Purpose: We evaluated safety and efficacy outcomes in a case series of subjects who received open label intravesical bacillus Calmette-Guerin after failing to respond to bacillus Calmette-Guerin or intravesical placebo in a randomized clinical trial.
Materials and methods: Subjects who met National Institutes of Health-National Institute of Diabetes and Digestive and Kidney Diseases criteria for IC and reported at least moderate pain and frequency were initially randomized to 6 weekly intravesical instillations of bacillus Calmette-Guerin or placebo and followed for a total of 34 weeks. At 34 weeks subjects who reported that they had not responded to treatment were offered treatment with open label bacillus Calmette-Guerin, using the same course of treatment and followup. Outcomes included a patient reported global response assessment, a 24-hour voiding diary, pain, urgency, validated interstitial cystitis symptom indexes and adverse events.
Results: A total of 156 subjects elected open label bacillus Calmette-Guerin, of whom 18 (12%) withdrew during the open label series. The response rate based on the global response assessment was 18% and it was identical between those initially randomized to placebo (first course of bacillus Calmette-Guerin in the open label series) and those initially randomized to bacillus Calmette-Guerin (second course). Small improvements were observed for most secondary efficacy outcomes. Most participants reported at least 1 adverse event, primarily pain, genitourinary symptoms and gastrointestinal disturbances. However, there was no difference in adverse events between those who received the first course of bacillus Calmette-Guerin in this series compared to those who received 2 courses.
Conclusions: The low response rate for bacillus Calmette-Guerin in this open label case series further argues against the routine use of bacillus Calmette-Guerin as treatment for interstitial cystitis.