Veliparib, Radiation Therapy, and Temozolomide in Treating Participants With Newly Diagnosed Malignant Glioma Without H3 K27M or BRAFV600E Mutations

PRIMARY OBJECTIVES:

I. To determine whether veliparib (ABT-888), when added to radiotherapy (RT) and
temozolomide, is efficacious for the treatment of patients with newly-diagnosed high-grade
glioma (HGG) whose tumors' molecular profile are wild-type for H3 K27M, BRAFV600E, and
IDH1/2.

II. To determine whether veliparib (ABT-888), when added to RT and temozolomide, is
efficacious for the treatment of patients with newly-diagnosed HGG whose tumors' molecular
profile are wild-type for H3 K27M and BRAFV600E and harbor an IDH1/2 mutation.

SECONDARY OBJECTIVES:

I. To explore associations of genomic, transcriptomic, and/or epigenetic alterations of the
tumors with treatment response and outcome.

II. To explore the extent to which patients with BRCA1/2 gene alterations and other
deoxyribonucleic acid (DNA) damaged genes display tumor genomic features consistent with
homologous repair deficiency (HRD), including large scale state transitions (LSTs),
mutational signature 3, and an enrichment for deletions flanked by sequences of (micro)
homology.

III. To explore the burden of high, moderate, and low penetrant germline alterations in HRD
genes (such as BRCA1, BRCA2, PALB2, Fanconi complex genes, ATM, CHEK2, RAD51B/C/D), mis-match
repair genes (such as MLH1, MSH2, MSH6, PMS2, EPCAM), and energy metabolism genes (such as
SDHA, SDHB, SDHC, SDHAF2, SDHD, IDH1, IDH2, and FH).

IV. To explore constitutional imprinting abnormalities associated with EP300 and IGF2 in
peripheral blood from patients with HGGs.

OUTLINE:

CHEMORADIOTHERAPY PHASE: Participants receive veliparib orally (PO) twice daily (BID) and
undergo 30 daily fractions of radiation therapy 5 days per week for 6-7 weeks in the absence
of disease progression or unacceptable toxicity.

MAINTENANCE CHEMOTHERAPY: Beginning 4 weeks after chemoradiotherapy phase, participants
receive veliparib PO BID and temozolomide PO once daily (QD) on days 1-5. Treatment repeats
every 28 days for up to 10 courses in the absence of disease progression or unacceptable
toxicity.

Inclusion Criteria:

- Stratum 1 (IDH wild-type): Patients must be >= 3 years of age and =< 21 years of age
at the time of enrollment

- Stratum 2 (IDH mutant): Patients must be >= 3 years of age and =< 25 years of age at
the time of enrollment

- Patients must have eligibility confirmed by rapid central pathology and central
molecular screening reviews performed on APEC14B1:

- Newly-diagnosed high-grade glioma such as anaplastic astrocytoma or glioblastoma

- Negative results for H3 K27M by immunohistochemistry (IHC)

- Negative results for BRAFV600E mutation by next-generation sequencing (NGS)

- Patients must have histological verification of diagnosis. Patients with M+ disease
(defined as evidence of neuraxis dissemination) are not eligible. Cerebrospinal fluid
(CSF) cytology is not required but may be obtained if clinically indicated prior to
study enrollment. If cytology is positive, the patient would be considered to have
metastatic disease and would, therefore, be ineligible

- Pre-operative and post-operative brain magnetic resonance imaging (MRI) with and
without contrast must be obtained. The requirement for a post-operative MRI is waived
for patients who undergo biopsy only. A spine MRI is not required, but may be obtained
if clinically indicated. If the spine MRI is positive, the patient would be considered
to have M+ disease (defined as neuraxis dissemination) and would be ineligible

- Patients must have a performance status of >= 50 by Lansky or Karnofsky, corresponding
to Eastern Cooperative Oncology Group (ECOG) scores of 0, 1, or 2. Use Karnofsky for
patients > 16 years of age and Lansky for patients =< 16 years of age. Patients who
are unable to walk because of paralysis, but are up in a wheelchair will be considered
ambulatory for the purposes of assessing the performance score

- Peripheral absolute neutrophil count (ANC) >= 1,000/uL

- Platelet count >= 100,000/uL (transfusion independent)

- Hemoglobin >= 8.0 gm/dL (can be transfused)

- Creatinine clearance or radioisotope glomerular filtration rate (GFR) >= 70
mL/min/1.73 m^2 OR a serum creatinine based on age/gender as follows:

- 3 to < 6 years: 0.8 (male and female) maximum serum creatinine (mg/dL)

- 6 to < 10 years: 1 (male and female) maximum serum creatinine (mg/dL)

- 10 to < 13 years: 1.2 (male and female) maximum serum creatinine (mg/dL)

- 13 to < 16 years: 1.5 (male), 1.4 (female) maximum serum creatinine (mg/dL)

- >= 16 years: 1.7 (male), 1.4 (female) maximum serum creatinine (mg/dL)

- Total bilirubin =< 1.5 x upper limit of normal (ULN) for age

- Serum glutamic-oxaloacetic transaminase (SGOT) (aspartate aminotransferase [AST]) or
serum glutamate pyruvate transaminase (SGPT) (alanine aminotransferase [ALT]) < 2.5 x
upper limit of normal (ULN) for age

- Patients with seizure disorder may be enrolled if seizures are well-controlled (i.e.,
patients must not have required rescue medications for uncontrolled seizures within 14
days prior to enrollment)

- Patients must be enrolled and protocol therapy must be projected to begin no later
than 31 days after definitive diagnostic surgery (Day 0)

- All patients and/or their parents or legal guardians must sign a written informed
consent

- All institutional, Food and Drug Administration (FDA), and National Cancer Institute
(NCI) requirements for human studies must be met

Exclusion Criteria:

- Patients with the following histologies:

- Diffuse astrocytoma (grade 2)

- Oligodendrogliomas (any grade)

- Pleomorphic xanthoastrocytoma (PXA, any grade)

- Patients with primary tumor location of brainstem or spinal cord

- Patients with M+ disease (defined as neuraxis dissemination either by imaging or by
cytology)

- Patients must not have received any prior tumor-directed therapy including radiation
therapy, chemotherapy (tumor-directed therapy), molecularly targeted agents, or
immunotherapy for the treatment of HGG other than surgical intervention

- Lumbar CSF cytology is not required, but may be performed if clinically indicated
prior to study enrollment. If lumbar CSF cytology is positive, the patient is
considered to have M+ disease and is ineligible

- Note: False positive cytology can occur within 10 days of surgery

- Patients with gliomatosis cerebri type 1 or 2

- Patients who are not able to receive protocol specified radiation therapy

- Patients must not be currently receiving other anti-cancer agents

- Patients with known constitutional mismatch repair deficiency syndrome
(CMMR-D)/biallelic mismatch repair deficiency (bMMRD)

- Female patients who are pregnant are ineligible due to risks of fetal and teratogenic
adverse events as seen in animal/human studies

- Lactating females are not eligible unless they have agreed not to breastfeed their
infants

- Female patients of childbearing potential are not eligible unless a negative pregnancy
test result has been obtained

- Sexually active patients of reproductive potential are not eligible unless they have
agreed to use an effective contraceptive method for the duration of their study
participation and for 4 months after the last dose of veliparib