Rationale for a Trial of Blinatumomab in MRD-Negative ALL

Mark R. Litzow, MD, chair and professor of medicine in the division of hematology at the Mayo Clinic, discusses the purpose of a trial of blinatumomab (Blincyto) for patients with newly diagnosed B-lineage acute lymphoblastic leukemia (B-ALL).

Blinatumomab is a bispecific T-cell engager approved by the FDA for patients with relapsed/refractory B-ALL and patients who are positive for measurable residual disease (MRD) with a morphological complete response (CR). Patients who respond to chemotherapy may still have relapsed disease even after displaying MRD-negative status by flow cytometry or molecular testing. Litzow says it has not yet been tested in patients who are MRD negative.

This phase 3 trial (NCT02003222) was designed to assess whether BCR::ABL1 negative patients with B-ALL who have a CR and are MRD negative after chemotherapy have improved outcomes with blinatumomab. Patients were randomly assigned 1:1 after chemotherapy to receive blinatumomab with consolidation chemotherapy or chemotherapy alone. The primary end point was overall survival, and secondary end points included relapse-free survival, MRD status, and incidence of adverse events.

TRANSCRIPTION:

0:08 | This was a trial to...see if blinatumomab would improve the outcome of newly diagnosed patients with B-lineage ALL who are BCR::ABL1 negative. Now blinatumomab…is already FDA approved for treatments with relapsed/refractory ALL, and also patients [who] are MRD-positive. So MRD can be measured by flow cytometry and also by molecular means. It's not been tested yet in patients who are MRD negative, so we didn't know whether it would be a benefit to those patients. We know those patients have a better prognosis overall than the MRD-positive patients. But they still relapse during the course of their treatment and after, so we know that they still have some leukemia in their system even though they're MRD negative. We wanted to add blinatumomab to chemotherapy in that group to see if we can improve their outcome.