CTIM-14. RANDOMIZED PHASE II OPEN LABEL STUDY OF NIVOLUMAB PLUS STANDARD DOSE BEVACIZUMAB VS NIVOLUMAB PLUS LOW DOSE BEVACIZUMAB IN RECURRENT GLIOBLASTOMA (RGBM). NIVOLUMAB BENEFITS OLDER POPULATION

Abstract

BACKGROUND: Approaches using anti-PD1 therapy alone in rGBM is of limited efficacy. VEGF is upregulated proangiogenic growth factor in GBM that contributes to tumor-associated immunosuppression. Preclinical data suggests a potential dose effect of anti-VEGF therapy on immunomodulation. Hence, a combination of anti-PD1 and anti-VEGF may be a promising approach in rGBM. METHODS: 90 patients with GBM at first recurrence were randomized (1:1) to nivolumab (240 mg IV Q2 weeks) with bevacizumab at standard (10 mg/kg; Arm A) or at low dose (3 mg/kg; Arm B) IV Q2 weeks. Stratification included extent of resection, age, performance status and MGMT methylation status. Progressionfree survival (PFS) and overall survival (OS) were compared between two arms. RESULTS: 90 patients (Median age 60.6 years ranged 27.4-86.4, 67.8% male, median KPS 80) were enrolled between May 2018 and Jan 2020. Patients were followed in median 7.7 months (Range 0.7, 28.2). 35 patients were MGMT methylated and 53 patients were MGMT not hypermethylated and 2 were indeterminate. Overall Survival was not significantly different between arm A and arm B (1 year: 41.1 vs 37.7%, p=0.14), while OS was better for arm A in age > 60 (At 1-year: 46.2% vs 23.8%; Median: 10.6 vs 5.9 months; P=0.046). OS was no different in the two arms for age ≤ 60 years (At 1-year: 35.6% vs 56.4; Median 8.0 vs 12.4 months; P=0.90). Most frequent toxicities ( >20%) included fatigue (45.6%), proteinuria (34.4 %), diarrhea (28.9%), hypertension (23.3%) and lipase increase (21.1%). Toxicities in grade 3-4 were hypertension (7.8%), fatigue (5.6) and other non-neurological toxicities including DVT, PE, infection, and abnormal liver function. CONCLUSIONS: Overall PFS and OS rates appear similar for nivolumab with either standard or lowdose bevacizumab compared to historical benchmarks of bevacizumab monotherapy. Nivolumab with standard bevacizumab seem to benefit patients older than 60 years old.