Experience with rituximab immunotherapy as an early intervention in patients with Rai stage 0 to II chronic lymphocytic leukemia.

Abstract

Management of asymptomatic early stage chronic lymphocytic leukemia (CLL) centered on expectant surveillance for active disease warranting chemotherapy. In CLL, elevated serum β-2 microglobulin (β2M) levels were associated with more rapid disease progression and shorter survival (OS). An early intervention trial was designed to assess response, time-to-progression (TTP), and OS after immunotherapy with standard-dose rituximab (375 mg/m² intravenously weekly for 8 consecutive weeks) in 34 asymptomatic untreated early stage CLL with β2M level ≥ 2 mg/dL. Long-term follow-up and results are reported. The overall response rate in 34 patients was 82% (9% complete [CR]), median TTP in the 28 responders was 23 months, the median time to subsequent treatment was 43 months, and the 8-year OS rate was 74% (median follow-up, 102 months). Early treatment with rituximab was well tolerated and safe. Further studies are needed to determine if this intervention can decrease CLL-related morbidity and mortality.