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Aim: Investigate oncologist and patient preferences for the first-line treatment of advanced urothelial carcinoma. Materials & methods: A discrete-choice experiment was used to elicit treatment attribute preferences, including patient treatment experience (number and duration of treatments and grade 3/4 treatment-related adverse events), overall survival and treatment administration frequency. Results: The study included 151 eligible medical oncologists and 150 patients with urothelial carcinoma. Both physicians and patients appeared to prefer treatment attributes related to overall survival, treatment-related adverse events and the number and duration of the medications in a regimen over frequency of administration. Overall survival had the most influence in driving oncologists' treatment preferences, followed by the patient’s treatment experience. Patients found the treatment experience the most important attribute when considering options, followed by overall survival. Conclusion: Patient preferences were based on treatment experience, while oncologists preferred treatments that prolong overall survival. These results help to direct clinical conversations, treatment recommendations and clinical guideline development.

Over the past decade, multiple trials, including the precision medicine trial National Cancer Institute-Molecular Analysis for Therapy Choice (NCI-MATCH, EAY131, NCT02465060) have sought to determine if treating cancer based on specific genomic alterations is effective, irrespective of the cancer histology. Although many therapies are now approved for the treatment of cancers harboring specific genomic alterations, most patients do not respond to therapies targeting a single alteration. Further, when antitumor responses do occur, they are often not durable due to the development of drug resistance. Therefore, there is a great need to identify rational combination therapies that may be more effective. To address this need, the NCI and National Clinical Trials Network have developed NCI-ComboMATCH, the successor to NCI-MATCH. Like the original trial, NCI-ComboMATCH is a signal-seeking study. The goal of ComboMATCH is to overcome drug resistance to single-agent therapy and/or utilize novel synergies to increase efficacy by developing genomically-directed combination therapies, supported by strong preclinical in vivo evidence. Although NCI-MATCH was mainly comprised of multiple single-arm studies, NCI-ComboMATCH tests combination therapy, evaluating both combination of targeted agents as well as combinations of targeted therapy with chemotherapy. Although NCI-MATCH was histology agnostic with selected tumor exclusions, ComboMATCH has histology-specific and histology-agnostic arms. Although NCI-MATCH consisted of single-arm studies, ComboMATCH utilizes single-arm as well as randomized designs. NCI-MATCH had a separate, parallel Pediatric MATCH trial, whereas ComboMATCH will include children within the same trial. We present rationale, scientific principles, study design, and logistics supporting the ComboMATCH study.

Background Advanced pelvic squamous cell carcinoma (pSCC) is a broad category of cancers affecting different pelvic organs and usually featuring unfavorable clinical outcomes. Thus, we aimed to assess genomic differences among pSCC cases and learn whether pSCC could potentially benefit from targeted therapies and/or immunotherapy. Materials and Methods A total of 1917 advanced pSCCs, including penile (penSCC), male urethral (murthSCC), male anal (manSCC), female urethral (furthSCC), vulvar (vulSCC), cervical (crvSCC), female anal (fanSCC), and vaginal (vagSCC), underwent comprehensive genomic profiling (CGP). We used hybrid capture-based CGP to evaluate recurrent genomic alterations (GAs). Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA and microsatellite instability (MSI) was determined on up to 95 loci. Programmed cell-death-ligand-1 (PD-L1) expression was determined by immunohistochemistry (IHC; Dako 22C3). Results PIK3CA was the most frequently identified potentially “actionable” GA (22%-43%), followed by mTOR pathway [PTEN (0%-18%), FBXW7 (7%-29%)], and cell-cycle GAs. DNA-damage response (DDR) GAs and receptor-tyrosine kinase (RTK) targeted options were uncommon. NOTCH1 GAs were present in >15% of penSCC and vulvSCC. TMB ≥10 mut/Mb was >15% in manSCC, fanSCC, crvSCC, and vagSCC. PD-L1 high expression was >18% in all pSCC except urthSCC, manSCC, and vagSCC. HPV-16/18 detection was highest in manSCC, fanSCC, and crvSCC. Conclusion Despite similar histology, pSCCs can differ in GAs and HPV status. Overall, PIK3CA is the most frequent potentially “targetable” GA followed by mTOR and cell cycle pathway. RTK and DDR GAs are rare in pSCC. Immunotherapy could be considered for pSCC management based on TMB and PD-L1 expression.

PROOF 302 is an ongoing randomized, double-blind, placebo-controlled, adjuvant phase III trial (NCT04197986) in approximately 218 patients from 120 centers worldwide. Eligibility criteria include post-surgical high-risk muscle-invasive upper tract urothelial cancer (85% of patients) or urothelial bladder cancer (15%), susceptible FGFR3 alterations (activating mutations, gene fusions or rearrangements), ≤120 days following radical surgery and ineligible for/or refusing cisplatin-based (neo)adjuvant chemotherapy. Patients receive either oral infigratinib 125 mg or placebo daily on days 1–21 of a 28-day cycle for up to 52 weeks or until recurrence, unacceptable toxicity or death. Primary end point: centrally determined disease-free survival (DFS); secondary end points: investigator-assessed DFS, metastasis-free survival, overall survival and safety/tolerability; exploratory end points: correlative biomarker analysis, quality-of-life and infigratinib pharmacokinetics.

Background Despite the low rate of urothelial carcinoma of the bladder (UCB) in patients of South Asian (SAS) and East Asian (EAS) descent, they make up a significant portion of the cases worldwide. Nevertheless, these patients are largely under-represented in clinical trials. We queried whether UCB arising in patients with SAS and EAS ancestry would have unique genomic features compared to the global cohort. Methods Formalin-fixed, paraffin-embedded tissue was obtained for 8728 patients with advanced UCB. DNA was extracted and comprehensive genomic profiling was performed. Ancestry was classified using a proprietary calculation algorithm. Genomic alterations (GAs) were determined using a 324-gene hybrid-capture-based method which also calculates tumor mutational burden (TMB) and determines microsatellite status (MSI). Results Of the cohort, 7447 (85.3%) were EUR, 541 (6.2%) were AFR, 461 (5.3%) were of AMR, 74 (0.85%) were SAS, and 205 (2.3%) were EAS. When compared with EUR, TERT GAs were less frequent in SAS (58.1% vs. 73.6%; P = .06). When compared with non-SAS, SAS had less frequent GAs in FGFR3 (9.5% vs. 18.5%, P = .25). TERT promoter mutations were significantly less frequent in EAS compared to non-EAS (54.1% vs. 72.9%; P < .001). When compared with the non-EAS, PIK3CA alterations were significantly less common in EAS (12.7% vs. 22.1%, P = .005). The mean TMB was significantly lower in EAS vs. non-EAS (8.53 vs. 10.02; P = .05). Conclusions The results from this comprehensive genomic analysis of UCB provide important insight into the possible differences in the genomic landscape in a population level. These hypothesis-generating findings require external validation and should support the inclusion of more diverse patient populations in clinical trials.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. Initial results from the phase III JAVELIN Bladder 100 trial (ClinicalTrials.gov identifier: NCT02603432 ) showed that avelumab first-line (1L) maintenance plus best supportive care (BSC) significantly prolonged overall survival (OS) and progression-free survival (PFS) versus BSC alone in patients with advanced urothelial carcinoma (aUC) who were progression-free after 1L platinum-containing chemotherapy. Avelumab 1L maintenance treatment is now a standard of care for aUC. Here, we report updated data with ≥ 2 years of follow-up in all patients, including OS (primary end point), PFS, safety, and additional novel analyses. Patients were randomly assigned 1:1 to receive avelumab plus BSC (n = 350) or BSC alone (n = 350). At data cutoff (June 4, 2021), median follow-up was 38.0 months and 39.6 months, respectively; 67 patients (19.5%) had received ≥2 years of avelumab treatment. OS remained longer with avelumab plus BSC versus BSC alone in all patients (hazard ratio, 0.76 [95% CI, 0.63 to 0.91]; 2-sided P = .0036). Investigator-assessed PFS analyses also favored avelumab. Longer-term safety was consistent with previous analyses; no new safety signals were identified with longer treatment duration. In conclusion, longer-term follow-up continues to show clinically meaningful efficacy benefits with avelumab 1L maintenance plus BSC versus BSC alone in patients with aUC. An interactive visualization of data reported in this article is available.

PURPOSE Germline mutations in DNA repair genes are present in approximately 10% of men with metastatic prostate cancer (mPC), and guidelines recommend genetic germline testing. Notable barriers exist, including access to genetic counseling, insurance coverage, and out-of-pocket costs. The GENTleMEN study was designed to determine the feasibility of an Internet-based, patient-driven germline genetic testing approach for men with mPC. PATIENTS AND METHODS In this prospective cohort study, men with mPC provided informed consent via an Internet-based platform and completed a questionnaire including demographics and family cancer history. Supporting medical data were also collected. Genetic testing was performed using the Color Genomics 30-gene targeted panel of cancer predisposition genes on a mailed saliva sample. Men whose test results identified a germline pathogenic or likely pathogenic variant received results by phone or telehealth genetic counseling; other participants received results by email with an option for phone-based or telehealth genetic counseling. RESULTS As of August 18, 2021, 816 eligible men were consented, of whom 68% (551) completed genetic testing, and 8.7% (48 of 551) were found to carry a pathogenic or likely pathogenic variant in a germline DNA repair gene: CHEK2 (17), BRCA2 (15), ATM (6), NBN1 (3), BRCA1 (2), PALB2 (2), PMS2 (2), and MSH6 (1). Participants were more likely to complete the testing process if they were non-Hispanic White, married, highly educated, or from a higher-income bracket. CONCLUSION Here, we show the feasibility of delivering germline (inherited) genetic testing by a voluntary, patient-driven, Internet-based platform to men with mPC. Preliminary results show rates of germline DNA repair mutations, consistent with other cohorts. Although feasible for some, reduced steps for participation, more dedicated diverse outreach and participant support, and identification and addressing of additional barriers is needed to ensure equitable access and optimization.

Bipolar androgen therapy (BAT) results in rapid fluctuation of testosterone (T) between near-castrate and supraphysiological levels and has shown promise in metastatic castration-resistant prostate cancer (mCRPC). Its clinical effects may be mediated through induction of DNA damage, and preclinical studies suggest synergy with PARP inhibitors.This was a single-center, Phase II trial testing olaparib plus BAT (T cypionate/enanthate 400 mg every 28 days) with ongoing androgen deprivation. Planned recruitment was 30 subjects (equal proportions with/without homologous recombination repair [HRR] gene mutations) with mCRPC post abiraterone and/or enzalutamide. The primary objective was to determine PSAThirty-six patients enrolled and 6 discontinued prior to response assessment. In the ITT cohort, PSABAT plus olaparib is associated with high response rates and long PFS. Clinical benefit was observed regardless of HRR gene mutational status.

Background: Adult primary retroperitoneal sarcomas (RPSs) are a group of heterogeneous tumors with different histological subtypes. Comprehensive genomic profiling (CGP) analyses have recently provided significant insights into the biology of sarcomas by identifying genomic alterations (GAs) which could benefit from targeted therapies. Methods: RPS were evaluated by CGP using next-generation sequencing of up to 406 cancer-related genes. Tumor mutational burden (TMB) was determined on 0.83 to 1.14 mut/Mb of sequenced DNA. Finally, PD-L1 expression was determined. Results: Overall, 296 cases of primary RPS were analyzed. Liposarcoma (LPS) subtype had more GA/tumor than leiomyosarcoma (LMS) subtypes, with follicular dendritic cell sarcomas harboring the highest and synovial sarcomas the lowest. TP53 and Rb1 alterations were the highest in LMS, and CDK4/6 and MDM2 in LPS. However, both the TMB and targetable GA rates were low across subtypes. PD-L1 immunostaining was low positive in 21% and high positive in 5% of patients, respectively. Conclusions: CGP analysis revealed that potentially actionable genomic targets were rare in our cohort of RPS. Moreover, RPSs seem less likely to respond to immune checkpoint inhibitors based on putative biomarkers status. Nevertheless, genomic stratification according to histological subtypes led to description of GAs that can inform future clinical trials design.

Detecting genomic alterations (GAs) in advanced urothelial carcinoma (aUC) can expand treatment options by identifying candidates for targeted therapies. Erdafitinib is FDA-approved for patients with platinum-refractory aUC with activating mutation or fusion in FGFR2/3. We explored the prevalence and spectrum of FGFR2/3 GAs identified with plasma cfDNA NGS testing (Guardant360) in 997 patients with aUC. FGFR2/3 GAs were detected in 201 patients (20%) with characterized activating GAs in 141 (14%). Our results indicate the Guardant360-based FGFR2/3 GA detection rate is similar to those described from previous studies employing tumor tissue testing, suggesting that plasma-based cfDNA NGS may non-invasively identify candidates for anti-FGFR targeted therapies.

BACKGROUND: Reliable biomarkers that can be serially monitored to predict treatment response to immune checkpoint inhibitors (ICIs) are still an unmet need. Here, we present a multiplex immunofluorescence (IF) assay that simultaneously detects circulating tumor cells (CTCs) and assesses CTC expression of programmed death ligand-1 (PD-L1) and interferon regulatory factor 1 (IRF-1) as a candidate biomarker related to ICI use. OBJECTIVE: To assess the potential of CTC PD-L1 and IRF-1 expression as candidate biomarkers for patients with advanced epithelial solid tumors receiving ICIs. PATIENTS AND METHODS: We tested the IF CTC assay in a pilot study of 28 patients with advanced solid tumors who were starting ICI. Blood for CTC evaluation was obtained prior to starting ICI, after a single cycle of therapy, and at the time of radiographic assessment or treatment discontinuation. RESULTS: At baseline, patients with 0–1 CTCs had longer progression-free survival (PFS) compared to patients with ≥2 CTCs (4.3 vs 1.3 months, p = 0.01). The presence of any PD-L1+ CTCs after a single dose of ICI portended shorter PFS compared to patients with no CTCs or PD-L1- CTCs (1.2 vs 4.2 months, p = 0.02); the presence of any PD-L1+ or IRF-1+ CTCs at time of imaging assessment or treatment discontinuation also was associated with shorter PFS (1.9 vs 5.5 months, p < 0.01; 1.6 vs 4.7 months, p = 0.05). CTC PD-L1 and IRF-1 expression did not correlate with tumor tissue PD-L1 or IRF-1 expression. Strong IRF-1 expression in tumor tissue was associated with durable (≥1 year) radiographic response (p = 0.02). CONCLUSIONS: Based on these results, CTC PD-L1 and IRF-1 expression is of interest in identifying ICI resistance and warrants further study.

PURPOSE: Current first-line treatment options in patients with metastatic urothelial carcinoma (mUC) unfit to receive cisplatin-containing chemotherapy include PD-1/L1 inhibitors and carboplatin-containing chemotherapy. However, the optimal sequencing of these therapies remains unclear. MATERIAL AND METHODS: We conducted a multicenter retrospective analysis. Consecutive cisplatin-ineligible patients with mUC treated with first-line carboplatin-containing chemotherapy followed sequentially by second-line PD-1/L1 inhibitor, or the reverse order, were included. Patient demographics, objective response, time to treatment failure for first-line (TTF1) and second-line (TTF2) therapy, interval between end of first-line and initiation of second-line treatment (Interval(1L-2L)), and overall survival (OS) were collected. Multivariate analysis was conducted to examine the association of sequencing on OS. RESULTS: In this multicenter retrospective study, we identified 146 cisplatin-ineligible patients with mUC treated with first-line (1L) PD-1/L1 inhibitor therapy followed by second-line (2L) carboplatin-containing chemotherapy (Group 1, n=43) or the reverse sequence (Group 2, n=103). In the overall cohort, median age was 72, 76% were men, and 18% had liver metastasis. In both groups, objective response rates were higher with carboplatin-containing chemotherapy (45.6% 1L, 44.2% 2L) compared to PD-1/L1 inhibitors (9.3% 1L, 21.3% 2L). On multivariate analysis, treatment sequence was not associated with overall survival (HR 1.05, p=0.85). Site of metastasis was the only factor significantly associated with overall survival (p=0.002). CONCLUSIONS: In this biomarker-unselected cohort of cisplatin-ineligible patients with mUC, PD-1/L1 inhibitor followed by carboplatin-containing chemotherapy and the reverse sequence had comparable OS.

Prostate cancer incidence and mortality in the United States in African Americans (AA) are higher than in Caucasians. Eastern Cuyahoga County in Ohio is majority AA and is considered an underserved population particularly vulnerable to healthcare disparities. There is a paucity of data about shared decision making among high-risk AA men with regard to prostate cancer screening. This study aims to examine shared versus informed decision making (SDM versus IDM) in a randomized, control trial among a large, high-risk AA population.Patients were included in annual one-day outreach events, each held over 3 years (2017-2019), and were randomized at each event into IDM (control) and SDM (investigational) groups and then were offered screening via prostate specific antigen (PSA) and digital rectal exam (DRE). The primary endpoints were proportion of participants over 40 who did not demonstrate decisional conflict about prostate cancer screening measured by the SURE score, as well as change of knowledge score about prostate cancer screening.Overall, 175 patients were enrolled in the trial; 79 in the SDM arm and 96 in the IDM arm. The investigational (SDM) arm had 3/79 (3.9%) conflict versus 6/96 (6.4%) in the control (IDM) arm (Our education-based study showed no significant difference between SDM and IDM with regard to decisional conflict about prostate cancer screening. The study also demonstrated significant improvement in knowledge about prostate cancer screening in a high-risk AA population in both groups. Our results should be interpreted with caution due to several limitations; however, the study can serve as a benchmark for future studies in this very important topic.

TPS592 Background: SG is an antibody-drug conjugate composed of an anti-trophoblast cell-surface antigen-2 (Trop-2) antibody coupled to SN-38 via a proprietary hydrolyzable linker. In Cohort 1 of the phase 2 TROPHY-U-01 trial, SG monotherapy resulted in a 27% objective response rate (ORR) and median overall survival (OS) of 10.9 months with an overall manageable toxicity profile in pts with locally advanced or mUC who previously received platinum-based therapy and a checkpoint inhibitor (CPI; Tagawa S, et al. J Clin Oncol. 2021). The results led to accelerated FDA approval of SG for this population. ZIM (anti-PD-1) and DOM (anti-TIGIT) are CPIs under clinical investigation for anti-tumor activity. Cohort 6 of TROPHY-U-01 trial (C6) will assess SG monotherapy vs SG plus CPI combinations (SG + ZIM; SG + ZIM + DOM) vs CARBO/GEM followed by avelumab maintenance in treatment naive cis-ineligible pts with locally advanced or mUC. Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, global, phase 2 trial. C6 includes pts with cis-ineligible unresectable locally advanced or mUC who are ≥18 y; have an ECOG performance status 0-1; have available tissue for biomarker testing; have no prior mUC therapy, except (neo)adjuvant chemotherapy with recurrence >12 mo from completion; are CPI-naive or >12 mo from completion; have adequate hematologic and hepatic function; and have creatinine clearance ≥30 mL/min. A safety lead-in will occur where 6-8 pts will be treated with SG 10 mg/kg on D1 and D8 of a 21-D cycle + ZIM 360 mg q3wk. A second safety lead-in will occur where 6-8 pts will be treated with SG 10 mg/kg on D1 and D8 of a 21-D cycle + ZIM 360 mg q3wk + DOM 1200 mg q3wk. After the safety lead-in, pts will be randomized 1:2:2:2 to: Arm 1: SG 10 mg/kg on D1 and D8 of a 21-D cycle; Arm 2: SG 10 mg/kg on D1 and D8 of a 21-D cycle and ZIM 360 mg q3wk; Arm 3: SG 10 mg/kg on D1 and D8 of a 21-D cycle and ZIM 360 mg q3wk and DOM 1200 mg q3wk; and Arm 4: CARBO (AUC 4.5-5) on D1 of each 21-D cycle + GEM 1000 mg/m2 on D1 and D8 of each 21-D cycle for the first 4-6 cycles followed by switch maintenance avelumab 800 mg q2wk in the absence of progression. All pts will continue treatment until progression, unacceptable toxicity, or loss of clinical benefit. Primary endpoint is ORR per central review based on RECIST 1.1. Secondary endpoints include progression-free survival, duration of response, and clinical benefit rate by central review and investigator review, as well as ORR by investigator review, and OS, and safety and tolerability (Arms 1-3). C6 aims to enroll an estimated 226 pts. With 60 subjects each in Arms 2-4, a comparison of Arm 2 or 3 vs Arm 4 will have ~88% power at one-sided α of 0.05 to demonstrate an improvement in ORR, with a null hypothesis of ORR 40% for Arms 2-3 and an alternative hypothesis of ORR at 65% for Arms 2-4. Clinical trial information: NCT03547973 .

TPS598 Background: SG is an antibody-drug conjugate composed of an anti-trophoblast cell-surface antigen-2 (Trop-2) antibody coupled to a topoisomerase-I inhibitor, SN-38, via a hydrolyzable linker. In Cohort 1 of the phase 2 TROPHY-U-01 trial, SG monotherapy resulted in a 27% objective response rate (ORR) and median overall survival (OS) of 10.9 months with an overall manageable toxicity profile in pts with locally advanced or mUC who previously received platinum-based therapy and a checkpoint inhibitor (CPI; Tagawa S, et al. J Clin Oncol. 2021). These results led to accelerated FDA approval of SG in this population. The CPI ZIM is a fully human IgG4 monoclonal antibody targeting PD-1. CPIs are active in mUC, including avelumab that is FDA-approved as switch maintenance therapy for locally advanced or mUC that has not progressed with first-line platinum-based chemotherapy. Cohort 5 of the TROPHY-U-01 trial will evaluate the safety, tolerability, and efficacy of SG + ZIM vs ZIM alone vs avelumab as switch maintenance in pts with mUC who have received gemcitabine (GEM)/cisplatin without progressive disease (PD). Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, global, phase 2 trial. Cohort 5 includes pts who have not progressed after completion of 4-6 cycles of GEM/cisplatin. Key eligibility requirements include ≥18 y; ECOG PS 0-1; available tissue for biomarker testing; adequate blood counts without transfusion or growth factor within 2 weeks of study drug initiation; creatinine clearance ≥30 mL/min. A safety lead-in of 6-8 pts will be conducted, where pts will be treated with SG 10 mg/kg IV on D1 and D8 of a 21-D cycle plus ZIM 360 mg IV q3wk on a 21-D cycle. On safety lead-in, if SG + ZIM is deemed safe, pts will be randomized 1:1:1. Those in Arm 1 will receive SG 10 mg/kg IV on D1 and D8 of a 21-D cycle followed by ZIM 360 mg IV, q3wk (D1 of a 21-D cycle). Pts in Arm 2 will receive avelumab 800 mg IV q2wk (D1 of a 14-D cycle). Pts in Arm 3 will receive ZIM 360 mg IV q3wk. All pts will continue treatment until PD, unacceptable toxicity, or loss of clinical benefit. The primary endpoint is progression-free survival based on central review by RECIST 1.1 criteria. Secondary endpoints include OS (all arms), safety/tolerability of SG in combination with ZIM (Arm 1). Cohort 5 aims to enroll an estimated 158 pts. A sample size of 50 pts per randomized arm is determined based on clinical consideration for exploring the activity of anticancer agents. Clinical trial information: NCT03547973 .

508 Background: For platinum-eligible patients (pts) with advanced UC, 1L cisplatin- or carboplatin-based chemotherapy regimens followed by avelumab maintenance in pts without progression has become the standard of care. This is based on the results of the phase 3 JAVELIN Bladder 100 trial (NCT02603432), which showed significantly longer OS and progression-free survival (PFS) from start of maintenance (randomization) with avelumab maintenance + best supportive care (BSC) vs BSC alone (median OS, 23.8 vs 15.0 months; HR, 0.76 [95% CI, 0.63-0.91]; p=0.0036). We report post hoc analyses of long-term outcomes by 1L chemotherapy regimen and OS from start of 1L chemotherapy. Methods: Pts with unresectable locally advanced or metastatic UC that did not progress with 4-6 cycles of 1L cisplatin + gemcitabine or carboplatin + gemcitabine were randomized 1:1 to receive avelumab + BSC (n=350) or BSC alone (n=350). The primary endpoint was OS measured from randomization. Secondary endpoints included PFS and safety. Results: At data cutoff (June 4, 2021), median follow-up from randomization was ≥38 months in both arms. In subgroups treated with 1L cisplatin + gemcitabine or carboplatin + gemcitabine, OS and PFS (measured from start of maintenance [randomization]) were longer in the avelumab + BSC arm than in the BSC alone arm (Table). Safety findings were similar in both subgroups. In the overall population, median OS measured from the start of 1L chemotherapy was 29.7 months (95% CI, 25.2-34.0) in the avelumab + BSC arm and 20.5 months (95% CI, 19.0-23.5) in the BSC alone arm (HR, 0.77 [95% CI, 0.635-0.921]). Conclusions: Long-term follow-up from the JAVELIN Bladder 100 trial confirms that avelumab 1L maintenance provides similar OS and PFS benefits in pts with advanced UC who are progression free following standard-of-care 1L cisplatin- or carboplatin-based chemotherapy, with an acceptable safety profile. The median OS measured from start of chemotherapy further supports the use of avelumab 1L maintenance as standard of care in this setting and provides a benchmark for future clinical trials. Clinical trial information: NCT02603432 . [Table: see text]

478 Background: Erdafitinib is FDA-approved for patients (pts) with advanced urothelial carcinoma (aUC) with FGFR2/3 mutation or fusion and progression after platinum-based chemotherapy. It is postulated that FGFR3-altered aUC may be a “cold tumor” and associated with non-T cell-inflamed phenotype and, thus, may be less responsive to ICI. We hypothesized that pts with aUC that harbor FGFR2/3 alterations would have lower response and shorter survival on ICI. Methods: We performed a retrospective cohort study of pts with aUC treated with ICI and available genomic data in 11 institutions; pts with pure non-UC, treated with combinations or on clinical trial were excluded. Outcomes (overall response rate [ORR], progression free survival [PFS] and overall survival [OS] were compared in pts with and without FGFR2/3 alterations. PFS and OS was compared using Cox proportional hazards. All analyses were performed in the overall population and also categorized by treatment line (1st line [1L] vs salvage [2+L]). Multivariable models were adjusted for an internally developed risk score for 1L and Bellmunt risk score for 2+L; p

547 Background: Despite recent therapeutic advancements for patients with mUC, including checkpoint inhibitors (CPIs), anti-FGFR and antibody-drug conjugates (ADCs), biomarker data to predict therapeutic response and identify mechanisms of resistance remain limited. Ongoing randomized clinical trials evaluating the combination of CPIs and ADCs in these pts underscore the need to develop biomarkers to better understand who might best respond to these therapies. Here, we employ a liquid biopsy approach to molecularly characterize circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), including those isolated with Trop-2, the target of the novel drug Sacituzumab Govitecan and Datopotamab Deruxtecan. Methods: 104 blood samples serially collected from pts being treated for mUC were used for CTC collection using anti-EpCAM and Trop-2 antibodies in parallel. CTCs were isolated and stained for immune markers PD-L1 and HLA I using the VERSA (Versatile Exclusion-based Rare Sample Analysis) platform. Plasma was isolated for paired analysis of CTC and ctDNA content. CTCs were analyzed for enumeration and single-cell protein analysis. Overall survival (OS) was defined from time of sample collection, and survival analyses were performed using the Kaplan-Meier method. Results: We observed significantly shorter OS in pts with higher CTC burden (≥ 20 CTCs/7.5 mL blood) in samples captured with either EpCAM (median 34.1 vs 3.1 mo, P < 0.01) or Trop-2 (median 34.1 vs 6.2 months, P < 0.01). Furthermore, EpCAM and Trop-2 CTC burdens were higher at progression timepoints relative to responding or stable timepoints, when stratified according to treatment modality (table). Inter and intra-patient heterogeneous PD-L1 and HLA I expression and co-expression was observed on CTCs although no significant differences were seen globally between EpCAM and Trop-2 CTCs. In a cohort of pts treated with CPIs, we observed dynamic phenotypic changes in the ratio of HLA:PD-L1 that differed between EpCAM and Trop-2 CTCs. ctDNA analysis identified concordant increases in tumor fraction and acquired genomic mutations. When examined longitudinally across individual pts, these findings in tandem with changes in enumeration, suggest the emergence of different CTC subpopulations that may serve as biomarkers of resistance. Conclusions: We identify the prognostic significance of CTC enumeration with parallel EpCAM and Trop-2 CTC isolation and demonstrate the utility of a liquid biopsy assay that can detect pharmacodynamic changes in CTC burden and immune marker expression throughout the course of treatment. [Table: see text]

258 Background: Tumors harboring 2 or more PIK3CA Short variants (SV) (“Multi-hit”) have been described in breast cancer as linked to enhanced clinical outcome from anti-PIK3CA targeted therapies including alpelisib and investigational agents in clinical trials. The landscape and clinical implications of multi-hit PIK3CA alterations in other tumors, including in CAPC, are underexplored. Methods: 19,978 CAPC samples underwent hybrid capture based comprehensive genomic profiling (CGP) to evaluate all classes of GA and determine tumor mutational burden (TMB), microsatellite instability (MSI), genomic ancestry, signature and loss of heterozygosity (gLOH). Tumor cell PD-L1 expression was determined by IHC (Dako 22C3). Results: 18,741 (93.8%) CAPC were PIK3CA wild type (WT), 1,155 (5.8%) featured a single PIK3CA SV and 82 (0.4%) featured multi-hit PIK3CA SVs. The median ages of CAPC patients with single hit (69.1 yrs) or multi-hit (68.7 yrs) PIK3CA SV were older than the PIK3CA WT (67.6 yrs) CAPC (p

465 Background: The JAVELIN Bladder 100 clinical trial demonstrated a significant overall survival and progression-free survival benefit with avelumab 1LM + best supportive care (BSC) vs BSC alone for la/mUC not progressing on platinum-based chemotherapy (PBC). PATRIOT-II aims to describe RW data for avelumab 1LM treatment (tx) of patients (pts) with la/mUC. Methods: PATRIOT-II collected data from pts with la/mUC treated in 37 geographically dispersed oncology practices/communities and academic centers in the US. Pts who initiated avelumab 1LM following PBC were retrospectively enrolled and will be followed up via medical record review for 52 weeks post avelumab 1LM initiation. This analysis focused on pt characteristics and tx data from la/mUC diagnosis through the PBC period and at avelumab 1LM initiation. Disease and PBC tx characteristics, as well as response to PBC, were assessed. All analyses were descriptive. Results: A total of 160 pts were enrolled (Table), 118 (74%) were white, non-Hispanic, 16 (10%), were Black, Asian, or Hispanic, and the rest unknown; 102 (64%) were current or former smokers. 77 (48%) were tested for PD-L1 via various assays, with 44 (57%) of those tumor samples reported as positive. 1L PBC was cisplatin-based in 100 (63%) of pts and carboplatin-based in 60 (38%). Pts received a median of 4 PBC cycles (interquartile range [IQR], 3-6) for a median of 13 weeks (IQR, 10-17). 31 (19%) discontinued PBC due to unacceptable side effects/toxicity. Best observed response was complete response in 21 (13%), partial response in 109 (68%), and stable disease in 17 (11%), with the remainder unknown. Median time to first imaging was 10 weeks (IQR, 5-14) after PBC initiation. 23 (14%) were hospitalized while receiving PBC, and 25 (16%) were seen in the emergency department. Pts proceeded to avelumab 1LM at a median of 4 weeks (IQR, 3-6) following PBC completion. Avelumab was administered at 800 mg every 2 weeks in 130 (81%), 10 mg/kg in 15 (9%), 800 mg in 7 (4%) pts. Conclusions: This ‘RW’ study offers valuable insights into characteristics and outcomes of pts with la/mUC treated in the US. Baseline factors, tx patterns and response to PBC were consistent with usual therapy paradigms in the 1L induction setting. Ongoing trials are evaluating the optimal number of PBC cycles and predictive biomarkers. Limitations include the retrospective nature, lack of randomization and central review, potential selection and confounding biases. [Table: see text]

564 Background: CDH1 mutated UBCs are characterized by plasmacytoid histology and are associated with an aggressive clinical course at the time of diagnosis. Methods: Cohort 1: 6,676 clinically advanced UBC patients (pts) underwent comprehensive genomic profiling (CGP) to evaluate all classes of genomic alterations (GA), microsatellite instability (MSI), tumor mutational burden (TMB), and genomic loss of heterozygosity (gLOH, high ≥16%). Predominant genetic ancestry was determined using a SNP-based approach and classified as one of the 5 categories: African (AFR), European (EUR), Central and South American (AMR), South Asian (SAS), or East Asian (EAS). Cohort 2: 586 UBC pts underwent a RWCOS using the nationwide (US-based) de-identified Flatiron Health-Foundation Medicine urothelial clinico-genomic database (FH-FMI CGDB). The de-identified data originated from approximately 280 US cancer clinics (~800 sites of care) Jan 2011-Apr 2022. Differences in real-world progression-free survival (rwPFS) and overall survival (rwOS) were evaluated by Cox proportional hazard models. Results: Cohort 1: 217 (3.3%) of UBC had a CDH1 short variant (SV) mutation with 65.2% featuring plasmacytoid histology. When compared with CDH1 wild-type (WT) UBC, the CDH1-mutated UBC had similar age, gender, and genetic ancestry. The CDH1-mutated UBC featured a higher frequency of MSI (2.7% vs 0.8%; p=.002), mean TMB (14.8 vs 9.9 mut/Mb p

526 Background: SG is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38, a topoisomerase-I inhibitor, via a proprietary hydrolyzable linker. SG received accelerated FDA approval in April 2021 in pts with mUC who previously received PT-based therapy and a CPI based on the primary analysis of the pivotal TROPHY-U-01 Cohort 1 study. With 9.1 mo median (med) follow-up, SG monotherapy demonstrated a 27% objective response rate (ORR) and med overall survival (OS) of 10.9 mo in 113 pts with locally advanced or mUC progressing after receiving at least a PT-based therapy and a CPI (Tagawa, et al. J Clin Oncol. 2021). Here we report updated Cohort 1 outcomes. Methods: TROPHY-U-01 (NCT03547973) is a multicohort, open-label, phase 2 study. Cohort 1 pts (≥18 y) had progression of mUC following PT (as first-line metastatic therapy or as (neo)adjuvant therapy with recurrence/progression ≤12 mo) and CPI, had ECOG PS 0-1, and creatinine clearance ≥30 mL/min. Pts received 10 mg/kg of SG intravenously on D1 and D8 of 21-D cycles. The primary endpoint was ORR per central review by RECIST 1.1. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), clinical benefit rate (CBR), OS, and safety. Results: As of July 26, 2022, med follow-up was 10.5 mo (range, 0.3-40.9) for treated pts (N=113). As previously reported, pts (78% men; med age, 66 y; 66% with visceral metastases, 34% liver), were heavily pretreated with a med of 3 prior therapies (range, 1-8). Med time since last prior therapy was 1.5 mo (range, 0-60.0). At data cutoff, per central review, ORR was 28% (95% CI, 20.2-37.6); CBR was 38% (95% CI, 29.1-47.7), med DOR was 6.1 mo (95% CI, 4.7-9.7, n=32) and med PFS was 5.4 mo (95% CI, 3.5-6.9). Med time to response was 1.6 mo (range, 1.2-5.6) and med OS was 10.9 mo (95% CI, 8.9-13.8). DOR, PFS, and OS rates (95% CI) at 12 mo were 30% (13.6-48.8), 14% (7.2-23.3), and 45% (35.4-53.8), respectively, with 7 (6%) pts still receiving SG at 12 mo. In pts who received prior enfortumab vedotin (n=10) and prior PT in the (neo)adjuvant setting (n=39), results were consistent with the overall population. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 65% of pts and were similar to prior reports; the most common Grade ≥3 TRAEs were neutropenia (35%), leukopenia (18%), anemia (14%), diarrhea (10%), and febrile neutropenia (10%). One treatment-related death occurred due to febrile neutropenia-related sepsis. Conclusions: At 10.5-mo med follow-up, the response rate remains high in pts with heavily pretreated mUC, including pts with visceral metastases, prior EV therapy and prior (neo)adjuvant PT therapy. No new safety signals were observed. These data support the use of SG in pts with mUC who received PT and a CPI and further evaluation of SG in earlier lines of therapy. Clinical trial information: NCT03547973 .

566 Background: Given the recent approval in lung cancer for the first anti-HER2 targeted therapy directed against activating kinase domain exon 20 ERBB2 insertion mutations, considerable interest has arisen in targeting additional locations in the ERBB2 gene in other tumor types. Methods: 5,485 UBC samples were sequenced using a hybrid capture-based comprehensive genomic profiling (CGP) assay to assess all classes of genomic alterations (GA), tumor mutational burden (TMB), microsatellite instability (MSI), genomic loss of heterozygosity (gLOH), trinucleotide signatures and predominant genetic ancestry. Statistical comparisons utilized the Bonferroni correction. Results: 548 (10.0%) of UBC featured ERBB2 gene amplification (amp) and 219 (4.0%) featured an ERBB2 ECD+ sequence mutation (74% S310F and 26% S310Y). ERBB2 ECD+ mutations and ERBB2 amplification were mutually exclusive. 16.4% of ERBB2 ECD+ UBC had more than one E RBB2 sequence mutation. Central pathology review of the 219 ERBB2 ECD+ UBC revealed that 63 (28.8%) featured a micropapillary histologic appearance (MPUC). ERBB2 ECD+ UBC featured more patients with European ancestry than both ERBB2 WT (90.9% vs 84.2%; p=.03) and ERBB2 amp (90.9% vs 83.2%; p=.04). ECD mut+ UBC also featured lower association with African ancestry than ERBB2 amp (2.7% vs 7.8%; p=.04) and lower frequency of gLOH > 16% (9.3% vs 19.1%; p=.04). MSI-High status was similar and rare in all 3 groups (range 0 to 0.9%). ERBB2 ECD+ UBC had a higher frequency of APOBEC signature than ERBB2 amp (82.9% vs 72.4%; p=.03). TMB > 10 mut/mb was higher in ERBB2 amp (49.2% vs 31.4%; p

472 Background: PBC followed by avelumab switch maintenance in non-progressors is the standard first line (1L) aUC treatment. We describe clinical features and outcomes in a ‘real-world’ cohort treated with avelumab maintenance for aUC. We hypothesized that outcomes would be similar with JavelinBladder100 trial data. Methods: This was a retrospective cohort study of pts from 12 sites who received 1L switch maintenance avelumab after no progression to PBC for aUC. We calculated overall response rate (ORR), median overall and progression-free survival (mOS, mPFS) using Kaplan Meier method from avelumab start. We also described OS and PFS for specific subsets using Cox regression. Results: We found 77 pts with aUC (78% pure, 22% mixed UC) with median age 68, 81% men, 91% White, 17% upper tract primary, 66% prior cisplatin, 17% liver metastasis (mets), 80% ECOG PS 0-1 at time of PBC start. There was a median of 6 weeks (range 1-30) from end of PBC to avelumab start; median follow-up time from avelumab start was 22 months (95%CI 16-24). ORR with avelumab maintenance: 28% (complete response [CR] 17%, partial response [PR] 11%), stable disease (SD) 32%; progression as best response 30% (10% unknown); mPFS 7 months (95%CI 5-9), mOS 22 months (95%CI 16-NR). Table shows HR for OS and PFS for specific subsets. Absence (vs presence) of liver mets (p=0.04), ECOG PS 0-1 (vs >1; p=0.01) and CR/PR (vs SD) to 1L PBC (p=0.03) were associated with longer OS. Conclusions:‘Real world’ outcomes with avelumab maintenance in pts with aUC align with JavelinBladder100 trial data (but higher ORR). Good PS, response to PBC and absence of liver mets are favorable prognostic factors. Limitations include moderate sample size, retrospective design, lack of randomization and central scan review, possible selection and confounding biases. Other studies (e.g. PATRIOT-II) can generate more data in pts on maintenance avelumab outside clinical trials. [Table: see text]

4 Background: TMB has emerged as a major biomarker of efficacy in immune checkpoint inhibitor (ICPI) therapies in the neoadjuvant, adjuvant and metastatic disease setting in a wide variety of malignancies, but not in PSCC. Methods: 397 clinically advanced (local major recurrence and/or metastatic disease) PSCC underwent hybrid capture-based comprehensive genomic profiling (CGP) to evaluate all classes of genomic alterations (GA). Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. Trinucleotide mutation signatures were evaluated (Alexandrov, et al. 2013). Genome-wide loss of heterozygosity (gLOH) was determined using validated pipelines and excluding whole-arm and whole-chromosome events. TMB was categorized into three cohorts: 20 muts/Mb (very high). Tumor cell PD-L1 expression was determined by IHC (Dako 22C3) and defined as tumor proportion score (TPS) >1. The presence of HPV16/18 was determined by next generation sequencing (NGS). Statistical comparisons were corrected for multiple comparisons using the Bonferonni method. Results: There were 339 (85.4%) TMB low, 40 (10.1%) TMB 10-19 and 18 (4.5%) TMB very high PSCC cases in this study. The mean age of PSCC with very high TMB at 70.1 yrs was older than for TMB low at 63.4 yrs (p=.08). There were no significant differences in genomic ancestry among the 3 groups. The TMB 10-19 and TMB very high tended to feature an APOBEC genomic mutational signature more than the TMB low PSCC cases (74 and 76% vs 44%). MSI high status was absent in the TMB low PSCC, but was present in 7.5% of the TMB 10-19 and 11.8% of the TMB very high cases. gLOH levels above 16% were similar in all 3 groups and ranged from 6.2 to 9.4%. GA associated with differences in TMB status in the PSCC cases included higher PIK3CA GA in TMB 10-19 (40.0%) vs TMB low (18.3%; p=.035) and TMB very high (66.7%) vs TMB low (p=.0002). CDKN2A GA were higher in TMB low (45.7%) than in the combined TMB 10-19 + very high (25.9%; p=.049). GA in KMT2D were higher in the combined TMB 10-19 + very high (29.3%) than the TMB low PSCC (7.7%; p=0002). FGFR3 GA were similar in all 3 groups. PD-L1 expression was not significantly different among the 3 groups with TMB low (78.3%), TMB 10-19 (64.2%) and TMB very high (54.5%). HPV identification was more frequent as TMB increased: 28.3% for the TMB low, 50.0% for the TMB high and 58.8% for the TMB very high groups. Conclusions: The evaluation of PSCC by CGP based on TMB levels revels significant differences in biomarkers for the near 15% of cases that have TMB >10 muts/Mb. Further study of TMB as a biomarker in ICPI-based clinical trials for advanced PSCC appear warranted.

518 Background: Pembro is standard of care for pts with mUC who progress after 1L PT therapy but only ~21% of pts respond, highlighting an unmet need (Bellmunt, et al. NEJM. 2017). SG is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38 via a hydrolyzable linker. In Cohort 1 of the TROPHY-U-01 study, SG demonstrated a 27% objective response rate (ORR) with manageable safety in 113 pts with locally advanced or mUC who previously received PT and a checkpoint inhibitor (CPI; Tagawa, et al. J Clin Oncol. 2021), leading to accelerated FDA approval in this pt population. Preliminary results of the phase 2 TROPHY-U-01 Cohort 3 study showed that SG plus Pembro demonstrated a high ORR (34%) as a 2L therapy in 41 CPI-naive pts with mUC who progressed after PT (Grivas et al. J Clin Oncol. 2021). Here we present the primary analysis of Cohort 3. Methods: Cohort 3 pts (≥18 y) had progression of mUC following PT in the metastatic setting or following ≤12 mo of PT in the (neo)adjuvant setting and ECOG PS 0-1. Pts received 10 mg/kg of SG on D1 and D8 and 200 mg of Pembro on D1 of a 21-D cycle for ≤2 y. The primary endpoint was ORR [complete response (CR) + partial response (PR)] per central review by RECIST 1.1. Secondary endpoints include clinical benefit rate [CBR; CR + PR + stable disease for at least 6 mo], duration of response (DOR) and progression-free survival (PFS) per central review; and safety. Target enrollment was approximately 41 pts based on a Simon two-stage design for 90% power at one-sided α of 0.05 to demonstrate 21% improvement in ORR, with a null hypothesis of historical ORR ≤20% and an alternate hypothesis of ORR ≥41%. Results: As of July 26, 2022, median follow-up was 12.5 mo (range, 0.9-24.6) for treated pts (N=41); median age, 67 y (range, 46-86), 83% male, 61% ECOG PS 1, 76% ≥1 Bellmunt risk factors, and 78% visceral metastases (29% liver). Median duration of last prior anti-cancer therapy was 2.7 mo (range, 0-13). Per central review, ORR was 41% (95% CI, 26.3-57.9; 20% CR); CBR was 46% (95% CI, 30.7-62.6); median DOR was 11.1 mo (95% CI, 4.8-NE [not estimable]; n=17); and median PFS was 5.3 mo (95% CI, 3.4-10.2). Median time to response was 1.4 mo (95% CI, 1.3-2.7) and median OS was 12.7 mo (95% CI, 10.7-NE). Grade ≥3 treatment-related adverse events (TRAEs) occurred in 61% of pts; most common Grade ≥3 TRAEs were neutropenia (37%; 10% febrile neutropenia), leukopenia (20%), and diarrhea (20%). TRAEs led to a 15% discontinuation rate. Systemic steroid and G-CSF use were both 34%. No treatment-related death occurred. Conclusions: SG plus Pembro demonstrated a high ORR and CBR with a manageable safety profile in 2L mUC in CPI-naive pts who progressed after PT-based therapy. No new safety signals were observed with the combination. These data support further evaluation of SG plus CPI in mUC. Clinical trial information: NCT03547973 .

LBA442 Background: Although most pts with HR NMIBC respond to BCG, pts whose cancer does not respond or who relapse within 12 mo have poor prognosis and require radical cystectomy (RC). The single-arm, multicohort phase 2 KEYNOTE-057 trial (NCT02625961) was designed to investigate the safety and efficacy of pembro monotherapy for pts with BCG-unresponsive HR NMIBC (per FDA) who were ineligible or declined to undergo RC. Results from cohort A (carcinoma in situ [CIS] ± papillary tumors) showed a clinical complete response rate of 41% at 3 mo and led to approval of pembro monotherapy for such pts in the United States. We describe the results from cohort B (papillary tumors without CIS). Methods: Pts were aged ≥18 y with BCG-unresponsive HR NMIBC with papillary tumors only (high-grade Ta or any-grade T1) at baseline and ECOG PS 0-2. Pts received pembro 200 mg every 3 wk (Q3W) for ≤35 cycles (~2 y). Cancer was assessed at 12 wk and Q12W thereafter if no recurrent HR NMIBC or progression was observed; CT urography was done Q24W. Primary end points for cohort B were 12-mo disease-free survival (DFS) rate of HR NMIBC as assessed by central pathology/radiology review and safety, assuming a 12-mo DFS of >20% for HR NMIBC. Secondary efficacy end points were 12-mo DFS rate of any disease; progression-free survival (PFS) to worsening of grade, stage, or death; PFS to muscle invasion, metastasis, or death; and overall survival (OS). Results: Overall, 132 pts received pembro for a median of 9.5 cycles (range, 1.0-35.0). Median age was 72 y (range, 37-87); 57 pts (43.2%) had T1 stage; all pts (100%) had urothelial histology; 104 pts (78.8%) were male; pts received a median of 10 (range, 6-33) prior BCG instillations. Median follow-up was 45.4 mo (range, 14.9-77.1). Efficacy data are shown in Table. Thirty-one pts (23.5%) had RC after stopping pembro. Treatment-related AEs occurred in 97 pts (73.5%); 19 (14.4%) had a grade 3/4 treatment-related AE and 14 pts (10.6%) discontinued due to a treatment-related AE. No deaths from treatment-related AEs occurred. Conclusions: Pembro showed notable antitumor activity in pts with BCG-unresponsive non-CIS papillary HR NMIBC after ~45 mo of follow-up. Toxicity was manageable and consistent with that in cohort A, with no new safety signals. Results suggest pts with non-CIS papillary HR NMIBC unresponsive to BCG who declined or were ineligible to undergo RC may also benefit from pembro monotherapy. Clinical trial information: NCT02625961 . [Table: see text]

520 Background: Pts with PT-ineligible mUC have limited treatment options following CPI therapies; thus, new treatment options are needed. SG is an antibody-drug conjugate composed of an anti-Trop-2 antibody coupled to SN-38, a topoisomerase-I inhibitor, via a proprietary hydrolyzable linker. SG received accelerated FDA approval in April 2021 for pts with mUC who progressed after PT and CPI therapies based on the positive results of the pivotal TROPHY-U-01 Cohort 1 study. In Cohort 1, SG demonstrated an objective response rate (ORR) of 27%, a median overall survival (OS) of 10.9 mo, and a manageable safety profile in 113 pts with locally advanced or mUC (Tagawa, et al. J Clin Oncol. 2021). SG demonstrated an ORR of 28% in PT-ineligible pts with mUC who progressed after CPI therapy in preliminary results of the phase 2 TROPHY-U-01 Cohort 2 study (Petrylak et al. J Clin Oncol. 2020). Here, we report the primary analysis of TROPHY-U-01 Cohort 2. Methods: Cohort 2 pts (≥18 y) were PT-ineligible at screening, had ECOG PS 0-1, and creatinine clearance ≥30 mL/min. Pts received 10 mg/kg of SG on D1 and D8 of 21-day continuous cycles. The primary endpoint was ORR per central review by RECIST 1.1. Secondary endpoints included duration of response (DOR) and progression-free survival (PFS), per central review, and OS. Target enrollment was approximately 40 pts. Assuming the second-line ORR of 40%, 40 pts would give a 95% CI with a lower limit of 25% (CI is 0.25 to 0.57) for ORR. Results: As of July 26, 2022, the median follow-up was 9.3 mo (range, 0.5-30.6) for treated pts (N=38); median age, 72.5 y (range, 41-87), 61% male, 50% ECOG PS 1, and 66% visceral metastases (29% liver). Median number of prior therapies was 2 (range, 1-5); 50% received prior (neo)adjuvant PT, 18% received prior enfortumab vedotin, and 3% received prior erdafitinib. Median time since last prior anticancer therapy was 1.6 mo (range, 1-8) and median duration of last prior anticancer therapy was 4.2 mo (range, 1-12). Per central review, ORR was 32% (95% CI, 17.5-48.7; 32% partial response); median DOR was 5.6 mo (95% CI, 2.8-13.3; n=12); and median PFS was 5.6 mo (95% CI, 4.1-8.3). Median time to response was 1.4 mo (range, 1.3-1.5) and median OS was 13.5 mo (95% CI, 7.6-15.6). Grade ≥3 treatment-related adverse events (TRAEs) occurred in 68% of pts; the most common Grade ≥3 TRAEs were neutropenia (34%), anemia (21%), leukopenia (18%), fatigue (18%), and diarrhea (16%). TRAEs resulted in an 18% discontinuation rate. No treatment-related deaths were reported. Conclusions: SG monotherapy demonstrated a high response rate with an overall manageable safety profile in PT-ineligible pts with mUC who progressed after CPI therapy. No new safety signals were observed. These data support further evaluation of SG in pts with mUC post CPI therapy. Clinical trial information: NCT03547973 .

567 Background: UBC is the 10th most common cancer worldwide, with more than 550,00 new cases annually (WHO, International Agency for Research on Cancer, 2020). Rates vary by regions of the world, explained in part by the fact that different genetic ancestries demonstrate varying germline genetics, environmental exposures, and social risk factors. Methods: 8,728 UBC samples underwent hybrid capture-based comprehensive genomic profiling (CGP) to determine all classes of genomic alterations (GA), microsatellite instability (MSI) status, tumor mutational burden (TMB), and genomic trinucleotide signature. Predominant genetic ancestry was determined using a SNP-based approach using an algorithm trained on the 1000 Genomes data (Connelly et al. AACR 2018). Ancestry was classified as one of the five following categories: African (AFR), European (EUR), Central and South American (AMR), South Asian (SAS), or East Asian (EAS). Results: Of the cohort, 7,447 (85.3%) were EUR, 541 (6.2%) were AFR, 461 (5.3%) were of AMR, 74 (0.85%) were SAS, and 205 (2.3%) were EAS. Age, gender, genomic signature distributions, and MSI status (range 0.9%-1.5%) were similar in all cohorts. The frequency of TMB >10 mutations/Megabase was similar in all cohorts (range 30.7%-39.1%) as was the median TMB (6.3 mutations/Megabase for all). At 67.6%, TP53 was the most frequent GA in SAS cohort. When compared with the non-SAS cohort, TERT GA were lower in the SAS cohort (58.1% vs 72.6%; p=0.06) as were GA in FGFR3 (9.5% vs 18.5%, p=0.25). In the EAS cohort, at 59.0%, GA in TP53 were the most common. TERT mutations were significantly lower in EAS compared to the non-EAS cohort (54.1% vs 72.9%; p

514 Background: EV is FDA-approved in pts with aUC and ≥1 prior therapy line. Data from EV-103 trial indicate robust response to first-line EV/pembrolizumab, suggesting potentially at least additive treatment effect with EV/ICI combination. Given the long half-life of ICIs, pts who start EV treatment immediately after ICI may potentially derive benefit from that therapy sequence. We hypothesized that the last systemic therapy prior to EV would impact outcomes, as pts treated with ICI immediately prior to EV would have superior outcomes relative to pts treated with chemotherapy (chemo). Methods: UNITE is a retrospective study of pts treated with EV at 16 US sites. Pt characteristics and outcomes were abstracted from EMR review at each site. Observed response was determined by investigators for evaluable pts with scans following ≥1 EV dose. Pts treated with EV monotherapy were divided into two groups based on whether they received chemo or ICI as the line of therapy immediately prior to EV, regardless of other therapy received. Chi-squared test was used to assess differences in pt characteristics and ORR while log-rank tests were used for OS and PFS measured from EV start. Results: Among 325 pts treated with EV monotherapy, 247 had chemo or ICI as immediate prior treatment, with 186 pts receiving ICI (Group A) and 61 pts receiving platinum-based chemo (Group B). In 247-pt cohort, ORR to EV was 52% and mPFS and mOS were 6 and 13 mos. Group B pts were younger, had more bone mets and higher Bellmunt risk factors, but were otherwise similar to Group A (Table). Most pts had both prior chemo and ICI in both group A (58%) and group B (84%). Group A pts had shorter time from last treatment (median 1.2 vs 3.2 mo, p

450 Background: EV, an antibody-drug conjugate (ADC) targeting Nectin-4, is used widely in treatment-refractory aUC, but limited data are available on biomarkers predictive of EV outcomes. We investigated potential biomarkers of response to EV in a pt cohort in the UNITE dataset. Methods: We included the retrospective UNITE study pts from 16 sites, with available next generation sequencing using institutional or commercial platforms, treated with EV alone outside clinical trials. Observed response (ORR) was determined by investigators for evaluable pts with scans after ≥1 dose of EV. Assessed molecular biomarkers included tumor mutation burden (TMB), PD-L1 status, somatic alterations (alts) in ≥ 10% of pts ( TERTp, TP53, ARID1A, CDKN2A, CDKN2B, FGFR3, ERBB2, CCND1, KDM6A, MTAP, PIK3CA, RB1, TSC1) and presence of ≥1 DNA damage response mutations ( ATM, BARD1, BRCA1, BRCA2, CDK12, CHEK2, PALB2, PPP2R2A, or RAD51B). ORRs were compared using Chi-squared test, while median progression-free and overall survival (mPFS, mOS) from EV start were compared with log-rank test and Cox proportional hazards in pts with and without biomarker presence. Results: A total of 170 pts had outcomes and NGS data available. Median age was 70, 133 (78%) were men, 144 (85%) Caucasian, 110 (65%) with pure urothelial histology, 118 (69%) with primary bladder tumor, and 116 (68%) had ≥ 2 lines of therapy before EV. For all pts, ORR 47%, mPFS 6 mos, mOS 12 mos. ORRs were higher in pts with ERBB2 (67% vs 44%; p = 0.05) and TSC1 (68% vs 25%; p=0.04) alts vs wild-type. Shorter mPFS was noted in pts with CDKN2A, CDKN2B, and MTAP alts, and longer mOS in pts with high TMB (table). Conclusions: This large, multi-site, retrospective cohort of pts with aUC identified several potential biomarkers associated with differential outcomes to EV. These findings, upon external validation, may help inform clinical decision making and potential therapy sequencing with available ADCs. Limitations include retrospective nature, pt selection, and confounding biases. [Table: see text]

DNA damage response (DDR) gene alterations in cancer are associated with a higher tumor mutational burden (TMB) and may impact clinical outcomes of urothelial cancer (UC). Here, we explore the prognostic role of DDR alterations in advanced UC treated with anti‐PD‐1/PD‐L1 agents. The study included 53 patients who had FoundationOne genomic sequencing and received anti‐PD‐1/PD‐L1 therapy. Fisher exact test and trend test were used to assess differences in objective response rate (ORR). Overall survival (OS) was measured from the time of initial UC diagnosis and Cox proportional hazard regression analysis was performed to calculate hazard ratio (HR) and 95% confidence interval (CI). The cohort had a median age of 66 with 64% receiving platinum‐based chemotherapy. DDR alterations (including ATM) were associated with a non‐significantly higher ORR to PD‐1/PD‐L1 blockade (41% vs. 21%, p = 0.136). Patients with DDR alterations (excluding ATM) had non‐significantly longer OS, likely due to a small sample size (HR = 0.53, 95% CI 0.20–1.38, p = 0.19). ATM alterations were associated with a non‐significantly higher ORR (40% vs. 29%, p = 0.6), but also with significantly shorter OS (HR = 5.7, 95% CI 1.65–19.74, p = 0.006). Patients with ≥ 3 DDR alterations (including ATM) had substantially higher TMB (p = 0.01) and higher ORR (80%) with PD‐1/PD‐L1 blockade versus 24% ORR in patients with, DDR alterations are associated with higher ORR and nonsignificantly prolonged OS in patients with advanced UC receiving PD‐1/PD‐L1 inhibitors. However, presence of ATM alterations correlated with shorter OS, irrespective of a nonsignificant trend towards higher ORR to anti‐PD‐1/PD‐L1 agents.

The mammalian target of rapamycin (mTOR) pathway regulates important cellular functions. Aberrant activation of this pathway, either through upstream activation by growth factors, loss of inhibitory controls, or molecular alterations, can enhance cancer growth and progression. Bladder cancer shows high levels of mTOR activity in approximately 70% of urothelial carcinomas, suggesting a key role for this pathway in this cancer. mTOR signaling initiates through upstream activation of phosphatidylinositol 3 kinase (PI3K) and protein kinase B (AKT) and results in activation of either mTOR complex 1 (mTORC1) or mTOR complex 2 (mTORC2). While these complexes share several key protein components, unique differences in their complex composition dramatically alter the function and downstream cellular targets of mTOR activity. While significant work has gone into analysis of molecular alterations of the mTOR pathway in bladder cancer, this has not yielded significant benefit in mTOR-targeted therapy approaches in urothelial carcinoma to date. New discoveries regarding signaling convergence onto mTOR complexes in bladder cancer could yield unique insights the biology and targeting of this aggressive disease. In this review, we highlight the functional significance of mTOR signaling in urothelial carcinoma and its potential impact on future therapy implications.

PURPOSE It has been estimated that 5% to 10% of cancers are due to hereditary causes. Recent data sets indicate that the incidence of hereditary cancer may be as high as 17.5% in patients with cancer, and a notable subset is missed if screening is solely by family history and current syndrome-based testing guidelines. Identification of germline variants has implications for both patients and their families. There is currently no comprehensive overview of cancer susceptibility genes or inclusion of these genes in commercially available somatic testing. We aimed to summarize genes linked to hereditary cancer and the somatic and germline panels that include such genes. METHODS Germline predisposition genes were chosen if commercially available for testing. Penetrance was defined as low, moderate, or high according to whether the gene conferred a 0% to 20%, 20% to 50%, or 50% to 100% lifetime risk of developing the cancer or, when percentages were not available, was estimated on the basis of existing literature descriptions. RESULTS We identified a total of 89 genes linked to hereditary cancer predisposition, and we summarized these genes alphabetically and by organ system. We considered four germline and six somatic commercially available panel tests and quantified the coverage of germline genes across them. Comparison between the number of genes that had germline importance and the number of genes included in somatic testing showed that many but not all germline genes are tested by frequently used somatic panels. CONCLUSION The inclusion of cancer-predisposing genes in somatic variant testing panels makes incidental germline findings likely. Although somatic testing can be used to screen for germline variants, this strategy is inadequate for comprehensive screening. Access to genetic counseling is essential for interpretation of germline implications of somatic testing and implementation of appropriate screening and follow-up.

Purpose: In an exploratory analysis, we investigated the association between programmed death ligand 1 (PD-L1), tumor mutational burden (TMB), T-cell–inflamed gene expression profile (TcellinfGEP), and stromal signature with outcomes of pembrolizumab in urothelial carcinoma (UC). Patients and Methods: Patients with advanced UC received first-line pembrolizumab 200 mg every 3 weeks in the single-arm phase II KEYNOTE-052 trial (NCT02335424) and salvage pembrolizumab 200 mg every 3 weeks or chemotherapy (paclitaxel/docetaxel/vinflunine) in the randomized phase III KEYNOTE-045 trial (NCT02256436). The association of each biomarker (continuous variable) with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic regression (ORR) and Cox PH (PFS, OS), adjusted for ECOG PS; nominal P values were calculated without multiplicity adjustment (one-sided, pembrolizumab; two-sided, chemotherapy). Significance was prespecified at α = 0.05. Results: In KEYNOTE-052, PD-L1, TMB, and TcellinfGEP were significantly associated with improved outcomes; stromal signature was significantly associated with worse outcomes. In KEYNOTE-045, although findings for TMB and TcellinfGEP with pembrolizumab were consistent with those of KEYNOTE-052, PD-L1 was not significantly associated with improved outcomes, nor was stromal signature associated with worse outcomes with pembrolizumab; chemotherapy was not associated with outcomes in a consistent manner for any of the biomarkers. Hazard ratio (HR) estimates at prespecified cutoffs showed an advantage for pembrolizumab versus chemotherapy regardless of PD-L1 or TMB, with a trend toward lower HRs in the combined positive score ≥10 and the TMB ≥175 mutation/exome subgroup. For TcellinfGEP, PFS and OS HRs were lower in the TcellinfGEP-nonlow subgroup regardless of treatment. Conclusions: Multiple biomarkers characterizing the tumor microenvironment may help predict response to pembrolizumab monotherapy in UC, and potential clinical utility of these biomarkers may be context-dependent.

PURPOSE The phase II single-arm KEYNOTE-052 study evaluated the efficacy and safety of first-line pembrolizumab for patients with locally advanced or metastatic cisplatin-ineligible urothelial carcinoma (UC). PATIENTS AND METHODS Three hundred seventy patients received pembrolizumab 200 mg intravenously every 3 weeks for up to 24 months. Positive tumor programmed death ligand 1 (PD-L1) expression was defined as combined positive score (CPS) ≥ 10. Response was assessed by independent central review every 9 weeks per RECIST v1.1. The primary end point was objective response rate (ORR). RESULTS At data cutoff (September 26, 2018), the minimum follow-up was 2 years since the last patient enrolled. ORR was 28.6% (95% CI, 24.1% to 33.5%); 33 patients (8.9%) and 73 patients (19.7%) achieved complete and partial response, respectively. The median duration of response was 30.1 months (95% CI, 18.1 months to not reached [NR]); responses lasted ≥ 12 and ≥ 24 months in 67% and 52% of patients, respectively. Forty patients with complete or partial response completed 2 years of study treatment, and 32 had ongoing response at completion. Median overall survival (OS) was 11.3 months (95% CI, 9.7 to 13.1 months), and 12- and 24-month OS rates were 46.9% and 31.2%, respectively. In patients with CPS ≥ 10, ORR was 47.3% (95% CI, 37.7% to 57.0%) and median OS was 18.5 months (95% CI, 12.2 to 28.5 months). In patients with lymph node–only disease, ORR was 49.0% (95% CI, 34.8% to 63.4%), and median OS was 27.0 months (12.4 months to NR). There were no new safety signals. CONCLUSION First-line pembrolizumab confers meaningful and durable clinical response in cisplatin-ineligible patients with advanced UC and is associated with prolonged OS, particularly with PD-L1 CPS ≥ 10 and lymph node–only disease.

LAY SUMMARY Despite longer survival with immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1), metastatic urothelial carcinoma remains lethal. There is an unmet need to further improve the efficacy of these agents. In their phase 2 trial, Zhang et al. evaluated the combination of pembrolizumab (a PD-1 inhibitor) plus acalabrutinib (a novel agent inhibiting an enzyme considered relevant to immunotherapy resistance) based on strong rationale but did not demonstrate clinical benefit compared with pembrolizumab alone. Future trials that examine such promising rational combinations may be able to evaluate selected patients based on validated biomarkers to optimize benefit in an endless pursuit of personalizing therapies.

Urinary tract cancer can be pure urothelial carcinoma, pure nonurothelial carcinoma or variant urothelial carcinoma (defined here as mixed urothelial carcinoma). Little is known regarding outcomes for patients with variant urothelial carcinoma receiving immune checkpoint inhibitors. We hypothesized that variant urothelial carcinoma does not compromise immune checkpoint inhibitor efficacy in patients with advanced urothelial carcinoma.We performed a retrospective cohort study across 18 institutions. Demographic, clinicopathological, treatment and outcomes data were collected for patients with advanced urothelial carcinoma who received immune checkpoint inhibitors. Patients were divided into pure vs variant urothelial carcinoma subgroups, with variant urothelial carcinoma further divided by type of variant (ie squamous, neuroendocrine etc). We compared overall response rate using univariate and multivariate logistic regression and progression-free survival and overall survival using Kaplan-Meier and univariate and multivariate Cox proportional hazards.Overall 519 patients were identified, with 395, 406 and 403 included in overall response rate, overall survival and progression-free survival analyses, respectively. Overall response rate to immune checkpoint inhibitors between patients with pure vs variant urothelial carcinoma was comparable (28% vs 29%, p=0.90) without significant differences for individual subtypes vs pure urothelial carcinoma. Median overall survival for patients with pure urothelial carcinoma was 11.0 months vs 10.1 months for variant urothelial carcinoma (p=0.60), but only 4.6 months for patients with neuroendocrine features (9 patients, HR 2.75, 95% CI 1.40-5.40 vs pure urothelial carcinoma, p=0.003). Median progression-free survival was 4.1 months for pure vs 5.2 months for variant urothelial carcinoma (p=0.43) and 3.7 months for neuroendocrine features (HR 1.87, 95% CI 0.92-3.79 vs pure urothelial carcinoma, p=0.09).Overall response rate to immune checkpoint inhibitors was comparable across histological types. However, overall survival was worse for patients with tumors containing neuroendocrine features. Variant urothelial carcinoma should not exclude patients from receiving immune checkpoint inhibitors.

Our goal was to identify discrete clinical characteristics associated with safe discharge from an emergency department/urgent care for patients with a history of cancer and concurrent COVID-19 infection during the SARS-CoV-2 pandemic and prior to widespread vaccination.We retrospectively analyzed 255 adult patients with a history of cancer who presented to Memorial Sloan Kettering Cancer Center (MSKCC) urgent care center (UCC) from March 1, 2020 to May 31, 2020 with concurrent COVID-19 infection. We evaluated associations between patient characteristics and 30-day mortality from initial emergency department (ED) or urgent care center (UCC) visit and the absence of a severe event within 30 days. External validation was performed on a retrospective data from 29 patients followed at Fred Hutchinson Cancer Research Center that presented to the local emergency department. A late cohort of 108 additional patients at MSKCC from June 1, 2020 to January 31, 2021 was utilized for further validation.In the MSKCC cohort, 30-day mortality and severe event rate was 15% and 32% respectively. Using stepwise regression analysis, elevated BUN and glucose, anemia, and tachypnea were selected as the main predictors of 30-day mortality. Conversely, normal albumin, BUN, calcium, and glucose, neutrophil-lymphocyte ratio3, lack of (severe) hypoxia, lack of bradycardia or tachypnea, and negative imaging were selected as the main predictors of an uneventful course as defined as a Lack Of a Severe Event within Thirty Days (LOSETD). Utilizing this information, we devised a tool to predict 30-day mortality and LOSETD which achieved an area under the operating curve (AUC) of 79% and 74% respectively. Similar estimates of AUC were obtained in an external validation cohort. A late cohort at MSKCC was consistent with the prior, albeit with a lower AUC.We identified easily obtainable variables that predict 30-day mortality and the absence of a severe event for patients with a history of cancer and concurrent COVID-19. This has been translated into a bedside tool that the clinician may utilize to assist disposition of this group of patients from the emergency department or urgent care setting.

Enfortumab vedotin (EV) is a novel antibody-drug conjugate approved for advanced urothelial cancer (aUC) refractory to prior therapy. In the Urothelial Cancer Network to Investigate Therapeutic Experiences (UNITE) study, the authors looked at the experience with EV in patient subsets of interest for which activity had not been well defined in clinical trials.UNITE was a retrospective study of patients with aUC treated with recently approved agents. This initial analysis focused on patients treated with EV. Patient data were abstracted from chart reviews by investigators at each site. The observed response rate (ORR) was investigator-assessed for patients with at least 1 post-baseline scan or clear evidence of clinical progression. ORRs were compared across subsets of interest for patients treated with EV monotherapy.The initial UNITE analysis included 304 patients from 16 institutions; 260 of these patients were treated with EV monotherapy and included in the analyses. In the monotherapy cohort, the ORR was 52%, and it was40% in all reported subsets of interest, including patients with comorbidities previously excluded from clinical trials (baseline renal impairment, diabetes, and neuropathy) and patients with fibroblast growth factor receptor 3 (FGFR3) alterations. Progression-free survival and overall survival were 6.8 and 14.4 months, respectively. Patients with a pure urothelial histology had a higher ORR than patients with a variant histology component (58% vs 42%; P = .06).In a large retrospective cohort, responses to EV monotherapy were consistent with data previously reported in clinical trials and were also observed in various patient subsets, including patients with variant histology, patients with FGFR3 alterations, and patients previously excluded from clinical trials with an estimated glomerular filtration rate30 mL/min and significant comorbidities.Enfortumab vedotin, approved by the Food and Drug Administration in 2019, is an important new drug for the treatment of patients with advanced bladder cancer. This study looks at the effectiveness of enfortumab vedotin as it has been used at multiple centers since approval, and focuses on important patient populations previously excluded from clinical trials. These populations include patients with decreased kidney function, diabetes, and important mutations. Enfortumab vedotin is effective for treating these patients. Previously reported clinical trial data have been replicated in this real-world setting, and support the use of this drug in broader patient populations.

Purpose: To explore relationships between biological gene expression signatures and pembrolizumab response. Experimental Design: RNA-sequencing data on baseline tumor tissue from 1,188 patients across seven tumor types treated with pembrolizumab monotherapy in nine clinical trials were used. A total of 11 prespecified gene expression signatures [18-gene T-cell–inflamed gene expression profile (TcellinfGEP), angiogenesis, hypoxia, glycolysis, proliferation, MYC, RAS, granulocytic myeloid-derived suppressor cell (gMDSC), monocytic myeloid-derived suppressor cell (mMDSC), stroma/epithelial-to-mesenchymal transition (EMT)/TGFβ, and WNT] were evaluated for their relationship to objective response rate (per RECIST, version 1.1). Logistic regression analysis of response for consensus signatures was adjusted for tumor type, Eastern Cooperative Oncology Group performance status, and TcellinfGEP, an approach equivalent to evaluating the association between response and the residuals of consensus signatures after detrending them for their relationship with the TcellinfGEP (previously identified as a determinant of pembrolizumab response) and tumor type. Testing of the 10 prespecified non-TcellinfGEP consensus signatures for negative association [except proliferation (hypothesized positive association)] with response was adjusted for multiplicity. Results: Covariance patterns of the 11 signatures (including TcellinfGEP) identified in Merck–Moffitt and The Cancer Genome Atlas datasets showed highly concordant coexpression patterns in the RNA-sequencing data from pembrolizumab trials. TcellinfGEP was positively associated with response; signatures for angiogenesis, mMDSC, and stroma/EMT/TGFβ were negatively associated with response to pembrolizumab monotherapy. Conclusions: These findings suggest that features beyond IFNγ-related T-cell inflammation may be relevant to anti–programmed death 1 monotherapy response and may define other axes of tumor biology as candidates for pembrolizumab combinations. See related commentary by Cho et al., p. 1479

Background This study assessed the contrasting genomic profiles from the primary tumors (PTs), metastatic (MET) sites, and circulating tumor DNA (ctDNA) of patients with prostate cancer (PC). Methods A total of 1294 PC tissue specimens and 2462 ctDNA specimens underwent hybrid capture-based comprehensive genomic profiling (CGP). Specimens included tissue from PTs; MET biopsies from bone, liver (LIV), lung (LU), brain (BN), lymph node, and soft tissue sites; and ctDNA. Results Differences in alteration frequencies between PT, MET, and ctDNA specimens for selected genes were observed. TMPRSS2:ERG fusion frequencies were similar between PTs and MET sites (35% vs 33%) but varied among MET sites. Genomic alterations (GAs) in AR were lowest in PTs (2%) and highest in MET sites (from 24% in LU to 50% in LIV). BN had the highest genomic alterations/tumor (8) and enrichment for PTEN GAs. The BRCA2 GA frequency varied from 0% in BN to 15% in LIV. ERBB2 amplification was increased in MET sites in comparison with PTs. RB1 GAs were increased in LIV. Biomarkers potentially associated with an anti-PD(L)1 response included CDK12 GAs (16% in LU) and a microsatellite instability-high status (29% in BN). Analyses of ctDNA featured a broad spectrum of GAs similar to those detected across MET sites. Conclusions CGP of PTs, MET sites, and ctDNA in PC exhibited differences most likely associated with tumor progression, clonal evolution, and exposure to systemic therapies; ctDNA can also capture a broad range of potential therapeutic opportunities for patients with PC.

A number of immunotherapies have been developed and adopted for the treatment of urothelial cancer (encompassing cancers arising from the bladder, urethra, or renal pelvis). For these immunotherapies to positively impact patient outcomes, optimal selection of agents and treatment scheduling, especially in conjunction with existing treatment paradigms, is paramount. Immunotherapies also warrant specific and unique considerations regarding patient management, emphasizing both the prompt identification and treatment of potential toxicities. In order to address these issues, the Society for Immunotherapy of Cancer (SITC) convened a panel of experts in the field of immunotherapy for urothelial cancer. The expert panel developed this clinical practice guideline (CPG) to inform healthcare professionals on important aspects of immunotherapeutic treatment for urothelial cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence- and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with urothelial cancer.

Background: Patients with sarcoma often require individualized treatment strategies and are likely to receive aggressive immunosuppressive therapies, which may place them at higher risk for severe COVID-19. We aimed to describe demographics, risk factors, and outcomes for patients with sarcoma and COVID-19. Methods: We performed a retrospective cohort study of patients with sarcoma and COVID-19 reported to the COVID-19 and Cancer Consortium (CCC19) registry (NCT04354701) from 17 March 2020 to 30 September 2021. Demographics, sarcoma histologic type, treatments, and COVID-19 outcomes were analyzed. Results: of 281 patients, 49% (n = 139) were hospitalized, 33% (n = 93) received supplemental oxygen, 11% (n = 31) were admitted to the ICU, and 6% (n = 16) received mechanical ventilation. A total of 23 (8%) died within 30 days of COVID-19 diagnosis and 44 (16%) died overall at the time of analysis. When evaluated by sarcoma subtype, patients with bone sarcoma and COVID-19 had a higher mortality rate than patients from a matched SEER cohort (13.5% vs 4.4%). Older age, poor performance status, recent systemic anti-cancer therapy, and lung metastases all contributed to higher COVID-19 severity. Conclusions: Patients with sarcoma have high rates of severe COVID-19 and those with bone sarcoma may have the greatest risk of death.

BackgroundATLAS evaluated the efficacy and safety of the PARP inhibitor rucaparib in patients with previously treated locally advanced/unresectable or metastatic urothelial carcinoma (UC).MethodsPatients with UC were enrolled independent of tumor homologous recombination deficiency (HRD) status and received rucaparib 600 mg BID. The primary endpoint was investigator-assessed objective response rate (RECIST v1.1) in the intent-to-treat and HRD-positive (loss of genome-wide heterozygosity ≥10%) populations. Key secondary endpoints were progression-free survival (PFS) and safety. Disease control rate (DCR) was defined post-hoc as the proportion of patients with a confirmed complete or partial response (PR), or stable disease lasting ≥16 weeks.ResultsOf 97 enrolled patients, 20 (20.6%) were HRD-positive, 30 (30.9%) HRD-negative, and 47 (48.5%) HRD-indeterminate. Among 95 evaluable patients, there were no confirmed responses. However, reductions in the sum of target lesions were observed, including 6 (6.3%) patients with unconfirmed PR. DCR was 11.6%; median PFS was 1.8 months (95% CI, 1.6–1.9). No relationship was observed between HRD status and efficacy endpoints. Median treatment duration was 1.8 months (range, 0.1–10.1). Most frequent any-grade treatment-emergent adverse events were asthenia/fatigue (57.7%), nausea (42.3%), and anemia (36.1%). Of 64 patients with data from tumor tissue samples, 10 (15.6%) had a deleterious alteration in a DNA damage repair pathway gene, including four with a deleteriousBRCA1orBRCA2alteration.ConclusionsRucaparib did not show significant activity in unselected patients with advanced UC regardless of HRD status. The safety profile was consistent with that observed in patients with ovarian or prostate cancer.Trial registrationThis trial was registered inClinicalTrials.gov(NCT03397394). Date of registration: 12 January 2018. This trial was registered in EudraCT (2017–004166-10).

PURPOSE Patients with metastatic urothelial carcinoma (mUC) who progress on platinum-based combination chemotherapy (PLT) and checkpoint inhibitors (CPIs) have limited options that offer objective response rates (ORRs) of approximately 10% with a median overall survival (OS) of 7-8 months. Sacituzumab govitecan (SG) is a TROP-2–directed antibody-drug conjugate with an SN-38 payload that has shown preliminary activity in mUC. METHODS TROPHY-U-01 (ClinicalTrials.gov identifier: NCT03547973 ) is a multicohort, open-label, phase II, registrational study. Cohort 1 includes patients with locally advanced or unresectable or mUC who had progressed after prior PLT and CPI. Patients received SG 10 mg/kg on days 1 and 8 of 21-day cycles. The primary outcome was centrally reviewed ORR; secondary outcomes were progression-free survival, OS, duration of response, and safety. RESULTS Cohort 1 included 113 patients (78% men; median age, 66 years; 66.4% visceral metastases; median of three [range, 1-8] prior therapies). At a median follow-up of 9.1 months, the ORR was 27% (31 of 113; 95% CI, 19.5 to 36.6); 77% had decrease in measurable disease. Median duration of response was 7.2 months (95% CI, 4.7 to 8.6 months), with median progression-free survival and OS of 5.4 months (95% CI, 3.5 to 7.2 months) and 10.9 months (95% CI, 9.0 to 13.8 months), respectively. Key grade ≥ 3 treatment-related adverse events included neutropenia (35%), leukopenia (18%), anemia (14%), diarrhea (10%), and febrile neutropenia (10%), with 6% discontinuing treatment because of treatment-related adverse events. CONCLUSION SG is an active drug with a manageable safety profile with most common toxicities of neutropenia and diarrhea. SG has notable efficacy compared with historical controls in pretreated mUC that has progressed on both prior PLT regimens and CPI. The results from this study supported accelerated approval of SG in this population.

First-line chemotherapy for many solid tumors is limited by toxicity. There is a growing interest in maintenance therapy as a strategy for prolonging the benefits of first-line therapy while minimizing toxicity. Maintenance therapy can comprise either continuation of an agent given as part of the first-line regimen (continuation maintenance) or treatment with a new agent (switch maintenance). Maintenance therapy is already established in several solid tumors, including lung, breast, gastric, colorectal, and ovarian cancer. Immune checkpoint inhibitor treatment has been shown to prolong duration of response and overall survival, but efficacy is generally restricted to a limited proportion of patients with selected tumors. Thus, efforts are ongoing to determine whether the clinical benefits of immune checkpoint inhibitors can be extended using novel treatment schedules and settings, including maintenance therapy. Early- and late-phase clinical trials have investigated the efficacy and safety of immune checkpoint inhibitors as switch and continuation maintenance in different tumors, and a range of phase III trials are ongoing. Interpretation of results requires consideration of trial designs, eligibility criteria, and primary endpoints, in addition to biomarker exploration, and assessment of quality of life and cost effectiveness. Findings from ongoing trials will help further define the role of immune checkpoint inhibitors as maintenance therapy across a spectrum of solid tumors.