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

Strategies for Safe Transurethral Injections of Botulinum Toxin into the Bladder Wall

Introduction: Transurethral injections into the bladder wall with botulinum toxin are an established treatment for refractory overactive bladder or detrusor overactivity. With the current injection technique, an average of approx. 18% and up to 40% of botulinum toxin is injected next to the bladder wall, potentially causing reduced efficacy or non-response. The article aims to evaluate the reasons for incorrect injections and propose strategies for complete delivery of the entire botulinum toxin fluid into the bladder wall. Material and Methods: Unstructured literature search and narrative review of the literature. Results: Incorrect injection of botulinum toxin fluid next to the bladder wall is caused by pushing the injection needle too deep and through the bladder wall. Bladder wall thickness decreases with increasing bladder filling and has a thickness of less than 2 mm beyond 100 mL in healthy individuals. Ultrasound imaging of the bladder wall before botulinum toxin injection can verify bladder wall thickness in individual patients. Patient movements during the injection therapy increase the chance of incorrect placement of the needle tip. Conclusions: Based on the literature search, it is helpful and recommended to (1) perform pretreatment ultrasound imaging of the bladder to estimate bladder wall thickness and to adjust the injection depth accordingly, (2) fill the bladder as low as possible, ideally below 100 mL, (3) use short needles, ideally 2 mm, and (4) provide sufficient anesthesia and pain management to avoid patient movements during the injection therapy.

A Novel Catalytically Inactive Construct of Botulinum Neurotoxin A (BoNT/A) Directly Inhibits Visceral Sensory Signalling

Botulinum neurotoxin A (BoNT/A) is a potent neurotoxin that silences cholinergic neurotransmission through the cleavage of the synaptic protein SNAP-25. Previous studies have shown that, in addition to its paralytic effects, BoNT/A can inhibit sensory nerve activity. The aim of this study was to identify how BoNT/A inhibits afferent signalling from the bladder. To investigate the role of SNAP-25 cleavage in the previously reported BoNT/A-dependent inhibition of sensory signalling, we developed a recombinant form of BoNT/A with an inactive light chain, rBoNT/A (0), unable to paralyse muscle. We also developed recombinant light chain (LC)-domain-only proteins to better understand the entry mechanisms, as the heavy chain (HC) of the protein is responsible for the internalisation of the light chain. We found that, despite a lack of catalytic activity, rBoNT/A (0) potently inhibited the afferent responses to bladder distension to a greater degree than catalytically active rBoNT/A. This was also clear from the testing of the LC-only proteins, as the inactive rLC/A (0) protein inhibited afferent responses significantly more than the active rLC/A protein. Immunohistochemistry for cleaved SNAP-25 was negative, and purinergic and nitrergic antagonists partially and totally reversed the sensory inhibition, respectively. These data suggest that the BoNT/A inhibition of sensory nerve activity in this assay is not due to the classical well-characterised 'double-receptor' mechanism of BoNT/A, is independent of SNAP25 cleavage and involves nitrergic and purinergic signalling mechanisms.

Progress and challenges in intravesical drug delivery

INTRODUCTION

Intravesical drug delivery (IDD) has gained recognition as a viable approach for treating bladder-related diseases over the years. However, it comes with its set of challenges, including voiding difficulties and limitations in mucosal and epithelial penetration. These challenges lead to drug dilution and clearance, resulting in poor efficacy. Various strategies for drug delivery have been devised to overcome these issues, all aimed at optimizing drug delivery. Nevertheless, there has been minimal translation to clinical settings.

AREAS COVERED

This review provides a detailed description of IDD, including its history, advantages, and challenges. It also explores the physical barriers encountered in IDD, such as voiding, mucosal penetration, and epithelial penetration, and discusses current strategies for overcoming these challenges. Additionally, it offers a comprehensive roadmap for advancing IDD into clinical trials.

EXPERT OPINION

Physical bladder barriers and limitations of conventional treatments result in unsatisfactory efficacy against bladder diseases. Nevertheless, substantial recent efforts in this field have led to significant progress in overcoming these challenges and have raised important attributes for an optimal IDD system. However, there is still a lack of well-defined steps in the workflow to optimize the IDD system for clinical settings, and further research is required to establish more comprehensive in vitro and in vivo models to expedite clinical translation.

Current optimal pharmacologic therapies for overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a common syndrome in adults. Current pharmacologic treatment includes antimuscarinic agents and β-3 adrenoceptor agonists. For non-responders to oral medication, intravesical injection of botulinum toxin A (BoNT-A) is an effective option. However, these treatments have potential adverse events and should be cautiously selected for appropriate patients. This review presents the recently published results of clinical trials and studies for patients with OAB and the underlying pathophysiology of OAB. Appropriate medical therapy based on pathophysiology of OAB is also presented.

AREAS COVERED

Literature search from Pubmed from 2001 to 2023 including clinical background, pharmacology, and clinical studies for OAB medications.

EXPERT OPINION

Treatment of OAB syndrome with any antimuscarinic or β-3 adrenoceptor agonist is feasible as a first-line approach. For patients with suboptimal therapeutic effect to full-dose antimuscarinics or mirabegron, combination with both drugs can improve efficacy. Intravesical BoNT-A 100-U injection provides therapeutic effects for refractory OAB. Patients who are refractory to initial pharmacotherapies should be investigated for the underlying pathophysiology; then an appropriate medication can be added, such as an α1-blocker or anti-inflammatory agents. Patient education about behavioral modification and therapies should always be provided with oral medication or BoNT-A injection for OAB patients.

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.

Treating Lower Urinary Tract Symptoms in Older Adults: Intravesical Options

This article provides an overview of the diagnosis and the treatment of lower urinary tract symptoms in older adults complicated by the neurodegenerative changes in the micturition reflex and further confounded by age-related decline in hepatic and renal clearance raising the propensity of adverse drug reactions. The first-line drug treatment for lower urinary tract symptoms, orally administered antimuscarinics, fails to reach the equilibrium dissociation constant of muscarinic receptors even at their maximum plasma concentration and tends to evoke a half-maximal response at a muscarinic receptor occupancy of just 0.206% in the bladder with a minimal difference from exocrine glands, which raises the adverse drug reaction risk. On the contrary, intravesical antimuscarinics are instilled at concentrations 1000-fold higher than the oral maximum plasma concentration and the equilibrium dissociation constant erects a downhill concentration gradient that drives passive diffusion and achieves a mucosal concentration around ten-fold lower than the instilled concentration for a long-lasting occupation of muscarinic receptors in mucosa and sensory nerves. A high local concentration of antimuscarinics in the bladder triggers alternative mechanisms of action and is supposed to engage retrograde transport to nerve cell bodies for neuroplastic changes that underlie a long-lasting therapeutic effect, while an intrinsically lower systemic uptake of the intravesical route lowers the muscarinic receptor occupancy of exocrine glands to lower the adverse drug reaction relative to the oral route. Thus, the traditional pharmacokinetics and pharmacodynamics of oral treatment are upended by intravesical antimuscarinics to generate a dramatic improvement (~ 76%) noted in a meta-analysis of studies enrolling children with neurogenic lower urinary tract symptoms on the primary endpoint of maximum cystometric bladder capacity as well as the secondary endpoints of filling compliance and uninhibited detrusor contractions. The therapeutic success of intravesical multidose oxybutynin solution or oxybutynin entrapped in the polymer for sustained release in the pediatric population bodes well for patients with lower urinary tract symptoms at the other extreme of the age spectrum. Though generally used to predict oral drug absorption, Lipinski's rule of five can also explain the ten-fold lower systemic uptake from the bladder of positively charged trospium over oxybutynin, a tertiary amine. Chemodenervation by an intradetrusor injection of onabotulinumtoxinA is merited for patients with idiopathic overactive bladder discontinuing oral treatment because of a lack of efficacy. However, age-related peripheral neurodegeneration potentiates the adverse drug reaction risk of urinary retention that motivates the quest of liquid instillation, delivering larger fraction of onabotulinumtoxinA to the mucosa as opposed to muscle by an intradetrusor injection can also probe the neurogenic and myogenic predominance of idiopathic overactive bladder. Overall, the treatment paradigm of lower urinary tract symptoms in older adults should be tailored to individual's overall health status and the risk tolerance for adverse drug reactions.

Botulinum Toxin Therapy for Bladder Pain Syndrome/Interstitial Cystitis

Purpose of Review

Bladder pain syndrome (BPS)/interstitial cystitis (IC) can also be classified as either non-ulcerative or ulcerative, corresponding to the characteristic cystoscopic findings under hydrodistention. Promising therapeutic effects, including decreased bladder pain, have been reported from recent clinical trials using botulinum toxin A (BoNTA) for the treatment of BPS/IC. This review summarizes the current state of the literature on the underlying mechanisms of BoNTA therapy in BPS/IC as well as new forms of its application.

Recent Findings

BoNTA has its effect in the central nervous system in the afferent nerves as well as in the bladder wall. Besides the well-known effects of BoNTA in the nervous system, pain control as well as reduction of urinary urgency in BPS patients could be achieved by mast cell stabilization effecting histamine release as well as modulation of TRPV and PGE2 pathways, among other systems. In addition, new forms of BoNTA administration have focused on intravesical instillation of the drug in order to circumvent bladder wall injections. Hyperthermia, intravesical hydrogel, and lysosomes have been studied as new ways of BoNTA application in BPS/IC patients. From the available studies, bladder instillation of BoNTA in combination with EMDA is the most promising and effective novel approach.

Summary

The most promising novel application methods for BoNTA in patient with BPS/IC are bladder instillations. Future research needs to point out if bladder instillations with BoNTA with some form of bladder absorption enhancement such as hyperthermia or EMDA would be able to replace BoNTA injections in patients with BPS/IC

Long-Term Surveillance and Management of Urological Complications in Chronic Spinal Cord-Injured Patients

Bladder dysfunction is a common complication after chronic spinal cord injury (SCI). Patients may experience renal function loss, urinary tract infection (UTI), urolithiasis, bladder cancer, and even life-threatening events such as severe sepsis or renal failure. Suitable patient care may prevent UTI and urinary incontinence, decrease medication use, and preserve renal function. As the primary goal is to preserve renal function, management should be focused on facilitating bladder drainage, the avoidance of UTI, and the maintenance of a low intravesical pressure for continence and complete bladder emptying. Currently, several bladder management options are available to SCI patients: (1) reflex voiding; (2) clean intermittent catheterization; (3) indwelling catheterization. The target organ may be the bladder or the bladder outlet. The purposes of intervention include the following: (1) increasing bladder capacity and/or decreasing intravesical pressure; (2) increasing bladder outlet resistance; (3) decreasing bladder outlet resistance; (4) producing detrusor contractility; (5) urinary diversion. Different bladder management methods and interventions may have different results depending on the patient's lower urinary tract dysfunction. This review aims to report the current management options for long-term bladder dysfunction in chronic SCI patients. Furthermore, we summarize the most suitable care plans for improving the clinical outcome of SCI patients.

Liposome-Encapsulated Botulinum Toxin A in Treatment of Functional Bladder Disorders

Botulinum toxin A (BoNT-A) intravesical injections have been used to treat patients with refractory functional bladder disorders such as overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS), but the risk of adverse events and the need for repeated injections continue to prevent widespread application of this treatment. Liposomes are vesicles that comprise concentric phospholipid layers and an aqueous core; their flexible compositions enable them to adsorb and fuse with cell membranes and to deliver drugs or proteins into cells. Therefore, liposomes have been considered as promising vehicles for the less invasive delivery of BoNT-A. In previous placebo-controlled trials including patients with OAB refractory to medical treatment, it was shown that liposomal BoNT-A could significantly decrease the frequency and urgency of urination. In patients with IC/BPS, it was shown that liposomal BoNT-A could also improve bladder pain, but the therapeutic efficacy was not superior to that of the placebo. As the therapeutic mechanisms of BoNT-A include the decreased expression of nerve growth factors, P2X3 receptors, and vanilloid receptors on C-fibers, liposomal BoNT-A might play a more promising role in the treatment of bladder oversensitivity. This article features the contemporary literature regarding BoNT-A, liposomes, and liposomal BoNT-A treatment for functional bladder disorders and potential clinical applications in the future.

Nanotechnology as a tool to advance research and treatment of non-oncologic urogenital diseases

Nanotechnology represents an expanding area of research and innovation in almost every field of science, including Medicine, where nanomaterial-based products have been developed for diagnostic and therapeutic applications. Because of their small, nanoscale size, these materials exhibit unique physical and chemical properties that differ from those of each component when considered in bulk. In Nanomedicine, there is an increasing interest in harnessing these unique properties to engineer nanocarriers for the delivery of therapeutic agents. Nano-based drug delivery platforms have many advantages over conventional drug administration routes as this technology allows for local and transdermal applications of therapeutics that can bypass the first-pass metabolism, improves drug efficacy through encapsulation of hydrophobic drugs, and allows for a sustained and controlled release of encapsulated agents. In Urology, nano-based drug delivery platforms have been extensively investigated and implemented for cancer treatment. However, there is also great potential for use of nanotechnology to treat non-oncologic urogenital diseases. We provide an update on research that is paving the way for clinical translation of nanotechnology in the areas of erectile dysfunction (ED), overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and catheter-associated urinary tract infections (CAUTIs). Overall, preclinical and clinical studies have proven the utility of nanomaterials both as vehicles for transdermal and intravesical delivery of therapeutic agents and for urinary catheter formulation with antimicrobial agents to treat non-oncologic urogenital diseases. Although clinical translation will be dependent on overcoming regulatory challenges, it is inevitable before there is universal adoption of this technology to treat non-oncologic urogenital diseases.

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.

Nano-BTA: A New Strategy for Intravesical Delivery of Botulinum Toxin A

Botulinum neurotoxin subtype A (BoNT-A) has been part of the urology treatment arsenal since it was first used in the treatment of detrusor-sphincter dyssynergia more than 30 years ago. BoNT-A has been recommended as an effective treatment for neurogenic detrusor overactivity and overactive bladder. However, direct intradetrusor injection of BoNT-A using cystoscopy after anesthesia may cause hematuria, pain, and infection; these adverse events have motivated urologists to find less invasive and more convenient ways to administer BoNT-A. The development of nanotechnology has led to the advancement of intravesical drug delivery. Using versatile nanocarriers to transport BoNT-A across the impermeable urothelium is a promising therapeutic option. In this review, we discuss the effectiveness and feasibility of liposomes, thermosensitive polymeric hydrogels, and hyaluronan-phosphatidylethanolamine as carriers of BoNT-A for intravesical instillation. To date, these carriers have not reached a similar efficacy as intradetrusor injections in long-term observations. Hopefully, researchers will make a breakthrough with new nanomaterials to develop clinical applications in the future.

Emerging molecular mechanisms and genetic targets for developing novel therapeutic strategies for treating bladder diseases

Bladder diseases affect millions of patients worldwide and compromise their quality of life with a substantial economic impact. The not fully understood aetiologies of bladder diseases limit the current diagnosis and therapeutic options to primarily symptomatic treatment. In addition, bladder targeted drug delivery is challenging due to its unique anatomical features and its natural physiological function of urine storage and frequent voiding. Therefore, current treatment options often fail to provide a highly effective, precisely targeted and long-lasting treatment. With the growing maturity of gene therapy, comprehensive studies are needed to provide a better understanding of the molecular mechanisms underpinning bladder diseases and help to identify novel gene therapeutic targets and biomarkers for treating bladder diseases. In this review, molecular mechanisms involved in pathology of bladder cancer, interstitial cystitis and overactive bladder syndrome are reviewed, with focus on establishing potential novel treatment options. Proposed novel therapies, including gene therapy combined with nanotechnology, localised drug delivery by nanoparticles, and probiotics, are discussed in regard to their safety profiles, efficacy, treatment lenght, precise targeting, and in comparison to conventional treatment methods.

The clinical application of intravesical botulinum toxin A injection in patients with overactive bladder and interstitial cystitis

Botulinum toxin A (BoNT-A) has been widely used in several urological functional disorders including neurogenic detrusor overactivity (NDO), overactive bladder (OAB), lower urinary tract dysfunction, and interstitial cystitis/bladder pain syndrome (IC/BPS). Chronic inflammation is found in a large proportion of patients with OAB and IC/BPS. The chronic inflammation activates sensory afferents which resulting in central sensitization and bladder storage symptoms. Because BoNT-A can inhibit the sensory peptides released from the vesicles in sensory nerve terminals, the inflammation can be reduced and symptom subsided. Previous studies have demonstrated that the quality of life improved after BoNT-A injections, both in neurogenic and non-NDO. Although the use of BoNT-A in treatment of IC/BPS has not been approved by FDA, intravesical BoNT-A injection has been included in the AUA guideline as the fourth line therapy. Generally, intravesical injections of BoNT-A are well tolerated, though transient hematuria and urinary tract infection can occur after the procedure. In order to prevent these adverse events, experimental trials have been conducted to test if BoNT-A can be delivered into the bladder wall without intravesical injection under anesthesia such as using liposomes encapsulated BoNT-A or application of low energy shock wave on the bladder to facilitate BoNT-A penetrating across the urothelium and treat OAB or IC/BPS. This article reviews current clinical and basic researches of BoNT-A on OAB and IC/BPS.

Low-Energy Shock Wave Plus Intravesical Instillation of Botulinum Toxin A for Interstitial Cystitis/Bladder Pain Syndrome: Pathophysiology and Preliminary Result of a Novel Minimally Invasive Treatment

Low-energy shock wave (LESW) therapy is known to facilitate tissue regeneration with analgesic and anti-inflammatory effects. LESW treatment has been demonstrated to be effective in treating chronic prostatitis and pelvic pain syndrome as well as overactive bladder, and it has a potential effect on interstitial cystitis/bladder pain syndrome (IC/BPS) in humans. LESW reduces pain behavior, downregulates nerve growth factor expression, and suppresses bladder overactivity by decreasing the expression of inflammatory proteins. Previous rat IC models have shown that LESW can increase urothelial permeability, facilitate intravesical delivery of botulinum toxin A (BoNT-A), and block acetic acid-induced hyperactive bladder, suggesting that LESW might be a potential therapeutic module for relieving bladder inflammatory conditions, such as bladder oversensitivity, IC/BPS, and overactive bladder. A recent clinical trial showed that LESW monotherapy was associated with a significant reduction in pain scores and IC symptoms. BoNT-A detrusor injection or liposome-encapsulated BoNT-A instillation could also inhibit inflammation and improve IC symptoms. However, BoNT-A injection requires anesthesia and certain complications might occur. Our preliminary study using LESW plus intravesical BoNT-A instillation every week demonstrated an improvement in global response assessment without any adverse events. Moreover, an immunohistochemistry study revealed the presence of cleaved SNAP25 protein in the suburothelium of IC bladder tissue, indicating that BoNT-A could penetrate across the urothelial barrier after application of LESW. These results provide evidence for the efficacy and safety of this novel IC/BPS treatment by LESW plus BoNT-A instillation, without anesthesia, and no bladder injection. This article reviews the current evidence on LESW and LESW plus intravesical therapeutic agents on bladder disorders and the pathophysiology and pharmacological mechanism of this novel, minimally invasive treatment model for IC/BPS.

An indirect comparison meta-analysis of noninvasive intravesical instillation and intravesical injection of botulinum toxin-A in bladder disorders

BACKGROUND

Botulinum toxin type A (BTX-A) intravesical instillation and BTX-A intravesical injection are both effective treatments or overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS), but direct comparative studies of the two treatments are lacking.

METHODS

We conducted a pairs-comparison meta-analysis and an adjusted indirect comparison meta-analysis extracting published data from randomized controlled trials in literature databases from the inception of each database to Aug. 31, 2021, evaluating efficacy and safety of BTX-A intravesical instillation and BTX-A intravesical injection. We also carried out a subgroup analysis.

RESULTS

We identified 24 trials in 21 studies were included in our study, of which 18 trials in 17 studies were BTX-A intravesical injections, 6 trials in 4 studies were BTX-A intravesical instillation. Compared with the normal saline injection, BTX-A intravesical injections for patients with OAB and IC/ BPS can obviously improve the symptoms of urinary frequency, urgency episode, UI and UUI, but BTX-A significantly increased the rate of urinary retention and urinary tract infection and increased PVR (p < 0.05). Adjusted indirect comparison meta-analysis showed that BTX-A intravesical injections was more effective than BTX-A intravesical instillation (p > 0.05). Surprisingly, BTX-A intravesical instillation had fewer side effects than BTX-A intravesical injections (p < 0.05).

CONCLUSIONS

Although BTX-A intravesical injections of OAB and IC/BPS has been significantly superior the BTX-A intravesical instillation, it has major side effects, but this needs to be confirmed by more large-scale, multicenter, direct comparison randomized controlled trials.

BoNT/A in the Urinary Bladder-More to the Story than Silencing of Cholinergic Nerves

Botulinum neurotoxin (BoNT/A) is an FDA and NICE approved second-line treatment for overactive bladder (OAB) in patients either not responsive or intolerant to anti-cholinergic drugs. BoNT/A acts to weaken muscle contraction by blocking release of the neurotransmitter acetyl choline (ACh) at neuromuscular junctions. However, this biological activity does not easily explain all the observed effects in clinical and non-clinical studies. There are also conflicting reports of expression of the BoNT/A protein receptor, SV2, and intracellular target protein, SNAP-25, in the urothelium and bladder. This review presents the current evidence of BoNT/A’s effect on bladder sensation, potential mechanisms by which it might exert these effects and discusses recent advances in understanding the action of BoNT in bladder tissue.

Therapeutic effects of nerve growth factor-targeting therapy on bladder overactivity in rats with prostatic inflammation

BACKGROUND

The present study examined the effect of liposomes conjugated with antisense oligonucleotide of nerve growth factor (NGF-OND) on local overexpression of NGF and bladder overactivity using rats with prostatic inflammation (PI).

METHODS

Male Sprague-Dawley rats were divided into three groups: (1) Control group; intact rats, (2) PI-NS group; rats with PI and intravesical instillation of normal saline (NS), (3) PI-OND group; rats with PI and intravesical instillation of NGF-OND. On Day 0, PI was induced by intraprostatic 5%-formalin injection. On Day 14, NGF-OND or NS was instilled directly into the bladder after laparotomy. On Day 28, therapeutic effects of NGF-OND were evaluated by awake cystometry and histological analysis as well as reverse-transcription polymerase chain reaction measurements of messenger RNA (mRNA) levels of NGF in the bladder and prostate, inflammatory markers in the prostate, C-fiber afferent markers, and an A-type K⁺ channel α-subunit (Kv 1.4) in L6-S1 dorsal root ganglia (DRG).

RESULTS

Intravesical NFG-OND treatment reduced PI-induced overexpression of NGF in both bladder and prostate, and reduced PI-induced bladder overactivity evident as longer intercontraction intervals in association with reductions of TRPV1 and TRPA1 mRNA expression levels in DRG. mRNA expression of Kv1.4 in DRG was reduced after PI, but improved in the PI-OND group.

CONCLUSIONS

These results indicate that NGF locally expressed in the bladder is an important mediator inducing bladder overactivity with upregulation of C-fiber afferent markers and downregulation of an A-type K⁺ channel subunit in DRG following PI, and that liposome-based, local NGF-targeting therapy could be effective for not only bladder overactivity and afferent sensitization, but also PI. Thus, local blockade of NGF in the bladder could be a therapeutic modality for male LUTS due to BPH with PI.

Pharmacological Management of Urinary Incontinence: Current and Emerging Treatment

Pharmacological management of urinary incontinence (UI) is currently based on antimuscarinic and beta-3-agonist drugs. Botulinum toxin A detrusor injections represent an effective but more invasive alternative. This review covers the latest developments of the currently available drugs and the emerging compounds for the treatment of UI. Evidence shows that new antimuscarinics and beta-3-agonists with improved safety profiles may offer unique options to patients intolerant to currently available drugs. Combination therapy proved to be a non-invasive alternative for patients refractory to first-line monotherapy. Exciting advances are ongoing in the research to improve the efficacy/tolerability profile of botulinum toxin, through innovative routes of administration. Several new agents emerged from preclinical studies, some of which have now entered the clinical phase of development and could represent, in the coming years, a new way for the treatment of UI. Recent evidence on the existence of different overactive bladder phenotypes could be the key to tailored treatment. Rather than discovering new molecules, reaching the ability to identify the right drug for the right patient could be the real gamechanger of the future.

Botulinum Toxin Injection for Medically Refractory Neurogenic Bladder in Children: A Systematic Review

The objective was to evaluate the use of botulinum toxin A (BTX-A) injection in children with medically refractory neurogenic bladder. A systematic review of the literature was conducted using three databases (Medline via PubMed, Cochrane, and EMBASE). Articles evaluating BTX-A in children with neurogenic bladder were collected. The clinical and urodynamic parameters were reviewed for the safety and efficacy evaluation. Sixteen studies were selected into this study and a total of 455 children with medical refractory neurogenic bladder were evaluated. All of the patients had received traditional conservative medications such as antimuscarinics and intermittent catheterization as previous treatment. The duration of treatments ranged from 2 months to 5.7 years. Improvements in incontinence and vesicoureteral reflux were the most common clinical outcomes. The detrusor pressure, bladder capacity and bladder compliance improvement were the most common urodynamic parameters which had been reported. However, patient satisfaction with the procedure remained controversial. There was only a minimal risk of minor adverse effects. In all of the studies, BTX-A injection was well tolerated. In conclusion, BTX-A injection appears to be a safe and effective treatment in the management of medically unresponsive neurogenic bladder in children. There is currently no evidence that the use of BTX-A injection could be used as a first-line therapy for neurogenic bladder in children.

Novel Applications of Non-Invasive Intravesical Botulinum Toxin a Delivery in the Treatment of Functional Bladder Disorders

Although intravesical botulinum toxin type A (BoNT-A) injection for functional bladder disorders is effective, the injection-related problems-such as bladder pain and urinary tract infection-make the procedure invasive and inconvenient. Several vehicles have recently been developed to deliver BoNT-A without injection, thereby making the treatment less or non-invasive. Laboratory evidence revealed that liposome can carry BoNT-A across the uroepithelium and act on sub-urothelial nerve endings. A randomized placebo controlled study revealed that intravesical administration of liposome-encapsulated BoNT-A and TC-3 hydrogel embedded BoNT-A can improve urinary frequency, urgency, and reduce incontinence in patients with overactive bladders. A single-arm prospective study also revealed that intravesical administration of TC-3 hydrogel embedded BoNT-A can relieve bladder pain in patients with interstitial cystitis/bladder pain syndrome (IC/BPS). We recently administered suprapubic energy shock wave (ESW) after BoNT-A intravesical administration in six patients with IC/BPS. Although pain reduction and symptom improvement were not significant, immunochemical staining showed cleaved synaptosome-associated protein 25 in the bladder after the procedure. This suggests that ESW can promote passage of BoNT-A across the uroepithelium. In conclusion, using vehicles to intra-vesically deliver BoNT-A for functional bladder disorders is promising. Further studies are necessary to confirm the efficacy and explore novel applications.

Local drug delivery systems for inflammatory diseases: Status quo, challenges, and opportunities

Inflammation that is not resolved in due course becomes a chronic disease. The treatment of chronic inflammatory diseases involves a long-term use of anti-inflammatory drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, often accompanied by dose-dependent side effects. Local drug delivery systems have been widely explored to reduce their off-target side effects and the medication frequency, with several products making to the market or in development over the years. However, numerous challenges remain, and drug delivery technology is underutilized in some applications. This review showcases local drug delivery systems in different inflammatory diseases, including the targets well-known to drug delivery scientists (e.g., joints, eyes, and teeth) and other applications with untapped opportunities (e.g., sinus, bladder, and colon). In each section, we start with a brief description of the disease and commonly used therapy, introduce local drug delivery systems currently on the market or in the development stage, focusing on polymeric systems, and discuss the remaining challenges and opportunities in future product development.

The effect of botulinum toxin on ureteral inflammation

PURPOSE

The impact of onabotulinum toxin type A (BoNT-A) on bladder afferent nerve pathways and chemosensory functions is an active area of investigation. There may be a role for BoNT-A in disorders of the ureter; however, no histologic studies have assessed the effects of BoNT-A on ureteral tissue. Our objective was to develop an animal model of ureteral inflammation and determine the impact of ureteral BoNT-A instillation on known mechanisms of inflammation.

METHODS

The safety and feasibility of a novel animal model of ureteral inflammation was assessed. Through open cystotomy, the effect of ureteral BoNT-A instillation on inflammation was determined through H&E, masson's trichrome, Ki-67 stain, and prostaglandin E (PGE) synthase expression, a known marker of pain and inflammation in ureteral tissue. Urothelial microstructure was assessed using electron microscopy and standard histologic techniques.

RESULTS

All experiments were carried to completion, and no systemic signs of botulinum toxicity were seen. BoNT-A exposure was associated with a decrease in PGE synthase expression in a dose-dependent fashion. BoNT-A exposure was not found to impact collagen deposition or cell proliferation. Disruption of tight junctions between urothelial cells was observed under conditions of inflammation.

CONCLUSION

We describe the feasibility of a novel in vivo model of ureteral inflammation and report the first histologic study of the effects of BoNT-A on the ureter. Preliminary findings show that BoNT-A attenuates ureteral PGE synthase expression under conditions of inflammation. The application of BoNT-A may provide anti-inflammatory and analgesic effects in the context of ureteral disorders.

Current management of refractory overactive bladder

Overactive bladder (OAB) is a common condition affecting one-sixth to one-fifth of the global population. The treatment of refractory OAB remains a challenge for urologists. Current treatment options include the use of combination therapy with antimuscarinic agents and beta-3 adrenoceptor agonists, and treating underlying curable disorders. Intravesical botulinum toxin type A (BoNT-A) injection, percutaneous tibial nerve stimulation, and sacral nerve stimulation are third-line management therapies suggested by the American Urological Association/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (AUA/SUFU) guidelines. In rare cases, more invasive surgical interventions can be considered after explaining the benefits and risks to the patients. Augmentation cystoplasty has a high success rate; however, it has also been associated with a high complication rate. In contrast, detrusor myomectomy is an easy procedure, but the treatment outcome remains controversial. Liposome-encapsulated BoNT-A is administered via bladder instillation, and promising results have been obtained in preliminary studies. More therapies are currently being investigated, and transient receptor potential vanilloid 1 antagonists may be new type of medication. Radiofrequency ablation and other targets for neuromodulation have also been studied; however, more evidence is needed to confirm their efficacy.

Therapeutic Effect of Botulinum Toxin A on Sensory Bladder Disorders-From Bench to Bedside

Bladder oversensitivity arises from several different conditions involving the bladder, bladder outlet, systemic or central nervous system diseases. Increase of the bladder sensation results from activation of the sensory receptors in the urothelial cells or suburothelial tissues. Medical treatment targeting the overactive bladder (OAB) or interstitial cystitis (IC) might relieve oversensitive bladder symptoms (frequency, urgency and pain) in a portion of patients, but a certain percentage of patients still need active management. Botulinum toxin A (BoNT-A) has been demonstrated to have anti-inflammatory and antinociceptive effects in bladder sensory disorders and has been shown effective in the reduction of bladder oversensitivity and the increase of functional bladder capacity. For patients with OAB, urgency and urinary incontinence improved, while in patients with IC, bladder pain could be relieved in association with reduction of bladder oversensitivity after BoNT-A intravesical injection. Histological evidence has confirmed the therapeutic mechanism and clinical efficacy of intravesical BoNT-A injection on patients with OAB or IC. Bladder oversensitivity can also be relieved with the instillation of liposome encapsulated BoNT-A or low energy show waves (LESWs), which enable the BoNT-A molecule to penetrate into the urothelium and suburothelial space without affecting the detrusor contractility. Liposome encapsulated BoNT-A or combined LESWs and BoNT-A instillation might be future treatment alternatives for bladder oversensitivity in sensory bladder disorders.

Therapeutic Efficacy of onabotulinumtoxinA Delivered Using Various Approaches in Sensory Bladder Disorder

Cystoscopic onabotulinumtoxinA (onaBoNTA) intradetrusor injection is an efficient and durable modality for treating sensory bladder disorders. However, the inconvenience of using the cystoscopic technique and anesthesia, and the adverse effects of direct needle injection (e.g., haematuria, pain, and infections) have motivated researchers and clinicians to develop diverse injection-free procedures to improve accessibility and prevent adverse effects. However, determining suitable approaches to transfer onaBoNTA, a large molecular and hydrophilic protein, through the impermeable urothelium to reach therapeutic efficacy remains an unmet medical need. Researchers have provided potential solutions in three categories: To disrupt the barrier of the urothelium (e.g., protamine sulfate), to increase the permeability of the urothelium (e.g., electromotive drug delivery and low-energy shock wave), and to create a carrier for transportation (e.g., liposomes, thermosensitive hydrogel, and hyaluronan-phosphatidylethanolamine). Thus far, most of these novel administration techniques have not been well established in their long-term efficacy; therefore, additional clinical trials are warranted to validate the therapeutic efficacy and durability of these techniques. Finally, researchers may make progress with new combinations or biomaterials to change clinical practices in the future.

Clinical application of intravesical botulinum toxin type A for overactive bladder and interstitial cystitis

After decades of clinical and basic science research, the clinical application of botulinum toxin A (Botox) in urology has been extended to neurogenic detrusor overactivity (NDO), idiopathic detrusor overactivity, refractory overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), lower urinary tract symptoms, benign prostatic hyperplasia, and neurogenic or non-neurogenic lower urinary tract dysfunction in children. Botox selectively disrupts and modulates neurotransmission, suppresses detrusor overactivity, and modulates sensory function, inflammation, and glandular function. In addition to motor effects, Botox has been found to have sensory inhibitory effects and anti-inflammatory effects; therefore, it has been used to treat IC/BPS and OAB. Currently, Botox has been approved for the treatment of NDO and OAB. Recent clinical trials on Botox for the treatment of IC/BPS have reported promising therapeutic effects, including reduced bladder pain. Additionally, the therapeutic duration was found to be longer with repeated Botox injections than with a single injection. However, the use of Botox for IC/BPS has not been approved. This paper reviews the recent advances in intravesical Botox treatment for OAB and IC/BPS.

Botulinum toxin A for refractory OAB and idiopathic urinary retention: Can phenotyping improve outcome for patients: ICI-RS 2019?

AIMS

Botulinum toxin A (BTX-A) is a well-established treatment for refractory idiopathic overactive bladder (OAB). It has also been used with short-term success in treating idiopathic urinary retention. However, efficacy and complication rates are variable and predicting those likely to benefit most from treatment would enable personalization of therapy and optimization of outcomes. At the International Consultation on Incontinence-Research Society (ICI-RS) meeting in 2019 a Think Tank addressed the question of how we can improve the way we phenotype patients undergoing BTX-A treatment.

METHODS

The Think Tank conducted a literature review and expert consensus meeting focussing on how advances in basic science research of the mechanism of action of BTX-A, as well as assessment of psychological comorbidity, can be translated into clinical practice to improve patient selection for therapy.

RESULTS

Idiopathic OAB and idiopathic urinary retention are heterogenous conditions encompassing several phenotypes with multiple potential pathophysiological mechanisms. Animal models have demonstrated a central nervous system mechanism of action of intravesically injected BTX-A and this has been confirmed in human functional MRI studies, but whether this tool can be used to predict outcome from treatment remains to be determined. Phenotyping based on psychological comorbidity using validated screening tools should be studied as a way to potentially optimize patient selection for therapy.

CONCLUSIONS

Advances in basic science research into the mechanism of action of BTX-A have improved our understanding of the pathophysiology of OAB and may lead to novel ways to phenotype patients. Psychological assessment is another way in which phenotyping may be improved. Areas for further research are proposed.

Delivery of intravesical botulinum toxin A using low-energy shockwaves in the treatment of overactive bladder: A preliminary clinical study

Objective: To evaluate the efficacy and safety of botulinum toxin A (BoNT-A) instillation in the bladder under the effect of low-energy shockwaves (LESWs) for the treatment of refractory idiopathic overactive bladder (OAB). Patients and methods: A preliminary clinical study was conducted, including 15 patients with refractory OAB, between September 2016 and July 2017. Intravesical instillation of 100 IU of BoNT-A was done followed by LESWs (3000 shocks over 10 min) exposure to the supra-pubic area. Patients were followed-up by urine analysis, urine culture, post-void residual urine volume (PVR), and Overactive Bladder Symptom Score (OABSS) at 1, 2 and 3 months. Results: There were statistically significant improvements in all OABSS domains and the total score after 1 and 2 months of treatment (P < 0.05). Whereas, only the nocturia domain remained significantly improved after 3 months (P = 0.02). There was no significant increase in PVR throughout the study period (P > 0.05) and none of the patients required clean intermittent catheterisation. Two, two and three patients developed urinary tract infections after 1, 2 and 3 months, respectively. Conclusion: Intravesical instillation of BoNT-A and LESWs is safe and effective method for the treatment of refractory OAB with a durable response for 2 months. Abbreviations: BoNT-A: botulinum toxin A; CIC: clean intermittent catheterisation; DO: detrusor overactivity; LESWs: low-energy shockwaves; OAB: overactive bladder; OABSS: Overactive Bladder Symptom Score; Qmax: maximum urinary flow rate; QoL: quality of life; UUI: urgency urinary incontinence.

Efficacy and Safety of Noninvasive Intravesical Instillation of Onabotulinum Toxin-A for Overactive Bladder and Interstitial Cystitis/Bladder Pain Syndrome: Systematic Review and Meta-analysis

OBJECTIVE

To investigate the efficacy and safety of noninvasive intravesical instillation of onabotulinum toxin-A (OBTX-A) through systematic review and meta-analysis. Recently, several studies of noninvasive intravesical instillation of OBTX-A have been published. However, its efficacy is not well validated yet compared to well-known efficacy of minimally invasive intravesical injection of OBTX-A.

METHOD

Systematic review and meta-analysis were performed to evaluate the efficacy of noninvasive intravesical instillation of OBTX-A in patients with overactive bladder and interstitial cystitis/bladder pain syndrome by measuring outcomes such as urgency episode per 72 hours, frequency per 72 hours, urgency urinary incontinence, voided volume (VV), postvoided residual volume, maximum flow rate, and patient perception of bladder condition.

RESULT

Six trials in 4 studies that compared instillation of OBTX-A and placebo involving 248 patients (121 experimental and 127 controls) were included for final data extraction. Instillation of OBTX-A significantly increased VV, with a mean difference of 38.48 (95% confidence interval: 76.05, 0.92) compared to the placebo group. However, other outcomes showed statistically insignificant changes. Major adverse events were not reported in the group receiving intravesical instillation of OBTX-A.

CONCLUSION

Intravesical instillation of OBTX-A showed limited efficacy with improvement of VV for treatment of overactive bladder or interstitial cystitis/bladder pain syndrome. More studies are needed to overcome the efficacy of current noninvasive bladder instillation of OBTX-A regarding effective drug transport.

Modifications to Botulinum toxin A delivery in the management of detrusor overactivity recalcitrant to initial injections: a review

PURPOSE

One quarter of patients will not respond to initial intra-detrusor Botulinum toxin A (BTX) injections for detrusor overactivity. Alternative treatment options include long-term catheterization, sacral neuromodulation, urinary diversion or bladder augmentation. Some of these procedures are invasive. This review explores modifications to BTX delivery that can improve outcome.

METHODS

A search of Medline, Embase and Cochrane Library to December 2017 was performed according to Preferred Reporting Items for Systematic Review and Metaanalysis (PRISMA) guidelines. Search criteria included, dose escalation, increasing injection site number, trigone injection, switching preparation and alternative methods of BTX delivery.

RESULTS

Several modifications to BTX delivery may improve response. There is moderate evidence that increasing the dose from 100 U to 200 U results in statistically better symptom control. Trigone-including injections were associated with significantly improved patient-reported symptom scores, as well as superior results in urodynamic outcomes without risking urinary retention and vesico-ureteric reflux. Switching from onabotulinum (OTA) or abobotulinum (ATA) or vice versa may also improve response in over 50% of patients as shown in limited studies. Increasing the number of injection sites is not beneficial. Indeed, decreasing the number of injections to as low as three sites does not result in decreased clinical outcomes. Injection-free delivery is associated with lower efficacy compared to conventional intradetrusor injections.

CONCLUSION

Before contemplating alternative treatments, practitioners can try to improve on BTX delivery. Firstly, the dose can be increased to 200 U; the trigone included in the injection sites and switching brands may also be helpful.

Current Therapeutic Strategies in Clinical Urology

The field of urology encompasses all benign and malignant disorders of the urinary tract and the male genital tract. Urological disorders convey a huge economic and patient quality-of-life burden. Hospital acquired urinary tract infections, in particular, are under scrutiny as a measure of hospital quality. Given the prevalence of these pathologies, there is much progress still to be made in available therapeutic options in order to minimize side effects and provide effective care. Current drug delivery mechanisms in urological malignancy and the benign urological conditions of overactive bladder (OAB), interstitial cystitis/bladder pain syndrome (IC/BPS), and urinary tract infection (UTI) will be reviewed herein. Both systemic and local therapies will be discussed including sustained release formulations, nanocarriers, hydrogels and other reservoir systems, as well as gene and immunotherapy. The primary focus of this review is on agents which have passed the preclinical stages of development.

The Expanding Therapeutic Utility of Botulinum Neurotoxins

Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.

Lower Urinary Tract Symptoms: What's New in Medical Treatment?

CONTEXT

Pharmacological treatment is a cornerstone in the management of patients with lower urinary tract symptoms (LUTS).

OBJECTIVE

To review emerging evidence in the medical treatment of LUTS.

EVIDENCE ACQUISITION

An Embase/Pubmed-based literature search was conducted in December 2017, screening for randomized controlled trials (RCTs), prospective and retrospective series, animal model studies, and reviews on medical treatment of LUTS.

EVIDENCE SYNTHESIS

The main medical innovation in recent years in overactive bladder (OAB) has been the approval of the first β₃-adrenoceptor agonists (mirabegron) and intradetrusor onabotulinum toxin A, while several other drugs such as antiepileptics, phosphodiesterase inhibitors, or other β₃-agonists have brought promising results in phase 3 trials. Intraprostatic injections of various drugs for LUTS/benign prostatic hyperplasia have been investigated, but results of phase 3 trials are still pending, while combination therapies of phosphodiesterase type 5 inhibitors+α-blockers or finasteride have been proved as superior to single therapies in RCTs conducted in these patients. Two new formulations of desmopressin have been approved for nocturia in the USA (desmopressin nasal spray) and Europe/Canada/Australia (desmopressin orally disintegrated tablet). Fedovapagon, a vasopressin V₂ receptor agonist, has recently completed a large phase 3 trial in male patients with nocturia. Other phase 3 trials are ongoing in bladder pain syndrome (AQX 11-25, a SHIP-1 activator) and in neurogenic detrusor overactivity (mirabegron and abobotulinum toxin A).

CONCLUSIONS

Medical treatment of LUTS is a very active research field with recently approved drugs for nocturia (desmopressin acetate nasal spray/orally disintegrated tablet) and numerous emerging drugs currently investigated in OAB, LUTS/benign prostatic hyperplasia, nocturia, bladder pain syndrome, and neurogenic detrusor overactivity.

PATIENT SUMMARY

Medical treatment of lower urinary tract symptoms is a very active research field with recently approved drugs for nocturia (desmopressin acetate nasal spray/orally disintegrated tablet) and numerous emerging drugs in overactive bladder, nocturia, neurogenic detrusor overactivity, bladder pain syndrome, or benign prostatic hyperplasia.

Applicability of botulinum toxin type A in paediatric neurogenic bladder management

PURPOSE OF REVIEW

The purpose of this article is to provide an overview about the applicability of botulinum toxin type A (BTX-A) in paediatric neurogenic bladder based on the recently published literature combined with hypothetical notes and future perspectives.

RECENT FINDINGS

The indications, clinical outcomes, urodynamic outcome parameters and cost-effectiveness are presented from recent publications. Also, alternative routes of application of BTX-A in the bladder are discussed as well as the influence of BTX-A on conservative and invasive treatment.

SUMMARY

Intradetrusor BTX-A injections for neurogenic bladder dysfunction are effective in resolving both urinary incontinence and improving urodynamic parameters in most children with a sustained response at repeated injections. In low-compliance bladders, however, if no response is seen after initial BTX-A injection, repeated injections seem to be unnecessary. Because general anaesthesia is mandatory for BTX-A injections in children, alternative routes of application have been investigated such as intravesical installation, electromotive drug application and liposomal drug delivery; however, no definite results have been found in a paediatric clinical setting.

Current best practice management of interstitial cystitis/bladder pain syndrome

Introduction

Over the last 100 years, the terminology and diagnosis criteria for interstitial cystitis have evolved. Many therapeutic options have changed, but others have endured. This article will review the idea of separating 'classic' Hunner lesion interstitial cystitis (HL IC) from non-Hunner lesion interstitial cystitis and bladder pain syndrome (N-HL IC/BPS) and their respective treatment algorithms.

Methods/Results

A literature search was performed to identify articles and research on HL IC and N-HL IC/BPS including definitions, etiological theories, and treatments. This article is an overview of the existing literature. We also offer insight into how HL IC and N-HL IC/BPS are approached at our tertiary referral center. Additionally, American Urological Association guidelines have been integrated and newer treatment modalities and research will be introduced at the conclusion.

Conclusion

The AUA guidelines have mapped out a stepwise fashion to treat IC/BPS; at our institution we separate patients with HL IC from those with N-HL IC/BPS prior to them entering a treatment pathway. We identify the rarer patient with HL as having classic 'IC'; this cystoscopic finding is critical in guiding treatment. We believe HL IC is a distinct disease from N-HL IC/BPS and therapy should focus on the bladder. The vast majority of patients with N-HL IC/BPS need management of their pelvic floor muscles as the primary therapy, complemented by bladder-directed therapies as needed as well as a multidisciplinary team to manage a variety of other regional/systemic symptoms. Ongoing research into IC/BPS will help us better understand the pathophysiology and phenotypes of this complex disease while exciting and novel research studies are developing promising treatments.

Use of botulinum toxin for voiding dysfunction

The use of botulinum toxin A (BoNT-A) has expanded across a range of lower urinary tract conditions. This review provides an overview of the current indications for BoNT-A in the lower urinary tract and critically evaluates the published evidence within each area. The classic application of BoNT-A has been in the management of refractory neurogenic detrusor overactivity (NDO) and overactive bladder (OAB). There is a large volume of high-quality evidence, including numerous randomized placebo-controlled trials, which demonstrate the efficacy of BoNT-A over a long follow-up period. The culmination of this robust evidence-base has led to onabotulinumtoxin A (onaBoNT-A) receiving regulatory approval as a second-line treatment for NDO at a dose of 200 U and OAB at dose of 100 U. Other applications for BoNT-A are used on an off-license basis and include interstitial cystitis/bladder pain syndrome (IC/BPS), benign prostatic hyperplasia (BPH), and detrusor sphincter dyssynergia (DSD). These applications are associated with a less mature evidence-base although the literature is rapidly evolving. At present, the results for painful bladder syndrome (PBS) are promising and BoNT-A injections are recommended as a fourth line option in recent international guidelines, although larger randomized study with longer follow-up are required to confirm the initial findings. As a treatment for DSD, BoNT-A injections have shown potential but only in a small number of trials of limited quality. No definite recommendation can be made based on the current evidence. Finally, the results for the treatment of BPH have been variable and recent high quality randomized controlled trials (RCTs) have suggested no benefit over placebo so at present it cannot be recommended for routine clinical practice. Future advances of BoNT-A include liposome encapsulated formulations which are being developed as an alternative to intravesical injections.

A Prospective, Multicenter, Double-Blind, Randomized Trial of Bladder Instillation of Liposome Formulation OnabotulinumtoxinA for Interstitial Cystitis/Bladder Pain Syndrome

PURPOSE

Intravesical instillation of liposomal formulated botulinum toxin A (lipotoxin) has shown therapeutic effects as treatment of refractory overactive bladder without needle injections. We assessed lipotoxin to treat refractory interstitial cystitis/bladder pain syndrome.

MATERIALS AND METHODS

This 2-center, double-blind, randomized, placebo controlled, physician initiated study enrolled patients with refractory interstitial cystitis/bladder pain syndrome. A total of 31 patients were assigned to intravesical instillation of lipotoxin (onabotulinumtoxinA 200 U with 80 mg sphingomyelin), 28 were assigned to onabotulinumtoxinA 200 U in normal saline and 31 were assigned to normal saline alone. The primary end point was the average change in O'Leary-Sant symptom scores, including ICSI (Interstitial Cystitis Symptom Index) and ICPI (Interstitial Cystitis Problem Index) between baseline and 4 weeks after treatment. Other end points included the average changes in a 3-day voiding diary, a visual analog scale for pain and a global response assessment of patient satisfaction.

RESULTS

Improvements in the pain scale and O'Leary-Sant symptom scores occurred in all 3 groups by 4 weeks after treatment. Lipotoxin instillation was associated with a statistically significant decrease in O'Leary-Sant symptom scores (mean ± SD 7.38 ± 8.75), ICSI (4.00 ± 4.28), ICPI (3.35 ± 5.11) and the visual analog scale pain scale (1.64 ± 2.52), and an increase in the global response assessment (1.35 ± 1.28). However, there was no difference in improvement among the 3 groups. No significant adverse events were found in any group.

CONCLUSIONS

Lipotoxin failed to demonstrate a positive proof of concept compared to onabotulinumtoxinA or placebo. However, a single intravesical instillation of lipotoxin was associated with decreased interstitial cystitis/bladder pain syndrome symptoms compared to baseline in patients with moderate to severe interstitial cystitis/bladder pain syndrome. The effect was likely due to a significant placebo effect.

Past, Present and Future of Chemodenervation with Botulinum Toxin in the Treatment of Overactive Bladder

PURPOSE

We systematically reviewed preclinical and clinical studies on bladder chemodenervation with onabotulinumtoxin A to highlight current limitations and future drug delivery approaches.

MATERIALS AND METHODS

We identified peer reviewed basic and clinical research studies of onabotulinumtoxin A in the treatment of neurogenic bladder and refractory idiopathic overactive bladder published between March 2000 and March 2016. Paired investigators independently screened 125 English language articles to identify controlled studies on onabotulinumtoxin A administration in the MEDLINE® database and abstracts presented at annual American Urological Association meetings. The review yielded an evidence base of more than 50 articles relevant to the approach of injection-free onabotulinumtoxin A chemodenervation.

RESULTS

The efficacy and safety of intradetrusor injection of onabotulinumtoxin A for the treatment of overactive bladder are sensitive to injection volume and depth, and this issue has motivated researchers to study injection-free modes of drug delivery into the bladder. Urothelial denudation with protamine sulfate or dimethyl sulfoxide, liposome encapsulated onabotulinumtoxin A and other physical approaches are being studied to increase toxin permeability and avoid intradetrusor injections. Liposome encapsulated onabotulinumtoxin A enhances toxin activity while reducing its toxin degradation. The safety and efficacy of liposome encapsulated onabotulinumtoxin A were tested in a multicenter, placebo controlled study. Although this treatment successfully reduced urinary frequency and urgency, it did not significantly reduce urgency urinary incontinence episodes.

CONCLUSIONS

Intradetrusor injection of onabotulinumtoxin A is a safe and effective treatment as reported in several large multicenter, randomized controlled trials. Injection of the toxin into the bladder wall impairs afferent and efferent nerves, but injection-free drug delivery approaches only impair the bladder afferent nerves. Further studies are needed to develop better drug delivery platforms that overcome the drawbacks of intradetrusor injection, increase patient acceptance and reduce treatment costs.

Efficacy and Safety of OnabotulinumtoxinA in Patients with Neurogenic Detrusor Overactivity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Neurogenic detrusor overactivity (NDO) affects the quality of life (QoL) of millions of individuals worldwide. The purpose of this study was to assess the efficacy and safety of onabotulinumtoxinA in patients with NDO using a network meta-analytic approach, which can also quantify and compare the efficacy of onabotulinumtoxinA across different dosages.

METHODS

PubMed, EMBASE, and the Controlled Trials Register were searched to identify randomized controlled trials comparing onabotulinumtoxinA to a control for NDO in adult patients. The primary outcome was the mean number of urinary incontinence (UI) episodes per week. Urodynamic parameters included the maximum cystometric capacity (MCC) and the maximum detrusor pressure (MDP). The safety of onabotulinumtoxinA was determined by the incidence of various frequent adverse events (AEs). Two authors extracted data independently, and the statistical analyses were performed using RevMan 5.1.0 software.

RESULTS

A total of 1,915 patients from six randomized controlled trials were included in this meta-analysis. The onabotulinumtoxinA-treated groups had a significantly decreased mean number of urinary incontinence episodes per week (at week 6) (onabotulinumtoxinA200U: MD: -10.72, 95% CI: -13.4 to -8.04, P<0.00001; 300 U: MD: -11.42, 95% CI: -13.91 to -8.93, P<0.00001), MDP (200 U: MD: -33.46, 95% CI: -39.74 to -27.18, P<0.00001; 300 U: MD: -31.72, 95% CI: -37.69 to -25.75, P<0.00001), and greater increased MCC (200 U: MD: 141.30, 95% CI: 121.28 to 161.32, P<0.00001; 300 U: MD: 151.39, 95% CI: 130.43 to 172.34, P<0.00001) compared to the placebo-treated groups. However, there were no significant differences between the onabotulinumtoxinA-treated groups for the number of weekly UI episodes at 6 weeks (MD: 0.08, 95% CI: -2.57 to 2.73, P = 0.95). Similarly, we also observed that there were no significant differences in MCC (MD: -9.97, 95% CI: -33.15 to 13.20, P = 0.40) and MDP (MD: -1.86, 95% CI: -8.09 to 4.37, P = 0.56). Considering the AEs, the onabotulinumtoxinA-treated groups were often associated with more complications, including urinary tract infections (UTIs) (RR: 1.47, 95% CI: 1.29 to 1.67, P<0.00001), urinary retention (RR: 5.58, 95% CI: 3.53 to 8.83, P<0.00001), hematuria (RR: 1.70, 95% CI: 1.01 to 2.85, P = 0.05), and muscle weakness (RR: 2.59, 95% CI: 1.36 to 4.91, P = 0.004).

CONCLUSIONS

OnabotulinumtoxinA can significantly reduce the frequency of urge urinary incontinence and improve urodynamic parameters (MCC and MDP) in patients with NDO at 6 weeks after treatment. This meta-analysis indicates that onabotulinumtoxinA is effective and safe for treating patients with NDO compared to placebo. Additionally, we did not observe any statistical or clinical differences in efficacy between 300 and 200 U dosages.

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.