- Second course of BCG therapy (patients who failed previous induction BCG): Patients receive intravesical BCG (1 instillation) once a week for 6 weeks. The suspension is maintained in the bladder for up to 2 hours. Patients then receive maintenance therapy consisting of BCG once a week for 3 weeks in months 3, 6, 12, 18, and 24. Patients who are disease-free at 24 months may continue treatment at the discretion of the clinician.