A Phase 1, Multiple-Dose Study to Evaluate the Safety and Tolerability of XmAb®819 in Subjects with Relapsed or Refractory Clear Cell Renal Cell Carcinoma

The purpose of this study is to determine whether an investigational drug called XmAb819, administered intravenously (in the vein) or subcutaneously (just under the skin), has any effects on a participant's kidney cancer, to determine if it is safe and well tolerated, and to determine the dosing schedule. XmAb819 is an investigational drug in this study being manufactured and developed by Xencor, Inc., for the treatment of Clear Cell Renal Cell Carcinoma (ccRCC) that did not respond (refractory) or has come back (relapsed) after standard anti-cancer treatment. This is the first study testing XmAb819 in humans.This study will also see how the body affects the study drug and how much study drug is in the participant's blood (pharmacokinetics, or “PK”), how the drug affects the tumour(s) and the participant's body (pharmacodynamics, or “PD”), and if the participant's body develops antibodies against the study drug. An antibody is a protein made by the body’s immune (defence) system to fight foreign substances by binding to them. Antibodies against XmAb819 could reduce the amount of the study drug in the blood and the effects of the study drug on the participant's cancer. Participants blood will be checked regularly during this study to see if their immune system has made antibodies against XmAb819.Approximately 190 participants will take part in the study at sites globally.The total length of time a participant stays on the study will depend upon the number of individual treatment cycles that a participant receives. The study includes a screening period of up to 28 days and a post-treatment follow-up period of up to 90 days after participants have ended treatment. After this, participants will be contacted every 6 months after they have ended treatment.