LUGANO, SwitzerlandThe chemotherapy/immunotherapy regimen FCR (fludarabine, cyclophosphamide(Drug information on cyclophosphamide), rituximab(Drug information on rituximab)) has produced the highest complete response (CR) rate seen thus far in first-line treatment of chronic lymphocytic leukemia (CLL), according to investigator Michael J. Keating, MB. The FCR regimen, which is well tolerated, also results in molecular remissions in a "significant number" of complete responders, said Dr. Keating, professor of medicine, M.D. Anderson Cancer Center.
"I think we now have an outpatient regimen that can accomplish PCR [polymerase chain reaction] negativity to a level that was formerly only achievable with various transplant procedures," Dr. Keating said. "It will be intriguing to follow these patients and see how durable these responses are."
The study, which included 135 patients with CLL who received six cycles of FCR, achieved a complete response rate of 67% (90 patients), Dr. Keating reported at the 8th International Conference on Malignant Lymphoma (ICML abstract 008). By comparison, front-line fludarabine (Fludara), in previous investigations, has resulted in a 35% complete remission rate, while adding cyclophosphamide to fludarabine increases the CR rate to 43%.
The FCR regimen is an infusion of rituximab (Rituxan) at a conventional dose (375 mg/m²) on the first day of the first cycle, with fludarabine and cyclophosphamide given on days 2, 3, and 4. In subsequent cycles, rituximab is given at a higher dose (500 mg/m²) on day 1, along with the 3-day fludarabine/cyclophosphamide couplet. Cycles are repeated every 4 weeks for a total of six cycles.
The median patient age was 57 years, or somewhat lower than in previous studies of first-line treatment for CLL. Dr. Keating attributes this to the "Internet phenomenon"younger patients seeking out more aggressive therapies.
The treatment was well tolerated, with 74% of patients completing six cycles, and only 4% completing less than three cycles.
Overall Response Rate