Itacitinib and Alemtuzumab in Treating Patients With T-Cell Prolymphocytic Leukemia

PRIMARY OBJECTIVES: I. To evaluate the safety and tolerability of itacitinib in combination with alemtuzumab in patients with T-cell prolymphocytic leukemia (T-PLL). SECONDARY OBJECTIVES: I. To evaluate the event free survival (EFS) in patients (pts) with T-PLL treated with itacitinib in combination with alemtuzumab. II. To evaluate response complete remission (CR), complete remission without blood count recovery (CRi), or partial remission (PR) (CR/CRi or PR) of itacitinib in combination with alemtuzumab in patients with T-PLL. III. To explore the single-agent activity of itacitinib in pts with T-PLL. IV. To assess the time to response, response duration, and overall survival (OS) in pts with T-PLL treated with the combination of itacitinib and alemtuzumab. EXPLORATORY OBJECTIVES: I. To explore the effect of itacitinib on STAT5 phosphorylation in pts with T-PLL II. To explore the association of pretreatment somatic mutations and the dynamics of STAT5 phosphorylation with response. OUTLINE: This is a dose-escalation study of alemtuzumab. CYCLE 1: Patients receive itacitinib orally (PO) once daily (QD) on days 1-28 and alemtuzumab intravenously (IV) over 2 hours on days 15, 17, 19, 21, 23, 25, and 27 in the absence of disease progression of unacceptable toxicity. CYCLE 2 AND BEYOND: Patients receive itacitinib PO QD on day 1-28 and alemtuzumab IV over 2 hours on days 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, and 27. Treatment repeats every 28 days for up to 4 cycles in the absence of disease progression or unacceptable toxicity. MAINTENANCE: Patients who achieve a response (CR/CRi or PR) may receive itacitinib for up to 8 additional cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically.