Robert Kreitman, MD of @NIHClinicalCntr @NIH discusses the phase II study of cladribine with delayed or concurrent rituximab in patients with hairy cell leukemia.
Single-agent purine analog, usually cladribine, has been the preferred hairy cell leukemia (HCL) first-line therapy for 30 years. High levels of complete remission (CR) often include minimal residual disease (MRD) which leads to relapse and repeated treatments. Rituximab may clear MRD but uncertain and optimal timing of rituximab is unclear for long-term performance.
Patients were randomly administered first-line cladribine 0.15 mg / kg intravenously 1-5 days with 8 weekly doses of rituximab 375 mg / m2 either day 1 (concurrent, CDAR) or 6 months later (delayed) after blood MRD was observed. MRD research involved cytometry of the blood and bone marrow (BM) flow, and immunohistochemistry of BM.