This study is looking at the effects of Sirolimus (Rapamycin) on BCG-specific immunity during treatment of non-muscle invasive bladder cancer (NMIBC) with maintenance BCG.

This study will evaluate change from baseline in gamma-delta T cell numbers and function and Ag85 peptide-specific T cell responses following treatment.

Inclusion Criteria:

• Pathologically (histologically) proven diagnosis of non-muscle invasive (Ta, Tis or T1) bladder cancer
• In their treating physician's opinion is a good candidate for BCG therapy
• Be able to give informed consent
• Be age 18 or older
• Not be in an immunosuppressed state (e.g. HIV, use of chronic steroids)
• Not have active, uncontrolled infections
• Not be on agents known to alter rapamycin metabolism significantly
• Not have a reported history of liver disease (e.g. cirrhosis)
• Not have a prior history of non-bladder cancer unless the cancer is clinically stable and not requiring active treatment except basal cell carcinoma or squamous cell carcinoma of the skin.
• Not pregnant, or taking effective contraception before rapamycin therapy, during therapy and for 12 weeks after discontinuation of therapy.

Exclusion Criteria:

• Have muscle-invasive (≥T2) bladder cancer
• Unable to give informed consent
• Age < 18
• Immunosuppressed state (e.g. HIV, use of chronic steroids)
• Active, uncontrolled infections
• On agents known to alter rapamycin metabolism significantly
• Another cancer requiring active treatment (except basal cell carcinoma or squamous cell carcinoma of the skin)
• Patients at risk of pregnancy who are unwilling or unable to take effective contraception before rapamycin therapy, during therapy, and for 12 weeks after discontinuation of therapy.
• Individuals with a reported history of liver disease (e.g. cirrhosis)
• Individuals who are not a good candidate for BCG in their treating physician's opinion