Porten, Sima P.

686 Background: Blue-light cystoscopy (BLC) is an established procedure for use in the diagnosis and surveillance of patients with non-muscle-invasive bladder cancer (NMIBC). It is associated with improved detection rates compared to white light cystoscopy (WLC); however, limited data is available regarding its role in upstaging and/or upgrading when used alongside WLC. The aim of this study is to assess the incidence and features of patients undergoing upstaging and/or risk-group migration with the implementation of BLC. Methods: Using data from the prospective multi-institutional Cysview Registry (2014-2024), patients with NMIBC who underwent transurethral resection or biopsy of bladder tumors were identified. The patients in whom malignant lesions were exclusively detected by BLC, as well as those experiencing an upward change in risk category (as defined by the American Urological Association [AUA] classification) based on BLC findings, were documented. The clinical features of these patients were subsequently reviewed. Results: In this study, 2,854 patients were enrolled, who collectively underwent 4,158 resections and provided 6,432 separate pathology samples. A total of 201 (7%) patients had at least one malignant lesion detected exclusively by BLC while having negative WLC. These lesions (total 335) included carcinoma in-situ (CIS) in 145 (43%), low-grade Ta in 53 (16%), high-grade Ta in 95 (28%), high-grade T1 in 37 (11%), and high-grade T2 in 5 (1%). In patients with multifocal disease, BLC resulted in AUA risk-group upward migration in 66 (2.3%) patients.Theclinical features of these two groups are presented in the table. Taken together, the total rate of upgrading or upstaging using BLC was 9.3%, including migration to low-risk in 1.2%, intermediate-risk in 2.1%, and high-risk in 6%. Conclusions: Using BLC during transurethral resection or biopsy of bladder tumors results in risk group migration in over 9% of patients with NMIBC. This impacts patient management, including the administration of intravesical therapy when it was not initially planned, an extension in the duration of therapy, or the decision to proceed with radical cystectomy. Clinical features of patients with malignant lesions detected by BLC only (A) and those with risk group migration (B). Clinical features A B Age, median (IQR), year 71 (63-76) 71 (61-77) Gender, n (%) Male Female 140 (74)49 (26) 54 (82)12 (18) History of smoking, n (%) 117 (62) 40 (61) Primary occurrence, n (%) 65 (34) 14 (21) History on intravesical therapy, n (%) 92 (49) 40 (61) Urine cytology * , n (%) Positive Suspicious Atypical Negative/NA 33 (17)21 (10)41 (20)106 (53) 13 (20)7 (11)10 (15)36 (54) IQR: interquartile range; NA: not available. *Detected by either voided urine or bladder wash.

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.

529 Background: Radical cystectomy is recommended for patients with BCG-unresponsive (BU) non-muscle invasive bladder cancer (NMIBC) due to high risk of progression. Improved methods for assessing these risks would greatly facilitate the potential for bladder preservation. Here, we tested the capacity of the urinary comprehensive genomic profile (uCGP) to predict event-free survival (EFS) in patients with BU-NMIBC treated with atezolizumab in the single arm phase 2 trial SWOG S1605. Methods: Urine was collected from patients with BU NMIBC (CIS, Ta, T1) treated with at least one dose of intravenous atezolizumab at baseline and before the 5th cycle of therapy (3 months). The uCGP was assessed using UroAmp (Convergent Genomics). Risk scores for recurrence at baseline and at 3 months were calculated by a prespecified machine learning algorithm incorporating alterations in 60 genes and low pass whole genome sequencing, and categorized as high versus low. Molecular response was classified based on change in uCGP between the two time points. Risk scores and molecular response were submitted to SWOG for clinical correlation with EFS using a Cox model, adjusting for CIS status. Time to event was calculated from date of study entry (baseline risk) or from the 2nd collection time (3-month risk) to first high grade (HG) recurrence or persistent CIS at 3 months. Death unrelated to bladder cancer and patients last known to be alive without HG recurrence were censored at date of last visit. Results: Samples were provided at baseline in 89 patients and before the 5th cycle in 77; 68 had both samples available for paired analysis. The risk score at baseline was classified as high in 69% of samples (73% for CIS ±Ta/T1 and 62% for Ta/T1). At 12 and 18 months the EFS probabilities were 26% and 23% for high-risk and 67% and 51% for low-risk patients, respectively, with a HR of 2.82 (95% CI: 1.58, 5.03; p<0.001). The risk score at the 3-month timepoint was classified as high in 81% of samples, and the EFS probabilities at 12 and 18 months after urine collection were 26% and 22% for high-risk and 80% and 72% for low-risk patients, respectively, with a HR of 3.39 (95% CI: 1.41, 8.13; p<0.006). Molecular response to treatment was classified as complete (CR) in 8%, partial (PR) in 14%, stable (SD) in 25% and progression (PD) in 46%, with 7% having no detectable genomic abnormalities at both time points. Clinical recurrence was observed by 18 months in 0/6 patients with CR, 7/9 (78%) with PR, 11/14 (79%) with SD and 25/33 (76%) with PD by genomic profile. Conclusions: This study suggests that uCGP at baseline and after 4 cycles of treatment can identify genomic patterns associated with an increased risk of HG persistence, recurrence or progression in BU NMIBC treated with immune checkpoint inhibition. Future studies will determine if this can be used to guide early treatment intensification.

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 .

Objectives To evaluate the role of blue‐light cystoscopy (BLC) in detecting invasive tumours that were not visible on white‐light cystoscopy (WLC). Patients and Methods Using the multi‐institutional Cysview registry database, patients who had at least one white‐light negative (WL–)/blue‐light positive (BL+) lesion with invasive pathology (≥T1) as highest stage tumour were identified. All WL–/BL+ lesions and all invasive tumours in the database were used as denominators. Relevant baseline and outcome data were collected. Results Of the 3514 lesions (1257 unique patients), 818 (23.2%) lesions were WL−/BL+, of those, 55 (7%) lesions were invasive (48 T1, seven T2; 47 unique patients) including 28/55 (51%) de novo invasive lesions (26 unique patients). In all, 21/47 (45%) patients had WL−/BL+ concommitant carcinoma in situ and/or another T1 lesions. Of 22 patients with a WL−/BL+ lesion who underwent radical cystectomy (RC), high‐risk pathological features leading to RC was only visible on BLC in 18 (82%) patients. At time of RC, 11/22 (50%) patients had pathological upstaging including four (18%) with node‐positive disease. Conclusions A considerable proportion of invasive lesions are only detectable by BLC and the rate of pathological upstaging is significant. Our present findings suggest an additional benefit of BLC in the detection of invasive bladder tumours that has implications for treatment approach.

4541 Background: Radical cystectomy (RC) is the standard of care for patients with BCG-unresponsive high risk non-muscle invasive bladder cancer (NMIBC), but many patients are unfit for surgery or elect bladder preservation. This trial was designed to evaluate the activity of atezolizumab in BCG-unresponsive high risk NMIBC. Methods: This single arm phase II registration trial testing systemic atezolizumab (1200 mg IV) every 3 weeks for one year aimed to enroll 135 (70 CIS and 65 non-CIS) eligible patients with histologically proven BCG-unresponsive high risk NMIBC who were unfit for or declined RC. Here we report the 18 month results for all eligible patients who received at least one protocol treatment. The co-primary endpoints were pathological complete response (CR) rate at 6 months in patients with CIS (reported at ASCO 2020), and event-free survival (EFS) in all patients at 18 months using Kaplan-Meier methods (KM), conditional on a positive CIS response rate. A sample size of 135 evaluable patients provided 93% statistical power for detecting a 30% 18-month EFS rate versus 20% using a one-sided alpha = 0.05. EFS in the subset with Ta/T1 disease and duration of response in CIS patients were secondary endpoints. Results: 172 patients were enrolled, 166 received at least one dose of atezolizumab and are included in the safety analysis, and, of those, 128 were eligible and included in the efficacy analysis. As previously reported, 20 (27%) out of 74 patients with CIS attained a pathologic CR at 6 months. The KM estimate of 12 month (actual 11.9 mo) duration of response after 6 month CR for CIS patients was 54% (95% CI 30%, 78%) and the median duration of response was 16.5 months. The KM EFS rate at 18 months in 74 patients with CIS was 17% (90% CI 9%, 25%). The 18 month KM EFS rate in the overall population of 128 patients with Ta, T1 and CIS was 29% (90% CI 22%, 36%). The 18 month actuarial EFS rate in 54 patients with Ta/T1 disease was 45% (90% CI 34, 57%). Any possibly or probably treatment-related adverse event (TRAE) was observed in 142 out of 166 (86%) patients who received any atezolizumab regardless of eligibilty. The most frequent TRAEs were fatigue 72 (43%), diarrhea 34 (20%), and anemia 38 (23%). Grade 3-5 TRAEs occurred in 28 (17%) patients, including rash in 4 (2%), hyponatremia in 4 (2%), hypertension in 3 (2%) and elevated liver function tests in 3 (2%). There were two treatment-related deaths (sepsis and respiratory failure due to myasthenia gravis). Conclusions: The observed response of atezolizumab at 6 and 18 months in patients with BCG-unresponsive CIS suggests that this could be a valuable treatment to address a critical unmet need in this patient population. The 18 month EFS in patients with Ta/T1 disease suggests activity in this patient subset. This trial provided no new safety concerns. Funding: NIH/NCI grants: CA180888, CA180819, CA180820, CA180821, CA180863 and in part by Genentech. Clinical trial information: NCT02844816.

5022 Background: Radical cystectomy (RC) is the standard of care for patients with BCG-unresponsive high risk non-muscle invasive bladder cancer (NMIBC), but many patients are unfit for surgery or elect bladder preservation. Based on the reported efficacy of atezolizumab in metastatic urothelial carcinoma and the known expression of PD-L1 in NMIBC after BCG therapy, this trial was designed to evaluate the activity of atezolizumab in BCG-unresponsive high risk NMIBC. Methods: This single arm phase II registration trial testing systemic atezolizumab (1200 mg IV) every 3 weeks for one year aimed to enroll 135 (70 CIS and 65 non-CIS) eligible patients with histologically proven BCG-unresponsive high risk NMIBC who were unfit for or declined RC. Here we report on the subset with CIS (with or without concomitant Ta/T1) among patients who received at least one protocol treatment. The primary endpoint was pathological complete response (CR) rate at 6 months as defined by mandatory biopsy with a null hypothesis of 30% and alternative of 50% with a 1-sided alpha = 0.05 and 96% power. The 3 month CR rate, defined by cytology, cystoscopy and for-cause biopsy, is reported here as a secondary endpoint, in addition to safety. Results: Seventy-five eligible CIS patients were enrolled. Two received no treatment and are not evaluable. Of 73, median patient age was 73.4 years and median number of prior BCG doses was 12. Concomitant Ta/T1 tumor was found in 30 (41.1%) patients, including T1 disease in 16 (21.9%). A CR was observed in 30 (41.1%; 95% CI 29.7%, 53.2%) patients at 3 months and 19 (26.0%; 95% CI 16.5%, 37.6%) at 6 months. Any possibly or probably treatment-related adverse event (AE) was observed in 61 (83.6%) patients. The most frequent AEs were fatigue 36 (49.3%), pruritis 8 (11.0%), hypothyroidism 8 (11.0%), and nausea 8 (11.0%). Grade 3-5 AEs occurred in 9 (12.3%) patients and there was one treatment-related death (myasthenia gravis with respiratory failure and sepsis). Conclusion: The observed response to atezolizumab at 3 and 6 months in patients with BCG-unresponsive CIS was similar to that reported in recent similar trials and meets the benchmark for initial CR defined by the FDA guidance. This trial provided no new safety concerns. The duration of response will determine if this is a suitable treatment option for patients with BCG-unresponsive high risk CIS. Clinical trial information: 02844816 .

295 Background: While 18F-fluciclovine PET/CT is approved in the US and recommended by the NCCN, prostate-specific membrane antigen (PSMA) PET/CT is more common in Europe/Australia and recommended by the EAU. Less is known about the biology of lesions detected by either modality. 18F-fluciclovine PET relies on radiotracer uptake by amino acid transporters LAT1-4 and ASCT1-2. PSMA PET is dependent on surface expression of PSMA. We compared relative expression of PSMA and fluciclovine transporter genes in radical prostatectomy (RP) samples to determine their distribution across subtypes and correlation with outcomes. Methods: Gene expression data of 19,102 RP samples were analyzed using the Affymetrix Human Exon 1.0 ST microarray. 1,135 patients had long term follow up. Associations between expression of PSMA and fluciclovine transporter genes (LAT1-4 and ASCT1-2) and pathologic variables, molecular subtypes, and clinical outcomes were conducted. Results: All fluciclovine transporter genes (LAT 1-4, ASCT1-2) were expressed at lower levels than PSMA (p <0.0001). PSMA expression was positively correlated with genomic risk score and pathologic Gleason score (p<0.0001), but LAT2-3 and ASCT2 were inversely correlated with genomic risk in primary tumors (p<0.0001) and less expressed in GS 9-10 tumors (p<0.0001). PSMA expression was associated with worse metastasis-free survival (MFS) (HR 1.45, p=0.001) and lymph node involvement (HR 2.14, p<0.0001). Expression of LAT2, LAT3, ASCT2 expression was associated with better MFS (HR 0.85, 0.63, 0.74, p<0.0001-0.04). After multivariable adjustment, PSMA expression remained independently prognostic of poorer MFS (HR 1.3, p=0.028). Luminal B subtype was notable for PSMA overexpression; Luminal A was enriched in ASCT2 and LAT2 (p<0.0001). PSMA expression did not correlate with ERG fusion prostate cancers, but LAT2, ASCT1, and ASCT2 were overexpressed in ERG fusion negative tumors (p<0.0001). Conclusions: PSMA expression is associated with more aggressive disease and poorer clinical outcomes than fluciclovine transporter genes in localized prostate cancer. Molecular subtypes of prostate cancer vary in PSMA and fluciclovine transporter gene expression.