On Aug. 6, 2024, the U.S. Food and Drug Administration (FDA) announced it had approved vorasidenib (Voranigo, Servier Pharmaceuticals), an isocitrate dehydrogenase-1 (IDH1) and isocitrate dehydrogenase-2 (IDH2) inhibitor, for adult and pediatric patients 12 years and older with Grade 2 astrocytoma or oligodendroglioma with a susceptible IDH1 or IDH2 mutation, following surgery including biopsy, sub-total resection, or gross total resection.

This is the first approval by the FDA of a systemic therapy for patients with Grade 2 astrocytoma or oligodendroglioma with a susceptible IDH1 or IDH2 mutation.

Efficacy was evaluated in 331 patients with Grade 2 astrocytoma or oligodendroglioma with a susceptible IDH1 or IDH2 mutation following surgery enrolled in INDIGO (NCT04164901), a randomized, multicenter, double-blind, placebo-controlled trial. Patients were randomized 1:1 to receive vorasidenib 40 mg orally once daily or placebo orally once daily until disease progression or unacceptable toxicity. IDH1 or IDH2 mutation status was prospectively determined by the Life Technologies Corporation Oncomine Dx Target Test. Patients randomized to placebo were allowed to cross over to vorasidenib after documented radiographic disease progression. Patients who received prior anti-cancer treatment, including chemotherapy or radiation therapy, were excluded.

The major efficacy outcome measure was progression-free survival (PFS) using a blinded independent review committee per modified Response Assessment in Neuro-Oncology for Low Grade Glioma (RANO-LGG) criteria. An additional efficacy outcome measure was time to next intervention. The hazard ratio for PFS was 0.39 (95% CI: 0.27, 0.56), p-value <0.0001. The median time to next intervention was not reached for the vorasidenib arm and was 17.8 months for the placebo arm (HR=0.26; 95% CI: [0.15, 0.43], p <0.0001).

The most common (≥15%) adverse reactions were fatigue, headache, COVID-19 infection, musculoskeletal pain, diarrhea, nausea, and seizure. The most common Grade 3 or 4 laboratory abnormalities (>2%) were increased alanine aminotransferase, increased aspartate aminotransferase, GGT increased, and decreased neutrophils.