Main Inclusion Criteria:

1. Patient is at least 18 years of age.
2. Naive or recurrent patients with low grade (LG), non-invasive Upper Tract Urothelial Carcinoma (UTUC) in the pyelocalyceal system.
3. Patient has at least one (1) measurable papillary LG tumor, evaluated visually, ≤ 15 mm. The largest lesion should not exceed 15mm.
4. Biopsy taken from one or more tumors located above the ureteropelvic junction (UPJ) showing LG urothelial carcinoma. Diagnosed not more than 2 months prior to the screening.
5. Patient should have at least one remaining papillary LG tumor evaluated visually with a diameter of at least 5 mm.
6. Wash urine cytology sampled from the pyelocalyceal system documenting the absence of High Grade (HG) urothelial cancer, diagnosed not more than 2 months prior to the screening.
7. Patient with bilateral LG UTUC may be enrolled if at least one side meets the inclusion criteria for the trial and if the other kidney does not require further treatments (The other kidney can be treated prior to the beginning of the study).

Main Exclusion Criteria:

1. Patient received Bacille de Calmette et Guérin (BCG) treatment for Urothelial carcinoma (UC) during the 6 months prior to Visit 1.
2. The patient has untreated concurrent urothelial cancer in other locations other than the target area (unless treated during screening)
3. Carcinoma in situ (CIS) in the past in the urinary tract.
4. Patient has a history of invasive urothelial carcinoma in the urinary tract during the past 5 (Five) years.
5. Patient has a history of high grade papillary urothelial carcinoma in the urinary tract during the past 2 (Two) years.
6. Patient is actively being treated or intends to be treated with systemic chemotherapy during the duration of the trial.