Study BT7480-100 in Patients With Advanced Malignancies Associated With Nectin-4 Expression

This clinical study is evaluating a drug called BT7480 alone and in combination with nivolumab in participants with advanced solid tumors associated with Nectin-4 expression. The main goals of the study are to: * Find the recommended dose of BT7480 that can be given safely to participants alone and in combination with nivolumab * Learn about the side effects and effectiveness of BT7480 alone and in combination with nivolumab * Learn about the effect BT7480 has on the body and how BT7480 is cleared by the body * Learn about the side effects and effectiveness of BT7480 in patients with reduced kidney function

BT7480 is a tumor targeted immune cell agonist consisting of three bicyclic peptides (Bicycle®) conjugated via a linker, one that binds selectively to Nectin-4 and two that bind to CD137. This study is a Phase 1/2, multicenter, first-in-human, open-label study of BT7480 given as a single agent and in combination with nivolumab once weekly. There are five parts to the trial: 1) Phase 1 dose escalation in patients with select advanced solid tumors primarily to evaluate safety and tolerability of BT7480 as a monotherapy and determine a recommended Phase 2 dose (RP2D); 2) Phase 1 dose escalation in combination with nivolumab, once the monotherapy RP2D has been determined; 3) Phase 2 dose expansion as a monotherapy once the RP2D has been determined; 4) Phase 2 dose expansion in combination with nivolumab; 5) Phase 1 monotherapy dose confirmation in patients with renal insufficiency once the monotherapy RP2D has been determined