumomab pasudotox as a treatment for patients with relapsed/refractory hairy cell leukemia (HCL).

The first-in-class recombinant immunotoxin moxetumomab pasudotox was evaluated in a pivotal multicenter, single-arm study of patients with relapsed/refractory HCL. Responses were durable in a substantial number of patients, and the best overall response was a complete remission (CR) in 41% of patients and a CR with no minimal residual disease (MRD) in 34% of patients by blinded independent central review.

The goal was to achieve complete remission with a resolution of normal blood counts, Kreitman says, as blood counts are low in patients with HCL at baseline. Patients who were MRD-positive achieved CRs that lasted a median of 5.9 months, but investigators observed a significantly prolonged median duration of response for those who were MRD-negative by comparison, Kreitman says.