Rituximab in B-Lineage Adult Acute Lymphoblastic Leukemia.

Background: Treatment with rituximab has improved the outcome for patients with non-Hodgkin's lymphoma. Patients with B-lineage acute lymphoblastic leukemia (ALL) may also have the CD20 antigen, which is targeted by rituximab. Although single-group studies suggest that adding rituximab to chemotherapy could improve the outcome in such patients, this hypothesis has not been tested in a randomized trial.

Methods: We randomly assigned adults (18 to 59 years of age) with CD20-positive, Philadelphia chromosome (Ph)-negative ALL to receive chemotherapy with or without rituximab, with event-free survival as the primary end point. Rituximab was given during all treatment phases, for a total of 16 to 18 infusions.

Results: From May 2006 through April 2014, a total of 209 patients were enrolled: 105 in the rituximab group and 104 in the control group. After a median follow-up of 30 months, event-free survival was longer in the rituximab group than in the control group (hazard ratio, 0.66; 95% confidence interval [CI], 0.45 to 0.98; P=0.04); the estimated 2-year event-free survival rates were 65% (95% CI, 56 to 75) and 52% (95% CI, 43 to 63), respectively. Treatment with rituximab remained associated with longer event-free survival in a multivariate analysis. The overall incidence rate of severe adverse events did not differ significantly between the two groups, but fewer allergic reactions to asparaginase were observed in the rituximab group.

Conclusions: Adding rituximab to the ALL chemotherapy protocol improved the outcome for younger adults with CD20-positive, Ph-negative ALL. (Funded by the Regional Clinical Research Office, Paris, and others; ClinicalTrials.gov number, NCT00327678 .).