Rationale: Chronic lymphocytic leukemia (CLL) is a disease characterized by the accumulation of mature lymphocytes. These CLL lymphocytes are blocked from undergoing terminal differentiation and apoptosis. Patients with CLL have limited options for therapy, especially after the failure of standard chemotherapy regimens. Histone deacetylase inhibitors (HDACs) comprise a new class of drugs being evaluated in the treatment of various malignancies. In vitro data suggest that HDAC inhibition leads to terminal B-cell differentiation and may therefore play a therapeutic role in the treatment of CLL. Pivanex (pivaloyloxymethyl butyrate) is an HDAC inhibitor that has been shown to induce apoptosis of CLL lymphocytes in vitro. In previous clinical trials, Pivanex has been well tolerated. The goal of this protocol is to determine the effects of Pivanex in patients with CLL.~Purpose: This open-label trial will determine the response rate of Pivanex in patients with CLL.~Objectives: (1) Determine the response rate of Pivanex in patients with relapsed CLL; (2) Determine time to disease progression in patients with relapsed CLL treated with Pivanex; and (3) Determine the safety profile of Pivanex in CLL.~Design: This is an open label, single arm, multiple dose, pilot study of patients with relapsed CLL. Patients will be treated with 2.5 g/m2 of Pivanex administered intravenously over 6 hours daily on Days 1 - 3. Treatment will be repeated every 21 days until disease progression or the patient is withdrawn from treatment for protocol-specified reasons.~Disease status will be assessed prior to every odd-numbered treatment cycle using response criteria based upon the Revised National Cancer Institute-sponsored Working Group Guidelines for CLL. Patients withdrawn due to disease progression will be followed for survival. Patients withdrawn from study for reasons other than disease progression will be followed for disease progression and survival.
This pilot study will assess the safety and efficacy of Pivanex alone in patients with chronic lymphocytic leukemia (CLL) who have relapsed or refractory disease after previous chemotherapy treatment. Pivanex is an investigational agent.