Study of Relatlimab and Nivolumab (Opdualag) in Replication Repair Deficient HGG and DIPG

This is a multicenter, international study of post-radiotherapy (RT) fixed dose combination of nivolumab and relatlimab (Opdualag) to treat adolescent and young adult patients newly diagnosed with replication repair deficient (RRD) HGG and DIPG. The objectives of the study are to further evaluate feasibility and tolerability of Opdualag after RT, and to further characterize the safety and toxicity of Opdualag for patients with RRD HGG. We will also assess the progression free survival and overall survival distribution in patients. Protocol maintenance therapy of Opdualag must begin no later than 56 days post-completion of RT. The earliest patients can begin protocol treatment is 28 calendar days post-completion of RT. Each cycle will be 28 days in duration and treatment can continue up to a total of 26 cycles. Opdualag will be given intravenously once every 4 weeks.