P14.58 Extending adjuvant temozolomide longer than six cycles doesn’t add any benefit to glioblastoma patients according to the randomized GEINO-014 TRIAL

BACKGROUND Standard treatment of glioblastoma (GBM) is focal radiation with concomitant and adjuvant temozolomide (TMZ) for 6 cycles. The GEINO-14-01 trial (NCT02209948) investigated the role of extending adjuvant TMZ to 12 cycles in a randomized multicenter study. MATERIAL AND METHODS Between Aug/2014 and Nov/2018, 166 patients (p) were screened and 159 randomized to extend (80p) or not (79p) TMZ treatment to 12 cycles after proving stable disease in the MRI performed before inclusion. The trial was stratified by MGMT status and presence or absence of residual disease (defined as a residual enhancement larger than 1cm on the MRI). The primary endpoint was differences in 6monthsPFS, secondary endpoints were differences in PFS, OS, toxicity, between arms and per stratification factors. RESULTS Median age was 60.4 (range 29–83), 97p (61%) were methylated and 83 p (52.2%) were reported with residual disease. Median (m) PFS was 7.9 months (95%CI: 6.1–9.8) and mOS: 20.9 (95%CI: 17.6–24.1). A methylated status was a factor of better PFS (HR=0.29, 95% CI 0.46–0.95; p=0.029) and better OS (HR= 0.43: 95% CI 0.28–0.66; p=0.000) as well as the absence of residual disease (PFS: HR = 0.84: 95% CI =0.71–1.01; p=0.068; OS: HR=0.77, 95%CI 0.63–0.96; p=0.019). We didn’t find any difference in PFS (HR=1.02, 95%CI 0.85–1.21; p=0.82), or OS (HR=0.90; 0.73–1.11; p=0.34) on extending treatment with temozolomide longer than 6 cycles. CONCLUSION There is no benefit of continuing TMZ treatment for more than 6 cycles in the adjuvant treatment of glioblastoma. Final data will be presented at the congress. Supported by a Grant of the ISCIII: PI13/01751