Adding the monoclonal antibody rituximab to chemotherapy signicantly increases both progression-free and overall survival in previously untreated patients with chronic lymphocytic leukemia (CLL), the German Lymphocytic Leukaemia Study Group reports.
In a study by Michael Hallek, MD, of the University of Cologne, Germany, and associates, 408 patients were randomized to fludarabine, cyclophosphamide, and rituximab (chemoimmunotherapy group) and 409 to fludarabine and cyclophosphamide (chemotherapy group). Patients ranged in age from 30 to 81 years (median, 61 years).
Three years after randomization, 65% of the patients in the chemoimmunotherapy group were free of disease progression compared with 45% of those in the chemotherapy group. In addition, 87% of patients in the chemoimmunotherapy group were alive at 3 years compared with 85% of those in the chemotherapy group. The results are reported in the October 2 issue of The Lancet.
Subgroup analysis showed that patients with the del(17p) abnormality had the worst outcomes with chemoimmunotherapy, suggesting that another type of therapy may be called for in patients with this genetic subtype, according to the authors.
They note too their findings may not be generalizable because patients in their study were younger and healthier than the usual population of patients with CLL.
Grade 3 and 4 neutropenia and leukocytopenia were more frequent in the patients who received rituximab. Other side effects were not significantly different in the two groups.
“The results suggest that the choice of a specific first-line treatment changes the natural course of chronic lymphocytic leukemia,” the researchers conclude.