Consolidative Radiation Therapy or Cystectomy After Initial Favorable Response Succeeding Enfortumab Vedotin Plus Pembrolizumab (REINFORCE)--- A Pilot Feasibility Trial
This pilot feasibility clinical trial is evaluating a novel treatment strategy for patients with advanced bladder cancer that is unresectable, has spread to nearby lymph nodes or a limited number of distant sites (oligometastatic disease), and has responded to initial treatment with enfortumab vedotin and pembrolizumab. Although this combination has significantly improved outcomes compared to traditional chemotherapy, many patients are left with residual cancer in the bladder or other sites, and there is currently no established standard approach for managing this remaining disease or determining the optimal duration of systemic therapy. Prolonged treatment can lead to cumulative side effects and negatively impact quality of life. This study investigates whether adding consolidative treatment-such as radiation therapy to the bladder and metastatic sites or surgical removal of the bladder (radical cystectomy)-can safely eliminate residual disease and delay cancer progression. Radiation therapy uses high-energy x-rays to precisely target and destroy cancer cells while minimizing exposure to surrounding normal tissues. In selected patients, surgery may be used to remove remaining tumor in the bladder. Targeted radiation techniques, such as stereotactic body radiation therapy (SBRT), may also be used to treat small metastatic sites. This approach may allow for safe discontinuation of systemic therapy, potentially reducing long-term treatment-related side effects. A key component of this trial is the integration of biomarker testing using circulating tumor DNA (ctDNA) from blood and urine tumor DNA (utDNA). These tests detect small amounts of tumor-derived genetic material and may help identify patients most likely to benefit from consolidative treatment, as well as guide decisions about ongoing therapy. By combining response to systemic therapy with personalized local treatment and biomarker-driven monitoring, this study aims to improve cancer control, reduce complications from untreated local disease, and inform future treatment strategies for patients with advanced bladder cancer.
• Age \>= 18 at the time of screening
• Ability to understand and willingness to sign a written informed consent document
• Histopathologically confirmed cTxN1-3M0, cTxNxM1 or cT4bNxM0 muscle invasive bladder cancer at initial diagnosis
• Achieved a radiographic complete response (CR) or partial response (PR), per Response Evaluation Criteria in Solid Tumors (RECIST) version (v) 1.1 criteria and at the determination of treating physicians) after 3-9 cycles of induction EV + pembro
• If M1 after completion of EV + pembro, patients need to have =\< 5 sites of metastasis and all sites of metastasis should be extracranial
⁃ Note: when counting the number of oligometastatic lesions, each lymph node lesion, whether pelvic or extrapelvic, is counted (for example, 2 distinct lymph nodes in the right external iliac basin count as 2 oligometastatic lesions; one extrapelvic and one pelvic node count as 2 oligometastatic lesions, etc). Five or fewer sites of metastasis applies after the completion of EV + pembro, not at initial diagnosis
• Be a candidate for consolidative radiation therapy (RT) to the pelvis (if indicated) or cystectomy (if indicated), and all sites of metastasis are amenable to RT
• Life expectancy \> 6 months
• Eastern Cooperative Oncology Group (ECOG) performance 0-2
• Absolute neutrophil count (ANC) \>= 1500 /mcL (within 180 days of trial registration)
• Platelets \>= 100,000/mcL (within 180 days of trial registration)
• Hemoglobin \> 9 g/dL (within 180 days of trial registration)
• Creatinine =\< 1.5 x upper limit of normal (ULN) OR \>= 60 mL/min (within 180 days of trial registration)
• Total bilirubin =\< 1.5 ULN OR direct bilirubin =\< ULN if total bilirubin \> 1.5 x ULN (within 180 days of trial registration)
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =\< 2.5 x ULN OR \< 5 x ULN if patient has live metastasis (within 180 days of trial registration)
• Albumin \>= 2.5 g/dL (within 180 days of trial registration)
• International normalized ratio (INR) or prothrombin time (PT) =\< 1.5 x ULN unless on anticoagulation therapy, in which case PT or partial thromboplastin time (PTT) should be in the therapeutic range (within 180 days of trial registration)
• PTT =\< 1.5 x ULN unless on anticoagulation therapy, in which case PT or PTT should be in the therapeutic range (within 180 days of trial registration)
• Participants of child-bearing potential must be willing to employ two highly effective and acceptable forms of contraception during, and for at least 90 days after the end of radiation therapy. Women of childbearing potential (WOCBP) must have a negative serum pregnancy test within 72 hours of treatment initiation
• HIV-infected patients who are healthy and have a low risk of AIDS-related outcomes are included in this trial