Combination Regimen Is Option for Older Adults with Ph- ALL

Older adult patients with newly diagnosed Philadelphia-chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) may benefit from combination treatment with inotuzumab ozogamicin induction and blinatumomab consolidation, according to data presented at the 2023 American Society of Clinical Oncology Annual Meeting.

According to study researcher Matthew Joseph Wieduwilt, MD, of Atrium Health Wake Forest Baptist Comprehensive Cancer Center in Winston-Salem, North Carolina, and colleagues, patients with newly diagnosed Ph- ALL have poor survival with chemotherapy. In contrast, phase III studies of the α-CD22 antibody-drug conjugate inotuzumab ozogamicin and α-CD19/CD3 T-cell engager blinatumomab showed superior outcomes compared with chemotherapy.

In this trial, 33 patients aged 60 or older with Ph-, CD22-positive B-ALL without plan for allogeneic hematopoietic stem cell transplant received induction therapy with inotuzumab.

In course IA induction inotuzumab was given at 0.8 mg/m² on day 1, 0.5 mg/m² on day 8, day 15 IV on a 21-day cycle. Patients with adequate cytoreduction after IA went to course IB if they were in complete response or complete response with incomplete count recovery (CR/CRi) and received inotuzumab 0.5 mg/m² on day 1, day 8, day 15 IV; 28-day cycle or to course IC if there was no CR/CRi and received inotuzumab 0.8 mg/m² day 1, day 8, day 15 IV; 28-day cycle). Those without cytoreduction to IA started course II with blinatumomab.

Patients without events in IA/B/C received course II blinatumomab. Patients with CR/CRi received two more 28-day cycles of blinatumomab; others received three more cycles.

The cumulative CR rates through course IA/B/C and course II were 85% and 97%, respectively.

With a median follow-up of 22 months, the one-year event-free survival rate was 75%.

Twelve patients had events. These included nine relapses, two deaths in remission, and one death without remission from respiratory failure with sinusoidal occlusion syndrome of the liver.

The one-year overall survival rate was 84%.

Reference

Wieduwilt MJ, Yin J, Kour O, et al. Chemotherapy-free treatment with inotuzumab ozogamicin and blinatumomab for older adults with newly diagnosed, Ph-negative, CD22-positive, B-cell acute lymphoblastic leukemia: Alliance A041703. Abstract #7006. Presented at the 2023 American Society of Clinical Oncology Annual Meeting; June 2-6, 2023; Chicago, Illinois.