ESTRO 2024 - Abstract Book

S878

Clinical - CNS

ESTRO 2024

Conclusion:

Pre-treatment stratification by MGMT status in a phase I GBM study is feasible and enables optimisation of olaparib dosing and scheduling with RT and TMZ. In MGMT unmethylated patients, olaparib can be combined with RT at the full single agent dose (300 mg twice daily) if TMZ is withheld. Of 29 patients receiving this dose, a quarter have survived more than 2 years. In MGMT methylated patients, olaparib can be safely combined with radical CRT when given at lower doses on an intermittent basis (currently 150 mg four days per week). Ongoing biomarker studies