A phase I study of escalated dose subcutaneous alemtuzumab given weekly with rituximab in relapsed chronic lymphocytic leukemia/small lymphocytic lymphoma.

This study assessed the safety and preliminary efficacy of escalated dose subcutaneous alemtuzumab in combination with rituximab in chronic lymphocytic leukemia. Twenty-eight patients with relapsed refractory chronic lymphocytic leukemia were treated on four dosing cohorts of weekly rituximab at 375 mg/m(2) and alemtuzumab doses that started at 30 mg three times per week and escalated to weekly dosing over four weeks, culminating with 90 mg weekly. One dose limiting toxicity of a rituximab infusion reaction was seen in cohort 2, but the regimen was otherwise well tolerated without evidence of differential toxicity by cohort. The overall response rate by National Cancer Institute-Working Group criteria was 61%, and the rate of complete bone marrow response was 43%, most of whom were negative for minimal residual disease. The addition of CT scan evaluation per International Workshop on Chronic Lymphocytic Leukemia 2008 criteria reduced the overall response rate to 14%. Median overall survival was 35 months, with 12 patients able to proceed to stem cell transplantation. Pharmacokinetic studies showed that chronic lymphocytic leukemia involving more than 80% of the bone marrow at study start was associated with lower trough concentrations of alemtuzumab and rituximab, and that higher trough serum concentrations of alemtuzumab were associated with complete bone marrow clearance. We conclude that escalated subcutaneous doses of alemtuzumab given weekly are well tolerated and result in excellent bone marrow clearance of chronic lymphocytic leukemia, helping patients to proceed to stem cell transplantation. This study is registered at ClinicalTrials.gov (Identifier:00330252).

Obatoclax in combination with fludarabine and rituximab is well-tolerated and shows promising clinical activity in relapsed chronic lymphocytic leukemia.

Obatoclax is a small molecule mimetic of the BH3 domain of BCL-2 family proteins. This phase 1 study combining obatoclax with FR was undertaken in chronic lymphocytic leukemia (CLL) patients relapsed after at least one prior therapy. Obatoclax was given as a 3-h infusion on days 1 and 3 and escalated through three dose levels, with standard dose FR days 1-5. Thirteen patients were enrolled, with a median of two prior therapies. One dose-limiting toxicity (DLT) of a 2-week treatment delay for persistent grade 2-3 neutropenia was observed at the highest obatoclax dose (20 mg/m2), but no maximum tolerated dose (MTD) was reached. The overall response rate (ORR) was 85%, with 15% complete responses (CRs) by NCI-96 criteria and 54% by IWCLL 2008 criteria. Median time to progression was 20 months. It is concluded that obatoclax can be safely administered to relapsed CLL patients in combination with FR and shows promising clinical activity.

Current therapeutic options in hairy cell leukemia.

Hairy cell leukemia (HCL) is a B-cell chronic lymphoproliferative disorder that was initially described as leukemic reticuloendotheliosis. The disease is characterized by monocytopenia, organomegaly, constitutional symptoms, and bone marrow fibrosis. Significant advances have improved the diagnosis and management of HCL over the last 55 years. Although HCL has an indolent course, most patients will require treatment of the disease. Indications to initiate therapy include disease-related symptoms, signs of bone marrow failure, or frequent infections. Asymptomatic patients without cytopenias can be observed without the need for therapeutic interventions. Therapeutic options usually consist of chemotherapy, immunotherapy, biological agents, and surgery.