456P - Real-world data of IDH mutant gliomas in Spain, a RETSINE: GEINO study

Background

IDH-mutant gliomas are brain tumors with a high impact on quality of life and morbidity in the AYA (young adults and adolescents) population. It is a very heterogeneous disease with different treatment options and a new effective targeted therapy (vorasidenib) which is very well tolerated. More real-world data is needed to advance the best management of this population.

Methods

A retrospective cohort study of all IDH-mutant gliomas diagnosed from 2019 to 2023 in 21 Spanish centers, a total of 485 cases. This study includes data from a GEINO questionnaire (21 centers) and from the RETSINE (Spanish registry of CNS tumors).

Results

From 2019 to 2023, 485 cases of IDH-mutant glioma were diagnosed in 21 centers, 67% astrocytomas (A) (326/485) and 33% oligodendrogliomas (O) (159/485). A watch-and-wait (WW) strategy was relatively frequent in low-grade gliomas (LGG) 33% (75/226), and slightly more frequent in O grade 2 40% (41/103) than in A grade 2 28% (34/123). Despite this, with a very short follow-up, 24% (19/80) of the WW population have ended up receiving treatment, radiotherapy (RT) or chemotherapy (CT). We have collected all data from 241 cases in RETSINE. Median age was 46 years old and 56% were male. Nearly half were glioma gr2 46%, 32% gr3 and 21% gr4. Complete resection was achieved in 35%, Karnofksy performance status (KPS) was superior to 80% in 70%, and neurologic deficit at diagnosis was present in 35%. Overall survival (OS) at 2 years is 94% (O gr2), 96% (O gr3), 91% (A gr2), 82% (A gr3) and 55% (A gr4) and progression-free survival at 2 years is 80% (O gr2), 91% (O gr3), 74% (A gr2), 51% (A gr3) and 27% (A gr4), with a median follow up of 1.8 years. Univariate analyses for OS in astrocytomas confirm the prognostic role of various factors: histologic grade 3-4 (HR 4.07; p=0.004), KPS >80% (HR 0.19; p<0.001); tumor size ≥ 6 cm (HR 2.53; p=0.03) and previous neurologic deficit (HR 2.64; p=0.01). The WW population was enriched with complete resection and younger age. All detailed data of > 600 patients will be presented at the congress.

Conclusions

Real-world data of IDH-mutant gliomas in Spain demonstrates that WW is a strategic decision in 33% of LGG, 40% in oligodendrogliomas gr2. Despite this, in short follow-up, 24% of these end up receiving treatment. Real-world data can help to better understand the disease and optimize patient care strategies in the new era of IDH inhibitors.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

GEINO group, Spanish Group of Neuro-Oncology.

Funding

Has not received any funding.

Disclosure

A. Garcia Castano: Financial Interests, Personal, Advisory Role: Bristol Myers Squibb, MSD, Pierre-Fabre, Pfizer, Roche, Novartis. G. Velilla: Financial Interests, Personal, Invited Speaker: Neuraxpharm Spain. M. Domenech Vinolas: Financial Interests, Personal, Invited Speaker: BMS, Roche; Financial Interests, Personal, Research Funding: Roche. M. Alonso Garcia: Financial Interests, Personal, Advisory Role: BMS, Pfizer, Roche, Takeda, Lilly. I. Ceballos Lenza: Financial Interests, Personal, Invited Speaker: Pfizer, Novartis, Merck, MSD, BMS, Roche, AstraZeneca; Financial Interests, Personal, Advisory Board: Seagen, Novartis; Non-Financial Interests, Principal Investigator: BMS, GSK. E. Almagro Casado: Financial Interests, Personal, Speaker’s Bureau: MSD; Financial Interests, Institutional, Principal Investigator: MSD; Financial Interests, Institutional, Other, Subinvestigator: AstraZeneca, Roche. E. Pineda: Financial Interests, Personal, Advisory Board: Novocure, Novartis; Financial Interests, Personal, Other, Speakers Bureau: Novocure. All other authors have declared no conflicts of interest.