A phase II, randomized study of nivolumab (nivo) or nivo plus BMS-986205 with or without intravesical Bacillus Calmette-Guerin (BCG) in BCG-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC): CheckMate 9UT

TPS493

Background: Immune checkpoint inhibitors, including nivo (anti–PD-1), have demonstrated favorable tolerability and efficacy profiles, ushering in a new treatment (tx) paradigm for advanced bladder cancer (advBC). However, an unmet need exists for new effective tx options in earlier stages of disease, specifically for patients (pts) with BCG-unresponsive, high-risk NMIBC. Increased IDO and PD-L1 expression in NMIBC tumors (Inman, et al. Cancer 2007; Hudolin, et al. Anticancer Res 2017), support the combination of anti–PD-1 and IDO1 inhibition in NMIBC. BMS-986205, a selective, potent, once-daily IDO1 inhibitor that works early in the IDO1 pathway, has demonstrated clinical activity in combination with nivo in pts with immunotherapy-naive advBC who received ≥ 1 prior line of therapy (objective response rate, 37%; Tabernero, et al. J Clin Oncol 2018;36(suppl) [abstr 4512]). These findings provide a rationale for investigation of nivo + BMS-986205 ± intravesical BCG therapy in BCG-unresponsive high-risk NMIBC. Here we describe a phase 2, randomized, open-label study assessing the safety and efficacy of nivo ± BMS-986205 ± intravesical BCG in pts with BCG-unresponsive, high-risk NMIBC. Methods: Pts aged ≥ 18 years with BCG-unresponsive (per February 2018 FDA guidance), high-risk NMIBC, defined as carcinoma-in-situ (CIS) with or without papillary component, any T1, or Ta high-grade lesions, will be enrolled. Pts must have urothelial carcinoma as the predominant histological component (>50%). Key exclusion criteria include locally advanced or metastatic BC, upper urinary tract disease within 2 years, prostatic urethral disease within 1 year, and prior immunotherapy. Using a novel adaptive-type design, pts will be randomized to 1 of 4 tx arms with nivo ± BMS-986205 ± BCG. Primary endpoints include proportion of pts with CIS with complete response (CR), duration of CR in pts with CIS, and event-free survival for all pts without CIS. Secondary endpoints are progression-free survival and safety. This global study in 13 countries is underway, with a target enrollment of 436 pts. ( Clinical trial information: NCT03519256.

Combined Next-generation Sequencing and Flow Cytometry Analysis for an Anti-PD-L1 Partial Responder over Time: An Exploration of Mechanisms of PD-L1 Activity and Resistance in Bladder Cancer

Anti-PD-L1/PD-1 immunotherapy has improved survival for certain patients with metastatic urothelial carcinoma. However, the mechanisms of resistance to these agents have not been fully elucidated. We report the first combined analysis using RNA sequencing, whole-exome sequencing (WES), and flow cytometry of multiple tumor specimens over a 5-yr period for a patient undergoing anti-PD-L1 therapy. Initial sensitivity to anti-PD-L1 immunotherapy was associated with conversion to a basal molecular subtype and a rising tumor mutational burden. We found that as the tumor became more resistant to anti-PD-L1, the proportion of regulatory T cells and CD8⁺ T cells expressing alternative immune checkpoints including CTLA-4, TIM-3, and LAG-3 increased. This suggests that alternative immune checkpoint upregulation may be one form of anti-PD-L1 resistance in urothelial carcinoma. These data support the concept of combined immune checkpoint blockade for urothelial carcinoma, a concept that is being evaluated in prospective clinical trials. PATIENT SUMMARY: In this study we characterized how a patient with metastatic urothelial cancer became resistant to anti-PD-L1 immunotherapy. By tracking changes in protein and gene expression over time, we found that as urothelial carcinoma becomes resistant to PD-L1 blockade, additional immune checkpoints may be upregulated. These data support the concept of combined checkpoint blockade for urothelial carcinoma.

Mocetinostat for patients with previously treated, locally advanced/metastatic urothelial carcinoma and inactivating alterations of acetyltransferase genes

Background

The authors evaluated mocetinostat (a class I/IV histone deacetylase inhibitor) in patients with urothelial carcinoma harboring inactivating mutations or deletions in CREB binding protein [CREBBP] and/or E1A binding protein p300 [EP300] histone acetyltransferase genes in a single‐arm, open‐label phase 2 study.

Methods

Eligible patients with platinum‐treated, advanced/metastatic disease received oral mocetinostat (at a dose of 70 mg 3 times per week [TIW] escalating to 90 mg TIW) in 28‐day cycles in a 3‐stage study (ClinicalTrials.gov identifier NCT02236195). The primary endpoint was the objective response rate.

Results

Genomic testing was feasible in 155 of 175 patients (89%). Qualifying tumor mutations were CREBBP (15%), EP300 (8%), and both CREBBP and EP300 (1%). A total of 17 patients were enrolled into stage 1 (the intent‐to‐treat population); no patients were enrolled in subsequent stages. One partial response was observed (11% [1 of 9 patients; the population that was evaluable for efficacy comprised 9 of the 15 planned patients]); activity was deemed insufficient to progress to stage 2 (null hypothesis: objective response rate of ≤15%). All patients experienced ≥1 adverse event, most commonly nausea (13 of 17 patients; 77%) and fatigue (12 of 17 patients; 71%). The median duration of treatment was 46 days; treatment interruptions (14 of 17 patients; 82%) and dose reductions (5 of 17 patients; 29%) were common. Mocetinostat exposure was lower than anticipated (dose‐normalized maximum serum concentration [C_max] after TIW dosing of 0.2 ng/mL/mg).

Conclusions

To the authors’ knowledge, the current study represents the first clinical trial using genomic‐based selection to identify patients with urothelial cancer who are likely to benefit from selective histone deacetylase inhibition. Mocetinostat was associated with significant toxicities that impacted drug exposure and may have contributed to modest clinical activity in these pretreated patients. The efficacy observed was considered insufficient to warrant further investigation of mocetinostat as a single agent in this setting.

After the genomic‐based selection of patients with urothelial cancer with inactivating mutations/deletions in the histone acetyltransferase genes CREBBP and/or EP300, single‐agent mocetinostat appears to be associated with significant toxicities that limit drug exposure. This may have contributed to the limited activity noted in the current phase 2 study (response rate of 11%) among heavily pretreated patients with platinum‐refractory disease.

CD24 regulates cancer stem cell (CSC)-like traits and a panel of CSC-related molecules serves as a non-invasive urinary biomarker for the detection of bladder cancer

BACKGROUND

CD24 is a cornerstone of tumour progression in urothelial carcinoma of the bladder (UCB). However, its contribution to cancer stem cell (CSC)-like traits and the clinical utility of CD24 as a urinary biomarker for cancer detection have not been determined.

METHODS

The functional relevance of CD24 was evaluated using in vitro and in vivo approaches. The clinical utility of CSC-related molecules was assessed in urine samples by quantitative RT-PCR.

RESULTS

The knockdown of CD24 attenuated cancer stemness properties. The high-CD24-expressing cells, isolated from patient-derived UCB xenograft tumours, exhibited their enhanced stemness properties. CD24 was overexpressed not only in primary tumours but also in urine from UCB subjects. By assessment of 15 candidate CSC-related molecules in urine samples of a training cohort, a panel of three molecules (CD24, CD49f, and NANOG) was selected. The combination of these three molecules yielded a sensitivity and specificity of 81.7% and 74.3%, respectively, in an independent cohort. A combined set of 84 cases and 207 controls provided a sensitivity and specificity of 82% and 76%, respectively.

CONCLUSION

CD24 has a crucial role in maintaining the urothelial cancer stem-like traits and a panel of CSC-related molecules has potential as a urinary biomarker for non-invasive UCB detection.

SIU-ICUD recommendations on bladder cancer: systemic therapy for metastatic bladder cancer

The SIU (Société Internationale d'Urologie)-ICUD (International Consultation on Urologic Diseases) working group on systemic therapy for metastatic bladder cancer has summarized the most recent findings on the aforementioned topic and came to conclusions and recommendations according to the evidence published. In Europe and the United States, treatment for metastatic UC has changed a great deal recently, mainly involving a move from chemotherapy to immune checkpoint blockers. This is particularly true in platinum-refractory disease, where supportive randomized data exist. Five checkpoint blockers have been approved in this setting by the FDA: avelumab, atezolizumab, durvalumab, nivolumab, and pembrolizumab. Nivolumab, pembrolizumab, and atezolizumab have been approved in Europe.

Naturally-occurring canine invasive urothelial carcinoma harbors luminal and basal transcriptional subtypes found in human muscle invasive bladder cancer

There is growing evidence that molecular subtypes (e.g. luminal and basal subtypes) affect the prognosis and treatment response in patients with muscle invasive urinary bladder cancer (invasive urothelial carcinoma, iUC). Modeling these subtypes in pre-clinical animal studies is essential, but it is challenging to produce these subtypes, along with other critical host and tumor features, in experimentally-induced animal models. This study was conducted to determine if luminal and basal molecular subtypes are present in naturally-occurring canine iUC, a cancer that mimics the human condition in other key aspects. RNA sequencing was performed on 29 canine treatment naive iUC tissue samples and on four normal canine bladder mucosal samples. Data were aligned to CanFam 3.1, and differentially expressed genes were identified. Unsupervised hierarchical clustering of these genes revealed two distinct groups (n = 13, n = 16). When genes that distinguish basal and luminal subtypes in human cancer (n = 2015) were used to probe genes differentially expressed between normal canine bladder and iUC, 829 enriched signature genes were identified. Unsupervised hierarchical clustering of these genes revealed two distinct groups comprised of 18 luminal subtype tumors and 11 basal subtype tumors. The enriched genes included MMP9, SERPINE2, CAV1, KRT14, and RASA3 in basal tumors, and PPARG, LY6E, CTSE, CDK3, and TBX2 in luminal tumors. In supervised clustering, additional genes of importance in human iUC were identified in canine iUC associated with claudin-low and infiltrated tumors. A smaller panel of genes (n = 60) was identified that distinguished canine luminal and basal iUC with overall 93.1% accuracy. Immune signature patterns similar to those in human iUC were also identified with the greatest enrichment of immune genes being in the basal subtype tumors. These findings provide additional compelling evidence that naturally-occurring canine iUC is a highly relevant and much needed model of human iUC for translational research.

Commentary on "Prognostic effect of carcinoma in situ in muscle-invasive urothelial carcinoma patients receiving neoadjuvant chemotherapy."

BACKGROUND

Carcinoma in situ (CIS) is a poor prognostic finding in urothelial carcinoma. However, its significance in muscle-invasive urothelial carcinoma (MIUC) treated with neoadjuvant chemotherapy (NAC) is uncertain. We assessed the effect of CIS found in pretreatment transurethral resection of bladder tumor (TURBT) biopsies on the pathologic and clinical outcomes.

MATERIALS AND METHODS

Subjects with MIUC treated with NAC before cystectomy were identified. The pathologic complete response (pCR) rates stratified by TURBT CIS status were compared. The secondary analyses included tumor response, progression-free survival (PFS), overall survival (OS), and an exploratory post hoc analysis of patients with pathologic CIS only (pTisN0) at cystectomy.

RESULTS

A total of 137 patients with MIUC were identified. TURBT CIS was noted in 30.7% of the patients. The absence of TURBT CIS was associated with a significantly increased pCR rate (23.2% vs. 9.5%; odds ratio = 4.08; 95% CI: 1.19-13.98; P = 0.025). Stage pTisN0 disease was observed in 19.0% of the TURBT CIS patients. TURBT CIS status did not significantly affect the PFS or OS outcomes. Post hoc analysis of the pTisN0 patients revealed prolonged median PFS (104.5 vs. 139.9 months; P = 0.055) and OS (104.5 vs. 152.3 months; P = 0.091) outcomes similar to those for the pCR patients.

CONCLUSION

The absence of CIS on pretreatment TURBT in patients with MIUC undergoing NAC was associated with increased pCR rates, with no observed differences in PFS or OS. Isolated CIS at cystectomy was frequently observed, with lengthy PFS and OS durations similar to those for pCR patients. Further studies aimed at understanding the biology and clinical effect of CIS in MIUC are warranted.

Contemporary Patterns of Multidisciplinary Care in Patients With Muscle-invasive Bladder Cancer

BACKGROUND

Multidisciplinary clinics integrate the expertise of several specialties to provide effective treatment to patients. This exposure is especially relevant in the management of muscle-invasive bladder cancer (MIBC), which requires critical input from urology, radiation oncology, and medical oncology, among other supportive specialties.

MATERIALS AND METHODS

In the present study, we sought to catalog the different styles of multidisciplinary care models used in the management of MIBC and to identify barriers to their implementation. We surveyed providers from academic and community practices regarding their currently implemented multidisciplinary care models, available resources, and perceived barriers using the Bladder Cancer Advocacy Network and the Genitourinary Medical Oncologists of Canada e-mail databases.

RESULTS

Of the 101 responding providers, most practiced at academic institutions in the United States (61%) or Canada (29%), and only 7% were from community practices. The most frequently used model was sequential visits on different days (57%), followed by sequential same-day (39%) and concurrent (1 visit with all providers; 22%) models. However, most practitioners preferred a multidisciplinary clinic involving sequential same-day (41%) or concurrent (26%) visits. The lack of clinic space (58%), funding (41%), staff (40%), and time (32%) were the most common barriers to implementing a multidisciplinary clinic.

CONCLUSION

Most surveyed practitioners at academic centers use some form of a multidisciplinary care model for patients with MIBC. The major barriers to more integrated multidisciplinary clinics were limited time and resources rather than a lack of provider enthusiasm. Future studies should incorporate patient preferences, further evaluate practice patterns in community settings, and assess their effects on patient outcomes.

Chemohormonal Therapy in Metastatic Hormone-Sensitive Prostate Cancer: Long-Term Survival Analysis of the Randomized Phase III E3805 CHAARTED Trial

Purpose Docetaxel added to androgen-deprivation therapy (ADT) significantly increases the longevity of some patients with metastatic hormone-sensitive prostate cancer. Herein, we present the outcomes of the CHAARTED (Chemohormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer) trial with more mature follow-up and focus on tumor volume. Patients and Methods In this phase III study, 790 patients with metastatic hormone-sensitive prostate cancer were equally randomly assigned to receive either ADT in combination with docetaxel 75 mg/m2 for up to six cycles or ADT alone. The primary end point of the study was overall survival (OS). Additional analyses of the prospectively defined low- and high-volume disease subgroups were performed. High-volume disease was defined as presence of visceral metastases and/or ≥ four bone metastases with at least one outside of the vertebral column and pelvis. Results At a median follow-up of 53.7 months, the median OS was 57.6 months for the chemohormonal therapy arm versus 47.2 months for ADT alone (hazard ratio [HR], 0.72; 95% CI, 0.59 to 0.89; P = .0018). For patients with high-volume disease (n = 513), the median OS was 51.2 months with chemohormonal therapy versus 34.4 months with ADT alone (HR, 0.63; 95% CI, 0.50 to 0.79; P < .001). For those with low-volume disease (n = 277), no OS benefit was observed (HR, 1.04; 95% CI, 0.70 to 1.55; P = .86). Conclusion The clinical benefit from chemohormonal therapy in prolonging OS was confirmed for patients with high-volume disease; however, for patients with low-volume disease, no OS benefit was discerned.

EV-201 study: A single-arm, open-label, multicenter study of enfortumab vedotin for treatment of patients with locally advanced or metastatic urothelial cancer who previously received immune checkpoint inhibitor therapy

TPS542

Background: The majority of patients with locally advanced or metastatic urothelial cancer (la/mUC) will not respond to immune checkpoint inhibitors (CPIs) given in the post-platinum or cisplatin ineligible setting, and there are currently no approved standard therapies after disease progression. Enfortumab vedotin (EV), an antibody-drug conjugate, delivers the microtubule-disrupting agent monomethyl auristatin E to tumors expressing Nectin-4, which is overexpressed in mUC. Preliminary results from an ongoing phase 1 study of EV monotherapy in pts with mUC (Petrylak ASCO 2017) showed that EV was well tolerated in pts with mUC. Nausea (36%), pruritus (31%), and fatigue (30%) were the most commonly reported treatment-related AEs. The most common grade ≥3 AEs (regardless of attribution) were urinary tract infection (11%) and hypophosphatemia (9%). EV showed an objective response rate (ORR) of 41% (29 out of 71 pts) across all dose levels and 53% (16 out of 30 pts) ORR at the recommended phase 2 dose of 1.25 mg/kg. The ORR was not diminished in pts with prior CPI use (44%), prior taxane use (41%) or in pts with liver metastases (47%). These encouraging results along with a favorable safety and tolerability profile warrant further investigation of EV as a monotherapy. Methods: This single-arm, open label, multicenter phase 2 study (NCT03219333) evaluates the antitumor activity and safety of EV monotherapy in ~120 pts with la/mUC. Pts must have previously received a CPI and either have received prior platinum or be ineligible for cisplatin. Pts must have histologically or cytologically documented transitional cell carcinoma of the urothelium that progressed during or following receipt of most recent therapy. The primary objective is to determine antitumor activity of EV as measured by ORR. Secondary objectives include assessment of duration of response, disease control rate, PFS, OS, and safety/tolerability of EV. Pts must have tumor tissue available for exploratory analyses. Response is assessed per RECIST v1.1. Study enrollment began in Sept 2017. Clinical trial information: NCT03219333.

A phase II trial of risk-adapted treatment for muscle invasive bladder cancer after neoadjuvant accelerated MVAC

TPS537

Background: Cisplatin-based neoadjuvant chemotherapy (NAC) followed by cystectomy (Cx) or chemoradiation (CRT) is the standard of care for urothelial carcinoma (UC) pts with muscle invasive bladder cancer (MIBC). Both Cx and CRT carry potential short and long-term toxicity and quality of life implications. Recent work has shown that mutations in DNA damage repair/response genes are predictive of pathologic downstaging after NAC at the time of Cx, with those pts achieving pT0 disease demonstrating excellent long-term survival (Van Allen et al. Cancer Discov. 2014; Plimack et al. Eur Urol. 2015; Liu et al. JAMA Oncol. 2016; Teo et al. CCR. 2017). Sparing pts Cx or CRT after NAC without compromising oncologic outcomes would improve quality of life and decrease morbidity. Methods: A phase II, parallel arm, multi-institutional clinical trial (NCT02710734) is being conducted to evaluate a risk-adapted approach to treatment of MIBC. Pts with cT2-T3N0M0 UC of the bladder, ECOG PS 0-1 and CrCl≥50 mL/min, undergo NAC with accelerated methotrexate, vinblastine, doxorubicin, and cisplatin. Simultaneously, the pre-NAC TURBT specimen is submitted for deep sequencing to identify variants in a panel of cancer-relevant genes (Caris Life Sciences, Phoenix, AZ). Those with an alteration in ATM, RB1, FANCC or ERCC2 and no clinical evidence of disease by restaging TUR and imaging post-NAC will begin a pre-defined active surveillance regimen that includes urinary cytological, cystoscopic, and radiographic evaluations. The remaining pts will undergo bladder-directed therapy at the discretion of the pt and clinician applying either intravesical therapy ( < cT2 post-NAC), CRT or Cx (≤cT2 post-NAC) or Cx (≥cT3 post-NAC). The primary objective is metastasis-free survival (MFS) at 2 years for all enrolled and evaluable pts. The trial has a non-inferiority design with a 14% margin between risk-adapted treatment (MFS = 78%) and standard-of-care (MFS = 64%) with a sample size of 70 pts, 82% power and a type I error of 0.045. Key secondary and translational objectives: assess the rate of UC recurrence in active surveillance pts; validate biomarkers of response to NAC; evaluate urinary biomarkers consistent with persistent UC. Clinical trial information: NCT02710734.

Characterization of Urothelial Cancer Circulating Tumor Cells with a Novel Selection-Free Method

OBJECTIVE

To investigate circulating tumor cells (CTCs) as biomarkers of urothelial carcinoma (UC). To date, the majority of work on this topic has utilized the CellSearch test, which has limited sensitivity due to reliance on positive selection for the cell surface protein epithelial cell adhesion molecule (EpCAM). We used a novel selection-free method to enumerate and characterize CTCs across a range of UC stages.

MATERIALS AND METHODS

Blood samples from 38 patients (9 controls, 8 nonmuscle invasive bladder cancer [NMIBC], 12 muscle-invasive bladder cancer [MIBC], and 9 metastatic UC) were processed with the AccuCyte-CyteFinder system. Slides were stained for the white blood cell markers CD45 and CD66b and the epithelial markers EpCAM and pancytokeratin. CTCs were defined as any cytokeratin postive and white blood cell marker negative cell. Separately, the more restrictive CellSearch definition was applied, with the additional requirement of EpCAM positivity. The Kruskal-Wallis ANOVA test compared CTC counts by stage.

RESULTS

Greater than or equal to 1 CTC was detected in 2 of 8 (25%) patients with NMIBC, 7 of 12 (58%) with MIBC, and 6of 9 (67%) with metastatic disease. No control had CTCs. Comparing CTC counts between groups, the only statistically significant comparison was between controls and patients with metastatic UC (P = .009). With EpCAM positivity as a CTC requirement, no CTCs were detected in any patient with NMIBC, and only 2 (17%) patients with MIBC had CTCs. CTCs tended to be larger in metastatic patients.

CONCLUSION

CTCs were detected at all UC stages and exhibited phenotypic diversity of cell size and EpCAM expression. EpCAM negative CTCs that would be missed with the CellSearch test were detected in patients with NMIBC and patients with MIBC.

Low levels of PSMA expression limit the utility of 18F-DCFPyL PET/CT for imaging urothelial carcinoma

OBJECTIVE

To explore the clinical utility of PSMA-targeted 18F-DCFPyL PET/CT in patients with metastatic urothelial carcinoma.

METHODS

Three patients with metastatic urothelial carcinoma were imaged with 18F-DCFPyL PET/CT. All lesions with perceptible radiotracer uptake above background were considered positive. Maximum standardized uptake values were recorded for each detected lesion and findings on 18F-DCFPyL PET/CT were compared to those on conventional imaging studies. To further explore PSMA as a molecular target of urothelial carcinoma, RNA-sequencing data from The Cancer Genome Atlas were used to compare the relative expression of PSMA among cases of bladder cancer, prostate cancer, and clear cell renal cell carcinoma. Additionally, immunohistochemical staining for PSMA was performed on a biopsy specimen from one of the imaged patients.

RESULTS

18F-DCFPyL PET/CT allowed for the detection of sites of urothelial carcinoma, albeit with low levels of radiotracer uptake. Analysis of RNA-sequencing data revealed that bladder cancer had significantly lower levels of PSMA expression than both prostate cancer and clear cell renal cell carcinoma. Consistent with this observation, immunohistochemical staining of tissue from one of the imaged patients demonstrated a low level of neovascularization and nearly absent PSMA expression.

CONCLUSION

The relatively scant expression of PSMA by urothelial carcinoma likely limits the utility of PSMA-targeted PET imaging of this malignancy. Future research efforts should focus on the development of other molecularly targeted imaging agents for urothelial carcinoma.

Phase 2 Trial of Gemcitabine, Cisplatin, plus Ipilimumab in Patients with Metastatic Urothelial Cancer and Impact of DNA Damage Response Gene Mutations on Outcomes

BACKGROUND

Chemotherapy may exert immunomodulatory effects, thereby combining favorably with the immune checkpoint blockade. The pharmacodynamic effects of such combinations, and potential predictive biomarkers, remain unexplored.

OBJECTIVE

To determine the safety, efficacy, and immunomodulatory effects of gemcitabine and cisplatin (GC) plus ipilimumab and explore the impact of somatic DNA damage response gene alterations on antitumor activity.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter single arm phase 2 study enrolling 36 chemotherapy-naïve patients with metastatic urothelial cancer. Peripheral blood flow cytometry was performed serially on all patients and whole exome sequencing of archival tumor tissue was performed on 28/36 patients.

INTERVENTION

Two cycles of GC followed by four cycles of GC plus ipilimumab.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was 1-yr overall survival (OS). Secondary endpoints included safety, objective response rate, and progression-free survival.

RESULTS AND LIMITATIONS

Grade ≥3 adverse events occurred in 81% of patients, the majority of which were hematologic. The objective response rate was 69% and 1-yr OS was 61% (lower bound 90% confidence interval: 51%). On exploratory analysis, there were no significant changes in the composition and frequency of circulating immune cells after GC alone. However, there was a significant expansion of circulating CD4 cells with the addition of ipilimumab which correlated with improved survival. The response rate was significantly higher in patients with deleterious somatic DNA damage response mutations (sensitivity=47.6%, specificity=100%, positive predictive value=100%, and negative predictive value=38.9%). Limitations are related to the sample size and single-arm design.

CONCLUSIONS

GC+ipilimumab did not achieve the primary endpoint of a lower bound of the 90% confidence interval for 1-yr OS of >60%. However, within the context of a small single-arm trial, the results may inform current approaches combining chemotherapy plus immunotherapy from the standpoint of feasibility, appropriate cytotoxic backbones, and potential predictive biomarkers.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01524991.

PATIENT SUMMARY

Combining chemotherapy and immune checkpoint blockade in patients with metastatic urothelial cancer is feasible. Further studies are needed to refine optimal combinations and evaluate tests that might identify patients most likely to benefit.

YAP1 and COX2 Coordinately Regulate Urothelial Cancer Stem-like Cells

Overcoming acquired drug resistance remains a core challenge in the clinical management of human cancer, including in urothelial carcinoma of the bladder (UCB). Cancer stem-like cells (CSC) have been implicated in the emergence of drug resistance but mechanisms and intervention points are not completely understood. Here, we report that the proinflammatory COX2/PGE2 pathway and the YAP1 growth-regulatory pathway cooperate to recruit the stem cell factor SOX2 in expanding and sustaining the accumulation of urothelial CSCs. Mechanistically, COX2/PGE2 signaling induced promoter methylation of let-7, resulting in its downregulation and subsequent SOX2 upregulation. YAP1 induced SOX2 expression more directly by binding its enhancer region. In UCB clinical specimens, positive correlations in the expression of SOX2, COX2, and YAP1 were observed, with coexpression of COX2 and YAP1 particularly commonly observed. Additional investigations suggested that activation of the COX2/PGE2 and YAP1 pathways also promoted acquired resistance to EGFR inhibitors in basal-type UCB. In a mouse xenograft model of UCB, dual inhibition of COX2 and YAP1 elicited a long-lasting therapeutic response by limiting CSC expansion after chemotherapy and EGFR inhibition. Our findings provide a preclinical rationale to target these pathways concurrently with systemic chemotherapy as a strategy to improve the clinical management of UCB.Significance: These findings offer a preclinical rationale to target the COX2 and YAP1 pathways concurrently with systemic chemotherapy to improve the clinical management of UCB, based on evidence that these two pathways expand cancer stem-like cell populations that mediate resistance to chemotherapy. Cancer Res; 78(1); 168-81. ©2017 AACR.

First-line pembrolizumab in cisplatin-ineligible patients with locally advanced and unresectable or metastatic urothelial cancer (KEYNOTE-052): a multicentre, single-arm, phase 2 study

BACKGROUND

More than half of all patients with advanced urothelial cancer cannot receive standard, first-line cisplatin-based chemotherapy because of renal dysfunction, poor performance status, or other comorbidities. We assessed the activity and safety of first-line pembrolizumab in cisplatin-ineligible patients with locally advanced and unresectable or metastatic urothelial cancer.

METHODS

In this multicentre, single-arm, phase 2 study (KEYNOTE-052), cisplatin-ineligible patients with advanced urothelial cancer who had not been previously treated with systemic chemotherapy were recruited from 91 academic medical centres in 20 countries. Enrolled patients received intravenous pembrolizumab 200 mg every 3 weeks. The primary endpoint was objective response (the proportion of patients who achieved complete or partial response) in all patients and by PD-L1 expression status according to the Response Evaluation Criteria in Solid Tumors, version 1.1, as assessed by independent central review. PD-L1 expression was assessed in tumour and inflammatory cells from tumour biopsies provided at study entry. Activity and safety were analysed in all patients who received at least one dose of pembrolizumab (all-patients-treated population). This study is registered with ClinicalTrials.gov, number NCT02335424, and follow-up is ongoing.

FINDINGS

Between Feb 24, 2015, and Aug 8, 2016, 374 patients were enrolled and 370 patients received at least one dose of pembrolizumab. 89 (24%, 95% CI 20-29) of 370 patients had a centrally assessed objective response, and as of Sept 1, 2016 (data cutoff), 74 (83%) of 89 responses were ongoing. Median follow-up was 5 months (IQR 3·0-8·6). A PD-L1-expression cutoff of 10% was associated with a higher frequency of response to pembrolizumab; 42 (38%, 95% CI 29-48) of 110 patients with a combined positive score of 10% or more had a centrally assessed objective response. The most common grade 3 or 4 treatment-related adverse events were fatigue (eight [2%] of 370 patients), alkaline phosphatase increase (five [1%]), colitis, and muscle weakness (both four [1%]). 36 (10%) of 370 patients had a serious treatment-related adverse event. 17 (5%) of 370 patients died from non-treatment-related adverse events associated with death, and one patient died from treatment-related adverse events (myositis in addition to grade 3 thyroiditis, grade 3 hepatitis, grade 3 pneumonia, and grade 4 myocarditis).

INTERPRETATION

First-line pembrolizumab has antitumour activity and acceptable tolerability in cisplatin-ineligible patients with urothelial cancer, most of whom were elderly, had poor prognostic factors, or had serious comorbidities. In view of this result, pembrolizumab has become a new treatment option for patients who are cisplatin-ineligible or not suitable candidates for chemotherapy. Pembrolizumab in the first-line setting is being further assessed in the phase 3 KEYNOTE-361 trial (ClinicalTrials.gov, NCT02335424).

FUNDING

Merck & Co.

Efficacy and Safety of Durvalumab in Locally Advanced or Metastatic Urothelial Carcinoma: Updated Results From a Phase 1/2 Open-label Study

Importance

The data reported herein were accepted for assessment by the US Food and Drug Administration for Biologics License Application under priority review to establish the clinical benefit of durvalumab as second-line therapy for locally advanced or metastatic urothelial carcinoma (UC), resulting in its recent US approval.

Objective

To report a planned update of the safety and efficacy of durvalumab in patients with locally advanced/metastatic UC.

Design, Setting, and Participants

This is an ongoing phase 1/2 open-label study of 191 adult patients with histologically or cytologically confirmed locally advanced/metastatic UC whose disease had progressed on, were ineligible for, or refused prior chemotherapy from 60 sites in 9 countries as reported herein.

Intervention

Patients were administered durvalumab intravenous infusion, 10 mg/kg every 2 weeks, for up to 12 months or until progression, starting another anticancer therapy, or unacceptable toxic effects.

Main Outcomes and Measures

Primary end points were safety and confirmed objective response rate (ORR) per blinded independent central review (Response Evaluation Criteria In Solid Tumors [RECIST], version 1.1).

Results

A total of 191 patients with UC had received treatment. As of October 24, 2016 (90-day update), the median follow-up was 5.78 months (range, 0.4-25.9 months). The median age of patients was 67.0 years and most were male (136 [71.2%]) and white (123 [71.1%]). All patients had stage 4 disease, and 190 (99.5%) had prior anticancer therapy (182 [95.3%] postplatinum). The ORR was 17.8% (34 of 191; 95% CI, 12.7%-24.0%), including 7 complete responses. Responses were early (median time to response, 1.41 months), durable (median duration of response not reached), and observed regardless of programmed cell death ligand-1 (PD-L1) expression (ORR, 27.6% [n = 27; 95% CI, 19.0%-37.5%] and 5.1% [n = 4; 95% CI, 1.4%-12.5%] in patients with high and low or negative expression of PD-L1, respectively). Median progression-free survival and overall survival were 1.5 months (95% CI, 1.4-1.9 months) and 18.2 months (95% CI, 8.1 months to not estimable), respectively; the 1-year overall survival rate was 55% (95% CI, 44%-65%), as estimated by Kaplan-Meier method. Grade 3/4 treatment-related adverse events (AEs) occurred in 13 patients (6.8%); grade 3/4 immune-mediated AEs occurred in 4 patients (2.1%); and treatment-related AEs led to discontinuation of 3 patients (1.6%), 2 of whom had immune-mediated AEs that led to death (autoimmune hepatitis and pneumonitis).

Conclusions and Relevance

Durvalumab, 10 mg/kg every 2 weeks, demonstrates favorable clinical activity and an encouraging and manageable safety profile in patients with locally advanced/metastatic UC.

Trial Registration

clinicaltrials.gov Identifier: NCT01693562.