Compared with treatment with the chemotherapy agent fludarabine alone, the combination of this drug and alemtuzumab, a monoclonal antibody, significantly increases progression-free survival (PFS) and prolongs the lives of patients with previously treated chronic lymphocytic leukemia (CLL), with less toxicity.
Fludarabine plus alemtuzumab administered to 168 adults with leukemia resulted in better PFS than did fludarabine monotherapy in 167 patients (median 23.7 months vs 16.5 months). This improvement was sustained in the subset of older patients (65 years or older), with a median PFS of 29.6 months for combination therapy, compared with 15.4 months for fludarabine alone.
The combination treatment also excelled in overall survival (OS): With a median follow-up for all enrolled patients of 29.5 months, 70% of persons undergoing combination therapy were alive at the data cutoff or last follow-up date, compared with 60% of patients from the monotherapy group.
As they reported in The Lancet Oncology, Dr. Thomas Elter of the University of Cologne (Cologne, Germany) and coinvestigators found that all-cause adverse events occurred in nearly all (98%) of the combination patients, compared with 90% of the monotherapy recipients. For example, a total of 23 cytomegalovirus events occurred in the combination group, whereas only one occurred with monotherapy. The two groups had a similar frequency of grade 3 or 4 neutropenia (59% for combination therapy compared with 68% for monotherapy) and thrombocytopenia (11% for combination therapy compared with 17% for monotherapy), but anemia was less prevalent in the combination group (9% vs 17%), and lymphopenia was more common (94% vs 33%).
Although the incidence of serious adverse events was higher with combination therapy (33% vs 25%), deaths due to adverse events were similar between the two groups (6% for combination therapy vs 7% for monotherapy).