New drugs currently available in non-muscle invasive bladder cancer: update on gemcitabine studies

Intravesical gemcitabine has been tested in several phase I studies. The 2000 mg dose of gemcitabine in 50/100 ml normal saline when administered intravesically for up to 2 hours once a week for 6 weeks has unremarkable systemic and local side effects and therefore should be considered the most convenient schedule. Phase II studies have assessed the activity of intravesical gemcitabine on a marker lesion in intermediate risk non-muscle invasive bladder cancer (NMIBC), showing complete responses in up to 60% of cases. Few attempts have been made to test the activity of intravesical gemcitabine in high risk NMIBC achieving unexpected complete responses in BCG refractory CIS. Initial trials have also documented "clinically relevant" responses in prophylaxis. The current level of evidence indicates that gemcitabine possesses clinical activity but further confirmation is awaited from additional exploratory phase II and preferably phase III trials.