Neo-Adjuvant Bladder Urothelial Carcinoma COmbination-immunotherapy

This is an open-label phase Ib trial to evaluate three different schedules of preoperative ipilimumab and nivolumab. Urothelial cancer patients will be included that are diagnosed with either:

• cT3-4aN0M0 OR
• T1-4aN1-3M0

Cohort 1 (n=24):

• Day 1: Ipilimumab 3 mg/kg
• Days 22: Ipilimumab 3 mg/kg + Nivolumab 1 mg/kg
• Day 43: Nivolumab 3 mg/kg
• Day 56-84: Radical cystectomy or nefro/ureterectomy with appropriate lymph node dissection

Patients in cohort 2 (n=30) were randomized between cohort 2a and 2b

Cohort 2a (n=15):

• Day 1: Ipilimumab 3 mg/kg + Nivolumab 1 mg/kg
• Days 22: Ipilimumab 3 mg/kg + Nivolumab 1 mg/kg
• Day 43: Nivolumab 3 mg/kg
• Day 56-84: Radical cystectomy or nefro/ureterectomy with appropriate lymph node dissection

Cohort 2b (n=15):

• Day 1: Ipilimumab 1 mg/kg + Nivolumab 3 mg/kg
• Days 22: Ipilimumab 1 mg/kg + Nivolumab 3 mg/kg
• Day 43: Nivolumab 3 mg/kg
• Day 56-84: Radical cystectomy or nefro/ureterectomy with appropriate lymph node dissection

The primary endpoint for cohort 1 in this trial was safety. We determined the number of patients that had surgical resection <12 weeks from first infusion, as this is an endpoint that is clinically meaningful for this population. After surgery, patients attended study visits at day 8 and day 29. Their final study visit for physical examination and laboratory testing is at day 57 (+/- 7 days), which is scheduled to anticipate late-onset adverse events (particularly endocrine). After this final visit, patients were followed according to standard clinical guidelines. Tumor biopsies/material preservation were required at baseline and during surgery.

In cohort 2, we randomized patients between 2 arms. Here, the main secondary outcomes were:

• To compare the efficacy of pre-operative ipilimumab + nivolumab in cohort 1 (sequenced ipilimumab/nivolumab), versus cohort 2a (ipi 3 mg/kg and nivo 1 mg/kg) and cohort 2b (ipi 1 mg/kg and nivo 3 mg/kg). Efficacy was defined as the pCR rate at resection.
• Provide an estimate of ≥grade 3 immune-related toxicity in the ipi3/nivo1 and ipi1/nivo3 cohorts as opposed to the initial cohort (Cohort 1)

An important additional secondary endpoint is translational. The main testable hypothesis is that a significant percentage of nonresponse can be explained by immune-inhibitory processes. Absence of immune infiltrates, presence of significant numbers of regulatory T-cells and presence of significant numbers of myeloid-derived suppressor cells will be compared between responders and nonresponders. The efficacy will be defined as the percentage of pathological complete response (pCR) at cystectomy (secondary endpoint).

Inclusion criteria

• Willing and able to provide informed consent
• Age ≥ 18 years
• High-risk resectable urothelial cancer (upper urinary tract allowed) defined as stage III UC:

cT3-4aN0M0 OR cT1-4aN1-3M0 4. Refusal of neoadjuvant/induction cisplatin-based chemotherapy or patients in whom neoadjuvant cisplatin based therapy is not appropriate.

• World Health Organization (WHO) performance Status 0 or 1. 6. Urothelial cancer is the dominant histology (>70%). 7. Formalin-fixed paraffin-embedded (FFPE) tumor specimens in paraffin blocks from diagnostic TUR available (or any other FFPE tumor specimens for upper tract tumors).8. Screening laboratory values must meet the following criteria: WBC ≥ 2.0x109/L, Neutrophils ≥1.0x109/L, Platelets ≥100 x109/L, Hemoglobin ≥5.5 mmol/L, GFR>30 ml/min, AST ≤ 2.5 x ULN, ALT ≤2.5 x ULN, Bilirubin ≤1.5 X ULN 9. Negative pregnancy test within 2 weeks of Day 1 Cycle 1 for female patients of childbearing potential.

• For female patients of childbearing potential to use a highly effecting form(s) of contraception (i.e. one that results in a low failure rate [<1% per year] when used consistently and correctly) and to continue its use for 180 days after the last dose of immunotherapy Adequate contraceptive methods are: condom, sterilization, other barrier contraceptive measures preferably in combination with condoms, oral contraceptives, intra-uterine device.

Exclusion criteria

• Subjects with active autoimmune disease in the past 2 years. Patients with diabetes mellitus, properly controlled hypothyroidism or hyperthyroidism, vitiligo, psoriasis or other mild skin disease can still be included.
• Documented history of severe autoimmune disease (e.g. inflammatory bowel disease, myasthenia gravis).
• Prior CTLA-4 or PD-1/PD-L1-targeting immunotherapy.
• Known history of Human Immunodeficiency Virus, positive tests for Hepatitis B surface antigen or Hepatitis C ribonucleic acid (RNA), active tuberculosis, or other active infection requiring therapy at the time of inclusion.
• Underlying medical conditions that, in the investigator's opinion, will make the administration of study drug hazardous or obscure the interpretation of adverse events
• Medical condition requiring the use of immunosuppressive medications, with the exceptions of intranasal and inhaled corticosteroids or systemic corticosteroids at physiological doses, which are not to exceed 10 mg/day of prednisone, or an equivalent corticosteroid. Steroids as premedication for hypersensitivity reactions (eg, CT scan premedication) will be allowed.
• Use of other investigational drugs before study drug administration
• Malignancy, other than urothelial cancer, in the previous 2 years, with a high chance of recurrence (estimated >10%). Patients with low risk prostate cancer (defined as Stage T1/T2a, Gleason score

≤ 6, and PSA ≤ 10 ng/mL) who are treatment-naive and undergoing active surveillance are eligible.

• Pregnant and lactating female patients.
• Major surgical procedure within 4 weeks prior to enrolment or anticipation of need for a major surgical procedure during the course of the study other than for diagnosis.
• Severe infections within 4 weeks prior to enrolment in the study including but not limited to hospitalization for complications of infection, bacteraemia, or severe pneumonia.
• Significant cardiovascular disease, such as New York Heart Association cardiac disease (Class II or greater), myocardial infarction within 3 months prior to enrolment, unstable arrhythmias, or unstable angina.
• Previous intravenous chemotherapy for bladder cancer. Prior chemoradiation is allowed.
• Patients in whom use of a colon segment for urinary diversion is planned