NIMG-42. DURABLE OVERALL RESPONSE RATE (ORR) TARGETS FOR RECURRENT GLIOBLASTOMA (RGBM) CLINICAL TRIALS BASED ON THE HISTORIC ASSOCIATION BETWEEN ORR AND MEDIAN OVERALL SURVIVAL (MOS)

Abstract Durable overall response rate (ORR) remains a meaningful endpoint in recurrent GBM; however, the target ORR for single arm GBM trials has not been based on historic information or tied to patient outcomes. The current study reviewed past order judiciously define ORRs use trials. After reviewing 69 treatment arms comprising 4,971 patients, was 6.1%[95% CI 4.23; 8.76%] cytotoxic chemotherapies (ORR=7.59% CCNU, 7.57% TMZ, 0.64% CPT-11, and 5.32% other agents), 3.37% biologic agents, 7.97% immunotherapies (select trials), 26.8% anti-angiogenic agents. were significantly correlated with median survival (mOS) across chemotherapy (R2=0.4078, P< 0.0001), biologics (R2=0.4003, P=0.0003), immunotherapy (R2=0.8994, but agents (R2=0, P=0.8937). Pooling data from chemotherapy, biologics, trials, meta-analysis indicated strong correlation between mOS (R2=0.3164, 0.0001; mOS[weeks]=0.6xORR+28.9), suggesting an >20% results of > 40.9 weeks, which is double estimate ORR=0% ≥ 2 months longer than treatments ORR=5%. Assuming ineffective therapy (control) ORR=5%, trial 32 patients ORR=20% leads 95% confidence interval higher control group. We conclude that phase II studies should have 20%. This associated OS approximately 1 year. Importantly, durability also be considered assessed meta-analysis.