Rituximab, cladribine and cyclophosphamide: Early results of a new treatment combination with and without maintenance therapy

This study examined a new treatment combination known as RCC followed by rituximab (Rituxan) maintenance therapy for chronic lymphocytic leukemia (CLL). These results support the safety and effectiveness of RCC followed by rituximab maintenance therapy. Risk factors of disease progression were identified.

The chemotherapy and immunotherapy combination known as FCR is a standard first-line treatment for physically fit CLL patients. FCR consist of the chemotherapies fludarabine (Fludara) and cyclophosphamide (Cytoxan) and the immunotherapy rituximab. Cladribine (Leustatin) is a similar drug to fludarabine, but it has been less intensely investigated. Early results that combine cladribine with cyclophosphamide and rituximab (a combination known as RCC) are very promising.

126 CLL patients were included in this study. All patients received first-line RCC. Treatment consisted of 6 cycles. 97 patients completed all 6 cycles. 66 of these patients were randomly assigned to maintenance therapy with rituximab or observation (no maintenance therapy). The aim of maintenance therapy is to sustain the response achieved with first-line treatment.

22.7% of patients achieved complete response directly after RCC. After maintenance therapy with rituximab, 57.1% of patients showed complete response. It was 50% for patients in the observation group.

Overall, 27 patients experienced disease progression. This included 9 patients receiving maintenance therapy and 18 from the observation group. The average time to disease progression was 3.1 years. This was about 58% longer for patients receiving maintenance therapy.

Further analysis identified risk factors that significantly increased the chance of disease progression. The presence of a genetic abnormality known as deletion 17p increased the risk of progression nearly 20-fold. Having high beta-2-microglobulin levels (a marker for leukemia in the blood) increased the risk 4.2-fold. The presence of an antibody called CD38 reduced progression risk by 76%.

This study concluded that RCC followed by maintenance therapy with rituximab is a safe and effective treatment option for newly diagnosed CLL patients.

Larger studies are needed to confirm these findings.