A Study of Escalating Doses of ASG-22CE Given as Monotherapy in Subjects With Metastatic Urothelial Cancer and Other Malignant Solid Tumors That Express Nectin-4

The purpose of this study is to evaluate the safety and pharmacokinetics of enfortumab vedotin as well as assess the immunogenicity and antitumor activity in subjects with metastatic urothelial cancer and other malignant solid tumors that express Nectin-4.

All subjects will receive a single 30 minute IV infusion of enfortumab vedotin once weekly for the first 3 weeks of every 4 weeks (i.e., on Days 1, 8, and 15). A cycle is 4 weeks. This is a 3 part study. Part A will evaluate enfortumab vedotin in subjects with histologically confirmed malignant solid tumors (excluding sarcomas) that are resistant or have recurred. Subjects will continue treatment until disease progression, intolerability of enfortumab vedotin, investigator decision or consent withdrawal. Part A will follow a modified Continual Reassessment Method (mCRM). Part B, will evaluate enfortumab vedotin in 3 different expansion cohorts: 1) Urothelial cancer subjects with renal insufficiency defined as a Creatinine Clearance ≥ 15 ml/min and \< 30 ml/min, 2) subjects with Metastatic Non Small Cell Lung Cancer (NSCLC) and 3) subjects with Metastatic Ovarian Cancer. With the exception of the renal insufficiency cohort, enrollment into Part B will occur at the recommended phase 2 dose (RP2D) established in Part A. Enrollment into the renal insufficiency cohort will begin at starting dose and escalated using a 3 + 3 dose escalation design. Subjects will continue treatment until disease progression, intolerability of enfortumab vedotin or consent withdrawal. Part C will evaluate enfortumab vedotin at the RP2D (determined from Part A) in subjects who have been previously treated with immune checkpoint inhibitors (CPI) in the metastatic setting. Subjects will continue treatment until disease progression, intolerability of enfortumab vedotin, investigator decision or consent withdrawal. All subjects will be followed post-treatment through the 30-day Safety Follow-up Visit.