Clinical Outcomes for Metastatic Renal Cell Carcinoma (mRCC) Patients Ineligible for Front-line Clinical Trials

Clinical trials for immunotherapy-based regimens in metastatic renal cell carcinoma (mRCC) have extensive inclusion and exclusion criteria. We investigated the clinical outcomes in a real-world cohort of patients who would not have met the criteria for inclusion in front-line mRCC trials. Patients treated with ipilimumab/nivolumab and axitinib/pembrolizumab for front-line mRCC were identified and divided into clinical trial eligible (CTE) and clinical trial ineligible (CTI) cohorts based on key inclusion or exclusion criteria from their respective Phase-3 registration trials. Clinical outcomes were compared in CTE and CTI cohorts. A total of 62 patients treated with axitinib/pembrolizumab and 103 treated with ipilimumab/nivolumab were identified. The International Metastatic RCC Database Consortium (IMDC) criteria were similar across CTE and CTI patients in axitinib/pembrolizumab and ipilimumab/nivolumab cohorts. In the axitinib/pembrolizumab cohort (n = 62), 24 (39%) patients were CTI. The major reasons for the ineligibility were lab abnormalities (n = 11), histology (n = 9), and brain metastases (n = 3). There was no significant difference in response rates (P = 0.08). The median progression-free survival (PFS) was numerically longer in CTE patients (28 vs 12 months; P = 0.09). The overall survival (OS) was higher in the CTE patients (P = 0.02). In the ipilimumab/nivolumab cohort (n = 103), 59 (57%) were CTI. The most common reasons for ineligibility were brain metastases (n = 18), lab abnormalities (n = 16), and histology (n = 16). There was no significant difference in response rates (P = 0.22). However, PFS (P = 0.003) and OS (P < 0.0001) were higher in the CTE patients. In conclusion, many real-world patients are ineligible for RCC clinical trials and had worse outcomes when compared to trial-eligible patients. Additional treatment options are needed for these patients, as well as strategies to include them in prospective trials.