Durable Efficacy and Safety of Long-Term OnabotulinumtoxinA Treatment in Patients with Overactive Bladder Syndrome: Final Results of a 3.5-Year Study

Purpose: These are the final results of the prospective, multicenter, long-term (3.5-year) study of the efficacy/safety of onabotulinumtoxinA for overactive bladder syndrome.

Materials and methods: Patients who completed either of 2, 24-week phase 3 trials could enter a 3-year extension and continue treatment with onabotulinumtoxinA 100 U as needed to control overactive bladder symptoms. Data were analyzed by the treatment(s) received (up to 6) and in discrete subgroups that received 1, 2, 3, 4, 5 or 6 treatments (to evaluate the consistency of the response after repeat treatments in the same patient groups). Assessments included the change from baseline in the number of urinary incontinence episodes per day and the proportion of patients who reported improvement/great improvement in urinary symptoms on the TBS (Treatment Benefit Scale) at week 12 as co-primary end points. Other end points were the change from baseline in I-QOL (Incontinence Quality of Life), the number of urgency and micturition episodes per day; duration of effect; the number of adverse events; and the initiation of intermittent catheterization.

Results: Consistent mean reductions in urinary incontinence were observed following continued onabotulinumtoxinA treatment, ranging from -3.1 to -3.8 in the overall population and -2.9 to -4.5 in the discrete subgroups. Durable improvements were seen in overactive bladder symptoms and quality of life. A high proportion of patients rated their condition as improved/greatly improved. The median duration of effect was 7.6 months. The most common adverse event was urinary tract infection. The rate of de novo catheterization after the first treatment was 4.0% and it ranged from 0.6% to 1.7% after subsequent treatments.

Conclusions: Long-term onabotulinumtoxinA treatment consistently decreased overactive bladder symptoms and improved quality of life with no new safety signals.