Veliparib, Radiation Therapy, and Temozolomide in Treating Younger Patients With Newly Diagnosed Diffuse Pontine Gliomas

PRIMARY OBJECTIVES: I. To identify the maximum-tolerated dose or recommended Phase II dose of ABT-888 (veliparib) which can be safely administered concurrently with radiation therapy, followed by maintenance therapy with ABT-888 and temozolomide (TMZ), in patients with newly diagnosed diffuse pontine gliomas (DIPG). (Phase I) II. To study the plasma pharmacokinetics (PK) of ABT-888 during ABT-888 and radiation therapy. (Phase I) III. To study the feasibility of intra-patient dose escalation of TMZ during maintenance therapy with ABT-888 and TMZ. (Phase I) IV. To describe the toxicities associated with administering ABT-888 and radiation therapy, followed by ABT-888 and TMZ, in patients with newly diagnosed DIPG. (Phase I) V. To estimate the proportion of newly diagnosed DIPG patients treated on protocol that are determined to have experienced pseudo progression. (Phase I) VI. To estimate the overall survival distribution for newly diagnosed patients with DIPG treated with the combination of ABT-888 and radiation therapy, followed by ABT-888 and TMZ, and compare to Pediatric Brain Tumor Consortium (PBTC) historical controls. (Phase II) VII. To study the feasibility of intra-patient dose escalation of TMZ during maintenance therapy with ABT-888 and TMZ. (Phase II) VIII. To estimate the proportion of newly diagnosed DIPG patients treated on protocol that are determined to have experienced pseudo progression. (Phase II) SECONDARY OBJECTIVES: I. To estimate the progression-free survival (PFS) distribution and to summarize the best tumor responses observed prior to progression or recurrence. II. To explore the plasma PK of ABT-888 during ABT-888 and radiation therapy. III. To explore peripheral blood mononuclear cell (PBMC) poly (ADP-ribose) polymerase 1(PARP) activity before and after treatment with ABT-888. IV. To explore quantifying non-homologous end-joining (NHEJ) activity or gamma-H2A histone family, member X (H2AX) levels (as surrogate markers of unrepaired double-strand breaks (DSBs)) in PBMC before and after treatment with ABT-888. V. To explore quantifying PARP activity and deoxyribonucleic acid (DNA)-repair protein levels in biopsied atypical pontine gliomas, if available. VI. To explore associations of molecular parameters from secondary aims III, IV, and V with PFS and overall survival (OS) after conclusion of clinical trial. VII. To explore the quantitative magnetic resonance (MR) measures of relative cerebral blood volume (rCBV), vascular permeability (Ktrans, fractional plasma volume \[vp\], and extravascular extracellular space volume fraction \[ve\] values), and apparent diffusion coefficient (ADC) within the first six months of initiating protocol treatment to correlate with disease outcome and determine whether such metrics differentiate patients with pseudo progression from those with true early progressive disease. VIII. To explore the potential utility of urine biomarkers as a novel, non-invasive method of detecting and tracking changes in the status of pediatric brain stem gliomas. OUTLINE: This is a phase I, dose-escalation study of veliparib followed by a phase II study. DOSE-ESCALATION: Patients receive veliparib orally (PO) twice daily (BID) 5 days a week for 6-7 weeks. Patients also undergo concurrent 3-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) once daily (QD) 5 days a week for 6-7 weeks. MAINTENANCE THERAPY: Beginning 3-4 weeks later, patients receive veliparib PO BID on days 1-5 and temozolomide PO QD on days 1-5. Treatment repeats every 28 days for up to 10 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically for up to 3 years.