Neoadjuvant accelerated methotrexate/vinblastine/adriamycin/cisplatin (AMVAC) in combination with nivolumab is under evaluation for the treatment of muscle invasive bladder cancer (MIBC). Patients with pre-specified tumor mutations and complete clinical response with neoadjuvant therapy will preserve their bladders and go on active surveillance.

Muscle invasive bladder cancer (MIBC) constitutes 20-25% of all cases with 5 year survival estimated at 45% regardless of treatment.1-4 Although neoadjuvant cisplatin-based chemotherapy (NAC) followed by a radical cystectomy or cystoprostatectomy with a lymph node dissection is the preferred treatment choice for MIBC in the United States, there are several drawbacks and challenges with this approach. Patients must be fit to undergo a surgical intervention. Grade 2 through 5 complications have been documented in 53% of patients undergoing cystectomy at a tertiary care center, and the surgical mortality rate is 1.5%.5, 6 Furthermore, urinary diversion commonly requires an ileal conduit and an external appliance, impacting patient's quality of life.

By incorporating neoadjuvant nivolumab with AMVAC, our goal in RETAIN-2 is to increase the number of patients who would be eligible for bladder preservation while maintaining the long-term oncologic outcomes. Nivolumab, an anti-PD1 therapy, is FDA approved for treatment of metastatic urothelial carcinoma post platinum-based chemotherapy.20 Recently, neoadjuvant pembrolizumab (anti-PD1) and atezolizumab (anti-PDL1) was tested in MIBC in the PURE-01 and ABACUS studies, and a pT0 rate of 38.6% and 29%, respectively, was achieved.21, 22 Additionally, recent work by Kim et al. presented at AACR 2019 demonstrated that AMVAC induces gene signatures in luminal tumors and may have a synergistic response with immunotherapy. Given the impressive activity of both AMVAC and nivolumab in the neoadjuvant setting, in this study the investigators hypothesize that using the combination of neoadjuvant nivolumab and AMVAC will lead to higher cT0 rate and metastasis-free survival at 2 years. At the same time by using the risk adapted strategy, a select group of patients will be able to preserve their bladders and significantly improve their quality-of-life.

Inclusion Criteria:

• Male or female patients ≥18 years
• Primary urothelial or predominantly urothelial carcinoma of the bladder confirmed from pathology report. Patients with some component of variant histology mixed with predominant urothelial carcinoma will be allowed. Upper tract urothelial carcinoma patients are not allowed.
• Urothelial carcinoma of the prostatic urethra in men is allowed
• Histologic evidence of muscularis propria invasion.
• AJCC23 clinical stage T2-T3 N0M0.
• No radiographic evidence of lymph node positive disease as per RECIST 1.1 (≥15 mm short axis diameter). Lymph node positive disease is defined as clinical lymphadenopathy on staging CT or MRI greater than 1.4 cm in the short axis. If a lymph node is greater than 1.4 cm, it has to be biopsy proven negative for the patient to be eligible.
• No metastatic disease (M0).
• ECOG performance status 0, or 1.
• Left ventricular ejection fraction ≥ 50% by MUGA or ECHO within 6 months of study entry.
• Negative pregnancy test in women of child bearing potential within 24 hours of study registration. If the pregnancy test is positive, the patient must not receive protocol treatment and must not be enrolled in the study.
• Normal organ and bone marrow function (Leukocytes ≥ 3,000/mcL, Absolute neutrophil count ≥ 1,500/mcL, Platelets ≥ 100,000/mcL, Total bilirubin ≤ institutional upper limit of normal (ULN) unless patient has known Gilbert's disease, in which case an elevated bilirubin is allowed, AST(SGOT)/ALT(SGPT) ≤ 2.5 X institutional ULN, Creatinine Clearance ≥ 50 mL/min calculated using the Cockroft-Gault formula or measured with 24 hour urine collection)

Exclusion Criteria:

• Any component of small cell histology.
• Prior systemic chemotherapy or radiation therapy for urothelial carcinoma or cytotoxic chemotherapy for another malignancy within 1 year of study entry are ineligible. Patients who received immunotherapy for non-muscle invasive bladder cancer will be excluded
• Has a known additional malignancy that has had progression or has required active treatments in the last three years. Exceptions include basal cell carcinoma of the skin, squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer. A history of prostate cancer that was treated with surgery is acceptable, provided that the following criteria are met: Stage T2N0M0 or lower; PSA undetectable for 1 year while off androgen deprivation therapy. Patients on active surveillance for low grade prostate cancer are allowed to participate.
• Patients who have received experimental agents within 4 weeks of study entry.
• History of allergic reactions attributed to compounds of similar chemical or biologic composition to Methotrexate, Vinblastine, Doxorubicin or Cisplatin or other agents used in the study
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection (defined by current oral or intravenous antibiotic therapy), symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
• Pregnant women are excluded from this study due to the potential for teratogenic or abortifacient effects of cytotoxic chemotherapy.
• Known HIV-positive patients on combination antiretroviral therapy are ineligible because of the potential for pharmacokinetic interactions with cytotoxic chemotherapy. In addition, these patients are at increased risk of lethal infections when treated with marrow-suppressive therapy.
• Patients with hydronephrosis that has not been addressed with a documented assessment (i.e. normal GFR, no intervention necessary) or an intervention such as placement of a stent or nephrostomy tube.
• Any condition requiring systemic treatment with corticosteroids (> 10 mg daily prednisone or equivalent) or other immunosuppressive medications within 14 days prior to first dose of study drug. Inhaled or topical steroids and adrenal replacement steroid doses > 10 mg daily prednisone or equivalent are permitted in the absence of active autoimmune disease. Use of steroids as pre-medication for contrast allergy prior to CT scans is permitted. It is acceptable to use steroids as pre-medication for AMVAC.
• History of autoimmune disease including but not limited to myasthenia gravis, myositis, autoimmune hepatitis, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, vascular thrombosis associated with antiphospholipid syndrome, Wegener's granulomatosis, Sjögren's syndrome, Guillain-Barré syndrome, multiple sclerosis, vasculitis, or glomerulonephritis.
• Prior treatment with CD137 agonists, anti-programmed death-1 (PD-1), or anti-PD-L1 therapeutic antibody or pathway-targeting agents.
• Treatment with systemic immunostimulatory agents (including but not limited to interferons or interleukin [IL]-2) within 4 weeks or five half-lives of the drug, whichever is shorter, prior to enrolment.