Bladder instillation of liposome encapsulated onabotulinumtoxina improves overactive bladder symptoms: a prospective, multicenter, double-blind, randomized trial

Use of Botulinum Toxin A in the Treatment of Lower Urinary Tract Disorders: A Review of the Literature

Botulinum neurotoxin (BoNT) is used to treat a variety of ailments, and its therapeutic application in lower urinary tract disorders (LUTDs) is well studied. Robust evidence supporting the efficacy and tolerability of BoNT in the treatment of neurogenic detrusor overactivity (NDO) and non-neurogenic overactive bladder (OAB) has led to regulatory approval for these conditions. Use of BoNT in the treatment of interstitial cystitis/bladder pain syndrome, chronic pelvic pain, and detrusor sphincter dyssynergia has demonstrated some promise, but is still evolving and off-label for these indications. Trials to date do not support the use of BoNT for benign prostatic hyperplasia. This comprehensive review outlines the mechanisms of BoNT in the treatment of LUTDs in adults and presents background and updated data examining the efficacy and adverse events associated with the use of BoNT in common urologic applications.

Investigational drugs for bladder pain syndrome (BPS) / interstitial cystitis (IC)

INTRODUCTION

Bladder pain syndrome (BPS)/interstitial cystitis (IC) is associated with sensory lower urinary tract symptoms. Unfortunately, many of the existing oral treatments are ineffective in most patients of BPS/IC, which is the motivation for developing new drugs and therapeutic approaches. This review covers the latest drugs that have been investigated in BPS/IC patients. Intravesical treatments offer the opportunity to directly target the painful bladder with less systemic side effects.

AREAS COVERED

In this review, the authors analyze the existing literature supporting the treatment of BPS/IC with conventional drugs including heparin, hyaluronic acid, chondroitin sulfate, and dimethylsulfoxide (DMSO). Furthermore, investigational drugs such as tanezumab and adalimumab, capable of sequestering nerve growth factor (NGF), and Tumor necrosis factor-α (TNF- α) are discussed. Investigational treatments such as liposomes, botulinum toxin (BTX), liposomal BTX, PD-0299685 (a Ca(2+) channel ɑ2δ ligand), continuous intravesical lidocaine, and AQX-1125 (a novel SHIP1 activating compound) are also covered.

EXPERT OPINION

New investigational drugs offer promising improvements in clinical outcomes for BPS/IC patients; however, BPS/IC is a chronic pain disorder that is very vulnerable to a strong placebo effect. In addition, BPS/IC is a heterogeneous disorder that can be classified into several phenotypes. Since different phenotypes of BPS/IC respond differently to systemic and intravesical treatments, the authors believe that new drugs developed for BPS/IC are more likely to meet their predetermined clinical endpoints if the inclusion/exclusion criterion is tailored to specific phenotype of BPS/IC patients.

Potential Effect of Liposomes and Liposome-Encapsulated Botulinum Toxin and Tacrolimus in the Treatment of Bladder Dysfunction

Bladder drug delivery via catheter instillation is a widely used treatment for recurrence of superficial bladder cancer. Intravesical instillation of liposomal botulinum toxin has recently shown promise in the treatment of overactive bladder and interstitial cystitis/bladder pain syndrome, and studies of liposomal tacrolimus instillations show promise in the treatment of hemorrhagic cystitis. Liposomes are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core that can encapsulate hydrophilic and hydrophobic drug molecules to be delivered to cells via endocytosis. This review will present new developments on instillations of liposomes and liposome-encapsulated drugs into the urinary bladder for treating lower urinary tract dysfunction.

The management of overactive bladder: percutaneous tibial nerve stimulation, sacral nerve stimulation, or botulinum toxin?

PURPOSE OF REVIEW

We have reviewed the evidence published on botulinum toxin A (BoNT/A), percutaneous tibial nerve stimulation (PTNS), and sacral nerve stimulation (SNS) in the management of overactive bladder (OAB).

RECENT FINDINGS

BoNT/A is effective irrespectively of the number of previous anticholinergic treatments and of the reason for failure. Doses up to 360U 3-monthly are well tolerated. BoNT/A is well tolerated and effective also in the pediatric population. Bladder instillation of liposome encapsulated BoNT/A is a new approach, deserving further research. When using PTNS, motor response from the electrical stimulus is not required, a sensory response suffices. PTNS has a lasting effect compared to oxybutynin alone. SNS is superior to standard medical treatment but the combination of SNS and anticholinergics is more effective than anticholinergic alone.

SUMMARY

The evidence published in the last 18 months has increased the level of evidence on safety and effectiveness of BoNT/A, PTNS, and SNS in the management of OAB. BoNT/A is now recommended as standard third-line treatment for OAB (in the USA) and urgency incontinence (in the USA and in Europe) in selected patients refractory to pharmacological therapy. All available third-line treatment options for OAB/urgency urinary incontinence should be offered before surgery is contemplated.

VIDEO ABSTRACT

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Intravesical liposome drug delivery and IC/BPS

Intravesical therapy has previously shown to be effective in delaying or preventing recurrence of superficial bladder cancer. This local route of drug administration is now demonstrating promise in the treatment of interstitial cystitis/bladder pain syndrome (IC/BPS) with the benefit of minimal systemic side effects. Liposomes (LPs) are lipid vesicles composed of phospholipid bilayers surrounding an aqueous core. They can incorporate drug molecules, both hydrophobic and hydrophilic, and vastly improve cellular uptake of these drug molecules via endocytosis. Intravesical LPs have therapeutic effects on IC/BPS patients, mainly due to their ability to form a protective lipid film on the urothelial surface and repair the damaged urothelium. This review considers the current status of intravesical LPs and LP mediated drug delivery for the treatment of IC/BPS.

Liposome Based Intravesical Therapy Targeting Nerve Growth Factor Ameliorates Bladder Hypersensitivity in Rats with Experimental Colitis

PURPOSE

Pelvic organ cross sensitization is considered to contribute to overlapping symptoms in chronic pelvic pain syndrome. Nerve growth factor over expression in the bladder is reportedly involved in the symptom development of bladder pain syndrome/interstitial cystitis. We examined whether a reduction of over expressed nerve growth factor in the bladder by intravesical treatment with liposome and oligonucleotide conjugates would ameliorate bladder hypersensitivity in a rat colitis model.

MATERIALS AND METHODS

Adult female rats were divided into 1) a control group, 2) a colitis-oligonucleotide group with intracolonic TNBS (2,4,6-trinitrobenzene sulfonic acid) enema and intravesical liposome-oligonucleotide treatments, 2) a colitis-saline group with intracolonic TNBS and intravesical saline treatments, 4) a sham oligonucleotide group with intravesical liposome-oligonucleotide treatment without colitis and 5) a sham-saline group with intravesical saline treatment without colitis. Liposomes conjugated with nerve growth factor antisense oligonucleotide or saline solution were instilled in the bladder and 24 hours later colitis was induced by TNBS enema. Effects of nerve growth factor antisense treatment were evaluated by pain behavior, cystometry, molecular analyses and immunohistochemistry 10 days after TNBS treatment.

RESULTS

In colitis-oligonucleotide rats nerve growth factor antisense treatment ameliorated pain behavior and decreased a reduction in the intercontraction interval in response to acetic acid stimulation as well as nerve growth factor expression in the bladder mucosa. All were enhanced in colitis-saline rats compared to sham rats.

CONCLUSIONS

Nerve growth factor over expression in the bladder mucosa and bladder hypersensitivity induced after colitis were decreased by intravesical application of liposome-oligonucleotide targeting nerve growth factor. This suggests that local antinerve growth factor therapy could be effective treatment of bladder symptoms in chronic pelvic pain syndrome.

Use of Botulinum Toxin in Urologic Diseases

OnabotulinumtoxinA (onaBoNTA) is approved by the US Food and Drug Administration for the treatment of urinary incontinence due to neurogenic detrusor overactivity and for the treatment of refractory overactive bladder. As a treatment for benign prostatic hyperplasia, onaBoNTA showed no difference over placebo in recently published studies. In contrast, treating interstitial cystitis/bladder pain syndrome with onaBoNTA has shown efficacy, and the current American Urological Association guideline for the diagnosis and treatment of interstitial cystitis/bladder pain syndrome lists onaBoNTA as fourth-line treatment. This comprehensive review will present all studied applications of onaBoNTA within the lower urinary tract.

OnabotulinumtoxinA Treatment for Overactive Bladder in the Elderly: Practical Points and Future Prospects

Overactive bladder (OAB) increases with age. OAB in the elderly may be associated with increased risks of falls, fractures and mortality. Degeneration of the central nervous system in the elderly is proposed as one of the pathogenic factors for OAB. Recently, onabotulinumtoxinA (BoNT-A) 100 U has been demonstrated to be well tolerated, and it significantly improves all OAB symptoms and health-related quality of life in patients who are inadequately managed with anticholinergics. However, an increased risk of a large post-void residual volume and a lower long-term success rate were noted in frail elderly patients. Careful patient selection for BoNT-A injection treatment is important in elderly OAB patients. Patients who are frail, are elderly, have comorbidity or have a post-void residual volume >100 mL should be monitored carefully after BoNT-A injection treatment to prevent urinary retention and subsequent urinary tract infection. Use of liposomes to carry BoNT-A across the urothelial barrier decreases urgency-frequency episodes without compromising detrusor contractility and might avoid urinary tract infection. This treatment might prevent undesired detrusor underactivity after BoNT-A injection treatment, especially in elderly patients who have low detrusor contractility. For treatment of OAB in the elderly, clinicians should be aware of the balance between therapeutic efficacy and safety.

The safety and efficiency of onabotulinumtoxinA for the treatment of overactive bladder: a systematic review and meta-analysis

PURPOSE

To assess the impact on safety and efficiency of onabotulinumtoxinA (BOTOX1, Allergan, Inc.) treatment in patients with an overactive bladder.

MATERIALS AND METHODS

We searched the PubMed(®), Embase(®), and Cochrane Library Databases to identify all randomized controlled trials comparing the outcomes of onabotulinumtoxinA and placebo for overactive bladder. The outcomes included reductions in overactive bladder symptoms or improvements in the function of bladder and the side effects of two treatments. The Cochrane Collaboration Review Manager software (RevMan 5.1.4) was used for statistical analysis.

RESULTS

The study inclusion criteria were met by eight randomized controlled trials involving 1875 patients. The synthesized data from these randomized controlled trials indicated that onabotulinumtoxinA was better than placebo in decreasing most overactive bladder symptoms (p < 0.00001, p < 0.00001, p < 0.00001, p < 0.00001, p = 0.0003) in the micturition, urgency, urinary incontinence, urgency urinary incontinence (UUI), and nocturia per day change, respectively; however, the maximum cystometric capacity change from the baseline appeared not to be significantly different between two methods (p = 0.05). In addition, the side effects in the onabotulinumtoxinA group were more serious than the placebo group (p < 0.00001, p = 0.009, p = 0.07, p < 0.0001, p = 0.03 in the UTI, bacteriuria, dysuria, urinary retention, residual urine volume, respectively).

CONCLUSIONS

Compared with the placebo, onabotulinumtoxinA had significantly and clinically relevant reductions in overactive bladder symptoms, but it also leaded to more side effects.

Emerging drugs for overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a common problem which can have disastrous effects on the quality of life of the sufferer. There are established treatments for the problem but they have significant adverse effects. Better drugs and new treatment modalities are necessary to deal with OAB.

AREA COVERED

Antimuscarinics, mirabegron and intravesical injection of botulinum toxin A are established treatments for OAB. Sacral neuromodulation is more invasive but has been successful in treating OAB. Phase II and III trials are in progress for newer β3-agonists and various combinations of antimuscarinics, β3-agonists and antidiuretics. Targeted secretion inhibitors (TSI) can increase efficacy and reduce adverse effects. Liposome integrated botulinum toxin A has an advantage of effective administration by intravesical instillation. Both medicines are in Phase II trials. Many other drugs which have promising results are discussed.

EXPERT OPINION

Newer antimuscarinics have better tolerability. Long-term data for mirabegron has shown that it is more effective in severe OAB. Combination drugs may prove to be more effective with less adverse effects. Emerging treatments with TSI, lipotoxin and gene therapy appear promising.

Current and potential urological applications of botulinum toxin A

Botulinum toxin subtype A (BoNT-A) is a potent neurotoxin that can selectively modulate neurotransmitter release from nerve endings, resulting in muscular paralysis. BoNT-A might also act on sensory nerves, and have an anti-inflammatory effect. In the first urological use of BoNT-A, injection into the urethral sphincters of patients with detrusor-sphincter dyssynergia resulted in a reduction of urethral resistance and improved voiding efficiency. Subsequently, intravesical BoNT-A injections have received regulatory approval for treatment of neurogenic detrusor overactivity owing to spinal cord lesions or multiple sclerosis, and idiopathic overactive bladder in adults. BoNT-A has also been widely used to treat patients with the off-label indications of neurogenic or non-neurogenic voiding dysfunction and male lower urinary tract symptoms owing to BPH and bladder-neck dysfunction. Other indications for which urologists have applied BoNT-A injections include interstitial cystitis/bladder pain syndrome, bladder oversensitivity and chronic pelvic pain syndrome. BoNT-A is currently delivered as an intravesical injection; however, use of liposome encapsulated formulations is also beginning to show some therapeutic potential.

Presence of Cleaved Synaptosomal-Associated Protein-25 and Decrease of Purinergic Receptors P2X3 in the Bladder Urothelium Influence Efficacy of Botulinum Toxin Treatment for Overactive Bladder Syndrome

OBJECTIVES

To evaluate whether botulinum toxin A (BoNT-A) injection and Lipotoxin (liposomes with 200 U of BoNT-A) instillation target different proteins, including P2X3, synaptic vesicle glycoprotein 2A, and SNAP-25, in the bladder mucosa, leading to different treatment outcomes.

MATERIALS AND METHODS

This was a retrospective study performed in a tertiary teaching hospital. We evaluated the clinical results of 27 OAB patients treated with intravesical BoNT-A injection (n = 16) or Lipotoxin instillation (n = 11). Seven controls were treated with saline. Patients were injected with 100 U of BoNT-A or Lipotoxinin a single intravesical instillation. The patients enrolled in this study all had bladder biopsies performed at baseline and one month after BoNT-A therapy. Treatment outcome was measured by the decreases in urgency and frequency episodes at 1 month. The functional protein expressions in the urothelium were measured at baseline and after 1 month. The Wilcoxon signed-rank test and ordinal logistic regression were used to compare the treatment outcomes.

RESULTS

Both BoNT-A injection and Lipotoxin instillation treatments effectively decreased the frequency of urgency episodes in OAB patients. Lipotoxin instillation did not increase post-void residual volume. BoNT-A injection effectively cleaved SNAP-25 (p < 0.01). Liposome encapsulated BoNT-A decreased urothelial P2X3 expression in the five responders (p = 0.04), while SNAP-25 was not significantly cleaved.

CONCLUSIONS

The results of this study provide a possible mechanism for the therapeutic effects of BoNT-A for the treatment of OAB via different treatment forms. BoNT-A and Lipotoxin treatments effectively decreased the frequency of urgency episodes in patients with OAB.