PDCT-16. SURVIVAL BENEFIT WITH TRIPLE CHEMOTHERAPY AND TTFIELDS FOR GLIOBLASTOMA

Abstract

Glioblastoma multiforme (GBM) is the most aggressive and common glial tumor. Historical data shows that median overall survival (OS) is 14.6 months with maximum safe resection followed by radiation and chemotherapies. We have been treating recurrent GBM patients with triple chemotherapies [Temozolomide (TMZ), bevacizumab (BV) and Irinotecan (CPT-11)] since 2010. We also offer patients tumor treating fields (TTFs) for recurrent GBM following FDA approval and participated in the EF-14 clinical trial for newly diagnosed GBM from 2011. Here we report OS data of our institute's patients on TTFs treatment, with or without the triple chemotherapy, from February 2011 to June 2016. Data review was approved by the Committee for the Protection of Human Subjects at UT Health. Kaplan-Meier survival curve and log rank test were used for statistical analysis. Primary objectives were OS and adverse events. Fifty-two GBM patients (21-76 years old, average age=54 ± 11.6) received TTFs treatment, 32 of which expired, 17 patients are alive and the survival status of 3 patients remains unknown. For patient received triple chemotherapies (TMZ cycles=17.9 ± 11.2; BV infusion times= 23.5 ± 10.8; CPT-11 infusion times=13.7 ± 6.8) plus TTFs (446 ± 396 days), median OS is 34.5 months (n=29, 95% CI: 27.8-49.7). Median OS is 14.0 months (n=23, 95% CI: 11.5-17.90) for patients receiving BV/CPT-11 (TMZ cycles=4.9 ± 7.2; BV infusion times=6.6 ± 6.2) plus TTFs (164 ± 198 days), log rank test p<0.05. For patients who started TTFs within 125 days from their initial diagnosis, OS is 39.4 months (n=15, 95% CI: 11.8-53.1). Major adverse events are chemotherapy related thrombocytopenia (grade III in 2 cases), neutropenia, anemia, GI toxicities (nausea, vomiting and diarrhea) and TTFs related scalp lesions. Molecular profile will be provided at the time of presentation. Treating recurrent GBM with triple chemotherapies (BV, TMZ, and CPT-11) is reasonably well-tolerated with manageable side effects. Triple chemotherapies plus TTFields demonstrates superior OS benefit compared to historical data.