Evaluation of thermal dose effect in radiofrequency-induced hyperthermia with intravesical chemotherapy for nonmuscle invasive bladder cancer.

PURPOSE: In nonmuscle invasive bladder cancer (NMIBC) patients who fail standard intravesical treatment and are unfit or unwilling to undergo a radical cystectomy, radiofrequency (RF)-induced hyperthermia combined with intravesical chemotherapy (RF-CHT) has shown promising results. We studied whether higher thermal dose improves clinical NMIBC outcome. METHODS AND MATERIALS: The cohort comprised 108 patients who started with RF-CHT between November 2013 and December 2019. Patients received intravesical mitomycin-C or epirubicin. Bladder hyperthermia was accomplished with an intravesical 915 MHz RF device guided by intravesical thermometry. We assessed the association between thermal dose parameters (including median temperature and Cumulative Equivalent Minutes of T50 at 43 °C [CEM43T50]) and complete response (CR) at six months for patients with (concomitant) carcinoma in situ (CIS), and recurrence-free survival (RFS) for patients with papillary disease. RESULTS: Median temperature and CEM43T50 per treatment were 40.9 (IQR 40.8-41.1) °C and 3.1 (IQR 0.9-2.4) minutes, respectively. Analyses showed no association between any thermal dose parameter and CR or RFS (p > 0.05). Less bladder spasms during treatment sessions was associated with increased median temperature and CEM43T50 (adjusted OR 0.01 and 0.34, both p < 0.001). CONCLUSIONS: No significant association between thermal dose and NMIBC outcome was found. Possibly thermal dose effect in patients of the current cohort exceeds a certain threshold value. On the other hand, occurrence of bladder spasms had a thermal dose limiting effect. We advise to treat patients with temperatures >40.5 °C for at least 45 min while respecting individual tolerability, including occurrence of bladder spasms.

The safety, tolerability, and efficacy of a neoadjuvant gemcitabine intravesical drug delivery system (TAR-200) in muscle-invasive bladder cancer patients: a phase I trial.

OBJECTIVES: Neoadjuvant chemotherapy and radical cystectomy (RC) are underutilized standards of care for the treatment of muscle-invasive bladder cancer (MIBC) due to high patient burden from systemic toxicities and postoperative complications, respectively. TAR-200 is a novel intravesical drug delivery system developed to release gemcitabine into the bladder urine continuously, resulting in distribution of drug into stromal layers of the bladder. The primary aim of the TAR-200-101 study was to evaluate the safety of TAR-200 in patients with MIBC prior to RC (NCT02722538). METHODS AND MATERIALS: This phase I, open-label study was conducted across 6 US and European sites. Eligible patients were aged ≥18 years with histologically confirmed T2a-T3b N0-N1 M0 urothelial cancer and had refusal or were ineligible to receive cisplatin-based combination chemotherapy. Two arms were enrolled serially. Patients in Arm 1 had residual tumor >3 cm after transurethral resection of bladder tumor (TURBT); those in Arm 2 had undergone maximal TURBT (residual tumor <3 cm). Patients received two 7-day cycles of intravesical gemcitabine delivery via TAR-200 before undergoing RC. Primary outcome was safety; secondary outcomes were tolerability, pharmacokinetics, and preliminary efficacy. RESULTS: Of 23 patients in the intention-to-treat population (11 in Arm 1, 12 in Arm 2), 20 completed both dosing cycles of TAR-200. No patients were classified as intolerant to TAR-200. Ten patients (4 in Arm 1, 6 in Arm 2) experienced ≥1 treatment-emergent adverse events (TEAEs). The most common TAR-200-related TEAEs were pollakiuria (n = 3) and urinary incontinence (n = 2). All TEAEs prior to RC were grade ≤2; 1 patient in Arm 2 experienced a grade 3 non-treatment-related TEAE. Plasma gemcitabine levels were undetectable. In Arm 1, those with residual tumor, 4 of 10 patients exhibited pathologic downstaging; 1 experienced a complete response (CR) and 3 a partial response (PR). In Arm 2, those undergoing maximal TURBT, 6 of 10 patients exhibited downstaging; 3 experienced a CR and 3 a PR. CONCLUSION: Controlled intravesical gemcitabine release via TAR-200 was safe and well tolerated in patients with MIBC.

DPPG2-based thermosensitive liposomes as drug delivery system for effective muscle-invasive bladder cancer treatment in vivo.

PURPOSE: Recommended treatments for muscle-invasive bladder cancer (MIBC) come with considerable morbidity. Hyperthermia (HT) triggered drug release from phosphatidylglycerol-based thermosensitive liposomes (DPPG2-TSL) might prevent surgical bladder removal and toxicity from systemic chemotherapy. We aimed to assess the efficacy of DPPG2-TSL with HT in a syngeneic orthotopic rat urothelial carcinoma model. METHODS: A total of 191 female Fischer F344 rats were used. Bladder tumors were initiated by inoculation of AY-27 cells and tumor-bearing rats were selected with cystoscopy and semi-randomized over treatment groups. On days 5 and 8, animals were treated with DOX in different treatment modalities: intravenous (iv) DPPG2-TSL-DOX with HT, iv free DOX without HT, intravesical DOX without HT, intravesical DOX with HT or no treatment (control group), respectively. Animals were euthanized on day 14 and complete tumor response was assessed by histopathological evaluation. RESULTS: Iv DPPG2-TSL-DOX + HT resulted in a favorable rate of animals with complete tumor response (70%), compared to iv free DOX (18%, p = .02), no treatment (0%, p = .001), and intravesical DOX with (43%, p = .35) or without HT (50%, p = .41). All rats receiving intravesical DOX with HT and 24% of rats treated with DPPG2-TSL-DOX containing the same DOX dose with HT had to be euthanized before day 14 because of substantial bodyweight loss, which was associated with dilated ureters urine retention in a few rats. CONCLUSION: Treatment with DPPG2-TSL-DOX combined with intravesical HT outperformed systemic and intravesical DOX in vivo. There might be a role for DPPG2-TSL encapsulating chemotherapeutics in the treatment of MIBC in the future.

DPPG2-Based Thermosensitive Liposomes with Encapsulated Doxorubicin Combined with Hyperthermia Lead to Higher Doxorubicin Concentrations in the Bladder Compared to Conventional Application in Pigs: A Rationale for the Treatment of Muscle-Invasive Bladder Cancer.

PURPOSE: Current treatment options for muscle-invasive bladder cancer (MIBC) are associated with substantial morbidity. Local release of doxorubicin (DOX) from phosphatidyldiglycerol-based thermosensitive liposomes (DPPG2-TSL-DOX) potentiated by hyperthermia (HT) in the bladder wall may result in bladder sparing without toxicity of systemic chemotherapy. We investigated whether this approach, compared to conventional DOX application, increases DOX concentrations in the bladder wall while limiting DOX in essential organs. MATERIALS AND METHODS: Twenty-one pigs were anaesthetized, and a urinary catheter equipped with a radiofrequency-emitting antenna for HT (60 minutes) was placed. Experimental groups consisted of iv low or full dose (20 or 60 mg/m2) DPPG2-TSL-DOX with/without HT, iv low dose (20 mg/m2) free DOX with HT, and full dose (50 mg/50 mL) intravesical DOX with/without HT. After the procedure, animals were immediately sacrificed. HPLC was used to measure DOX levels in the bladder, essential organs and serum, and fluorescence microscopy to evaluate DOX distribution in the bladder wall. RESULTS: Iv DPPG2-TSL-DOX with HT resulted in a significantly higher bladder wall DOX concentration which was more homogeneous distributed, than iv and intravesical free DOX administration with HT. Specifically in the detrusor, DPPG2-TSL-DOX with HT led to a >7- and 44-fold higher DOX concentration, compared to iv free DOX with HT and intravesical DOX, respectively. Organ DOX concentrations were significantly lower in heart and kidneys, and similar in liver, spleen and lungs, following iv DPPG2-TSL-DOX with HT, compared to iv free DOX. Intravesical DOX led to the lowest organ DOX concentrations. CONCLUSION: Iv DPPG2-TSL-DOX combined with HT achieved higher DOX concentrations in the bladder wall including the detrusor, compared to conventional iv and intravesical DOX application. In combination with lower DOX accumulation in heart and kidneys, compared to iv free chemotherapy, DPPG2-TSL-DOX with HT has great potential to attain a role as a bladder-sparing treatment for MIBC.

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.

The conundrum of recurrent low-grade tumours: to treat or to observe?

PURPOSE OF REVIEW: To describe the importance of risk stratification and the role of more conservative management like office fulguration, office laser ablation and active surveillance in recurrent low-grade Ta tumours. RECENT FINDINGS: Updated models have been designed for risk stratification of intermediate-risk tumours. Conservative forms of management like office fulguration or laser ablation and even active surveillance seem well tolerated; however, randomized, controlled trials are lacking. In patients who have been tumour free for 5 years, late recurrences have been described. SUMMARY: Recurrent low-grade Ta tumours are classified in the intermediate risk group, which is a heterogeneous group. Therefore, risk stratification should be done by updated models or patients should be stratified in a risk group sub-classification. Recurrent low-grade Ta patients have a favourable prognosis and consequently are prone to overtreatment. Office fulguration or laser ablation or even active surveillance could be implemented in strictly selected patients. For active surveillance, Miyake et al. proposed a helpful flowchart with criteria for patient selection and for intervention. Follow up using cystoscopy and cytology is essential, but an optimal scheme has not been identified. As late recurrences are not infrequent and recurrent low-grade Ta patients can even die from bladder cancer, long term follow-up should be performed yearly, by cystoscopy and cytology.