Faculty Bibliography

CONTEXT/BACKGROUND:Several recent phase 2 and 3 trials have evaluated the efficacy and toxicity of checkpoint inhibitor (CPI) therapy for urothelial carcinoma (UC) in the metastatic, localized muscle-invasive UC (MIUC), upper tract UC, and non-muscle-invasive bladder cancer (NMIBC) disease state. OBJECTIVE:To assess the outcomes and toxicity of CPIs across the treatment landscape of UC and contextualize their application to current real-world treatment. EVIDENCE ACQUISITION/METHODS:We queried PubMed, Web of Science, and EMBASE databases and conference abstracts to identify prospective trials examining CPIs in UC. The primary endpoints included overall survival, recurrence-free survival, and toxicity (when available). A secondary analysis included biomarker evaluation of response. EVIDENCE SYNTHESIS/RESULTS:We identified 21 trials, 12 phase 2 and nine phase 3 trials, in which a CPI was used for metastatic UC (seven), MIUC (nine), and NMIBC (five). For first-line (1L) metastatic UC, concurrent chemotherapy with CPIs failed to show superiority. Improved overall and progression-free survival for switch maintenance avelumab (after achieving stable disease or response with induction systemic chemotherapy) has established the current standard of care for 1L metastatic UC. A single-agent CPI is a consideration for patients unable to tolerate chemotherapy. CPIs in the perioperative setting are limited to only the adjuvant treatment with nivolumab after radical surgery for MIUC in patients at a higher risk of recurrence based on pathologic stage. Only pembrolizumab is approved by the Food and Drug Administration for carcinoma in situ unresponsive to bacillus Calmette-Guérin (BCG) in patients who are not fit for or who refuse radical cystectomy. Trials investigating CPIs in combination with multiple immune regulators, antibody drug conjugates, targeted therapies, antiangiogenic agents, chemotherapy, and radiotherapy are enrolling patients and may shape the future treatment of patients with UC. CONCLUSIONS:CPIs have an established role across multiple states of UC, with broadened applications likely to occur in the future. Several combinations are being evaluated, while the development of predictive biomarkers and their validation may help identify patients who are most likely to respond. PATIENT SUMMARY/RESULTS:Our findings highlight the broad activity of checkpoint inhibitors in urothelial carcinoma, noting the need for further investigation for the best application of combinations and patient selection to patient care.

BACKGROUND:Bacille Calmette-Guérin (BCG) is the standard therapy after transurethral resection of bladder tumour for high-risk non-muscle-invasive bladder cancer (NMIBC). However, post-BCG recurrence/progression occurs frequently, and noncystectomy options are limited. OBJECTIVE:To evaluate the safety and clinical activity of atezolizumab ± BCG in high-risk BCG-unresponsive NMIBC. DESIGN, SETTING, AND PARTICIPANTS/METHODS:This phase 1b/2 GU-123 study (NCT02792192) treated patients with BCG-unresponsive NMIBC who had carcinoma in situ with atezolizumab ± BCG. INTERVENTION/METHODS:Patients in cohorts 1A and 1B received atezolizumab 1200 mg IV q3w for ≤96 wk. Those in cohort 1B also received standard BCG induction (six weekly doses) and maintenance courses (three doses weekly starting at month 3) with optional maintenance at 6, 12, 18, 24, and 30 mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS/METHODS:Coprimary endpoints were safety and 6-mo complete response (CR) rate. Secondary endpoints included 3-mo CR rate and duration of CR; 95% confidence intervals were calculated using the Clopper-Pearson method. RESULTS AND LIMITATIONS/CONCLUSIONS:At data cut-off (September 29, 2020), 24 patients were enrolled (cohort 1A, n = 12; cohort 1B, n = 12), and the recommended BCG dose was 50 mg in cohort 1B. Four patients (33%) had adverse events (AEs) leading to BCG dose modification/interruption. Three patients (25%) in cohort 1A reported atezolizumab-related grade 3 AEs; cohort 1B had no atezolizumab- or BCG-related grade ≥3 AEs. No grade 4/5 AEs were reported. The 6-mo CR rate was 33% in cohort 1A (median duration of CR, 6.8 mo) and 42% in cohort 1B (median duration of CR, not reached [≥12 mo]). These results are limited by the small sample size of GU-123. CONCLUSIONS:In this first report of the atezolizumab-BCG combination in NMIBC, atezolizumab ± BCG was well tolerated, with no new safety signals or treatment-related deaths. Preliminary results suggested clinically meaningful activity; the combination favoured a longer duration of response. PATIENT SUMMARY/RESULTS:We studied atezolizumab with and without bacille Calmette-Guérin (BCG) to determine whether this combination was safe and had clinical activity in patients with high-risk noninvasive bladder cancer (high-grade bladder tumours that affect the outermost lining of the bladder wall) that has previously been treated with BCG and is still present or occurred again. Our results suggest that atezolizumab with or without BCG was generally safe and could be used to treat patients unresponsive to BCG.

PURPOSE/OBJECTIVE:The therapeutic benefit of intravesical instillation of hexaminolevulinate (HAL) at the time of transurethral resection of bladder tumor (TURBT) has been demonstrated in multiple studies. The purpose of this study was to prospectively assess the safety of repeated administration of HAL from a phase III pre-trial planned analysis. MATERIALS AND METHODS/METHODS:All patients evaluated in the study received at least 1 dose of HAL at the time of office cystoscopy, and a subset of these patients (n = 103, 33.2%) received a second dose a few weeks later at the time of TURBT. Adverse events (AEs) were recorded, and the safety of repeat use of HAL was determined by comparing the proportion of patients with AEs considered causally related to HAL in the surveillance examination compared to the OR examination. Association between categorical variables was tested using Fisher's Exact Test, and a P < 0.05 was considered statistically significant. RESULTS:HAL-related AEs were experienced by 6 patients (2.2%) during surveillance cystoscopy and 3 patients (3.4%) following TURBT (P = 0.76); 181 patients (59.5%) had prior exposure to HAL before enrolling in the study with no difference in the number of AEs when comparing prior exposure to HAL to no prior exposure (P = 0.76). Of the patients who previously received intravesical therapy, 8 (2.9%) had at least 1 AE during surveillance compared to 3 (9.7%) who had no prior intravesical therapy (P = 0.09). CONCLUSIONS:Repeat use of HAL is safe even when administered within a few weeks of receiving a dose of intravesical therapy.

CONTEXT/BACKGROUND:A large proportion of patients with non-muscle-invasive bladder cancer (NMIBC) fall in the gap between bacillus Calmette-Guérin (BCG)-naïve and BCG-unresponsive disease. As multiple therapeutic agents move into this gray area, there is a critical need to define the disease state and establish recommendations for optimal trial design. OBJECTIVE:To develop a consensus on optimal trial design for patients with BCG-exposed NMIBC, defined as high-grade recurrence after BCG treatment that does not meet the criteria for BCG-unresponsive disease. EVIDENCE ACQUISITION/METHODS:We conducted a literature review using the Cochrane Library, Medline, and Embase and a review of clinical trials in ClinicalTrials.gov as a basis to generate consensus recommendations for clinical trial design in BCG-exposed NMIBC. EVIDENCE SYNTHESIS/RESULTS:BCG-exposed NMIBC encompasses BCG resistance (presence of high-grade Ta or carcinoma in situ [CIS] at 3-mo evaluation after induction BCG) and delayed relapse. Randomized controlled trials are required to compare experimental therapies to a control arm receiving additional BCG, although ongoing BCG shortages may impact our ability to follow an optimal trial design. A placebo should be used in combination with BCG if the treatment arm includes BCG plus a study drug. Trials will either need to separate patients with and without CIS into two cohorts, or stratify by the presence of CIS at the time of randomization. If two cohorts are used, the primary endpoint for CIS patients should be complete response within a predetermined time. The primary endpoint in a cohort with Ta/T1 only, or if a single combined cohort is used, should be the duration of event-free survival. Suggested efficacy thresholds and corresponding sample sizes are provided. CONCLUSIONS:The International Bladder Cancer Group has developed recommendations regarding definitions, endpoints, and clinical trial design for BCG-exposed NMIBC to encourage uniformity among studies in this disease state. PATIENT SUMMARY/UNASSIGNED:Our consensus provides a precise definition of the disease state for bladder cancer not invading the bladder muscle and exposed to bacillus Calmette-Guérin (BCG) treatment. Clear guidance for conducting optimal clinical trials in this disease setting was established and we believe that this will promote further progress in this field.

OBJECTIVES/OBJECTIVE: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/METHODS: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/CONCLUSIONS:Controlled intravesical gemcitabine release via TAR-200 was safe and well tolerated in patients with MIBC.

A recent phase 3 trial of intravesical nadofaragene firadenovec reported a promising complete response rate for patients with bacillus Calmette-Guérin-unresponsive non-muscle-invasive bladder cancer. This study examined the ability of antiadenovirus antibody levels to predict the durability of therapeutic response to nadofaragene firadenovec. A standardized and validated quantitative assay was used to prospectively assess baseline and post-treatment serum antibody levels among 91 patients from the phase 3 trial, of whom 47 (52%) were high-grade recurrence free at 12 mo (responders). While baseline titers did not predict treatment response, 3-mo titer >800 was associated with a higher likelihood of durable response (p = 0.026). Peak post-treatment titers >800 were noted in 42 (89%) responders versus 26 (59%) nonresponders (p = 0.001; assay sensitivity, 89%; negative predictive value, 78%). Moreover, 22 (47%) responders compared with eight (18%) nonresponders had a combination of peak post-treatment titers >800 and peak antibody fold change >8 (p = 0.004; assay specificity, 82%; positive predictive value, 73%). A majority of responders continued to have post-treatment antibody titers >800 after the first 6 mo of therapy. In conclusion, serum antiadenovirus antibody quantification may serve as a novel predictive marker for nadofaragene firadenovec response durability. Future studies will focus on large-scale validation and clinical utility of the assay. PATIENT SUMMARY: This study reports on a planned secondary analysis of a phase 3 multicenter clinical trial that established the benefit of nadofaragene firadenovec, a novel intravesical gene therapeutic, for the treatment of patients with bacillus Calmette-Guérin (BCG)-unresponsive high-risk non-muscle-invasive bladder cancer. Prospective assessment of serum anti-human adenovirus type-5 antibody levels of patients in this trial indicated that a combination of post-treatment titers and fold change from baseline can predict treatment efficacy. While this merits additional validation, our findings suggest that serum antiadenovirus antibody levels can serve as an important predictive marker for the durability of therapeutic response to nadofaragene firadenovec.

Introduction & Objectives: Bacillus Calmette-Guerin (BCG) therapy is the standard of care for high-risk non-muscle invasive bladder cancer (NMIBC) after transurethral resection of bladder tumor. However, disease recurrence or progression is common and patients with BCGunresponsive disease are unlikely to respond to further BCG therapy. In these patients, the current standard of care is radical cystectomy and bladder-preserving treatment options, limited to intravesical chemotherapy or pembrolizumab administered intravenously. In a phase 1 study, sasanlimab (PF-06801591), a monoclonal antibody to programmed cell death protein 1 (PD-1), was administered subcutaneously at 300 mg every 4 weeks. Sasanlimab had an acceptable safety profile and showed clinical activity aligned to other anti-PD-1/PD-ligand 1 [PD-L1] agents in patients with advanced urothelial carcinoma and non-small cell lung cancer, while offering the convenience of subcutaneous administration. Therefore, CREST Study Cohort B aims to evaluate sasanlimab administered subcutaneously in patients with BCG-unresponsive NMIBC.
Material(s) and Method(s): CREST Study Cohort B is a non-randomized, multicenter, multinational, open-label, phase 3 study and will enroll ~160 patients with histologically confirmed BCG-unresponsive high-risk, non-muscle invasive transitional cell carcinoma of the bladder urothelium (highgrade Ta or T1 tumor, or carcinoma in situ [CIS]) in 2 separate Cohorts, B1 and B2 (~110 and ~50 patients, respectively). Cohort B1 will enroll patients with persistent or recurrent CIS +/- concomitant recurrent high-grade Ta/T1 disease within 12 months of completing adequate BCG therapy. Cohort B2 will enroll patients with recurrent high-grade Ta/T1 disease within 6 months of completing adequate BCG therapy. All patients will receive sasanlimab as single agent. Efficacy will be assessed at regular intervals by cystoscopy, urine cytology, biopsy, and imaging. The primary endpoint is complete response (CR) and event-free survival (EFS) for Cohort B1 and B2, respectively. Secondary endpoints include duration of CR (Cohort B1 only), EFS (Cohort B1 only), overall survival, time to cystectomy, safety, health-related quality of life, pharmacokinetic parameters, PD-L1 expression, and incidence of anti-drug antibodies. Recruitment of patients in CREST Study Cohort B will be opened in Belgium, France, Germany, Italy, Poland, Russia, Spain, and the United Kingdom, with other sites in Asia, Australia, and North America (NCT04165317).
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When it comes to the treatment of patients with non-muscle-invasive bladder cancer (NMIBC) with intravesical bacillus Calmette-Guerin (BCG), two questions must be considered: 1) what dose to give, and 2) for how long? The issue of optimal dose and duration has been the subject of several randomized trials and is especially pertinent in the context of a global BCG shortage. Despite this, there appears to be uncertainty as to whether BCG dose or duration may be compromised in the event of shortage. As such, we wish to summarize the available evidence as an aid to the practicing urologist.

Background: Cohort A of the phase 2 KEYNOTE-057 study showed that pembrolizumab monotherapy provided effective antitumor activity and acceptable safety in patients with BCG-unresponsive HR NMIBC with carcinoma in situ (CIS). Pembrolizumab in combination with BCG at earlier stages of HR NMIBC might provide benefit superior to that of BCG monotherapy. The open-label, comparator-controlled, phase 3 KEYNOTE-676 study (NCT03711032) will be conducted to investigate the efficacy and safety of pembrolizumab + BCG versus BCG monotherapy in patients with HR NMIBC. Cohort A will enroll patients with persistent or recurrent HR NMIBC after BCG induction. Cohort B is a new, randomly assigned cohort that will help evaluate pembrolizumab + BCG in BCG treatment-naive patients who either never received BCG treatment or received BCG treatment > 2 years before enrollment.
Method(s): Cohort B of KEYNOTE-676 will enroll approximately 975 patients with blinded independent central review (BICR)-confirmed HR NMIBC (T1, high-grade Ta CIS) and Eastern Cooperative Oncology Group performance status score 0-2 who underwent cystoscopy/transurethral resection of bladder tumor <=12 weeks before randomization and had not received BCG within the past 2 years. Patients will be randomly assigned 1:1:1 to receive pembrolizumab 400 mg intravenously (IV) every 6 weeks (Q6W) + BCG reduced maintenance (<=6 months), pembrolizumab 400 mg IV Q6W + BCG full maintenance (<=18 months), or BCG monotherapy (BCG full maintenance). Stratification factors include NMIBC stage (CIS or no CIS) and PD-L1 expression (combined positive score [CPS] >=10 or CPS < 10), determined by central laboratory. Disease status will be assessed by use of cystoscopy, urine cytology, and biopsy (as applicable) every 12 weeks (Q12W) through year 2, then every 24 weeks through year 5; imaging with computed tomography urography will occur every 72 weeks. Adverse events (AEs) will be monitored throughout the study and up to 30 days after cessation of study treatment (90 days for serious AEs). The primary end point is event-free survival (EFS). Secondary end points include complete response rate by BICR, duration of response (DOR), 12-month DOR rate (CIS only), 24-month EFS rate, disease-specific survival, time to cystectomy, overall survival, and safety. The study is enrolling or planning to enroll at sites in Asia, Australia, Europe, North America, and South America

Background: Patient preference is an important factor in selecting appropriate treatment choices. Although underutilized, the standard of care for MIUC is with NAC, whereas evidence for adjuvant therapy is less clear. With the introduction of novel adjuvant treatments such as immune checkpoint inhibitors, treatment options are expected to expand. This study examines whether preferences for adjuvant therapy is impacted in MIUC patients receiving NAC.
Method(s): A cross-sectional, web-based survey included patients >= 18 years old who self-reported being diagnosed with MIUC and underwent radical cystectomy or nephroureterectomy without recurrence. Patients were recruited from the US, UK, Canada, France, and Germany (May-Sep 2021). A DCE using 2 adjuvant treatment profiles included 8 attributes: cancer-free survival, overall survival (OS), hypothyroidism requiring life-long hormone therapy, risk of a serious adverse event (requiring medical intervention/possible hospitalization), nausea, fatigue, diarrhea, and a dosing regimen (frequency of treatment and monitoring); an opt-out option of no treatment was also shown. Patients were grouped according to self-reported receipt of NAC. Descriptive statistics and hierarchical Bayesian logistic model with estimated preference weights were used. Relative importance estimates (mean +/- standard error), or how much the attribute ranges accounted for the variation in preferences, were computed for each attribute. Bivariate comparisons used t-tests.
Result(s): This interim analysis identified 205 patients (70.7% of target sample; US, n = 99; Germany, n = 60; UK, n = 31; Canada, n = 14; France, n = 1). Of 82 patients (40.0%) receiving NAC, 32.7% were patients > 65 years and 55.1% were male; receipt of NAC did not differ by age (P = 0.248) or sex (P = 0.731). Patients were willing to accept increased risk in toxicities for increased treatment efficacy. Specifically, mean relative importance of treatment attributes showed that difference in median OS (25 months compared to 78 months) was most important (34.6% +/- 1.6), although less so for those who did not receive NAC (30.2% +/- 2.4 vs 37.5% +/- 2.0; P = 0.022). Patients chose an adjuvant treatment option over 'no treatment' 91% of the time, with similar findings by NAC status.
Conclusion(s): Preliminary data indicates that receipt of NAC impacts preferences for adjuvant treatment attributes. However, regardless of these attributes, patients still preferred adjuvant treatment over none. These results suggest that providing standard of care NAC does not reduce patient preference for adjuvant therapy; rather, patient preferences for adjuvant treatment attributes vary by treatment history, with implications for improving quality of care and outcomes