Oncolytic adenoviral therapy plus pembrolizumab in BCG-unresponsive non-muscle-invasive bladder cancer: the phase 2 CORE-001 trial

Cretostimogene grenadenorepvec is a serotype-5 oncolytic adenovirus designed to selectively replicate in cancer cells with retinoblastoma pathway alterations, previously tested as monotherapy in bacillus Calmette-Guérin (BCG)-experienced non-muscle-invasive bladder cancer. In this phase 2 study, we assessed the potential synergistic efficacy between intravesical cretostimogene and systemic pembrolizumab in patients with BCG-unresponsive non-muscle-invasive bladder cancer with carcinoma in situ (CIS). Thirty-five patients were treated with intravesical cretostimogene with systemic pembrolizumab. Induction cretostimogene was administered weekly for 6 weeks followed by three weekly maintenance infusions at months 3, 6, 9, 12 and 18 in patients maintaining complete response (CR). Patients with persistent CIS/high-grade Ta at the 3-month assessment were eligible for re-induction. Pembrolizumab was administered for up to 24 months. The primary endpoint was CR at 12 months as assessed by cystoscopy, urine cytology, cross-sectional imaging and mandatory bladder mapping biopsies. Secondary endpoints included CR at any time, duration of response, progression-free survival and safety. The CR rate in the intention-to-treat population at 12 months was 57.1% (20 out of 35, 95% confidence interval (CI) 40.7-73.5%), meeting the primary endpoint. A total of 29 out of 35 patients (82.9%, 95% CI 70.4-95.3%) derived a CR at 3 months. With a median follow-up of 26.5 months, the median duration of response has not been reached (95% CI 15.7 to not reached). The CR rate at 24 months was 51.4% (18 out of 35) (95% CI 34.9-68.0%). No patient progressed to muscle-invasive bladder cancer in this trial. Adverse events attributed to cretostimogene were low grade, self-limiting and predominantly limited to bladder-related symptoms. A total of 5 out of 35 patients (14.3%) developed grade 3 treatment-related adverse effects. There was no evidence of overlapping or synergistic toxicities. Combination intravesical cretostimogene and systemic pembrolizumab demonstrated enduring efficacy. With a toxicity profile similar to its monotherapy components, this combination may shift the benefit-to-risk ratio for patients with BCG-unresponsive CIS. ClinicalTrials.gov Identifier: NCT04387461 .

Urachal Carcinoma: Insights From a National Database

INTRODUCTION

Urachal carcinoma (UrC) is a rare, nonurothelial malignancy, comprising less than 1% of all bladder cancers. It usually affects males in their fifth to sixth decade and is often diagnosed at an advanced stage with metastasis. This study examines UrC population characteristics and management.

METHODS

We identified UrC patients from bladder biopsies or TURB in the PearlDiver Mariner database (2010-2022). Descriptive statistics detailed patient characteristics. Student's T-Tests compared ages for partial vs. radical cystectomy, and Fisher's exact test compared SDOH presence. Significance was set at P < .05. Analyses used R version 3.6.0 within PearlDiver's software.

RESULTS

Among 2475 UrC patients (mean age 69.2 ± 9.2 years, 73.1% men), most were in the south (36.5%), outpatient settings (84.5%), and privately insured (65.3%). A total of 418 (16.2%) had at least 1 SDOH. Imaging before diagnosis was used in 65.74% of patients, primarily ultrasound. Smoking was present in 54.5%, diabetes in 42.9%, and obesity in 25.2%. After diagnosis, 1246 (50.34%) had localized disease; 407 underwent radical cystectomy and 330 partial cystectomy. Patients undergoing radical cystectomy were older (66.74 ± 8.13 years) compared to those undergoing partial cystectomy (60.55 ± 12.92 years) (P < .001), with SDOH factors more prevalent in the partial cystectomy group (P = .03).

CONCLUSION

UrC is a rare, often advanced-stage cancer predominantly affecting older men. Our study shows a trend towards partial cystectomy for localized UrC. Further research is needed to personalize surgery and integrate multidisciplinary approaches for better outcomes.

Efficacy of Intravesical Nadofaragene Firadenovec for Patients With Bacillus Calmette-Guérin-Unresponsive Nonmuscle-Invasive Bladder Cancer: 5-Year Follow-Up From a Phase 3 Trial

PURPOSE

Nadofaragene firadenovec-vncg is a nonreplicating adenoviral vector-based gene therapy for bacillus Calmette-Guérin (BCG)-unresponsive carcinoma in situ (CIS) with/without high-grade Ta/T1. We report outcomes following 5 years of planned follow-up.

MATERIALS AND METHODS

This open-label phase 3 trial (NCT02773849) enrolled patients with BCG-unresponsive nonmuscle-invasive bladder cancer in 2 cohorts: CIS ± Ta/T1 (CIS; n = 107) and Ta/T1 without CIS (Ta/T1 cohort; n = 50). Patients received 75 mL (3 × 1011 vp/mL) nadofaragene firadenovec intravesically once every 3 months with cystoscopy and cytology assessments, with continued treatment offered to those remaining high grade recurrence-free (HGRF).

RESULTS

One hundred fifty-seven patients were enrolled from 33 US sites (n = 151 included in efficacy analyses). Median follow-up was 50.8 months (interquartile range 39.1-60.0), with 27% receiving ≥ 5 instillations and 7.6% receiving treatment for ≥ 57 months. Of patients with CIS 5.8% (95% CI 2.2-12.2) were HGRF at month 57, and 15% (95% CI 6.1-27.8) of patients with high-grade Ta/T1 were HGRF at month 57. Kaplan-Meier-estimated HGRF survival at 57 months was 13% (95% CI 6.9-21.5) and 33% (95% CI 19.5-46.6) in the CIS and Ta/T1 cohorts, respectively. Cystectomy-free survival at month 60 was 49% (95% CI 40.0-57.1): 43% (95% CI 32.2-53.7) in the CIS cohort and 59% (95% CI 43.1-71.4) in the Ta/T1 cohort. Overall survival at 60 months was 80% (71.0, 86.0): 76% (64.6-84.5) and 86% (70.9-93.5) in the CIS and Ta/T1 cohorts, respectively. Only 5 patients (4 with CIS and 1 with Ta/T1) experienced clinical progression to muscle-invasive disease.

CONCLUSIONS

At 60 months, nadofaragene firadenovec-vncg allowed bladder preservation in nearly half of the patients and proved to be a safe option for BCG-unresponsive nonmuscle-invasive bladder cancer.

CREST: phase III study of sasanlimab and Bacillus Calmette-Guérin for patients with Bacillus Calmette-Guérin-naïve high-risk non-muscle-invasive bladder cancer

Bacillus Calmette-Guérin (BCG) is the standard of care for patients with high-risk non-muscle-invasive bladder cancer (NMIBC) after transurethral resection of bladder tumor (TURBT). BCG in combination with programmed cell death-1 (PD-1) inhibitors may yield greater anti-tumor activity compared with either agent alone. CREST is a phase III study evaluating the efficacy and safety of the subcutaneous PD-1 inhibitor sasanlimab in combination with BCG for patients with BCG-naive high-risk NMIBC. Eligible participants are randomized to receive sasanlimab plus BCG (induction ± maintenance) or BCG alone for up to 25 cycles within 12 weeks of TURBT. The primary outcome is event-free survival. Secondary outcomes include additional efficacy end points and safety. The target sample size is around 1000 participants.

Interruptions in bladder cancer care during the COVID-19 public health emergency

BACKGROUND

Academic and community urology centers participating in a pragmatic clinical trial in non-muscle-invasive bladder cancer completed monthly surveys assessing restrictions in aspects of bladder cancer care due to the COVID-19 Public Health Emergency. Our objective was to describe pandemic-related restrictions on bladder cancer care.

METHODS

We invited 32 sites participating in a multicenter pragmatic bladder cancer trial to complete monthly surveys distributed through REDCap beginning in May 2020. These surveys queried sites on whether they were experiencing restrictions in the use of elective surgery, transurethral resection of bladder tumors (TURBT), radical cystectomy, office cystoscopy, and intravesical bacillus Calmette-Guerin (BCG) availability. Responses were collated with descriptive statistics.

RESULTS

Of 32 eligible sites, 21 sites had at least a 50% monthly response rate over the study period and were included in the analysis. Elective surgery was paused at 76% of sites in May 2020, 48% of sites in January 2021, and 52% of sites in January 2022. Over those same periods, coinciding with COVID-19 incidence waves, TURBT was restricted at 10%, 14%, and 14% of sites, respectively, radical cystectomy was restricted at 10%, 14%, and 19% of sites, respectively, and cystoscopy was restricted at 33%, 0%, and 10% of sites, respectively.

CONCLUSIONS

Bladder cancer care was minimally restricted compared with more pronounced restrictions seen in general elective surgeries during the COVID-19 pandemic.

Racial Differences in the Detection Rate of Bladder Cancer Using Blue Light Cystoscopy: Insights from a Multicenter Registry

The use of blue light cystoscopy (BLC) has been shown to improve bladder tumor detection. However, data demonstrating the efficacy of BLC across different races are limited. Herein, we aim to evaluate heterogeneity in the characteristics of BLC for the detection of malignant lesions among various races. Clinicopathologic information was collected from patients enrolled in the multi-institutional Cysview® registry (2014-2021) who underwent transurethral resection or biopsy of bladder tumors. Outcome variables included sensitivity and negative and positive predictive values of BLC and white light cystoscopy (WLC) for the detection of malignant lesions among various races. Overall, 2379 separate lesions/tumors were identified from 1292 patients, of whom 1095 (85%) were Caucasian, 96 (7%) were African American, 51 (4%) were Asian, and 50 (4%) were Hispanic. The sensitivity of BLC was higher than that of WLC in the total cohort, as well as in the Caucasian and Asian subgroups. The addition of BLC to WLC increased the detection rate by 10% for any malignant lesion in the total cohort, with the greatest increase in Asian patients (18%). Additionally, the positive predictive value of BLC was highest in Asian patients (94%), while Hispanic patients had the highest negative predictive value (86%). Our study showed that regardless of race, BLC increases the detection of bladder cancer when combined with WLC.

Neoadjuvant personalized cancer vaccines: the final frontier?

INTRODUCTION

Clinical trials of personalized cancer vaccines have shown that on-demand therapies that are manufactured for each patient, result in activated T cell responses against individual tumor neoantigens. However, their use has been traditionally restricted to adjuvant settings and late-stage cancer therapy. There is growing support for the implementation of PCV earlier in the cancer therapy timeline, for reasons that will be discussed in this review.

AREAS COVERED

The efficacy of cancer vaccines may be to some extent dependent on treatment(s) given prior to vaccine administration. Tumors can undergo radical immunoediting following treatment with immunotherapies, such as checkpoint inhibitors, which may affect the presence of the very mutations targeted by cancer vaccines. This review will cover the topics of neoantigen cancer vaccines, tumor immunoediting, and therapy timing.

EXPERT OPINION

Therapy timing remains a critical topic to address in optimizing the efficacy of personalized cancer vaccines. Most personalized cancer vaccines are being evaluated in late-stage cancer patients and after treatment with checkpoint inhibitors, but they may offer a greater benefit to the patient if administered in earlier clinical settings, such as the neoadjuvant setting, where patients are not facing T cell exhaustion and/or a further compromised immune system.

Definitions, End Points, and Clinical Trial Designs for Bladder Cancer: Recommendations From the Society for Immunotherapy of Cancer and the International Bladder Cancer Group

PURPOSE

There is a significant unmet need for new and efficacious therapies in urothelial cancer (UC). To provide recommendations on appropriate clinical trial designs across disease settings in UC, the Society for Immunotherapy of Cancer (SITC) and the International Bladder Cancer Group (IBCG) convened a multidisciplinary, international consensus panel.

METHODS

Through open communication and scientific debate in small- and whole-group settings, surveying, and responses to clinical questionnaires, the consensus panel developed recommendations on optimal definitions of the disease state, end points, trial design, evaluations, sample size calculations, and pathology considerations for definitive studies in low- and intermediate-risk nonmuscle-invasive bladder cancer (NMIBC), high-risk NMIBC, muscle-invasive bladder cancer in the neoadjuvant and adjuvant settings, and metastatic UC. The expert panel also solicited input on the recommendations through presentations and public discussion during an open session at the 2021 Bladder Cancer Advocacy Network (BCAN) Think Tank (held virtually).

RESULTS

The consensus panel developed a set of stage-specific bladder cancer clinical trial design recommendations, which are summarized in the table that accompanies this text.

CONCLUSION

These recommendations developed by the SITC-IBCG Bladder Cancer Clinical Trial Design consensus panel will encourage uniformity among studies and facilitate drug development in this disease.

Protocol of the Comparison of Intravesical Therapy and Surgery as Treatment Options (CISTO) study: a pragmatic, prospective multicenter observational cohort study of recurrent high-grade non-muscle invasive bladder cancer

BACKGROUND

Bladder cancer poses a significant public health burden, with high recurrence and progression rates in patients with non-muscle-invasive bladder cancer (NMIBC). Current treatment options include bladder-sparing therapies (BST) and radical cystectomy, both with associated risks and benefits. However, evidence supporting optimal management decisions for patients with recurrent high-grade NMIBC remains limited, leading to uncertainty for patients and clinicians. The CISTO (Comparison of Intravesical Therapy and Surgery as Treatment Options) Study aims to address this critical knowledge gap by comparing outcomes between patients undergoing BST and radical cystectomy.

METHODS

The CISTO Study is a pragmatic, prospective observational cohort trial across 36 academic and community urology practices in the US. The study will enroll 572 patients with a diagnosis of recurrent high-grade NMIBC who select management with either BST or radical cystectomy. The primary outcome is health-related quality of life (QOL) at 12 months as measured with the EORTC-QLQ-C30. Secondary outcomes include bladder cancer-specific QOL, progression-free survival, cancer-specific survival, and financial toxicity. The study will also assess patient preferences for treatment outcomes. Statistical analyses will employ targeted maximum likelihood estimation (TMLE) to address treatment selection bias and confounding by indication.

DISCUSSION

The CISTO Study is powered to detect clinically important differences in QOL and cancer-specific survival between the two treatment approaches. By including a diverse patient population, the study also aims to assess outcomes across the following patient characteristics: age, gender, race, burden of comorbid health conditions, cancer severity, caregiver status, social determinants of health, and rurality. Treatment outcomes may also vary by patient preferences, health literacy, and baseline QOL. The CISTO Study will fill a crucial evidence gap in the management of recurrent high-grade NMIBC, providing evidence-based guidance for patients and clinicians in choosing between BST and radical cystectomy. The CISTO study will provide an evidence-based approach to identifying the right treatment for the right patient at the right time in the challenging clinical setting of recurrent high-grade NMIBC.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03933826. Registered on May 1, 2019.

Checkpoint Inhibitors in Urothelial Carcinoma-Future Directions and Biomarker Selection

CONTEXT

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

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

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

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.

Advancing Clinical Trial Design for Non-Muscle Invasive Bladder Cancer

BACKGROUND

Despite recent drug development for non-muscle invasive bladder cancer (NMIBC), few therapies have been approved by the US Food and Drug Administration (FDA), and there remains an unmet clinical need. Bacillus Calmette-Guerin (BCG) supply issues underscore the importance of developing safe and effective drugs for NMIBC.

OBJECTIVE

On November 18-19, 2021, the FDA held a public virtual workshop to discuss NMIBC research needs and potential trial designs for future development of effective therapies.

METHODS

Representatives from various disciplines including urologists, oncologists, pathologists, statisticians, basic and translational scientists, and the patient advocacy community participated. The workshop format included invited lectures, panel discussions, and opportunity for audience discussion and comment.

RESULTS

In a pre-workshop survey, 92% of urologists surveyed considered the development of alternatives to BCG as a high drug development priority for BCG-naïve high-risk patients. Key topics discussed included definitions of disease states; trial design for BCG-naïve NMIBC, BCG-unresponsive carcinoma in situ, and BCG-unresponsive papillary carcinoma; strengths and limitations of single-arm trial designs; assessing patient-reported outcomes; and considerations for assessing avoidance of cystectomy as an efficacy measure.

CONCLUSIONS

The workshop discussed several important opportunities for trial design refinement in NMIBC. FDA encourages sponsors to meet with the appropriate review division to discuss trial design proposals for NMIBC early in drug development.

A Phase 1b/2 Study of Atezolizumab with or Without Bacille Calmette-Guérin in Patients with High-risk Non-muscle-invasive Bladder Cancer

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

This phase 1b/2 GU-123 study (NCT02792192) treated patients with BCG-unresponsive NMIBC who had carcinoma in situ with atezolizumab ± BCG.

INTERVENTION

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

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

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

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.

Phase 2 study of the efficacy and safety of erdafitinib in patients (pts) with bacillus Calmette-Guérin (BCG)-unresponsive, high-risk non–muscle-invasive bladder cancer (HR-NMIBC) with FGFR3/2 alterations (alt) in THOR-2: Cohort 2 interim analysis results

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Background: Pts presenting with NMIBC carcinoma in situ (CIS) have a high risk of progression. FGFR inhibition may benefit CIS pts with FGFRalt who are unresponsive to first-line BCG, for whom treatment (tx) options, other than radical cystectomy, are limited. Erdafitinib (erda), an oral selective pan-FGFR tyrosine kinase inhibitor, is approved for locally advanced or metastatic urothelial cancer in adults with FGFR3/2alt who have progressed during or after ≥1 line of platinum-containing chemotherapy. THOR-2 (NCT04172675) is a multicohort phase 2 study of erda in pts with HR-NMIBC. Here we report results from an exploratory cohort of pts with BCG-unresponsive CIS with FGFRalt with or without papillary disease (Cohort 2). Methods: Inclusion criteria: age ≥18 y, with histologically confirmed, BCG-unresponsive HR-NMIBC with FGFR3/2alt (by local/central testing) presenting as CIS, with or without a papillary tumor and who refused or were not eligible for cystectomy. In this cohort, pts received continuous oral erda 6 mg once daily without uptitration in 28-d cycles (dose selected to improve tolerability while maintaining activity to prevent disease recurrence, for this population). Erda was discontinued if no complete response (CR) was observed within 3 mos. Exploratory efficacy end points are CR rates at the Cycle 3 Day 1 (C3D1) disease evaluation and the Cycle 6 Day 1 (C6D1) disease evaluation; safety was a key secondary end point. Results: As of the data cutoff (Sep 2022) (median follow-up of 10 mos), 10 pts have received erda (enrolled population; median age 72 y [range 52-83]; 90% CIS [1 pt with Ta was mis-enrolled]). Pts received erda for a median duration 5.9 mos (range 1.1-17.0). Of 10 enrolled pts, the CR rates at first evaluation (C3D1) and second evaluation (C6D1) were 100% (9/9 evaluable pts) and 75% (6/8 evaluable pts), respectively. The median duration of response was 3.0 mos. The most common tx-emergent adverse events (TEAEs) were dry mouth (60%; n=6), hyperphosphatemia (50%; n=5), dysgeusia (50%; n=5), and diarrhea (50.0%; n=5). 1 pt (10%) had Gr 2 retinal detachment which led to tx discontinuation and 1 pt (10%) had Gr 1 subretinal fluid; both reported as resolved. Gr ≥3 tx-related TEAEs occurred in 3 pts (30%), and included dry mouth, stomatitis, nail disorder, onychomadesis, acute kidney injury, chronic kidney disease, sepsis, and hypotension in 1 pt each. 1 pt (10%) had serious tx-related TEAEs (dry mouth, hypotension, pneumonitis, acute kidney injury, and sepsis), and 1 pt (10%) discontinued tx due to a tx-related TEAE. No tx-related deaths were observed. Conclusions: Data from Cohort 2 of THOR-2 demonstrate efficacy at C3D1 and C6D1 evaluations in pts with HR-NMIBC with FGFRalt. Safety data were consistent with the known safety profile of erda. Clinical trial information: NCT04172675 .

Clinical results of a phase 1 study of intravesical EG-70 in patients with BCG-unresponsive NMIBC

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Background: enGene is developing non-viral gene therapy platforms to deliver nucleic acids (plasmids) to epithelial mucosal tissues such as urothelium of urinary bladder. EG-70 is a nanoparticle formulation of plasmids that activates both innate and adaptive immune responses to activate the immune system within the bladder. The plasmid encodes both IL-12 and activators of the innate immune receptor RIG-I. EG-70 is administered intravesically to elicit local stimulation of anti-tumor immune responses providing durable efficacy in high grade non-muscle invasive bladder cancer (NMIBC) while avoidingsystemic toxicities. Methods: In the Phase 1 study(LEGEND; NCT04752722), escalating doses of EG-70 were administered intravesically to patients with BCG-unresponsive Carcinoma in situ (CIS) NMIBC on weeks 1 and 2 or weeks 1, 2, 5, 6 of 12-week treatment cycle. At the week 12 assessment, patients with stable disease (SD) or complete response (CR), as assessed by urine cytology, cystoscopy, and bladder biopsy, were allowed electively to remain on EG-70 for up to 3 additional 12-week cycles. Results: To date, 19 patients have been treated. There have been no DLTs. AEs (48 GR1, 17 GR 2 and 1 GR3) have been largely consistent with urinary tract instrumentation, and were not dose related. Eighteen patients have completed one cycle of EG-70, and 67% have achieved CR. Fifteen patients with CR or SD at the end of cycle 1 elected to receive additional treatment cycles (continuation rate of 15/18 ( 83%)). Durable CRs were seen at all dose levels. Patients who receive additional cycles are followed for durability of response (Table). Complete Response. Conclusions: These results demonstrate the safety, tolerability and durable therapeutic potential of intravesical EG-70 in patients with BCG-unresponsive CIS. A Phase 2 study will proceed in 2023. Clinical trial information: NCT04752722 . [Table: see text]

Study EV-104: Phase 1 study of intravesical enfortumab vedotin for treatment of patients with non-muscle invasive bladder cancer (NMIBC)—Trial in progress

TPS582

Background: The majority of patients with bladder cancer present with non-muscle invasive disease (Chang 2016; Woldu 2017; Kates 2020; Li 2020). The standard of care for treatment of high risk NMIBC involves transurethral resection of the bladder tumor (TURBT) followed by intravesical Bacillus Calmette-Guerin (BCG) or chemotherapy. Although the response rate to BCG therapy is high, many patients recur within 1–5 years (Matulay JU 2021). For patients who have BCG unresponsive disease after adequate course of BCG, there are limited options. While radical cystectomy (RC) is still considered the standard of care, most patients are reluctant to undergo RC and their options are limited to intravesical chemotherapy or pembrolizumab. Enfortumab vedotin (EV) is an antibody-drug conjugate directed to Nectin-4, which is highly expressed in bladder tumors. In EV-301, a phase 3 study, EV showed an OS benefit vs chemotherapy in patients with locally advanced or metastatic urothelial carcinoma (la/mUC) who had previously received platinum-based therapy and a PD-1 or PD-L1 inhibitor (Powles NEJM 2021). Based on its demonstrated benefit in la/mUC, EV is currently being evaluated in earlier UC settings. The purpose of this study is to investigate the intravesical administration of EV for patients with NMIBC. Methods: EV-104 (NCT05014139) is a phase 1, open-label, multicenter, dose-escalation and dose-expansion study designed to evaluate the safety, tolerability, PK, and antitumor activity of intravesical EV in adults with high-risk BCG-unresponsive NMIBC (carcinoma in situ with or without papillary disease) who are ineligible for or refuse RC. The dose escalation part of the trial aims to identify the maximum tolerated dose (MTD) and/or recommended dose of intravesical EV. The dose expansion part will evaluate patients at the MTD or recommended dose and further characterize safety and antitumor activity of intravesical EV. The study treatment regimen will include an induction phase, where patients will receive intravesical EV weekly for 6 weeks followed by monthly maintenance for a total of 9 additional EV doses. Patients will be assessed for response every 3 months by cystoscopy and urine cytology, while on study. Safety and antitumor activity endpoints will be summarized using descriptive statistics. The study is currently enrolling in the US with additional sites planned in Canada and the EU. Clinical trial information: NCT05014139 .

Is a restaging TURBT necessary in high-risk NMIBC if the initial TURBT was performed with blue light?

OBJECTIVES

To evaluate whether a restaging transurethral resection of bladder tumor (TURBT) is necessary in high-risk nonmuscle invasive bladder cancer (NMIBC) if the initial TURBT was performed using blue light (BL) technology.

METHODS AND MATERIALS

Using the multi-institutional Cysview registry between 2014 and 2021, all consecutive adult patients with known NMIBC (Ta and T1 disease) who underwent TURBT followed by a restaging TURBT within 8 weeks were reviewed. Patients were stratified according to their initial TURBT, BL vs. white light (WL), and compared to determine rates of residual disease and upstaging. Univariate analysis was performed using Mann-Whitney U and chi-square tests, with P < 0.05 considered significant.

RESULTS

Overall, 115 patients had TURBT for NMIBC followed by a restaging TURBT within 8 weeks and were included in the analysis. Patients who underwent BL compared to WL for their initial TURBT had higher rates of benign pathology on restaging TURBT, although this was not statistically significant (47% vs. 30%; P = 0.08). Of patients with residual tumors on restaging TURBT, there were no differences in rates of Ta (22% vs. 26.5%; P = 0.62), T1 (22% vs. 26.5%; P = 0.62), or CIS (5.5% vs. 13%; P = 0.49) when the initial TURBT was done using BL compared to WL. Rates of upstaging to muscle invasive disease were also not different when initial TURBT was performed using BL compared to WL (3% vs. 4%; P = 0.78).

CONCLUSIONS

TURBT using BL does not reduce rates of residual disease or risk of upstaging on restaging TURBT in Ta or T1 disease. Thus, a restaging TURBT is still necessary even if initial TURBT was performed using BL.

Reduced Dose Intravesical Bacillus Calmette-Guérin: Why It Might Not Matter

When it comes to the treatment of patients with non-muscle-invasive bladder cancer (NMIBC) with intravesical bacillus Calmette-Guérin (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.

A phase 3 study of the subcutaneous programmed cell death protein 1 inhibitor sasanlimab as single agent for patients with bacillus Calmette-Guérin, unresponsiv,e high-risk, non-muscle invasive bladder cancer: CREST Study Cohort B

TPS4614

Background: Bacillus Calmette-Guérin (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 BCG-unresponsive 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 intravenous pembrolizumab. 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. Methods: 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 (high-grade 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 with or without 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 subcutaneous sasanlimab as a 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 Canada and the United States of America, with other sites in Asia, Australia, and Europe. Clinical trial information: NCT04165317.

CORE1: Phase 2, single-arm study of CG0070 combined with pembrolizumab in patients with nonmuscle-invasive bladder cancer (NMIBC) unresponsive to bacillus Calmette-Guerin (BCG)

4597

Background: CG0070, is an Ad5-based oncolytic vaccine engineered to express GM-CSF and replicate selectively in tumor cells with mutated or deficient RB. The CG0070 mechanism of action includes cell lysis and immunogenic cell death which is enhanced in the presence of GM-CSF. In an open label ph. 2 study, an overall CR rate of 62% and a CR at 12 months (m) of 29% have been observed in patients with high risk NMIBC previously treated with BCG. IV pembrolizumab, was recently approved by the FDA for patients with BCG-unresponsive CIS (with or without papillary tumors) with an overall complete RR of 41% and a 12 m CR rate of ̃20%. This ph. 2 study will assess the potential synergy of the two agents in the treatment of BCG-unresponsive NMIBC. Methods: 35 pts with BCG-unresponsive CIS with or without concurrent Ta or T1 disease will be treated with intravescical CG0070 (1x1012 vp) in combination with pembrolizumab at a dose of 400 mg IV q6 weeks. CG0070 will be administered weekly x 6 as induction followed by weekly x 3 maintenance instillations at months 3, 6, 9, 12, and 18. Pts with persistent CIS or HG Ta at 3 m may receive re-induction with weekly x 6 of CG0070. Pembrolizumab will be administered up to 24 m. Assessment of response will include q 3 m cystoscopy with biopsy of areas suspicious for disease, urine cytology, CTU/MRU, and mandatory bladder mapping biopsies at 12 m. Recurrence of HG disease will be enumerated as disease recurrence. The primary endpoint of the study is CR at 12 m. Secondary endpoints will include CR at any time, progression free survival, duration of response, cystectomy free survival and the safety. Correlate assessments will include changes in the tumor immune microenvironment, systemic immune induction,viral replication and transgene expression. Baseline expression of PD-L1, coxsackie adenovirus receptor, E2F transcription factor as well as anti-Ad5 Ab titer will be correlated with tumor response. Results: A CR rate of 87.5% (14/16) at the 3 m assessment timepoint has been observed thus far. All patients in CR at 3 m remain in CR at downstream timepoints including: 9/9 at 6 m, 6/6 at 9 m, and 3/3 at 12 m. Treatment related AE have been generally limited to transient grade 1-2 local-regional genitourinary adverse events with no reports of grade 3, 4 or SAE attributed to treatment with CG0070/Pembroluzimab. Conclusions: This initial data on the efficacy and safety of CG0070 plus pembrolizumab for the treatment of BCG unresponsive NMIBC is encouraging. Additional data on efficacy as well as safety and biomarker (CAR, E2F, and PDL1) assessment will be presented for at least 25 of the projected 35 patients at the time of the conference. Clinical trial information: NCT04387461.

Antiadenovirus Antibodies Predict Response Durability to Nadofaragene Firadenovec Therapy in BCG-unresponsive Non-muscle-invasive Bladder Cancer: Secondary Analysis of a Phase 3 Clinical Trial

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.

Atezolizumab (atezo) with or without Bacille Calmette-Guérin (BCG) in patients (pts) with high-risk nonmuscle-invasive bladder cancer (NMIBC): Results from a phase Ib/II study

493

Background: Standard treatment (tx) for high-risk NMIBC is transurethral resection of bladder tumor (TURBT) followed by BCG induction and maintenance. However, ≈50% of pts experience recurrence and/or progression after tx and may be ineligible for or refuse cystectomy. The PD-L1/PD-1 pathway may be involved with immune escape in NMIBC following BCG exposure. Here, we report results of atezo (anti–PD-L1) ± BCG in BCG-unresponsive, high-risk NMIBC. Methods: This multicenter study (NCT02792192) enrolled pts with BCG-unresponsive NMIBC with carcinoma in situ who had repeat TURBT. Cohort 1A and 1B pts received atezo 1200 mg IV q3w for ≤96 wk. Cohort 1B pts also received standard BCG induction (qw × 6 doses) and maintenance (qw × 3 doses at 3 mo), with optional maintenance courses at 6, 12, 18, 24, and 30 mo. For cohort 1B only, de-escalation was allowed for ≤3 BCG dose levels (full dose 50 mg, 66% and 33% of full dose). Co-primary outcomes were safety and complete response (CR) rate at 6 mo (6-mo bladder biopsy required). Duration of CR and 3-mo CR rate (key secondary outcomes) and 12-mo CR rate (exploratory) were also shown. Results: Cohorts 1A and 1B enrolled 12 pts each. Median age was 74 y; most pts had ECOG PS 0 (n = 7 [58%] in each cohort). At data cutoff (Sep 29, 2020), median atezo tx duration was 22.7 wk in cohort 1A and 31.6 wk in 1B. Following dose de-escalation in cohort 1B, the recommended BCG dose was 50 mg. BCG dose modification/interruption occurred in 4 pts (33%) due to an AE. The most common reason for tx discontinuation was disease recurrence or progression in both cohorts. Three pts (25%) in cohort 1A had atezo-related Gr 3 AEs (most common: maculopapular rash, n = 2); no atezo- or BCG-related Gr ≥3 AEs were seen in cohort 1B. Three dose-limiting toxicities occurred (1 [8%] in cohort 1A and 2 [17%] in cohort 1B), all reported as AEs of special interest. No Gr 4/5 AEs were reported. CRs, which appeared durable, were seen in both cohorts (Table). Conclusions: In this first report of atezo + BCG in NMIBC, atezo as mono- and combination therapy was well tolerated, with no new safety signals or tx-related deaths. Preliminary data suggested clinically meaningful activity, especially with atezo + BCG, requiring confirmation in a larger setting. Clinical trial information: NCT02792192. [Table: see text]

Randomized comparator-controlled study evaluating efficacy and safety of pembrolizumab plus Bacillus Calmette-Guérin (BCG) in patients with high-risk nonmuscle-invasive bladder cancer (HR NMIBC): KEYNOTE-676 cohort B

TPS597

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. Methods: 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. Clinical trial information: NCT03711032.