# INDIGO

Source: https://onco.cc/trials/indigo/  
OnCo record `indigo` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The first targeted-therapy win in low-grade brain tumours: a pill that more than doubled the time before the tumour grew, delaying radiation and chemotherapy by years.

## Summary

INDIGO, trial NCT04164901 sponsored by Servier and reported in 2023, delivered the first targeted-therapy win in low-grade brain tumours: the IDH inhibitor vorasidenib more than doubled the time before residual or recurrent grade 2 IDH-mutant glioma grew, delaying radiotherapy and chemotherapy by years. It randomised 331 patients with astrocytoma or oligodendroglioma after surgery and no prior radiotherapy or chemotherapy to vorasidenib or placebo, met its primary progression-free survival endpoint by blinded review with a large effect, sharply reduced the need for the next intervention, and led to FDA approval in August 2024. OnCo links it to IDH1 and IDH2 as targets, the mutant IDH pathway, Ingo K. Mellinghoff, Patrick Y. Wen and the brain as a bottleneck. Its long-term effect on survival and on malignant transformation is pending, which is the open question.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-06
- Registry id: NCT04164901
- Phase: 3
- Setting: Residual or recurrent grade 2 IDH-mutant astrocytoma or oligodendroglioma after surgery, no prior RT/chemo: vorasidenib vs placebo
- Sponsor: Servier
- Enrolled: 331
- Result: PFS 27.7 vs 11.1 months, HR 0.39.
- Outcomes: Progression-free survival (BIRC): Vorasidenib 27.7 months vs Placebo 11.1 months, HR 0.39
- Replication: Single pivotal trial; the first targeted therapy in low-grade glioma. Time to next intervention also improved (HR 0.26).

## Sources

- ClinicalTrials.gov NCT04164901: https://clinicaltrials.gov/study/NCT04164901

## Connected records

- cancers: [Astrocytoma, IDH-mutant (grades 2 to 4)](https://onco.cc/cancers/idh-mutant-astrocytoma/), [Glioma & glioblastoma](https://onco.cc/cancers/glioblastoma/), [Oligodendroglioma, IDH-mutant and 1p/19q-codeleted](https://onco.cc/cancers/oligodendroglioma/)
- technologies: [Epigenetic drugs (HDAC, DNMT, EZH2, IDH, menin, BET)](https://onco.cc/technologies/epigenetic-drugs/), [IDH inhibitors](https://onco.cc/technologies/idh-inhibitors/)
- targets: [IDH1 / IDH2](https://onco.cc/targets/idh/)
- drugs: [Vorasidenib](https://onco.cc/drugs/vorasidenib/)
- companies: [Servier](https://onco.cc/companies/servier/)
- people: [Ingo K. Mellinghoff](https://onco.cc/people/ingo-mellinghoff/), [Patrick Y. Wen](https://onco.cc/people/patrick-wen/)
- pathways: [Mutant IDH / 2-hydroxyglutarate](https://onco.cc/pathways/idh-2hg/)
- bottlenecks: [The brain: barrier and sanctuary](https://onco.cc/bottlenecks/b-brain-delivery/)

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