Cizolirtine Citrate, an Effective Treatment for Symptomatic Patients with Urinary Incontinence Secondary to Overactive Bladder: A Pilot Dose-Finding Study

Emerging drugs for the treatment of bladder storage dysfunction

INTRODUCTION

Current drug treatment of lower urinary tract disorders, for example, overactive bladder syndrome and lower urinary tract symptoms associated with benign prostatic hyperplasia, is moderately effective, has a low treatment persistence and some short- and long-term adverse events. Even if combination therapy with approved drugs may offer advantages in some patients, there is still a need for new agents.

AREAS COVERED

New b₃-adrenoceptor agonists, antimuscarinics, the naked Maxi-K channel gene, a novel 5HT/NA reuptake inhibitor and soluble guanylate cyclase activators are discussed. Focus is given to P2X3 receptor antagonists, small molecule blockers of TRP channels, the roles of cannabis on incontinence in patients with multiple sclerosis, and of drugs acting directly on CB1 and CB2 receptor or indirectly via endocannabinoids by inhibition of fatty acid aminohydrolase.

EXPERT OPINION

New potential alternatives to currently used drugs/drug principles are emerging, but further clinical testing is required before they can be evaluated as therapeutic alternatives. It seems that for the near future individualized treatment with approved drugs and their combinations will be the prevailing therapeutic approach.

Ocular adverse effects of bladder medication: a systematic review

BACKGROUND

With the ageing population, lower urinary tract symptoms are becoming more prevalent with an estimate that by 2025, 52 million adults in the USA will be affected. After lifestyle modifications fail to resolve symptoms, second-line therapy with medications is often recommended by both the European Association of Urology and the American Urological Association. Considering the vulnerability of older patients to co-morbidities, physicians must be more aware of adverse side effects. This study aims to identify a linkage between common overactive bladder and interstitial cystitis medication and adverse ocular symptoms.

METHODS

A comprehensive literature search was conducted in MEDLINE, EMBASE, CINAHL, PsycInfo, and HealthSTAR alongside a grey literature search in clinicaltrials.gov to include all articles relating to bladder medication and vision-threatening loss. Covidence review software was utilised to conduct the systematic review.

RESULTS

In total, 222 articles were screened, and 23 articles met the inclusion criteria. Comprehensive coverage of 10 available medications was analysed. All medications reported adverse vision effects stratified over 15 categories. The most common adverse effect was reported to be blurred vision (n = 12 studies). Mirabegron had the most number of adverse types of ocular symptoms that covered 6 categories. Cizolirthine Citrate and Elocatitol had the least amount of ocular side effects reported. From the total of 8459 patients that were treated for either overactive bladder syndrome or interstitial cystitis with oral medications, 422 reported adverse vision effects.

CONCLUSIONS

This review suggests that ocular safety should be assessed in patients requiring systematic drug therapy in order to guide future research, focussing on long-term tolerability.

Results from two-year rodent oral carcinogenicity studies of cizolirtine, a substance-P and calcitonin gene-related peptide release modulator

Cizolirtine is a substance-P and calcitonin gene-related peptide release modulator developed for the treatment of pain and urinary incontinence. To assess its carcinogenic potential, cizolirtine was administered by oral route once daily for up to 104 weeks to CD-1 mice at doses of 40, 90, or 200 mg/kg/day, and to Han Wistar rats at doses of 40, 90 or 200 mg/kg/day to males and 40, 110 or 160 mg/kg/day to females. There were treatment-related neoplastic findings both in mice and rats. In mice, administration of cizolirtine was associated to an increase in skin fibrosarcomas and sarcomas among high-dose males, considered secondary to increased aggression and specific to the animal model. In rats, there was an increased incidence of liver adenomas in males and females, and carcinomas in males, in association with an increased incidence of hepatocyte hypertrophy, vacuolation and clear cell foci, and considered related to sustained long-term enzyme induction resulting in increased liver metabolism and associated hypertrophic changes. The observed neoplastic findings in mouse skin and rat liver after life-time oral administration of cizolirtine are considered related to rodent-specific non-genotoxic mechanisms of questionable relevance to man.

Twenty six-week repeat dose oral rat toxicity study of cizolirtine, a substance-P and calcitonin gene-related peptide release modulator

Cizolirtine, a substance-P and calcitonin gene-related peptide release modulator developed for the treatment of pain and urinary incontinence, was orally administered for 26-weeks to rats at dosages of 20, 60 and 200 mg/kg/day. Clinical signs were limited to post-dosing salivation and brown staining on head and muzzle. There were slight decreases in bodyweight gain and slight increases in water consumption among cizolirtine-treated animals. Slight increases in plasma alkaline phosphatase activity, and cholesterol and phospholipid concentrations were observed in mid- and/or high-dose animals. Low urinary volume, pH and sodium and potassium outputs were observed after 12-weeks, and low urinary pH, low sodium and high potassium outputs at end of treatment. Increased relative (to bodyweight) liver weight was observed in high-dose animals. Treated males and high-dose females showed a dose-related increase in the incidence and severity of periacinar hepatocytic hypertrophy and midzonal/periacinar hepatocytic fat vacuolization. Increased incidences of hepatic clear cell foci were observed in all cizolirtine-treated male groups and, to a lesser extent, in treated females. Ovaries of treated females showed a dose-dependent increased incidence of absent corpora lutea and, occasionally, follicular cysts. The dosages of 20 and 60 mg/kg/day were considered as the No-Observed-Adverse-Effect Levels for males and females, respectively.

Assessment of the Genotoxic Potential of Cizolirtine a Substance-P and Calcitonin Gene-Related Peptide Release Modulator

The analysis of the genotoxic potential of cizolirtine, a compound being developed as a drug for analgesia and for urinary incontinence, was carried out using a battery of in vitro and in vivo assays as recommended in the guidelines for medicinal products. Negative results were obtained in an Ames test (up to 5000 µg/plate), in a Mouse Lymphoma assay (up to 2000 µg/ml) and in a single dose mouse bone marrow micronucleus assay (up to 300 mg/kg). In a human lymphocyte chromosome aberration assay, a slight statistical increase in the frequency of cells with chromosome aberrations including gaps was reported for the concentrations of 200 and 1600 μg/ml at the 24-h sampling time. This minor increase in chromosome aberrations was considered of questionable biological relevance since it was moderate, was within the laboratory historical control values, did no show a dose-dependent effect and was not observed at similar concentrations in a repeat assay. Taking into considerations the results obtained in the different in vitro and in vivo assays and a weight-of-evidence analysis, it suggests that cizolirtine would not pose a genotoxic risk when administered to humans.

Factors influencing efficacy endpoints in clinical trials for new oral medicinal treatments for overactive bladder: a systematic literature review and meta-analysis

PURPOSE

Overactive bladder (OAB) is a symptom-based disease; therefore, clinical trials to evaluate treatments for OAB employ a range of efficacy endpoints. Since factors that influence efficacy endpoints can affect trial outcomes, their identification could aid in the design of future OAB clinical trials. We investigated factors influencing different efficacy endpoints used in clinical trials with OAB patients and examined their characteristics to determine future clinical trial strategies for new medicinal treatments for OAB.

METHODS

Data from placebo-controlled double-blind trials in patients with OAB were extracted via a systematic literature review. The integrated differences for efficacy endpoints were calculated. Heterogeneity was assessed using the Q statistic and I² statistic. Factors influencing efficacy endpoints were identified through univariate and multivariate meta-regression analyses.

RESULTS

Forty-one controlled trials were analyzed. Substantial heterogeneity between studies was observed for each efficacy endpoint (P > 0.001, I² > 70%). We found with multivariate meta-regression analysis that period of recording in a bladder diary and year of publication were significantly likely to influence the change from baseline in the mean number of urgency episodes in 24 h, year of publication and gender were significantly likely to influence the change from baseline in the mean number of micturitions in 24 h, and gender was significantly likely to influence the change from baseline in the mean volume voided per micturition. In contrast, there were no factors significantly associated with change from baseline in the mean number of incontinence episodes in 24 h.

CONCLUSIONS

We identified that change from baseline in the mean number of incontinence episodes in 24 h should serve as a relatively stable endpoint. In contrast, we identified factors influencing other endpoints, and the identified factors should be taken into account when planning and conducting future clinical trials.

Potential Primary Endpoint for Exploratory Clinical Trial in Patients with Overactive Bladder: A Systematic Literature Review

OBJECTIVES

To identify a potential primary endpoint in an early-phase exploratory trial among key overactive bladder (OAB) symptoms.

METHODS

Placebo-controlled double-blinding trials in patients with OAB were extracted for systematic literature review. The correlation between key OAB symptoms recorded in bladder diaries and coefficient of variation (CV) in each study were assessed.

RESULTS

Forty-one controlled trials were extracted for the present review. Mean number of urgency episodes in 24 h was substantially associated with mean number of urgency incontinence episodes in 24 h, mean volume voided per micturition, and mean number of micturitions in 24 h (Spearman's r = 0.725, -0.661, and 0.657, respectively). Mean number of micturitions in 24 h was also substantially associated with mean volume voided per micturition (Spearman's r = -0.674). Mean number of incontinence episodes in 24 h was substantially associated with mean number of urgency incontinence episodes in 24 h and mean volume voided per micturition (Spearman's r = 0.840 and -0.628, respectively). The median CV of mean volume voided per micturition in each trial was the smallest among all endpoints.

CONCLUSIONS

Our findings suggest that volume voided per micturition is a useful symptom for evaluating OAB candidate compounds in a small sample size and represents an effective primary endpoint, especially in exploratory clinical trials.

Insight into new potential targets for the treatment of overactive bladder and detrusor overactivity

Although overactive bladder (OAB) and detrusor overactivity (DO) are not synonyms, they share therapeutic options and partially underlying physiopathological mechanisms. The aim of this overview is to give insight into new potential targets for the treatment of OAB and DO. A narrative review was done in order to reach this goal. Ageing, pelvic floor disorders, hypersensitivity disorders, morphologic bladder changes, neurological diseases, local inflammations, infections, tumors and bladder outlet obstruction may alter the normal voluntary control of micturition, leading to OAB and DO. The main aim of pharmacotherapy is to restore normal control of micturition, inhibiting the emerging pathological involuntary reflex mechanism. Therapeutic targets can be found at the levels of the urothelium, detrusor muscles, autonomic and afferent pathways, spinal cord and brain. Increased expression and/or sensitivity of urothelial-sensory molecules that lead to afferent sensitization have been documented as a possible pathogenesis of OAB. Targeting afferent pathways and/or bladder smooth muscles by modulating activity of ligand receptors and ion channels could be effective to suppress OAB.

Neuropeptides in lower urinary tract function

Numerous neuropeptide/receptor systems including vasoactive intestinal polypeptide, pituitary adenylate cyclase-activating polypeptide, calcitonin gene-related peptide, substance P, neurokinin A, bradykinin, and endothelin-1 are expressed in the lower urinary tract (LUT) in both neural and nonneural (e.g., urothelium) components. LUT neuropeptide immunoreactivity is present in afferent and autonomic efferent neurons innervating the bladder and urethra and in the urothelium of the urinary bladder. Neuropeptides have tissue-specific distributions and functions in the LUT and exhibit neuroplastic changes in expression and function with LUT dysfunction following neural injury, inflammation, and disease. LUT dysfunction with abnormal voiding, including urinary urgency, increased voiding frequency, nocturia, urinary incontinence, and pain, may reflect a change in the balance of neuropeptides in bladder reflex pathways. LUT neuropeptide/receptor systems may represent potential targets for therapeutic intervention.

Cizolirtine citrate is safe and effective for treating urinary incontinence secondary to overactive bladder: a phase 2 proof-of-concept study

BACKGROUND

Antimuscarinic agents currently dominate medical treatment for urinary incontinence secondary to overactive bladder (OAB). Alternatives to improve their risk-benefit ratio are welcomed.

OBJECTIVE

To demonstrate the efficacy and safety of oral cizolirtine citrate in this indication.

DESIGN, SETTING, AND PARTICIPANTS

A randomised, double-blind, placebo- and active-controlled, phase 2 multicentre clinical trial performed by urologists or gynaecologists at referral centres. A sample was composed of 135 outpatients with signs of lower urinary tract dysfunction and urodynamically documented detrusor overactivity; 20 patients left the study prematurely, chiefly (n=10) because of adverse events.

INTERVENTION

Allocation to treatments was asymmetrical (2:2:1) to cizolirtine citrate 800 mg/d, placebo, or oxybutynin 15 mg/d. Treatments were given for 12 wk.

MEASUREMENTS

Efficacy measures included a bladder diary, filling- and voiding-phase urodynamic evaluations, and measure of quality of life (QoL). Adverse events were systematically recorded. Statistical procedures included analysis of covariance, chi(2) tests, and calculation of 95% confidence intervals.

RESULTS AND LIMITATIONS

Most patients (92.6%) were female, and their mean age was 51.8 yr. Bladder diary variables improved significantly with active drug over placebo: The average number of voidings per 24 h was reduced by 33.4%, 17.0%, and 34.3% (p=0.001) in the cizolirtine citrate, placebo, and oxybutynin groups, respectively. The mean estimated voided volume per voluntary micturition increased by 17.8%, 0%, and 14.5% (p=0.002) in the cizolirtine citrate, placebo, and oxybutynin groups, respectively. The proportions of patients achieving fewer than eight voidings per 24 h, complete dryness, or both were also superior with active drugs over placebo. Only cizolirtine showed significant superiority over placebo to improve urodynamic parameters, although the asymmetrical allocation played against oxybutynin in the inferences. Cizolirtine citrate caused fewer antimuscarinic but more gastrointestinal (nausea) and neurologic (headache and vertigo) adverse events than oxybutynin.

CONCLUSIONS

Cizolirtine citrate is a promising agent in the treatment of OAB with urinary incontinence.