Entinostat in Treating Pediatric Patients With Recurrent or Refractory Solid Tumors

PRIMARY OBJECTIVES: I. To estimate the maximum tolerated dose (MTD) and/or recommended phase 2 dose of entinostat administered as a single-agent, once weekly to children with recurrent or refractory solid tumors. II. To define and describe the toxicities of entinostat administered as a single agent, once weekly to children with recurrent or refractory solid tumors. III. To characterize the pharmacokinetics of entinostat in children with recurrent or refractory cancer. SECONDARY OBJECTIVES: I. To preliminarily define the antitumor activity of entinostat within the confines of a phase 1 study. II. To assess change in histone H3 and H4 acetylation in peripheral blood mononuclear cells (PBMCs) as a marker of the biologic activity of entinostat. OUTLINE: This is a dose escalation study. Patients receive entinostat orally (PO) on days 1, 8, 15, and 22. Cycles repeat every 28 days for up to 5 years in the absence of disease progression or unacceptable toxicity.