Ofatumumab-based Induction Chemoimmunotherapy in Previously Untreated Patients With CLL/SLL

OUTLINE: Patients with adverse interphase cytogenetics (11q22 or 17p13 deletion) receive FCO induction therapy: * Ofatumumab is given IV on day 1 (300 mg) and day 8 (1000 mg) of course 1 and on day 1 (1000 mg) of all subsequent courses. * Fludarabine phosphate (25mg/m2/d) and cyclophosphamide (250mg/m2/d) are given IV on days 2 through 4 of course 1 and on days 1 through 3 of all subsequent courses. Patients age 70 or older will be given reduced doses of fludarabine (20mg/m2/d) and cyclophosphamide (150mg/m2/d). * Treatment repeats every 28 days for up to 6 courses in the absence of disease progression. Patients without adverse interphase cytogenetics receive FO induction therapy: * Ofatumumab is given IV on day 1 (300mg) and day 8 (1000mg) of course 1 and on day 1 (1000mg) of all subsequent courses. * Fludarabine phosphate (25mg/m2/d) is given IV on days 2 through 6 of course 1 and on days 1 through 5 of all subsequent courses. * Treatment repeats every 28 days for up to 6 courses in the absence of disease progression. All patients are evaluated for minimal residual disease (MRD) by four-color flow cytometric analysis of the peripheral blood after completion of FO or FCO induction therapy, and are subsequently stratified into two groups: * Patients who are MRD-positive and without evidence of disease progression proceed to consolidation therapy beginning approximately 5 months after completion of induction therapy, consisting of ofatumumab (1000mg) given IV on day 1 of all courses. Treatment repeats every 2 months for up to 4 courses in the absence of disease progression. Patients are followed clinically 2 and 6 months after the last dose of ofatumumab is given, and then every 6 months thereafter. * Patients who are MRD-negative and without evidence of disease progression are followed clinically every 4 months for 1 year and every 6 months thereafter.