Intravesical botulinum-A toxin in children with refractory non-neurogenic overactive bladder

Results of a study examining the use of onabotulinumtoxinA in pediatric patients with overactive bladder

BACKGROUND

There is a lack of approved treatments for pediatric patients with overactive bladder (OAB) with inadequate response to anticholinergic therapy. OnabotulinumtoxinA 100U is approved to treat OAB in adults based on data from randomized, pivotal trials.

OBJECTIVE

To investigate the efficacy and safety of onabotulinumtoxinA treatment of OAB in children aged 12-17 years who were not adequately managed with anticholinergics.

STUDY DESIGN

In this multinational, multicenter, randomized, double-blind, parallel-group, multiple-dose study (NCT02097121), pediatric patients with OAB were randomized 1:1:1 to receive onabotulinumtoxinA 25U, 50U, or 100U (≤6 U/kg). Patients could request retreatment starting at week 12. The primary endpoint was change from baseline to week 12 after treatment 1 in daily frequency of daytime urinary incontinence (UI) episodes. Safety assessments evaluated treatment-emergent adverse events (TEAEs).

RESULTS

Of 68 screened patients, 55 received ≥1 treatment. Mean age was 14 years; 85.5% of patients were female. At week 12 after treatment 1, least squares mean change from baseline in daily frequency of daytime UI episodes showed a numerically greater reduction in the 100U arm (-2.4) versus the 25U arm (-1.4; P = 0.38), with a significant within-group change from baseline in the 100U arm (P = 0.0027). Achievement of treatment response was significantly greater with onabotulinumtoxinA 100U vs 25U (Figure). Median time to request retreatment was ≥16 weeks in all groups. The most frequently reported TEAEs were nasopharyngitis (10.9%) and urinary tract infection (UTI; 10.9%). Urinary retention was observed in 1 patient during treatment cycle 2; there were no serious TEAEs of UTI or urinary retention. Throughout 2 additional treatment cycles continued efficacy for the 100U dose arm was observed along with a consistent safety profile.

DISCUSSION

Change in daily frequency of UI episodes at week 12 in treatment cycle 1 was not significantly different between arms. However, ≥50% response rate was significantly higher with onabotulinumtoxinA 100U versus 25U. Enrollment challenges that lowered the sample size could have reduced statistical power. Also, the lack of a placebo arm and the observed benefit with the 25U comparator limited interpretation.

CONCLUSIONS

OnabotulinumtoxinA injections were well tolerated in children with OAB at all doses studied. Although the primary endpoint was not met, the significantly greater treatment response rate observed with onabotulinumtoxinA 100U versus 25U suggests additional benefit of the higher dose, without additional safety concerns.

Treatment modalities for paediatric functional daytime lower urinary tract disorders: an updated review

Paediatric functional bladder disorders especially those causing daytime symptoms are a common cause of significant psychosocial and/or physical morbidity and impaired quality of life. Despite the availability of many therapeutic modalities, a significant number of children appear to be refractory to treatment and continue to have symptoms. In this review, we aim to evaluate the current evidence in the use of existing and novel therapeutic options for the management of daytime lower urinary tract disorders in children. We also aim to highlight the controversies around the terminology and diagnosis of paediatric lower urinary tract dysfunction (LUTD) and specific conditions. The article will then provide a reasonable critique of the existing and emerging treatment modalities in functional daytime LUTD in children including their mode of action, efficacy, indications, and recent advances. These include standard urotherapy, specific urotherapy comprised of biofeedback, alarm therapy and electrical neural stimulation and pharmacotherapy involving selective and non-selective anticholinergics, ß3 adrenergic agonists, alpha blockers and botulinum toxin. A better understanding of this common clinical problem may help clinicians achieve better profiling of these children's diagnoses to further enable specific, targeted treatment.

An evaluation of onobotulinumtoxinA as a therapeutic option for pediatric neurogenic detrusor overactivity

INTRODUCTION

Neurogenic detrusor overactivity (NDO) results in involuntary detrusor contractions during bladder filling or storage risking transmission of pressure to the upper urinary tracts and/or significant incontinence. The goals of bladder management in children with NDO prioritize the preservation of renal function, prevention of UTIs, and optimizing quality of life. First-line measures include intermittent catheterization and anticholinergic medication. However, when conservative measures fail, surgical intervention may be indicated. Historically, the next step was major reconstructive surgery to create a low-pressure urinary reservoir. The introduction of intravesical botulinum neurotoxin A (BoNT/A) for use in children in 2002 offered a less invasive option for management. However, its exact role is still evolving.

AREAS COVERED

This article summarizes the mechanism of action of BoNT/A for management of NDO and evaluates the current literature defining common practice and clinical efficacy in children with NDO. The findings of the recently completed phase III trial for intravesical onabotulinumtoxinA in children are discussed in detail.

EXPERT OPINION

As the first BoNT/A approved for use in children with NDO, onabotulinumtoxinA appears to be a safe and less invasive alternative to major reconstructive surgery. However, data defining appropriate patient selection and its role as a long-term treatment option continue to develop.

Clinical Application of Botulinum Neurotoxin in Lower-Urinary-Tract Diseases and Dysfunctions: Where Are We Now and What More Can We Do?

Botulinum toxin A (Botox) had been considered a promising drug that has an effect on functional disorders of the lower urinary tract. Because Botox exhibits anti-inflammatory and antispasmodic effects, Botox injection into the bladder can decrease detrusor contractility, reduce bladder hypersensitivity, and eliminate painful sensations. Injecting Botox into the bladder outlet can relax the hyperactivity of the bladder neck, and of the urethral smooth and striated muscles. Based on these therapeutic effects, Botox has been widely applied to treat lower-urinary-tract dysfunctions (LUTDs) such as overactive bladder and neurogenic detrusor overactivity. However, this treatment has not been licensed for use in other LUTDs such as interstitial cystitis, voiding dysfunction due to benign prostatic hyperplasia in men, and dysfunctional voiding in women. Botox has also not been approved for the treatment of children with overactive bladder and dysfunctional voiding; in patients with spinal cord injuries with detrusor sphincter dyssynergia and autonomic dysreflexia; or for poorly relaxed external sphincter in non-neurogenic patients. This article reviews the current knowledge regarding Botox treatment for LUTDs and discusses the potential clinical applications of Botox, as well as work that can be conducted in the future.