Minimal residual disease quantification is an independent predictor of progression-free and overall survival in chronic lymphocytic leukemia: a multivariate analysis from the randomized GCLLSG CLL8 trial.

PURPOSE: To determine the clinical significance of flow cytometric minimal residual disease (MRD) quantification in chronic lymphocytic leukemia (CLL) in addition to pretherapeutic risk factors and to compare the prognostic impact of MRD between the arms of the German CLL Study Group CLL8 trial. PATIENTS AND METHODS: MRD levels were prospectively quantified in 1,775 blood and bone marrow samples from 493 patients randomly assigned to receive fludarabine and cyclophosphamide (FC) or FC plus rituximab (FCR). Patients were categorized by MRD into low- (< 10(-4)), intermediate- (≥ 10(-4) to <10(-2)), and high-level (≥ 10(-2)) groups. RESULTS: Low MRD levels during and after therapy were associated with longer progression-free survival (PFS) and overall survival (OS; P < .0001). Median PFS is estimated at 68.7, 40.5, and 15.4 months for low, intermediate, and high MRD levels, respectively, when assessed 2 months after therapy. Compared with patients with low MRD, greater risks of disease progression were associated with intermediate and high MRD levels (hazard ratios, 2.49 and 14.7, respectively; both P < .0001). Median OS was 48.4 months in patients with high MRD and was not reached for lower MRD levels. MRD remained predictive for OS and PFS in multivariate analyses that included the most important pretherapeutic risk markers in CLL. PFS and OS did not differ between treatment arms within each MRD category. However, FCR induced low MRD levels more frequently than FC. CONCLUSION: MRD levels independently predict OS and PFS in CLL. Therefore, MRD quantification might serve as a surrogate marker to assess treatment efficacy in randomized trials before clinical end points can be evaluated.

Rituximab maintenance for 2 years in patients with high tumour burden follicular lymphoma responding to rituximab plus chemotherapy (PRIMA): a phase 3, randomised controlled trial.

BACKGROUND: Patients with follicular lymphoma can have long survival times, but disease progression typically occurs 3-5 years after initial treatment. We assessed the potential benefit of 2 years of rituximab maintenance after first-line treatment in patients with follicular lymphoma receiving a rituximab plus chemotherapy regimen. METHODS: The randomised, open-label PRIMA study was undertaken in 223 centres in 25 countries. 1217 patients with previously untreated follicular lymphoma needing systemic therapy received one of three non-randomised immunochemotherapy induction regimens used in routine practice. 1019 patients achieving a complete or partial response were then randomly assigned to receive 2 years of rituximab maintenance therapy (375 mg/m(2) every 8 weeks) or observation. Treatment was assigned equally by centralised block randomisation, stratified by induction regimen, response, region, and centre. Neither the participants nor those giving the interventions, assessing outcomes, and analysing data were masked to group assignments. The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00140582. FINDINGS: 505 patients were assigned to rituximab maintenance and 513 to observation (one patient died during randomisation). With a median follow-up of 36 months (IQR 30-42), PFS was 74·9% (95% CI 70·9-78·9) in the rituximab maintenance group (130 patients progressed) and 57·6% (53·2-62·0) in the observation group (218 progressed; hazard ratio [HR] 0·55, 95% CI 0·44-0·68, p<0·0001). 2 years after randomisation, 361 patients (71·5%) in the rituximab maintenance group were in complete or unconfirmed complete response versus 268 (52·2%) in the observation group (p=0·0001). Overall survival did not differ significantly between groups (HR 0·87, 95% CI 0·51-1·47). Grade 3 and 4 adverse events were recorded in 121 patients (24%) in the rituximab maintenance group and 84 (17%) in the observation group (risk ratio 1·46, 95% CI 1·14-1·87; p=0·0026). Infections (grades 2-4) were the most common adverse event, occurring in 197 (39%) and 123 (24%) patients, respectively (risk ratio 1·62, 95% CI 1·35-1·96; p<0·0001). INTERPRETATION: 2 years of rituximab maintenance therapy after immunochemotherapy as first-line treatment for follicular lymphoma significantly improves PFS. FUNDING: Groupe d'Etude des Lymphomes de l'Adulte (GELA) and F Hoffmann-La Roche.

Rituximab plus fludarabine and cyclophosphamide prolongs progression-free survival compared with fludarabine and cyclophosphamide alone in previously treated chronic lymphocytic leukemia.

PURPOSE: Rituximab, a monoclonal antibody that targets the CD20 cell surface antigen, has clinical activity in patients with non-Hodgkin's lymphoma and other B-lymphocyte disorders when administered alone or in combination with chemotherapy. Promising results have previously been reported in nonrandomized studies in patients with chronic lymphocytic leukemia (CLL). This trial was designed to compare chemoimmunotherapy with chemotherapy alone in patients with previously treated CLL. PATIENTS AND METHODS: This international, multicenter, randomized trial compared six cycles of rituximab plus fludarabine and cyclophosphamide (R-FC) with six cycles of fludarabine and cyclophosphamide alone (FC) in patients with previously treated CLL. A total of 552 patients with Binet stage A (1%), B (59%), or C (31%) disease entered the study and were randomly assigned to receive R-FC (n = 276) or FC (n = 276). RESULTS: After a median follow-up time of 25 months, rituximab significantly improved progression-free survival in patients with previously treated CLL (hazard ratio = 0.65; P < .001; median, 30.6 months for R-FC v 20.6 months for FC). Event-free survival, response rate, complete response rate, duration of response, and time to new CLL treatment or death were also significantly improved. Although the rates of adverse events, grade 3 or 4 events, and serious adverse events were slightly higher in the R-FC arm, R-FC was generally well tolerated, with no new safety findings and no detrimental effect on quality of life. CONCLUSION: R-FC significantly improved the outcome of patients with previously treated CLL.

CHOP-like chemotherapy plus rituximab versus CHOP-like chemotherapy alone in young patients with good-prognosis diffuse large-B-cell lymphoma: a randomised controlled trial by the MabThera International Trial (MInT) Group.

BACKGROUND: The role of rituximab in combination with different CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like chemotherapy regimens in young patients with good-prognosis diffuse large-B-cell lymphoma remains to be defined. We aimed to compare CHOP-like chemotherapy and rituximab with CHOP-like chemotherapy alone in these patients. METHODS: 824 patients who were from 18 countries; aged 18-60 years; and who had no risk factors or one risk factor according to age-adjusted International Prognostic Index (IPI), stage II-IV disease, or stage I disease with bulk were enrolled. These patients were randomly assigned to six cycles of CHOP-like chemotherapy and rituximab (n=413) or to six cycles of CHOP-like chemotherapy alone (n=411). Bulky and extranodal sites received additional radiotherapy. The primary endpoint was event-free survival; secondary endpoints were response, progression under therapy, progression-free survival, overall survival, and frequency of toxic effects. Analyses were done by intention to treat and per protocol. This trial is registered at http://www.clinicaltrials.gov, NCT 00064116. FINDINGS: After a median follow-up of 34 months (range 0.03-61), patients assigned chemotherapy and rituximab had increased 3-year event-free survival compared with those assigned chemotherapy alone (79% [95% CI 75-83] vs 59% [54-64]; difference between groups 20% [13-27], log-rank p<0.0001), and had increased 3-year overall survival (93% [90-95] vs 84% [80-88]; difference between groups 9% [3-13], log-rank p=0.0001). Event-free survival was affected by treatment group, presence of bulky disease, and age-adjusted IPI: after chemotherapy and rituximab, a favourable subgroup (ie, IPI=0, no bulk) could be defined from a less-favourable subgroup (ie, IPI=1 or bulk, or both). Groups did not differ in the frequency of adverse events. INTERPRETATION: Rituximab added to six cycles of CHOP is an effective treatment for young patients with good-prognosis diffuse large-B-cell lymphoma. The definition of two prognostic subgroups allows for a more refined therapeutic approach for these patients.