Multicenter phase 1 trial of indoximod-based chemo-immunotherapy for pediatric brain tumors

Indoleamine 2,3-dioxygenase (IDO) is a metabolic checkpoint that in preclinical models inhibits anti-tumor immunity following chemotherapy. A multicenter phase 1 trial evaluated the oral IDO-pathway inhibitor indoximod in combination with oral temozolomide or with palliative radiation among children with recurrent brain tumors or newly-diagnosed diffuse intrinsic pontine glioma. Indoximod was well tolerated and could be safely combined with chemotherapy or radiation. There was encouraging evidence of efficacy.