Lugano 2013: Chlorambucil plus Rituximab Produces Better Event-free and Progression-free Survival in Extranodal Marginal Zone B-cell Lymphoma
The International Extranodal Lymphoma Study Group (IELSG)-19 trial is the largest randomized trial in extranodal marginal zone B-cell lymphoma conducted to date. As reported by Emanuele Zucca, MD, of the Oncology Institute of Southern Switzerland, and colleagues, preliminary final results of the trial indicate that the combination of chlorambucil (Leukeran) and rituximab (Rituxan) resulted in improved event-free and progression-free survival compared with either agent alone although no differences in overall survival were observed. The findings were reported at a plenary session of the 12th International Conference on Malignant Lymphoma in Lugano, Switzerland (Abstract 007).
Trial Details
In the trial, patients with disseminated lymphoma or localized disease not suitable for local therapy were randomized to receive daily chlorambucil 6 mg/m2 for 6 weeks, with patients with response or stable disease receiving 6 mg/m2 daily for 14 consecutive days every 28 days for four cycles; intravenous rituximab 375 mg/m2 on days 1, 8, 15, 22, 56, 84, 112, and 140; or both.
The preliminary analysis included 393 patients with complete data, consisting of 130 patients in the chlorambucil group, 132 in the rituximab group, and 131 in the combination group. The primary site of lymphoma was the stomach in 43% of patients, lymph nodes were involved in 34%, 81% had low or low-intermediate International Prognostic Index scores, and 8% of patients had received prior local therapy.
Outcomes
With a median follow-up of 67 months, 5-year event-free survival, the primary endpoint of the trial, was 70% in the combination group compared with 52% in the chlorambucil group (P = .0005) and 51% in the rituximab group (P = .0015). Progression-free survival was also significantly longer in the combination group compared with the chlorambucil group (P = .0128) and the rituximab group (P = .0058). Overall survival was 90% at 5 years in the total population, with no significant differences between treatment arms. No unexpected severe side effects were reported. Hematologic toxicity was more pronounced in the combination group.
The investigators concluded, “This is the largest randomized study ever conducted in extranodal marginal zone B-cell lymphoma and is the first trial to compare chemotherapy vs rituximab and vs the combination of both. Longer event-free survival and progression-free survival were attained in the combination arm but this did not translate into improved overall survival.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
