Predictors of successful randomized phase III studies in the treatment metastatic renal cell carcinoma: A meta-analysis.

e17105 Background: The success of randomized phase III therapeutic trials (RP3TT) to reach their primary endpoint is critical given the enormous resources required to conduct such studies. In an era of accelerated therapeutic development in advanced kidney cancer, we aim to identify factors in such studies associated with a positive endpoint (PE) to better understand how to optimize trial design. Methods: Using PubMed and ClinicalTrials.gov, we identified all published RP3TT in patients with metastatic renal cell carcinoma between 1/2007-9/2019. Studies were considered PE if the primary endpoint was reached, and negative endpoint (NE) if otherwise. Studies were categorized as either first line only (FLO) or second line and beyond (SLB), with adjuvant and consolidation therapy studies excluded. We collected components of study design and baseline patient characteristics and analyzed with multivariate logistic regression to evaluate the associations between each factor and PE RP3TT. Results: Of the 65 studies evaluated, only 22 RP3TT (14 FLO, 8 SLB) were found to have published data and were included, with 14 PE and 8 NE. For all studies, those with larger enrollment size (OR = 1.008, 95% CI [1.001-1.015], p = 0.021) and clear cell requirements (OR = 0.077, 95% CI [0.007-0.901], p = 0.041) were associated with PE. After adjusting for sample size, only larger enrollment size remained significant (OR = 1.007, 95% CI [1.001-1.014], p = 0.032). Other baseline patient demographic and clinical characteristic variables were not associated with PE RP3TT. Subgroup analysis of only FLO or SLB studies also did not yield any significant associations with PE RP3TT. Conclusions: Higher enrollment size was identified as factor associated with PE in RP3TT. Incomplete trial data reporting was evident, particularly in earlier studies. Further efforts are needed to better characterize factors in order to optimize clinical trial design in this disease. [Table: see text]