Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial.

BACKGROUND: On the basis of promising results that were reported in several phase 2 trials, we investigated whether the addition of the monoclonal antibody rituximab to first-line chemotherapy with fludarabine and cyclophosphamide would improve the outcome of patients with chronic lymphocytic leukaemia. METHODS: Treatment-naive, physically fit patients (aged 30-81 years) with CD20-positive chronic lymphocytic leukaemia were randomly assigned in a one-to-one ratio to receive six courses of intravenous fludarabine (25 mg/m(2) per day) and cyclophosphamide (250 mg/m(2) per day) for the first 3 days of each 28-day treatment course with or without rituximab (375 mg/m(2) on day 0 of first course, and 500 mg/m(2) on day 1 of second to sixth courses) in 190 centres in 11 countries. Investigators and patients were not masked to the computer-generated treatment assignment. The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00281918. FINDINGS: 408 patients were assigned to fludarabine, cyclophosphamide, and rituximab (chemoimmunotherapy group) and 409 to fludarabine and cyclophosphamide (chemotherapy group); all patients were analysed. At 3 years after randomisation, 65% of patients in the chemoimmunotherapy group were free of progression compared with 45% in the chemotherapy group (hazard ratio 0·56 [95% CI 0·46-0·69], p<0·0001); 87% were alive versus 83%, respectively (0·67 [0·48-0·92]; p=0·01). Chemoimmunotherapy was more frequently associated with grade 3 and 4 neutropenia (136 [34%] of 404 vs 83 [21%] of 396; p<0·0001) and leucocytopenia (97 [24%] vs 48 [12%]; p<0·0001). Other side-effects, including severe infections, were not increased. There were eight (2%) treatment-related deaths in the chemoimmunotherapy group compared with ten (3%) in the chemotherapy group. INTERPRETATION: Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab improves progression-free survival and overall survival in patients with chronic lymphocytic leukaemia. Moreover, the results suggest that the choice of a specific first-line treatment changes the natural course of chronic lymphocytic leukaemia. FUNDING: F Hoffmann-La Roche.

Advances in chemotherapy for chronic lymphocytic leukemia.

While chemotherapy based on alkylating agents has been the standard treatment of chronic lymphocytic leukemia (CLL) for decades, purine analogues and their combinations have emerged as effective new therapies for previously untreated and pretreated patients. As single agents, fludarabine and cladribine are the most promising, showing higher remission rates compared to chlorambucil. For younger and physically fit patients, the combination of fludarabine and cyclophosphamide has shown benefit. Fludarabine plus epirubicin appears equally potent. The addition of monoclonal antibodies, such as rituximab and alemtuzumab, to purine analogues alone or in combination seems to be even more effective for chemotherapy-naive and pretreated CLL patients. Another promising agent in the armamentarium of therapies for CLL is bendamustine, which has properties of both an alkylating agent and a purine analogue. Clinical trials are ongoing with novel drugs that interfere with cell cycle regulation and signaling molecules in CLL, including flavopiridol, UCN-01, bryostatin 1, depsipeptide, and oblimersen. It remains to be seen whether these chemotherapeutic approaches offer real benefit for patients by prolonging survival with an improved quality of life.