Additional Study Information: The purposes of this clinical study are: To evaluate the safety and tolerability of up to 2 drug release periods of GemRIS for up to 7 days per drug release period To evaluate the pharmacokinetics (the study of the bodily absorption, distribution, metabolism, and excretion of the drug) of gemcitabine and a gemcitabine-related metabolite (product after metabolism in the blood) in urine and plasma during a 7 day drug release period of GemRIS and the 14 day recovery To determine the preliminary anti-tumor effects of gemcitabine when dosed continuously (as described above) in the bladder tumor and lymph nodes at radical cystectomy. Up to 20 participants are planned to be enrolled in this clinical study at multiple study sites in the United States. A participant who completes the clinical study is one that undergoes 2 drug release periods (GemRIS inside the bladder) for up to 7 days per drug release period. You will be followed for safety and health measures for about 118 days after the first GemRIS insertion.