The effect of fasting or desmopressin before treatment on the concentration of mitomycin C during intravesical administration

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.

Targeting Bladder Urothelial Carcinoma with pHLIP-ICG and Inhibition of Urothelial Cancer Cell Proliferation by pHLIP-amanitin

Acidity is a useful biomarker for the targeting of metabolically active-cells in tumors. pH Low Insertion Peptides (pHLIPs) sense the pH at the surfaces of tumor cells and can facilitate intracellular delivery of cell-permeable and cell-impermeable cargo molecules. In this study we have shown the targeting of malignant lesions in human bladders by fluorescent pHLIP agents, intracellular delivery of amanitin toxin by pHLIP for the inhibition of urothelial cancer cell proliferation, and enhanced potency of pHLIP-amanitin for cancer cells with 17p loss, a mutation frequently present in urothelial cancers. Twenty-eight ex-vivo bladder specimens, from patients undergoing robotic assisted laparoscopic radical cystectomy for bladder cancer, were treated via intravesical incubation for 15-60 minutes with pHLIP conjugated to indocyanine green (ICG) or IR-800 near infrared fluorescent (NIRF) dyes at concentrations of 4-8 μM. White light cystoscopy identified 47/58 (81%) and NIRF pHLIP cystoscopy identified 57/58 (98.3%) of malignant lesions of different subtypes and stages selected for histopathological processing. pHLIP NIRF imaging improved diagnosis by 17.3% (p < 0.05). All carcinoma-in-situ cases missed by white light cystoscopy were targeted by pHLIP agents and were diagnosed by NIRF imaging. We also investigated the interactions of pHLIP-amanitin with urothelial cancer cells of different grades. pHLIP-amanitin produced concentration- and pH-dependent inhibition of the proliferation of urothelial cancer cells treated for 2 hrs at concentrations up to 4 μM. A 3-4x enhanced cytotoxicity of pHLIP-amanitin was observed for cells with a 17p loss after 2 hrs of treatment at pH6. Potentially, pHLIP technology may improve the management of urothelial cancers, including imaging of malignant lesions using pHLIP-ICG for diagnosis and surgery, and the use of pHLIP-amanitin for treatment of superficial bladder cancers via intravesical instillation.

Mitomycin C: new strategies to improve efficacy of a well-known therapy

Mitomycin C (MMC) as an intravesical chemotherapeutic agent is a well-known option for treatment of nonmuscle invasive bladder cancer (NMIBC) recurrence; it is probably the most commonly used agent given its low rate of side effects and its efficacy.Both the American Urologic Association (AUA) and European Association of Urology (EAU) consider MMC as a standard treatment for immediate single-dose postoperative treatment and for adjuvant therapy in low and intermediate-risk NMIBC.Despite the popularity of this agent in the treatment of NMIBCs, many questions regarding the optimal approach to MMC therapy remain unanswered and the schedule widely used is empirical.Nevertheless, even when the current optimal approaches to MMC administration are used, a large proportion of NMIBCs recur.This apparent treatment resistance might be overcome by an optimization of standard MMC therapy or with a combination of MMC with other agents that have different mechanisms of action.Strategies to enhance passive delivery of MMC have been well studied and multiple measures are recommended for implementation of use in routine clinical practice.A modified scheme of instillation seems to be an easy and inexpensive alternative to increase efficacy of intravesical MMC and to also use this agent with an ablative intent.Enhancing tumor response with a sequential therapy is another option that has been investigated, mostly for chemo-immunotherapy wherein the different mechanisms of action of Bacillus of Calmette and Guerìn (BCG) and MMC are combined to achieve a higher response.

Hydrostatic pressure enhances mitomycin C induced apoptosis in urothelial carcinoma cells

OBJECTIVES

Urothelial carcinoma (UC) of the bladder is the second most common cancer of the genitourinary system. Clinical UC treatment usually involves transurethral resection of the bladder tumor followed by adjuvant intravesical immunotherapy or chemotherapy to prevent recurrence. Intravesical chemotherapy induces fewer side effects than immunotherapy but is less effective at preventing tumor recurrence. Improvement to intravesical chemotherapy is, therefore, needed.

METHODS AND MATERIALS

Cellular effects of mitomycin C (MMC) and hydrostatic pressure on UC BFTC905 cells were assessed. The viability of the UC cells was determined using cellular proliferation assay. Changes in apoptotic function were evaluated by caspase 3/7 activities, expression of FasL, and loss of mitochondrial membrane potential.

RESULTS

Reduced cell viability was associated with increasing hydrostatic pressure. Caspase 3/7 activities were increased following treatment of the UC cells with MMC or hydrostatic pressure. In combination with 10 kPa hydrostatic pressure, MMC treatment induced increasing FasL expression. The mitochondria of UC cells displayed increasingly impaired membrane potentials following a combined treatment with 10 μg/ml MMC and 10 kPa hydrostatic pressure.

CONCLUSIONS

Both MMC and hydrostatic pressure can induce apoptosis in UC cells through an extrinsic pathway. Hydrostatic pressure specifically increases MMC-induced apoptosis and might minimize the side effects of the chemotherapy by reducing the concentration of the chemical agent. This study provides a new and alternative approach for treatment of patients with UC following transurethral resection of the bladder tumor.

Investigational therapies for non-muscle invasive bladder cancer

IMPORTANCE OF THE FIELD

Bacillus Calmette-Guérin (BCG) is currently the most effective adjuvant intravesical agent at preventing disease recurrence and the only therapy shown to inhibit disease progression in non-muscle invasive bladder cancer (NMIBC). However, recurrence rates as high as 30% and significant local/systemic toxicity have resulted in an increased interest in the use of alternative intravesical agents.

AREAS COVERED IN THE REVIEW

Our aim is to discuss recent clinical trial evidence utilizing novel intravesical agents for treatment of NMIBC. A systematic literature review was performed via the National Center for Biotechnology Information databases to identify pertinent studies from 2000-2009.

WHAT THE READER WILL GAIN

A durable response has been demonstrated with alternative agents in patients refractory to or intolerant of BCG. This review compares the merits and shortcomings of these emerging agents, focusing on clinical trial safety and efficacy results.

TAKE HOME MESSAGE

Despite recent enthusiasm for novel agents, radical cystectomy remains the treatment of choice for patients with NMIBC who have failed intravesical therapy. However, evidence is accumulating that novel agents provide an efficacious alternative in patients refractory or intolerable to BCG or unfit for cystectomy. Further randomized prospective data are required to demonstrate a recurrence- and progression-free benefit compared with BCG.

[Intravesical therapy in non-muscle-invasive bladder cancer: indications and practical considerations]

Intravesical treatment with various agents is an accepted standard for treating patients with non-muscle-invasive bladder cancer; all guidelines recommend its use. Depending on the agent and the instillation schedule, a reduction in recurrence and a decrease in the progression rate can be achieved.However, many of the recommendations in the various guidelines are currently under debate. Early instillation with a chemotherapeutic agent is probably overtreatment in patients requiring further induction or maintenance therapy because it adds no further benefit. The economic aspects of early instillations are also being discussed. Recent studies question the ability of bacillus Calmette-Guérin (BCG) instillations to reduce the progression of non-muscle-invasive bladder cancer. Furthermore, the superiority of maintenance therapies compared with induction schedules is under debate.There is a great body of evidence that the effectiveness of intravesical chemotherapy can be increased by simple measures. Reduction of BCG side effects without compromising the oncological outcome is possible.

Intravesical treatments of bladder cancer: review

For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy.

Improving Efficacy of Intravesical Chemotherapy

OBJECTIVE

This paper reviews the most relevant findings published recently on intravesical chemotherapy for superficial bladder tumours and provides recommendations based on documented research.

METHODS

The evidence was categorised according to the North of England Evidence Based Guideline Development Project. Levels of evidence were based on the source of the information, meta-analyses, systematic reviews, well-designed randomised or nonrandomised controlled clinical trials, and uncontrolled studies or consensus. Three levels of recommendations were assigned to the evidence obtained.

RESULTS

Despite intravesical chemotherapy being used prophylactically after endoscopic resection of superficial bladder tumours, the recurrence rate is still 36-44%. Researchers have focused on improving the effectiveness of intravesical chemotherapy, each adopting a different strategy. Some have aimed to identify the optimum timing for instillations and others to improve the pharmacokinetics of agents by avoiding their dilution, increasing their stability, or improving the absorption of the drug by bladder mucosa. Some researchers are looking into new, single chemotherapeutic agents or combinations for intravesical use and others into avoiding chemoresistance with resistance-reverting agents (modulating agents) or by using in vitro chemosensitivity tests to identify the most sensitive drug.

CONCLUSION

Progress has been made in optimising intravesical chemotherapy for timing of instillations and pharmacokinetic interventions. Simple and inexpensive approaches may have a widespread, practical acceptance by urologists, but it is more difficult to extend new techniques requiring more complex and sometimes expensive instrumentation to the urologic community. Further research into finding more effective cytotoxic drugs, combinations, or modulating agents should be encouraged.

Practical Applications of Intravesical Chemotherapy and Immunotherapy in High-risk Patients with Superficial Bladder Cancer

The following steps are practical in the treatment of intermediate-to-high risk patients with superficial bladder cancer: Resect all visible tumor at the time of first TUR of bladder tumor. Strongly consider re-resection, especially for high-risk, large, multifocal, stage T1 tumors. Apply one dose of cytotoxic chemotherapy perioperatively within 6 hours of TUR (ideally immediately). Once histopathology is available, consider intravesical induction chemotherapy for intermediate-risk patients and BCG for intermediate- or high-risk patients and those having failed prior chemotherapy. At least 1 year of maintenance therapy should be planned for all intermediate-to-high risk BCG-treated patients. Chemotherapy maintenance may be useful if perioperative chemotherapy was omitted. For patients failing standard therapy, a thorough discussion of the risks (including progression and metastasis) and expected benefits should take place before the initiation of salvage therapy. The radical cystectomy option should be openly entertained. Consider BCG plus interferon or gemcitabine-based salvage programs if appropriate. Explore clinical trial options. Contact urologic cancer experts for guidance and advice.

Epirubicin and meglumine gamma-linolenic acid: a logical choice of combination therapy for patients with superficial bladder carcinoma

BACKGROUND

Anthracyclines have been established as first-line drugs for intravesical use in the treatment of patients with superficial bladder carcinoma, although they result only in a modest reduction in tumor recurrence rates. The essential fatty acid gamma-linolenic acid (GLA) also is an effective cytotoxic agent against superficial bladder carcinoma when it is applied topically. The objective of this study was to assess the efficacy of combined epirubicin and GLA with the purpose of developing a suitable model for modification of existing intravesical regimens.

METHODS

The human urothelial carcinoma cell lines MGH-U1 and RT112 were used in standard cytotoxicity assays and were exposed to meglumine GLA (MeGLA) and epirubicin in two-dimensional concentration matrices. A thiozolyl blue (methyl-thiazoldiphenyl tetrazolium) assay was used to determine residual cell biomass. Drug interaction was quantified by median-effect analysis software (CalcuSyn), and the evaluation of drug uptake utilized fluorescence confocal microscopy (FCM) and flow cytometry.

RESULTS

MeGLA caused a significant enhancement of anthracycline uptake, viewed by FCM, from 92 fluorescence units to 222 fluorescence units (P < 0.001). Flow cytometry confirmed the increased drug uptake and showed that the mean epirubicin content per cell increased from 23 to 57 units and from 8 to 24 units for MGH-U1 and RT112 cells, respectively (99% confidence interval < 0.3). This resulted in improved cytotoxicity, and it was shown that the drugs acted synergistically with all but the highest MeGLA concentrations.

CONCLUSIONS

The efficacy of epirubicin was enhanced significantly when it was used in combination with most concentrations of MeGLA (< 300 microg/mL), and the two agents acted synergistically. There was a corresponding increase in epirubicin uptake by cells under these conditions. At high MeGLA concentrations, however, anthracycline solubility was compromised, and drug synergy was lost.