Vinblastine in children and adolescents with high-risk anaplastic large-cell lymphoma: results of the randomized ALCL99-vinblastine trial.

PURPOSE: The impact of adding vinblastine to a 4-month chemotherapy regimen, based on the Non-Hodgkin's Lymphoma Berlin-Frankfurt-Münster 90 protocol, in childhood high-risk anaplastic large-cell lymphoma (ALCL) was assessed.

PATIENTS AND METHODS: Children and adolescents with high-risk ALCL, defined by mediastinal, lung, liver, spleen, or skin involvement, were eligible for the trial. After a prephase and one chemotherapy course, patients were randomly assigned to receive either five further chemotherapy courses without vinblastine or the same regimen with one vinblastine injection (6 mg/m(2)) during each course followed by weekly vinblastine to complete a total of 1 year of treatment. The primary end point was event-free survival (EFS), analyzed on the intent-to-treat population.

RESULTS: Between November 1999 and June 2006, 110 patients were randomly assigned to receive vinblastine, and 107 were randomly assigned not to receive vinblastine. Median follow-up was 4.8 years. Patients in the vinblastine arm had a significantly reduced risk of events during the first year (hazard ratio [HR] = 0.31; 95% CI, 0.15 to 0.67; P = .002) followed by an increased risk thereafter (HR = 4.98; 95% CI, 1.65 to 15.0; P = .003). Consequently, EFS at 1 year differed significantly (91% in the vinblastine group v 74% in the no-vinblastine group), with no difference at 2 years (73% and 70%, respectively). Overall EFS curves did not differ significantly (HR = 0.91; 95% CI, 0.55 to 1.5; P = .71). Thirty-one percent of weekly doses of vinblastine were reduced as a result of hematologic toxicity, although vinblastine was discontinued for toxicity in only three patients.

CONCLUSION: Adding vinblastine during induction and as maintenance for a total treatment duration of 1 year significantly delayed the occurrence of relapses but did not reduce the risk of failure.