Pharmacokinetic study to optimize the intravesical administration of gemcitabine

Single Early Intravesical Instillation of Epirubicin for Preventing Bladder Recurrence after Nephroureterectomy in Upper Urinary Tract Urothelial Carcinoma

PURPOSE

We aimed to assess the effectiveness of early single intravesical administration of epirubicin in preventing intravesical recurrence after radical nephroureterectomy for upper tract urothelial carcinoma.

MATERIALS AND METHODS

Patients with upper tract urothelial carcinoma who underwent radical nephroureterectomy between November 2018 and May 2022 were retrospectively reviewed. Intravesical epirubicin was administered within 48 hours if no evidence of leakage was observed. Epirubicin (50 mg) in 50 mL normal saline solution was introduced into the bladder via a catheter and maintained for 60 minutes. The severity of adverse events was graded using the Clavien-Dindo classification. We compared intravesical recurrence rate between the two groups. Multivariate analyses were performed to identify the independent predictors of bladder recurrence following radical nephroureterectomy.

RESULTS

Epirubicin (n=55) and control (n=116) groups were included in the analysis. No grade 1 or higher bladder symptoms have been reported. A statistically significant difference in the intravesical recurrence rate was observed between the two groups (11.8% at 1 year in the epirubicin group vs. 28.4% at 1 year in the control group; log-rank p=0.039). In multivariate analysis, epirubicin instillation (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.20 to 0.93; p=0.033) and adjuvant chemotherapy (HR, 0.29; 95% CI, 0.13 to 0.65; p=0.003) were independently predictive of a reduced incidence of bladder recurrence.

CONCLUSION

This retrospective review revealed that a single immediate intravesical instillation of epirubicin is safe and can reduce the incidence of intravesical recurrence after radical nephroureterectomy. However, further prospective trials are required to confirm these findings.

Induction and maintenance of sequential intravesical gemcitabine/docetaxel for intermediate and high-risk non-muscle invasive bladder cancer with different dosage protocols

INTRODUCTION

The combination of sequential intravesical gemcitabine and docetaxel (Gem/Doce) chemotherapy has been considered a feasible option for BCG (Bacillus Calmette-Guérin) treatment in non-muscle invasive bladder cancer (NMIBC), gaining popularity during BCG shortage period. We seek to determine the efficacy of the treatment by comparing Gem/Doce induction alone vs induction with maintenance, and to evaluate the treatment outcomes of two different dosage protocols.

METHODS

A bi-center retrospective analysis of consecutive patients treated with Gem/Doce for NMIBC between 2018 and 2023 was performed. Baseline characteristics, risk group stratification (AUA 2020 guidelines), pathological, and surveillance reports were collected. Kaplan-Meier survival analysis was performed to detect Recurrence-free survival (RFS).

RESULTS

Overall, 83 patients (68 males, 15 females) with a median age of 73 (IQR 66-79), and a median follow-up time of 18 months (IQR 9-25), were included. Forty-one had an intermediate-risk disease (49%) and 42 had a high-risk disease (51%). Thirty-seven patients (45%) had a recurrence; 19 (23%) had a high-grade recurrence. RFS of Gem/Doce induction-only vs induction + maintenance was at 6 months 88% vs 100%, at 12 months 71% vs 97%, at 18 months 57% vs 91%, and at 24 months 31% vs 87%, respectively (log-rank, p < 0.0001). Patients who received 2 g Gemcitabine with Docetaxel had better RFS for all-grade recurrences (log-rank, p = 0.017). However, no difference was found for high-grade recurrences.

CONCLUSION

Gem/Doce induction with maintenance resulted in significantly better RFS than induction-only. Combining 2 g gemcitabine with docetaxel resulted in better RFS for all-grade but not for high-grade recurrences. Further prospective trials are necessary to validate our results.

The Safety, Tolerability, and Preliminary Efficacy of a Gemcitabine-releasing Intravesical System (TAR-200) in American Urological Association-defined Intermediate-risk Non-muscle-invasive Bladder Cancer Patients: A Phase 1b Study

Background and objective

Patients with intermediate-risk non-muscle-invasive bladder cancer (IR NMIBC) have a high risk of recurrence and need effective therapies to reduce the risk of disease recurrence or progression. This phase 1b study (NCT02720367) assessed the safety and tolerability of TAR-200, an intravesical drug delivery system, in participants with IR NMIBC.

Methods

Participants with recurrent IR NMIBC were eligible. Participants received either two 7-d or two 21-d TAR-200 dosing cycles over a 4-6-wk period in a marker lesion/ablation design. TAR-200 was placed in the window between the cystoscopy showing recurrent papillary disease and the subsequent complete transurethral resection of the bladder tumour. The primary endpoint was TAR-200 safety. The secondary endpoints included TAR-200 tolerability, pharmacokinetics, and preliminary efficacy.

Key findings and limitations

Twelve participants received TAR-200 treatment. No TAR-200-related serious or grade ≥ 3 treatment-emergent adverse events (TEAEs) occurred. Nine participants had grade ≤ 2 TAR-200-related TEAEs, with urgency, dysuria, and haematuria being most common. Two participants refused a second dosing cycle due to urinary urgency and frequency. Insertion and removal of TAR-200 was successful in all cases. Plasma gemcitabine concentrations remained below the lower limit of detection. Five participants (42%) had complete response (CR): four had pathological CR and one had CR based on visual assessment.

Conclusions and clinical implications

TAR-200 appears to be safe and well tolerated, with encouraging preliminary efficacy in participants with IR NMIBC. This study lays the groundwork for the multiple phase 2 and 3 global studies that are currently on-going for TAR-200.

Patient summary

In this study, researchers evaluated the safety of the novel drug delivery system TAR-200 in participants with intermediate-risk non-muscle-invasive bladder cancer. They concluded that TAR-200 was safe and well tolerated with promising antitumour activity.

Safety Assessment of Ultrasound-Assisted Intravesical Chemotherapy in Normal Dogs: A Pilot Study

Intravesical chemotherapy after transurethral resection is a treatment option in patients with non-muscle invasive bladder cancer. The efficacy of intravesical chemotherapy is determined by the cellular uptake of intravesical drugs. Therefore, drug delivery technologies in the urinary bladder are promising tools for enhancing the efficacy of intravesical chemotherapy. Ultrasound-triggered microbubble cavitation may enhance the permeability of the urothelium, and thus may have potential as a drug delivery technology in the urinary bladder. Meanwhile, the enhanced permeability may increase systemic absorption of intravesical drugs, which may increase the adverse effects of the drug. The aim of this preliminary safety study was to assess the systemic absorption of an intravesical drug that was delivered by ultrasound-triggered microbubble cavitation in the urinary bladder of normal dogs. Pirarubicin, a derivative of doxorubicin, and an ultrasound contrast agent (Sonazoid) microbubbles were administered in the urinary bladder. Ultrasound (transmitting frequency 5 MHz; pulse duration 0.44 μsec; pulse repetition frequency 7.7 kHz; peak negative pressure −1.2 MPa) was exposed to the bladder using a diagnostic ultrasound probe (PLT-704SBT). The combination of ultrasound and microbubbles did not increase the plasma concentration of intravesical pirarubicin. In addition, hematoxylin and eosin staining showed that the combination of ultrasound and microbubble did not cause observable damages to the urothelium. Tissue pirarubicin concentration in the sonicated region was higher than that of the non-sonicated region in two of three dogs. The results of this pilot study demonstrate the safety of the combination of intravesical pirarubicin and ultrasound-triggered microbubble cavitation, that is, ultrasound-assisted intravesical chemotherapy.

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.

Hyperthermia Improves Solubility of Intravesical Chemotherapeutic Agents

BACKGROUND: Nearly 70% of all new cases of bladder cancer are non-muscle invasive disease, the treatment for which includes transurethral resection followed by intravesical therapy. Unfortunately, recurrence rates approach 50% in part due to poor intravesical drug delivery. Hyperthermia is frequently used as an adjunct to intravesical chemotherapy to improve drug delivery and response to treatment. OBJECTIVE: To assess the solubility profile of intravesical chemotherapies under varying conditions of pH and temperature. METHODS: Using microplate laser nephelometry we measured the solubility of three intravesical chemotherapy agents (mitomycin C, gemcitabine, and cisplatin) at varying physical conditions. Drugs were assessed at room temperature (23°C), body temperature (37°C), and 43°C, the temperature used for hyperthermic intravesical treatments. To account for variations in urine pH, solubility was also investigated at pH 4.00, 6.00, and 8.00. RESULTS: Heat incrementally increased the solubility of all three drugs studied. Conversely, pH largely did not impact solubility aside for gemcitabine which showed slightly reduced solubility at pH 8.00 versus 6.00 or 4.00. Mitomycin C at the commonly used 2.0 mg/mL was insoluble at room temperature, but soluble at both 37 and 43°C. CONCLUSIONS: Hyperthermia as an adjunct to intravesical treatment would improve drug solubility, and likely drug delivery as some current regimens are insoluble without heat. Improvements in solubility also allow for testing of alternative administration regimens to improve drug delivery or tolerability. Further studies are needed to confirm that improvements in solubility result in increased drug delivery.

Advances in intravesical therapy for urinary tract disorders

INTRODUCTION

Intravesical therapy is a valuable option in the clinical management of urinary tract disorders such as interstitial cystitis/ painful bladder syndrome (IC/PBS) and refractory overactive bladder. This review will cover the latest advances in this field using polymer and liposomes as delivery platform for drugs, protein and nucleic acids.

AREAS COVERED

This review summarizes the significance of intravesical therapy for lower urinary tract disorders. The recent advancement of liposomes as a drug delivery platform for botulinum toxin, tacrolimus and small interfering RNA is discussed. The importance of polymers forming indwelling devices and hydrogels are also discussed, where all preparations improved efficacy parameters in rodent models. Clinical experience of treating IC/PBS with indwelling devices and liposomes are summarized and preclinical evidence about the downregulation of target gene expression in rodent bladder with liposomes complexed with siRNA is also reviewed.

EXPERT OPINION

There have been several advances in the field of intravesical therapy for improving clinical outcomes. One of the most promising research avenues is the repurposing of drugs, given previously by other routes of administration, such as tacrolimus. Intravesical therapy also opens up novel therapeutic targets with improved efficacy and safety for underactive bladder.

Glycan-targeted drug delivery for intravesical therapy: in the footsteps of uropathogenic bacteria

The human urothelium belongs to the most efficient biobarriers, and represents a highly rewarding but challenging target for local drug administration. Inadequate urothelial bioavailability is a major obstacle for successful treatment of bladder cancer and other diseases, yet little research has addressed the development of advanced delivery concepts for the intravesical route. A prominent example of how to overcome the urothelial barrier by means of specific biorecognition is the efficient cytoinvasion of UPEC bacteria, mediated by the mannose-targeted lectin domain FimH. Similar mechanisms of non-bacterial origin may be exploited for enhancing drug uptake from the bladder cavity. This review covers the current status in the development of lectin-based delivery strategies for the urinary tract. Different concepts for preparing and optimizing carbohydrate-targeted delivery systems are presented, along with important design parameters, benefits and shortcomings. Bioconjugate- and nano-/microparticle-based systems are discussed in further detail with regard to their performance in preclinical testing.

Management of non-muscle-invasive (superficial) bladder cancer

Non-muscle-invasive (superficial) bladder cancer (NMIBC) represents 80% of incident cases of bladder cancer, and is characterized by a generally good prognosis, with a tendency to remain localized. Only 10%-20% of cases progress to invasion and/or metastasis. The biggest problem in management is the potential for local recurrence, and this will occur with relatively predictable prognostic determinants. Gene expression and other cell surface determinant are associated with outcome. In most cases, successful management is predicated on careful history taking and physical assessment, meticulous endoscopic assessment, and transurethral resection of bladder tumor tissue where indicated. Histology determines the potential for recurrence. Options of treatment include repeat resection, immunologic therapy via intravesical instillation, and the use of intravescally administered cytotoxic agents, including mitomycin C, doxorubicin, gemcitabine, and selected investigational compounds. Of importance, as some cases have the potential to invade and metastasize, timing of cystectomy for recurrent, high-risk tumors is important to avoid unnecessary morbidity and mortality.

Gemcitabine-loaded innovative nanocarriers vs GEMZAR: biodistribution, pharmacokinetic features and in vivo antitumor activity

INTRODUCTION

Gemcitabine, an anticancer drug, is a nucleoside analog deoxycytidine antimetabolite, which acts against a wide range of solid tumors. The limitation of gemcitabine is its rapid inactivation by the deoxycytidine deaminase enzyme following its in vivo administration.

AREAS COVERED

One of the most promising new approaches for improving the biopharmaceutical properties of gemcitabine is the use of innovative drug delivery devices. This review explains the current status of gemcitabine drug delivery, which has been under development over the past 5 years, with particular emphasis on liposomal delivery. In addition, the use of novel supramolecular vesicular aggregates (SVAs), polymeric nanoparticles and squalenoylation were treated as interesting innovative approaches for the administration of the nucleoside analog.

EXPERT OPINION

Different colloidal systems containing gemcitabine have been realized, with the aim of providing important potential advancements through traditional ways of therapy. A possible future commercialization of modified gemcitabine is desirable, as was true in the case of liposomal doxorubicin (Doxil(®), Caely(®)).

Contemporary management of patients with high-risk non-muscle-invasive bladder cancer who fail intravesical BCG therapy

It is advocated that patients with high-risk non-muscle-invasive bladder cancer (NMIBC) receive an adjuvant course of intravesical Bacille Calmette-Guerin (BCG) as first-line treatment. However, a substantial proportion of patients will 'fail' BCG, either early with persistent (refractory) disease or recur late after a long disease-free interval (relapsing). Guideline recommendation in the 'refractory' setting is radical cystectomy, but there are situations when extirpative surgery is not feasible due to competing co-morbidity, a patient's desire for bladder preservation or reluctance to undergo surgery. In this review, we discuss the contemporary management of NMIBC in patients who have failed prior BCG and are not suitable for radical surgery and highlight the potential options available. These options can be categorised as immunotherapy, chemotherapy, device-assisted therapy and combination therapy. However, the current data are still inadequate to formulate definitive recommendations, and data from ongoing trials and maturing studies will give us an insight into whether there is a realistic efficacious second-line treatment for patients who fail intravesical BCG but are not candidates for definitive surgery.