Long-Term Experience with Radiofrequency-Induced Hyperthermia Combined with Intravesical Chemotherapy for Non-Muscle Invasive Bladder Cancer

BACKGROUND

The recurrence rate of non-muscle invasive bladder cancer (NMIBC) is high, despite intravesical treatments. Importantly, patients are frequently unfit or unwilling to undergo a recommended radical cystectomy when standard intravesical treatments fail, due to the substantial risk of morbidity and mortality. For these patients, radiofrequency-induced hyperthermia combined with intravesical chemotherapy (RF-CHT) has shown promising results. We aim to determine treatment outcomes and assess the effect of (ablative) dose.

METHODS

299 intensively pretreated patients treated with RF-CHT were included in safety analysis. Of these, 274 patients who fulfilled induction treatments were included in efficacy analysis. Six-month complete response (CR) and durable response were reported for (concomitant) carcinoma in situ (CIS) patients and recurrence-free survival (RFS) for papillary patients.

RESULTS

For CIS, six-month CR-rate was 56.0%; and durable response rates were 79.7%, 66.5%, and 40.3% at one-, two- and five-year, respectively. RFS rates for papillary patients were 77.9%, 57.5%, and 37.2%, respectively. Patients treated with ablative dose are less likely to develop recurrence (adjusted Hazard Ratio 0.54, p = 0.01), compared to adjuvant dose.

CONCLUSIONS

RF-CHT is effective in NMIBC patients in whom standard intravesical treatments have failed and should be considered in patients who are unwilling or unfit to undergo radical cystectomy. Patients with CIS or residual papillary tumor at baseline benefit from ablative dose.

Apaziquone for Nonmuscle Invasive Bladder Cancer: Where Are We Now?

Apaziquone is an interesting drug for intravesical use in patients with nonmuscle invasive bladder cancer; however, more research is needed to prove its actual benefit. Although the apaziquone trials demonstrate the potential of this new drug, the singular phase 3 trials did not reach their primary endpoint. To date, no new trials are recruiting, so the development of apaziquone seems to have stopped.

[Chemohyperthermia using MMC in non-muscle-invasive bladder cancer: Current status and future perspectives.]

In an effort to decrease recurrence and progression rates in non-muscle-invasive bladder cancer (NMIBC), transurethral resection of a bladder tumor is followed by intravesical instillations using Mitomycin-C (MMC) and Bacillus Calmette-Guérin (BCG). In spite of these adjuvant treatment modalities, recurrence and progression rates remain high. Because of these limitations of current standard therapy and the shortage of BCG, there is a search for alternative forms of treatment in NMIBC. Intravesical MMC combined with hyperthermia, especially RF-induced QHT being most extensively investigated in the past 20 years, is one of these alternatives for intermediate- and high-risk NMIBC. There are several different techniques and devices to create hyperthermia of the bladder wall raising temperatures up to 40.5-44.0 ℴ C. Hyperthermia can be the result of ultrasound waves, direct thermal conduction, or electromagnetic fields. An overview of hyperthermia systems concerning their technical aspects, treatment outcomes and adverse events (AE's) will be described in this review. In patients failing standard treatment who are not fit or unwilling to undergo surgery, RF-induced QHT should be considered. Besides QHT, there are more forms of treatment currently being investigated in NMIBC like EMDA and neoadjuvant intravesical chemotherapy, these require more clinical trials to determine patient selection and efficiency.

Intravesical radiofrequency induced hyperthermia enhances mitomycin C accumulation in tumour tissue

INTRODUCTION

Non-muscle invasive bladder cancer (NMIBC) is a highly recurrent disease with potential progression to muscle invasive disease despite the standard bladder instillations with mitomycin C (MMC) or Bacille Calmette-Guérin immunotherapy. Therefore, alternatives such as radiofrequency-induced chemohyperthermia (RF-CHT) with MMC are being investigated. The mechanism explaining the efficacy of RF-CHT is only partly understood. We examined whether RF-CHT results in higher MMC tissue concentrations as compared to cold MMC instillation.

PATIENTS AND METHODS

Prior to a planned transurethral resection of bladder tumour (TURBT), patients with stage Ta NMIBC were allocated to either (1) cold MMC instillation or (2) RF-CHT. After MMC instillation, three biopsies were taken of both normal and tumour tissue. Biopsies were snap-frozen and MMC tissue concentrations were analysed using ultra-performance liquid chromatography.

RESULTS

Eleven patients were included of which six received RF-CHT. Ten patients had TaG2-LG/HG papillary tumours at pathology. One patient in the RF-CHT group appeared to be free of malignancy and was excluded from the analysis as no tumour biopsies were available. The median MMC concentration in tumour tissue was higher in the RF-CHT group (median 665.00 ng/g vs. 63.75 ng/g, U = 51.0, p = 0.018). Moreover, in both techniques the MMC concentration was lower in normal tissue compared to tumour tissue. Tissue MMC concentration measurements varied substantially within, and between, different patients from the same group.

CONCLUSION

Intravesical RF-CHT results in higher tumour MMC concentrations vs. cold MMC instillation which contributes to its superior efficacy.

Pharmacokinetic, Pharmacodynamic, and Activity Evaluation of TMX-101 in a Multicenter Phase 1 Study in Patients With Papillary Non-Muscle-Invasive Bladder Cancer

INTRODUCTION/BACKGROUND

Non-muscle-invasive bladder cancer (NMIBC) has a strong tendency to recur despite adjuvant instillations. TMX-101 is a new liquid form of imiquimod for intravesical instillation and has activity in vitro against urothelial carcinoma. The purpose was to analyze the activity of TMX-101 in low-grade NMIBC. Furthermore, pharmacokinetic and pharmacodynamic characteristics and adverse events were evaluated.

PATIENTS AND METHODS

A multicenter, prospective phase 1 trial in 7 patients with low-grade NMIBC was conducted. All patients underwent a marker lesion transurethral resection of the bladder tumor and 6 weekly instillations with TMX-101 0.2% or 0.4%. Cystoscopy 2 to 4 weeks after the last instillation evaluated the effect of TMX-101.

RESULTS

The effective biologic dose (EBD = complete response [CR] in > 2 patients) could not be defined because none of the patients experienced CR. Maximum plasma concentration was 75.1 ng/mL in the 0.4% dose group. No drug accumulation was observed. In the pharmacodynamic analysis, urinary interleukin 1 receptor agonist (IL-1ra) represents the most sensitive and uniform response after TMX-101 instillation. A total of 87.0% reported at least 1 adverse event. All events were of grade 2 severity or less (Common Terminology Criteria of Adverse Events version 4.02). No clinically significant changes in laboratory parameters or vital signs were observed during or after treatment.

CONCLUSION

Toll-like receptor 7 (TLR-7) agonists are effective in urothelial carcinoma in preclinical research. The EBD in this phase 1 study could not be determined because no patient experienced CR. IL-1ra could be valuable as a urinary biomarker in future developments. The safety of TMX-101 has been reconfirmed. New doses, other schedules, and NMIBC subgroups should be tested to define the EBD. A pilot study in carcinoma-in-situ patients is currently ongoing and results are expected shortly.

Expert review: an update in current and developing intravesical therapies for non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer is a highly prevalent disease and recurrences, after initial therapy, are common. Consequently, the healthcare costs for non-muscle-invasive bladder cancer are high. Despite a primary adequate response to adjuvant intravesical treatment, many patients suffer from recurrences, and some even from progression. To date, cystectomy remains the only option for those non-responding patients with high risk of recurrence and progression. Mainly because outcome after progression, in this group, is poor. Therefore, new intravesical therapies are needed. Moreover, new accurate and individual parameters, to distinguish responder from non-responders, will provide additional benefit in clinical decision-making. In this review, current diagnostics and therapies will be discussed. In addition, we will elucidate developing therapies in non-muscle-invasive bladder cancer.