PURPOSE: Patients with locally advanced or metastatic urothelial cancer (la/mUC) who are ineligible for cisplatin-based therapy have limited first-line (1L) treatment options and significant need for improved therapies. Enfortumab vedotin (EV) and pembrolizumab (Pembro) individually have shown a survival benefit in urothelial cancer in second-line + la/mUC settings. Here, we present data from the pivotal trial of EV plus Pembro (EV + Pembro) in the 1L setting. PATIENTS AND METHODS: In Cohort K of the EV-103 phase Ib/II study, cisplatin-ineligible patients with previously untreated la/mUC were randomly assigned 1:1 to receive EV as monotherapy or in combination with Pembro. The primary end point was confirmed objective response rate (cORR) per blinded independent central review. Secondary end points included duration of response (DOR) and safety. There were no formal statistical comparisons between treatment arms. RESULTS: The cORR was 64.5% (95% CI, 52.7 to 75.1) and 45.2% (95% CI, 33.5 to 57.3) for patients treated with EV + Pembro (N = 76) and EV monotherapy (N = 73), respectively. The median DOR was not reached for the combination and was 13.2 months for monotherapy; 65.4% and 56.3% of patients who responded to the combination and monotherapy, respectively, maintained a response at 12 months. The most common grade 3 or higher treatment-related adverse events (TRAEs) in patients treated with the combination were maculopapular rash (17.1%), fatigue (9.2%), and neutropenia (9.2%). EV TRAEs of special interest (any grade) in the combination arm included skin reactions (67.1%) and peripheral neuropathy (60.5%). CONCLUSION: EV + Pembro showed a high cORR with durable responses as 1L treatment in cisplatin-ineligible patients with la/mUC. Patients who received EV monotherapy had a response and safety profile consistent with previous studies. Adverse events for EV + Pembro were manageable, with no new safety signals observed.

PURPOSE: Locally advanced/metastatic urothelial cancer (la/mUC) affects patients' quality of life (QOL) and functioning. We describe the impact of first-line (1L) enfortumab vedotin (EV) alone or with pembrolizumab (P) on QOL/functioning/symptoms in patients with la/mUC who were cisplatin-ineligible from EV-103 Cohort K. METHODS: In this phase Ib/II trial, patients were randomly assigned 1:1 to EV + P or EV monotherapy (mono). Exploratory patient-reported outcomes (PROs) were assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire–Core Questionnaire (EORTC QLQ-C30) and Brief Pain Inventory Short Form (BPI-SF) at baseline, once per week for cycles 1-3, and then in every cycle through the end of treatment. Changes in scores from baseline to week 24, reported as least squares mean (standard error), were assessed by mixed models for repeated measures. There were no formal statistical comparisons between treatment arms. RESULTS: Of 149 patients treated, 65 (EV + P) and 63 (EV mono) comprised the PRO analysis set. For EV + P, EORTC QLQ-C30 QOL was maintained through week 24 with improvements in emotional functioning, pain, and insomnia. Clinically meaningful improvements were seen in EORTC QLQ-C30 pain after EV + P at weeks 12 (–14.41 [3.14]) and 24 (–14.99 [3.56]) and BPI-SF worst pain at week 24 (–2.07 [0.37]). For EV mono, EORTC QLQ-C30 QOL remained stable with clinically meaningful improvements in EORTC QLQ-C30 pain (–12.55 [4.27]), insomnia (–14.46 [4.69]), and constipation (–10.09 [4.35]) at week 24. There were small-to-moderate improvements in BPI-SF worst pain at week 24. CONCLUSION: EV + P in patients with la/mUC who were cisplatin-ineligible was associated with preservation or improvement of QOL/functioning/symptoms. Improvement in pain was seen in both PRO instruments and treatment arms. These data complement clinical outcomes of 1L EV + P.

Introduction: Prognosis for patients with lymph node positive or metastatic penile squamous cell carcinoma remains poor. Chemotherapy with paclitaxel, ifosfamide, and cisplatin (TIP regimen) is recommended as a first-line option in this cohort of patients. No standard preferred subsequent-line therapy exists for patients with relapsed or refractory penile carcinoma following TIP chemotherapy. Molecular pathogenesis of penile cancer can be subdivided into human papilloma virus-dependent and human papilloma virus-independent pathways. Recent studies have demonstrated increased expression of programmed death ligand-1 in some penile tumors, commonly those that are human papilloma virus-negative. Given the rarity of penile carcinoma in industrialized countries and lack of effective therapies, checkpoint inhibitors may be an attractive treatment option for this subset of patients. Case report: We report a case of metastatic penile cancer refractory to TIP chemotherapy, with a dramatic treatment response to ipilimumab and nivolumab. Molecular profiling of this tumor showed a high programmed death ligand-1 expression, high tumor mutational burden, high microsatellite instability, and alterations in DNA mismatch repair genes. Discussion: This case highlights another dimension of information that may be gained with molecular genomic profiling of penile tumors, providing insight into the biologic behavior of this neoplasm and assessing for predictive biomarkers of response to immune checkpoint inhibitors.

5544 Background: Pembro + olaparib has shown antitumor activity and acceptable safety in docetaxel-pretreated pts with mCRPC enrolled in cohort A of the phase I/II KEYNOTE-365 study (NCT02861573). Updated results with new biomarker data are reported. Methods: Pts with docetaxel-pretreated mCRPC who progressed within 6 mo of screening received pembro 200 mg IV Q3W + olaparib 400-mg capsule or 300-mg tablet PO BID. Pts might have received 1 other chemotherapy and ≤2 second-generation androgen-receptor targeted therapies. Primary end points: PSA response rate (decrease ≥50% from baseline, confirmed by a second value ≥3 wks later), ORR per RECIST v1.1, and safety. Key secondary end points: DCR, DOR, rPFS, and OS. Biospecimens (eg, blood, tissue) were collected for biomarker analysis (tissue PD-L1 expression, androgen receptor variant 7 [AR-v7] expression in circulating tumor cells [CTCs], and a T-cell–inflamed gene expression profile [GEP]). ctDNA was analyzed by Guardant Health 360 (GH360) and Omni (GH Omni) assays. FFPE tissue was analyzed by FoundationOne CDx (F1CDx) assay. Results: 84 of 87 enrolled pts were treated; 48/84 (57.1%) had measurable disease. Median (range) time from enrollment to data cutoff was 3.6 mo (0.0-29.2) for all pts and 26.7 mo (21.2-29.2) for 41 pts with ≥27 wks’ follow-up. Confirmed PSA response rate was 9% (95% CI, 3.5-16.8) in 82 pts with a baseline PSA assessment. Median time to PSA progression: 3.8 mo (95% CI, 2.9-4.4). In 24 pts with measurable disease and ≥27 wks’ follow-up, ORR was 8.3% (95% CI, 1.0-27.0; 2 PRs) and DCR ≥6 mo was 20.8% (95% CI, 7.1-42.2). Median (range) DOR was NR (12.0+ to 21.4+ mo); 2 pts had DOR ≥12 mo. In all pts, median rPFS was 4.3 mo (95% CI, 3.4-7.7) and median OS was 14.4 mo (95% CI, 8.1-18.5). Grade ≥3 TRAEs occurred in 29 pts (35%); 2 pts died of TRAEs (1 myocardial infarction, 1 unknown). Overall, 26% had PD-L1⁺ tumors (combined positive score ≥1). Of 31 pts with CTC data, 12.9% were AR-v7⁺. No BRCA1/2 mutation was detected by GH360 (n=42). Of 57 pts analyzed by GH Omni, 2 had BRCA2 mutations, 1 had a BRCA1 mutation, 4 had ATM mutations, 1 had a CHEK1 mutation, and 6 had CDK12 mutations. Of 49 pts analyzed by F1CDx, 4 had BRCA mutations; 1 pt had a copy number loss mutation not detected by ctDNA analysis. GEP was not associated with ORR or PSA response. Conclusions: Pembro + olaparib continued to show activity and acceptable safety in pts with docetaxel-pretreated mCRPC. A phase III study of this combination is ongoing (KEYLYNK-010, NCT03834519). Clinical trial information: NCT02861573 .

Introduction: Enfortumab vedotin is an antibody drug conjugate approved for management of pretreated locally advanced or metastatic urothelial carcinoma, which is associated with a rare risk of drug extravasation and soft tissue reactions. Case Report: We report two cases of EV extravasation with subsequent development of bullae and cellulitis. Management and Outcome: They were both treated for cellulitis and had conservative management without surgical intervention and were able to resume treatment with Enfortumab vedotin without subsequent adverse events. Discussion: We propose that EV acts as a vesicant upon extravasation, highlight measures to prevent extravasation events, and encourage appropriate measures when dealing such as attempt of aspiration, removal of catheter, application of compresses, and thorough documentation with photographic evidence.

Radical cystectomy with lymph node dissection and urinary diversion is the gold-standard treatment for non-metastatic muscle-invasive bladder cancer (MIBC). However, in patients who refuse cystectomy, or in whom cystectomy carries a high risk, bladder-preserving therapies remain potential options. Bladder preservation therapies can include maximal debulking transurethral resection of bladder tumor (TURBT), concurrent chemoradiation therapy, followed by cystoscopy to assess response. At this time, maximal TURBT is recommended for patients prior to the initiation of chemoradiation therapy or in patients with residual bladder tumors after the completion of chemoradiation therapy. That being said, TURBT carries significant risks such as bladder perforation, bleeding, and infection, ultimately risking delayed systemic treatment. Hence, understanding its role within trimodal therapy is crucial to avoid undue suffering in patients. Herein, we review the current literature on the impact of debulking TURBT in non-metastatic MIBC.