Rapid and sustained clearance of circulating lymphoma cells after chemotherapy plus rituximab: clinical significance of quantitative t(14;18) PCR monitoring in advanced stage follicular lymphoma patients.

This study of first-line treatment in advanced-stage follicular lymphoma patients analysed the effects of MCP (mitoxantrone, chlorambucil and prednisolone) chemotherapy alone or in combination with rituximab (R-MCP) on circulating lymphoma cells (CLC) and assessed the prognostic value of a quantitative monitoring of CLC. CLC numbers were determined by quantitative polymerase chain reaction (PCR) for the t(14;18)-translocation or by allele-specific PCR for rearranged immunoglobulin heavy chain genes. We analysed blood samples from 43 patients treated in a randomized trial comparing eight cycles of MCP versus R-MCP. Clearance of CLC at the end of therapy was achieved in 21/25 patients (84%) treated with R-MCP compared with 0/18 after MCP alone (P < 0.0001). A > or = 2 log CLC reduction was associated with a favourable clinical response (P = 0.0004) and prolonged event-free survival (P = 0.02). In R-MCP patients, stable CLC numbers or consistently PCR-negative blood samples were associated with a continuing clinical remission whereas in two patients a relapse was preceded by a > or = 2 log CLC increase. This study demonstrated that R-MCP led to a rapid and sustained eradication of CLC and a > or = 2 log CLC reduction was associated with a superior quality and duration of the clinical response.

Rituximab added to first-line mitoxantrone, chlorambucil, and prednisolone chemotherapy followed by interferon maintenance prolongs survival in patients with advanced follicular lymphoma: an East German Study Group Hematology and Oncology Study.

PURPOSE: Rituximab has been shown to be active in follicular lymphoma (FL), both as monotherapy and in combination with chemotherapy. We conducted a randomized trial comparing mitoxantrone, chlorambucil, and prednisolone (MCP) chemotherapy plus rituximab with MCP alone. PATIENTS AND METHODS: Previously untreated patients with stage III or IV CD20+ indolent or mantle cell lymphoma were randomly assigned to either eight 28-day cycles of MCP plus rituximab (R-MCP; n = 181) or eight cycles of MCP alone (n = 177). All patients who achieved a complete or partial remission were treated with interferon maintenance until relapse. Herein, we report the results from the primary analysis population of patients with FL, who constituted the majority of patients (56%) recruited to the trial (n = 201; R-MCP, n = 105; MCP, n = 96). RESULTS: Rates of overall and complete response were significantly higher in the R-MCP arm than the MCP arm (overall response, 92% v 75%, respectively; P = .0009; complete response, 50% v 25%, respectively; P = .004). With a median follow-up time of 47 months, median event-free survival (EFS) and progression-free survival (PFS) times were significantly prolonged with R-MCP compared with MCP (EFS, not reached v 26 months, respectively; P < .0001; PFS, not reached v 28.8 months, respectively; P < .0001), and overall survival (OS) was significantly improved with R-MCP compared with MCP (4-year OS rate, 87% v 74%, respectively; P = .0096). CONCLUSION: The R-MCP regimen significantly improves complete and overall response rates, EFS, PFS, and OS in patients with previously untreated advanced FL, without a clinically significant increase in toxicity.