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Updated: Feb 18, 2026
A Protocol for Explant Cultures of IDH1-mutant Diffuse Low-grade Gliomas
Published on: May 9, 2025
Ivosidenib treatment in IDH-mutant WHO grade 4 astrocytomas: illustrative case
Brittany Owusu- Adjei1,2, Janelle P Renterghem1, Cristina Hayes Meizoso1
1Department of Neurological Surgery, University of Massachusetts Chan Medical School, Worcester.
Background:
Isocitrate dehydrogenase (IDH) is a commonly mutated gene in gliomas. Although IDH-mutant WHO grade 4 astrocytomas tend to occur in younger patients and show an improved survival compared to IDH-wildtype, prognosis remains poor and treatment options are limited. Ivosidenib is a small-molecule inhibitor of IDH-1 that has shown promise for treating low-grade IDH-mutant glioma. However, little is known about its efficacy in IDH-mutant WHO grade 4 astrocytoma.
Observations:
The authors present the case of a 36-year-old male with a IDH-mutant WHO grade 4 astrocytoma. He was originally treated with resection, followed by radiation therapy and temozolomide. At the second recurrence, ivosidenib was started, after lomustine therapy had failed to control the disease. Radiological surveillance showed interval decrease in tumor size starting 2 months after initiation of ivosidenib. The patient remained neurologically intact, and no adverse effects were observed.
Lessons:
Here the authors report the effects of the off-label use of ivosidenib. The INDIGO trial published evidence of efficacy in using an IDH inhibitor for low-grade gliomas. The role of these drugs in high-grade IDH-mutant gliomas is currently unknown. Further studies are needed to assess their impact on overall and progression-free survival. https://thejns.org/doi/10.3171/CASE25572.
