Enfortumab Vedotin and Stereotactic Radiation for Localized Bladder Cancer

Prior treatment

• No prior systemic therapy (except prior therapy for non-muscle invasive bladder cancer \>12 prior to registration) for bladder cancer or prior pelvic radiotherapy. Prior intra-vesical therapies are allowed, including Bacillus Calmette-Guerin (BCG) for non-muscle invasive bladder cancer. Prior chemotherapy for other cancers is allowed if given \>=1 year prior to study registration.
• Subjects may not be receiving any other investigational agents for the treatment of the cancer under study.

Other illness

• History of allergic reactions attributed to compounds of similar chemical or biologic composition to enfortumab vedotin or other agents used in study.
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements.

Other

• Baseline \>= Grade 2 sensory or motor neuropathy
• Subjects must not be pregnant or nursing due to the potential for congenital abnormalities and the potential of this regimen to harm nursing infants.

• Urothelial carcinoma of the urinary bladder stage cT1-4a (AJCC 8th edition) N0M0 planned for radical cystectomy.
• For cR1 staged patients. the patient must have high grade disease AND be appropriate for cystectomy.
• Mixed cell types with variant histologies (including squamous, plasmacytoid, adenocarcinoma, sarcomatoid, micropapillary, nested, and lipid cell variants) are allowed as long as any urothelial histology is present (i.e. -not 100% variant histology). Small cell/neuroendocrine component is excluded.
• Age \>=18.
• Performance status Eastern Cooperative Oncology Group (ECOG) 0-1
• Adequate organ and marrow function as defined below:
  • •Hematologic:
  • -Absolute neutrophil count (ANC) \>=1500/mm3
  • Platelet count \>=100x109/L
  • Hemoglobin ≥ 9 g/dL
  • •Hepatic:
  • Serum bilirubin ≤ 1.5 × upper limit of normal (ULN) or ≤ 3 × ULN for subjects with Gilbert's disease
  • Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 × ULN
  • •Renal:
  • No end stage renal disease requiring dialysis allowed
• All men, as well as women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for 3 months following completion of study neoadjuvant therapy. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
  • 7a. A female of child-bearing potential is any woman (regardless of sexual orientation, marital status, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:
• Has not undergone a hysterectomy or bilateral oophorectomy; or
• Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months).
  • 8\. Ability to understand and the willingness to sign a written informed consent.