Second-line therapy in metastatic renal cell cancer—how do we treat after immuno-oncology drugs?

The treatment landscape of metastatic renal cell cancer (mRCC) is rapidly evolving. To date in 2019 twelve drugs are licensed for this indication, two more drugs are awaited to be introduced into our portfolio of treatment options by the end of the year. First-line treatment has robust clinical trial data and is clearly stated by the consensus guidelines. It consists either of a tyrosine kinase inhibitor (TKI) monotherapy for favorable risk patients—defined by the Heng or IMDC (International mRCC Database Consortium) score—or the immuno-oncology (IO) combination of ipilimumab and nivolumab (Ipi/Nivo) for intermediate- and poor-risk patients who are eligible for this treatment. To date we have a clearly positive phase III trial of a TKI-IO combination that was superior to standard of care with sunitinib in untreated metastatic patients independent of the risk group. Pembrolizumab and axitinib will be most likely introduced to the treatment landscape by the end of the year. Despite all these very enthusiastic treatment options in first line, subsequent treatment recommendations are missing due to the lack of data. Only retrospective data can be used as a tool to make the right choice after the use of an IO drug in first line.