A phase II study of gemcitabine, carboplatin, dexamethasone, and rituximab in patients with relapsed or refractory non-Hodgkin lymphoma

This study evaluated the efficacy and safety of salvage chemotherapy with gemcitabine, carboplatin, dexamethasone, and rituximab (GCD +/- R) for Japanese patients with relapsed or refractory non-Hodgkin lymphoma (NHL). A multicenter, phase II trial of GCD +/- R administered every 3 weeks for up to 6 cycles was conducted. Rituximab was administered as a therapeutic strategy for CD20-positive lymphoma. The primary endpoint was the complete response (CR) rate. Secondary endpoints included the overall response (OR) rate, overall survival (OS), progression-free survival (PFS), toxicity, and success rate of peripheral blood stem cell collection for eligible transplant patients. A total of 25 patients (median age 66 years) were evaluated, with a median follow-up period of 66.7 months. CR and OR rates were 28% and 52%, respectively. Median PFS and OS were 8.7 and 32.2 months, respectively. The major toxicity was myelosuppression, but the regimen was generally well-tolerated, with a low incidence of febrile neutropenia (20%) and no treatment-related deaths. Of the 6 patients who were eligible for autologous stem cell transplantation and underwent peripheral blood stem cell mobilization, the required number of CD34-positive cells was collected in 5 (83%). All 6 proceeded to transplantation and achieved successful engraftment without recurrence. The present results suggest that GCD +/- R may be effective and well-tolerated in Japanese patients with relapsed or refractory NHL. However, further investigation is needed to confirm these results.