The benefits of combining antibody treatment and chemotherapy for previously untreated CLL patients

This study compared the effectiveness of chemotherapy combined with antibody treatment to chemotherapy alone in patients with chronic lymphocytic leukemia (CLL). The authors concluded that combining treatments led to better progression-free survival rates (where the condition does not get worse) in untreated older patients with other medical conditions

CLL is most commonly diagnosed in people over the age of 70. It is likely that older patients will be experiencing other meaningful health problems. These patients may be more sensitive to side effects and treatment for CLL must be carefully prescribed.

Chemotherapy on its own has not been successful at improving CLL survival in the past. Rituximab (Rituxan) is a form of antibody treatment that targets cancer cells and kills them. A combination of rituximab and chemotherapy has prolonged progression-free survival (PFS; time from treatment until disease progression) in CLL patients. Newer forms of antibody treatment, such as obinutuzumab (Gazyva), may be more effective for treating CLL.

781 patients with previously untreated CLL who had multiple co-existing conditions were included in this study. The average age was 73 years. Patients were randomly assigned to one of three groups. Group 1 received mild chemotherapy with chlorambucil (Leukeran) on its own. Group 2 was treated with chlorambucil and rituximab. Group 3 was treated with chlorambucil and obinutuzumab. Patients were treated over six 28-day cycles.  

Time to disease progression was an average of 11.1 months in group 1, 16.3 months in group 2, and 26.7 months in group 3. A complete response was seen in 20.7% of those in group 3 and 7% of those in group 2.

The risk of death was 59% lower in group 3 compared to group 1.

The most common side effects were infections and reactions at the time of injection. Side effects were more common in the groups receiving antibody treatment than in group 1. Patients in group 3 experienced more side effects.