PRIMARY OBJECTIVES: I. To determine the lowest dose of neem leaf extract (NLE) with antileukemic effect and acceptable toxicity in patients with chronic lymphocytic leukemia (CLL). II. Establish the safety and toxicity of NLE in patients with CLL. SECONDARY OBJECTIVES: I. Determine the efficacy of NLE in patients with CLL defined as overall clinical response (CR + PR) by the IWCLL criterion. II. To develop a pharmacokinetic/pharmacodynamic model relating neem leaf extract exposure to toxicity and pharmacodynamic endpoints in CLL patients that will allow personalized dosing to target optimal drug exposure. III. To conduct correlative studies. OUTLINE: This is a dose-escalation study. Patients receive oral Azadirachta indica once daily on days 1-28. Treatment repeats every 28 days for up to 8 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 1 year.
RATIONALE: Azadirachta indica may be an effective treatment for chronic lymphocytic leukemia. PURPOSE: This phase I trial is studying the side effects and best dose of Azadirachta indica in treating patients with chronic lymphocytic leukemia.