Renal Retention in High Grade Upper Tract Urothelial Cancer

This trial will evaluate the use of combination pembrolizumab and enfortumab vedotin for patients with high grade non-metastatic (cN0/NxMx, no measurable regional lymph nodes, no metastases) upper tract urothelial cancer (UTUC), preferring to forego standard of care radical nephroureterectomy (RNU) surgery. Currently these patients would not be suitable candidates for neoadjuvant trials, as the patients intention is to forego surgery. The patients are also not candidates for metastatic trials, as the patients have no measurable metastasis. The Investigators hypothesize the combination of pembrolizumab and enfortumab vedotin for patients with high grade cN0/NxMx UTUC deferring RNU will lead to event free survival outcomes similar to that achieved by RNU in a historic dataset.