A multicentre, prospective, randomised, double-blind study to measure the treatment effectiveness of abobotulinum A (AboBTXA) among women with refractory interstitial cystitis/bladder pain syndrome.

INTRODUCTION AND HYPOTHESIS: To determine if abobotulinumtoxin A (AboBTXA) is an effective treatment for interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS: We performed a double-blind study of 54 women with severe, refractory IC from three referral centres whom we randomly allocated to treatment with hydrodistension + injection of normal saline or to hydrodistension + injection with AboBTXA. The O'Leary-Sant questionnaire consists of problem (OLS-PI) and symptom (OLS-PI) index scores, and bladder diary data were compared between AboBTXA and control patients at baseline and at 3 months of follow-up. Measurements were made beyond 3 months, but no further randomised comparison was possible due to the ability of nonresponsive patients in either group to have AboBTXA treatment.

RESULTS: Complete data were available in 50 patients, and in both groups, OLS questionnaires showed improvement at 3 months. Only the OLS-PI was improved in the AboBTXA group (p = 0.04). At 3 months, no difference was found in either OLS-SI or total OLS score. Twelve patients had urinary tract infection (UTI) treated during the follow-up period, which confounded results. In the 38 patients without UTI, there was improvement in total OLS score (p = 0.02), OLS-PI (0.08), and OLS-SI (p = 0.008) for the AboBTXA group at 3 months. Only five AboBTXA compared with two control patients had a 50% reduction in OLS score.

CONCLUSIONS: For chronic refractory IC/BPS patients, AboBTXA was associated with no overall improvement in total OLS score, although significant benefit was noted in a small number of patients. The absence of posttreatment UTI was associated with a better response to AboBTXA.