AUA 2018: No Increased Risk of Clean Intermittent Catheterization with Onabotulinumtoxina Retreatment

San Francisco, CA ( OnabotulinumtoxinA (onabotA) injection into the bladder has proven to be an efficacious treatment option for patients with overactive bladder (OAB). However, the risk of urinary retention following injection has a reported rate of 17% by the manufacturer (Allergan plc, Ireland). The clinical effect of onabotA injection also is known to diminish after time, lasting a median time of about 24 weeks. 

Gary Lemack, MD, from the University of Texas Southwestern Medical Center evaluated the risk of clean intermittent catheterization (CIC) following retreatment with onabotA. A post hoc analysis of pooled placebo-controlled trials was undertaken to evaluate the risk of CIC. His group also evaluated the efficacy and quality of life (QOL) outcomes following reinjection with onabotA 100U into the bladder for the treatment of OAB and urgency urinary incontinence (UUI).

Data was pooled from three phase 3 trials and a post-marketing study (NCT00910845, NCT00910520, NCT01767519, or NCT01945489) which enrolled OAB patients who had experienced ≥2 UUI episodes per day and had ≥8 micturitions per day, based on a 3-day bladder diary. OAB Patients who received onabotA 100U or placebo in studies were included. In each study, patients could be retreated as needed at an interval of ≥12 weeks since the prior onabotA treatment. CIC incidence was evaluated at week 12 following treatment cycles 1 and 2. The mean change from baseline in UUI episodes/day, mean changes from baseline in the Role (RL) and Social Limitations (SL) domains of the King’s Health Questionnaire (KHQ), and proportions of patients with improvements on the Treatment Benefit Scale (TBS) were also assessed at this time. 

831 patients who had undergone injection with onabotA 100U were included in the treatment arm, and 733 subjects who had received a placebo constituted the control arm. The study was predominantly female in both groups (88.2% treatment, 86.9% placebo) and were matched regarding duration and severity of OAB symptoms, as well as post-void residuals (PVR). 

Patients were instructed to perform CIC if their PVRs were 350 ml or more, and if PVRs were in the 200-350 ml range, the discussion to initiate CIC depended on the provider and patient. The majority of patients did not require CIC in the 12 weeks after the initial (6.2% for onabotA and 0.3% for placebo) treatment. Following the second cycle of the study, 26/469 (5.5%) required CIC, of which 9/469 (1.9%) who received onabotA treatments in both cycles required CIC within 12 weeks following treatment. The remaining 17/469 (3.6%) patients of those requiring CIC after the second cycle had received a placebo in the first cycle and were considered de novo CIC patients. 

UroToday AUA2018 Patients Requiring CIC

At 12 weeks after the first onabotA treatment, the mean change from baseline in UI episodes/day was -2.9 from a baseline of 5.4, and 29.1% of patients were dry, which was significantly improved compared to the placebo group (p<0.001 vs placebo). After the second onabotA treatment, there was also an improvement in UI episodes per day. Mean changes from baseline in KHQ RL and SL domains were >4 times the minimally important difference (-5 points) with onabotA at 12 weeks following both treatments. Improvements on the TBS saw at 12 weeks following the second treatment were consistent with treatment 1 in patients who were retreated with onabotA (59.3%) and those receiving onabotA (62.4%) for the first time (62.4%). 

The most common adverse effects of onabotA treatment were urinary tract infections (17.7-19.4%), dysuria (5.1-7.5%), bacteriuria (3.1-4.7%), residual urine volume (2.3-3.4%), and urinary retention (3.4-5.9%), and were similar after each treatment cycle. 

Based on these findings in a large, pooled population of OAB patients, the authors concluded that there was no observed increased risk of CIC with onabotA reinjection and that reinjection with onabotA 100U improved urinary symptoms and QOL.

Presented by: Gary Lemack, MD, University of Texas Southwestern Medical Center, Dallas, TX
Co-Authors: Eric Rovner, Charleston, SC, Kurt McCammon, Norfolk, VA, Francisco Cruz, Porto, Portugal, Rizwan Hamid, London, United Kingdom, Sidney Radomski, Toronto, Canada, Amelia Orejudos, Tamer Aboushwareb, Irvine, CA, Jennifer Sobol, West Bloomfield, MI

Written by:  Judy Choi, MD, Assistant Professor, Department of Urology, University of California, Irvine @judymchoi at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA