Dr van den Bent talks to ecancer at ASCO 2025 about the final analysis of the phase III CATNON trial he presented.

This evaluated the long-term effects of concurrent and adjuvant temozolomide in patients with non-codeleted anaplastic glioma, focusing on IDH mutation status and molecular subtypes.

Adjuvant temozolomide significantly improved overall survival in patients with IDH-mutant tumours (HR 0.54; p < 0.0001), with a median OS of 12.5 years.

Concurrent TMZ showed no OS benefit, regardless of IDH status (HR 0.906; p = 0.28).

In patients with IDH-wildtype (tumours, median OS was only 1.7 years, and no benefit from TMZ was observed.

Among IDHmt patients, adding concTMZ to adjTMZ did not provide additional benefit (HR 0.92; p = 0.69).

Adjuvant temozolomide after radiotherapy significantly improves survival in IDH-mutant anaplastic glioma but concurrent temozolomide does not add benefit. 

Dr van den Bent notes that the standard of care for high-grade IDHmt astrocytoma should be radiotherapy followed by 12 cycles of adjuvant temozolomide.