Promising response to axitinib rechallenge for metastatic renal cell carcinoma after progression on prior axitinib: report of two cases

With the marked improvement in the prognosis of patients with metastatic renal cell carcinoma (mRCC) in the era of molecularly targeted therapy, sequential therapies using multiple targeted agents have been intensively performed for these patients. Despite being conducted targeting small cohorts, several studies showed efficacious findings on rechallenge with some targeted agents, such as sunitinib and sorafenib; however, there has not been any report describing axitinib rechallenge for patients with mRCC. Here, we report two cases of mRCC showing a significant response to axitinib rechallenge after progression on prior systemic treatment with multiple agents, including axitinib. These findings suggest that mRCC, once refractory to axitinib, can still show favorable disease control on rechallenge with this agent during sequential treatment with targeted agents.