ACNS1723: A Study of the Drugs Dabrafenib and Trametinib after Radiation Therapy in Patients with Newly-Diagnosed High-Grade Glioma

PRIMARY OBJECTIVE:

I. To estimate the event-free survival (EFS) distribution for newly-diagnosed patients with BRAF\^V600-mutant high-grade glioma (HGG) without H3 K27M mutations excluding anaplastic pleomorphic xanthoastrocytoma (aPXA) and anaplastic ganglioglioma (aGG) treated with radiation therapy followed by a maintenance combination of dabrafenib mesylate (dabrafenib) and trametinib dimethyl sulfoxide (trametinib) and to compare this EFS to contemporary historical controls.

SECONDARY OBJECTIVES:

I. To describe the overall survival (OS) distribution for newly-diagnosed patients with BRAF\^V600-mutant HGG without H3 K27M mutations excluding aPXA and aGG treated with radiation therapy followed by a maintenance combination of dabrafenib and trametinib.

II. To describe the EFS and overall survival (OS) distribution for newly-diagnosed patients with BRAF\^V600E-mutant aPXA and aGG without H3 K27M mutations treated with radiation therapy followed by a maintenance combination of dabrafenib and trametinib.

III. To describe the EFS and overall survival (OS) distribution for newly-diagnosed patients with BRAF\^V600E-mutant HGG including aPXA and aGG with H3 K27M mutations treated with radiation therapy followed by a maintenance combination of dabrafenib and trametinib.

IV. To define and evaluate the toxicities of combination therapy with dabrafenib and trametinib after radiation therapy in newly-diagnosed patients with HGG.

EXPLORATORY OBJECTIVE:

I. To bank tumor specimens and body fluids (blood, urine and cerebrospinal fluid) for future studies.

OUTLINE:

Patients undergo standardized local radiation therapy (RT) 5 days a week (Monday-Friday) for 6-7 weeks. Four weeks after completion of RT, patients receive dabrafenib mesylate orally (PO) twice daily (BID) and trametinib dimethyl sulfoxide PO once daily (QD) on days 1-28 of each cycle. Treatment repeats every 28 days for up to 24 cycles in the absence of disease progression or unacceptable toxicity. Patients undergo a magnetic resonance imaging (MRI) at baseline, on day 1 of cycles 1, 3, 5, 7, 11, 14, 17, 20, and 23 while on treatment, then at time of relapse, every 3 months for year 1, every 4 months for year 3, every 6 months for year 3, and annually for years 4-5. Patients may also undergo lumbar puncture for cerebral spinal fluid (CSF) testing during treatment. Patients also undergo collection of blood on study.

After completion of study treatment, patients are followed up at disease relapse, every 3 months for year 1, every 4 months for year 2, every 6 months for year 3, then annually for years 4-5.