1
|
Efficacy of radioimmunotherapy with (90Y) ibritumomab tiuxetan is superior as consolidation in relapsed or refractory mantle cell lymphoma: Results of two phase II trials of the European MCL Network and the PLRG. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.7533] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
7533 Background: Radioimmunotherapy (RIT) has demonstrated high clinical efficacy in follicular lymphoma but varying results in mantle cell lymphoma (MCL). Methods: We performed a comparative analysis of two phase II studies with similar inclusion criteria to identify potential predictors of response. 32 patients with relapsed or refractory MCL, WHO performance status ≤2, appropriate hematopoesis (ANC > 1,500/mm3, platelets > 100,000/mm3) and adequate function of liver and kidneys were treated with RIT upfront (Arm A, n = 16) or as consolidation after initial cytoreduction (Arm B, n = 16). 28 patients (88%) had been previously treated with rituximab. Patients with >25% bone marrow involvement, known CNS lymphoma, HIV infection or other severe concurrent disease were excluded. Ibritumomab tiuxetan (Zevalin) was applied at a dose of 15 MBq 90Y/kg, whereas patients with reduced platelet counts (<150,000/mm3) received 11 MBq 90Y/kg. Results: The median age was 66.9 years (range 58–72) in Arm A and 63.1 years (range 45–79) in Arm B. The median number of prior regimens was 4 (range 2–6) in Arm A and 1 (1–5) in Arm B. RIT treatment was generally well tolerated with the most common toxicities being hematologic. Thrombocytopenia grade 3 and 4 was observed in 69% of patients, one patient died of hemorrhagic stroke. Granulocytopenia grade 4 occurred in 34% of patients, one patient developed a grade 4 infectious complication. Currently 22 patients are evaluable for response rate and duration of remission (DR). In Arm A a partial response (PR) was observed in 2 of 6 evaluable patients (33.3%) with a median DR of 3.9 months only. In Arm B chemoinduction achieved 2 complete responses (CR) and 14 PR. Following RIT seven of 14 PR patients (50%) converted to CR. Currently, 13 of 16 patients (81%) are still in remission. As expected the most important adverse risk factor was bulky disease before RIT with no responses seen in this patient population. Patients with less prior therapeutic lines (< 2) had significantly higher response rates. Conclusions: In future trials, RIT should be applied earlier in the treatment algorithm of MCL after a debulking strategy with combined immuno-chemotherapy. [Table: see text]
Collapse
|