Cabozantinib versus sunitinib for untreated patients with advanced renal cell carcinoma of intermediate or poor risk: Subgroup analysis of the Alliance A031203 CABOSUN trial

Cabozantinib treatment prolonged progression-free survival (PFS) and improved objective response rate (ORR) compared with sunitinib in patients with advanced renal cell carcinoma (RCC) of intermediate or poor risk by International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) criteria in the phase II CABOSUN trial (NCT01835158). In the trial, 157 patients were randomized 1:1 to receive cabozantinib or sunitinib, stratified by IMDC risk group and presence of bone metastases. Here, PFS and ORR, both determined by independent radiology committee (IRC), were analyzed by subgroups of baseline characteristics. Cabozantinib treatment was generally associated with improved PFS and ORR versus sunitinib across subgroups, including in groups defined by IMDC risk group, bone metastases, age, and tumor burden

Clinical Results and Biomarker Analyses of Axitinib and TRC105 versus Axitinib Alone in Patients with Advanced or Metastatic Renal Cell Carcinoma (TRAXAR)

Lessons learnedThe combination of carotuximab with axitinib did not provide a benefit over axitinib monotherapy in patients with metastatic clear cell renal cell carcinoma who had previously progressed on one or more vascular endothelial growth factor (VEGF)-targeted therapies. Exploratory evaluation of pretreatment circulating biomarkers suggested the combination might benefit patients who have low baseline VEGF levels.BackgroundEndoglin is an angiogenic receptor expressed on proliferating tumor vessels and renal cell carcinoma (RCC) stem cells that is implicated as a mechanism of resistance to vascular endothelial growth factor receptor (VEGFR) inhibitors. This study evaluated an antiendoglin monoclonal antibody (carotuximab, TRC105) combined with axitinib in patients with advanced or metastatic clear cell renal cell carcinoma (mccRCC) who had progressed following one or more prior VEGF inhibitors.MethodsTRAXAR was a multicenter, international randomized 1:1 (stratified by ECOG, 0 vs. 1), phase II study of carotuximab combined with axitinib versus axitinib alone in mccRCC patients who had progressed following one or more prior VEGF inhibitors. The primary endpoint was progression-free survival (PFS) assessed by independent central review (ICR) per RECIST 1.1 RESULTS: A total of 150 patients were randomized. The combination therapy resulted in shorter median PFS by RECIST 1.1 than axitinib monotherapy (6.7 vs. 11.4 months). The combination was tolerated similarly to axitinib monotherapy, and there were no treatment related deaths. Exploratory evaluation of pretreatment circulating biomarkers suggested the combination might benefit patients who have low baseline VEGF levels.ConclusionThe combination of carotuximab with axitinib did not demonstrate additional efficacy over single agent axitinib in patients with mccRCC who progressed following one or more prior VEGF inhibitor treatment