ATLANTA-A combination regimen of rituximab (Rituxan) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) appears to induce objective responses in patients with chronic lymphocytic leukemia (CLL), particularly in elderly untreated patients, according to a study presented at the 47th Annual Meeting of the American Society of Hematology (abstract 721).
Supplementation of rituximab therapy with GM-CSF is thought to increase therapeutic efficacy by upregulating surface CD20 expression and also enhancing the antibody-dependent cell-mediated cytotoxicity induced by ritux-i-mab. In previous studies, rituximab plus GM-CSF has demonstrated significant responses in patients with follicular lymphoma. In the current phase II study, Alessandra Ferrajoli, MD, assistant professor, Department of Leukemia, M.D. Anderson Cancer Center, and her colleagues looked at the combination in patients with CLL.
Patients enrolled in the trial were divided into three groups according to their disease profile:
Group 1: Untreated patients older than 70 years of age with indications for treatment based on National Cancer Institute Working Group (NCI-WG) criteria (n = 14).
Group 2: Untreated patients with Rai stage 0-2 disease at high risk for progression, defined as a β2-microglobulin level greater than 3 mg/dL, B symptoms, or severe fatigue (n = 35).
Group 3: Patients with relapsed/refractory active disease (n = 36).