Results of a Phase II trial of gemcitabine, mitoxantrone, and rituximab in relapsed or refractory mantle cell lymphoma

Background: Gemcitabine (G) has shown activity in mantle cell lymphoma (MCL) as a single agent. The combination of mitoxantrone (M) and rituximab (R) is also active in MCL. The primary objective of this study was to determine the efficacy of G+M+R in relapsed or refractory MCL. Patients and Methods: Sixteen patients were enrolled between April 2005 and January 2007, 88% had Stage IV MCL, Median patient age was 74 years. Patients received gemcitabine 900 mg/m2 IV (30–60 min infusion) on Days 1 and 8, mitoxantrone 10 mg/m2 IV (5–10 min infusion) on day 1, and rituximab 375 mg/m2 IV on Day 1 (max 400 mg/hour) of the 21-day cycle. Patients received a median of 6 cycles (range, 1–8). Results: Best responses were CR 20% (95%CI, 0, 40.2), PR 27% (95%CI, 4.3, 49.1), SD 40% (95%CI, 15.2, 64.8), and PD 13% (95%CI, 0, 30.5). Median survival and PFS have not been reached with a median follow-up of 10.7 months. The most common Grade 3–4 toxicities were neutropenia (100%), thrombocytopenia (67%), leukopenia (53%), and anemia (33%). The study was closed early due to slow accrual owing to an alternative treatment which became available at the time. Conclusion: The combination of G+M+R in MCL was well-tolerated with manageable toxicity using growth factors to minimize neutropenia; further studies are warranted.