Combinations of lenalidomide, fludarabine and rituximab for previously untreated chronic lymphocytic leukemia

This study aimed to investigate the safety and effectiveness of a combination of lenalidomide (Revlimid), fludarabine (Fludara) and rituximab (Rituxan) in patients with previously untreated chronic lymphocytic leukemia. This study concluded that this combination was effective, but the tolerability varied between patients.  

Chemoimmunotherapy is a standard treatment for patients with previously untreated chronic lymphocytic leukemia (CLL). Chemoimmunotherapy combines chemotherapy which kills cancer cells and immunotherapy which helps the immune system fight cancer. Lenalidomide is an immunotherapy. Side effects such as tumor lysis prevented it from being used as a single therapy. Tumor lysis occurs when large amounts of cancer cells are killed, and their toxic contents are released into the bloodstream. Fludarabine is a chemotherapy. Rituximab is another immunotherapy.

It was not known if a combination of the three drugs would be effective and tolerable in patients with CLL.

This study involved 45 patients with CLL who had not yet received chemotherapy. Patients were treated with a combination of lenalidomide (increasing doses) and six cycles of fludarabine and rituximab (FR) as induction treatment (treatment that is designed to bring about remission). This was followed by lenalidomide/rituximab maintenance (maintenance is designed to prevent relapse in patients who are in remission). Patients were followed up for an average of 78.7 months.

The overall response rate after induction was 89%. The complete response rate (no signs of cancer) after induction was 44%. After maintenance therapy, 12% of patients that had a partial response after induction had a complete response.

At follow-up, the average progression-free survival (PFS; time patients are alive without cancer growing) was 60.3 months. 

The side effects of the combination varied between patients. Severe neutropenia (low level of white blood cells) was experienced by 71% of patients. 7% of patients experienced infections. Skin reactions (rash/dryness etc.) were reported in 20% of patients and needed a dose reduction.

This study concluded that combining lenalidomide with FR was effective, but the side effects varied between patients.  

This study included a small number of patients. Further larger studies need to be carried out.