Trastuzumab, Paclitaxel, Carboplatin, and Gemcitabine in Advanced Human Epidermal Growth Factor Receptor-2/neu–Positive Urothelial Carcinoma: Results of a Multicenter Phase II National Cancer Institute Trial

The genetic landscapes of urological cancers and their clinical implications in the era of high-throughput genome analysis

OBJECTIVE

With the advent of high-throughput genome analysis, we are increasingly able to sequence and hence understand the pathogenic processes underlying individual cancers. Recently, consortiums such as The Cancer Genome Atlas (TCGA) have performed large-scale projects to this end, providing significant amounts of information regarding the genetic landscapes of several cancers.

PATIENTS AND METHODS

We performed a narrative review of studies from the TCGA and other major studies. We aimed to summarise data exploring the clinical implications of specific genetic alterations, both prognostically and therapeutically, in four major urological cancers. These were renal cell carcinoma, muscle-invasive bladder cancer/carcinoma, prostate cancer, and testicular germ cell tumours.

RESULTS

With these four urological cancers, great strides have been made in the molecular characterisation of tumours. In particular, recent studies have focussed on identifying molecular subtypes of tumours with characteristic genetic alterations and differing prognoses. Other prognostic alterations have also recently been identified, including those pertaining to epigenetics and microRNAs. In regard to treatment, numerous options are emerging for patients with these cancers such as including immune checkpoint inhibition, epigenetic-based treatments, and agents targeting MAPK, PI3K, and DNA repair pathways. There are a multitude of trials underway investigating the effects of these novel agents, the results of which are eagerly awaited.

CONCLUSIONS

As medicine chases the era of personalised care, it is becoming increasingly important to provide individualised prognoses for patients. Understanding how specific genetic alterations affects prognosis is key for this. It will also be crucial to provide highly targeted treatments against the specific genetics of a patient's tumour. With work performed by the TCGA and other large consortiums, these aims are gradually being achieved. Our review provides a succinct overview of this exciting field that may underpin personalised medicine in urological oncology.

Emerging biomarkers in urothelial carcinoma: Challenges and opportunities

Advanced urothelial carcinoma (UC) is a very important cause of cancer-related morbidity and mortality with, until recently, only a few available therapeutic options. The treatment landscape has dramatically changed in recent years with the introduction of immune checkpoint inhibitors and the development of novel targeted agents, such as erdafitinib, and antibody-drug conjugates, such as enfortumab vedotin. Cost-effective utilization of this rapidly expanding therapeutic armamentarium can be further optimized via the identification and validation of reliable prognostic and predictive biomarkers that inform prognostication and patient selection. In this review, we aim to summarize examples of recent developments in the rapidly expanding field of emerging biomarkers in UC, outlining challenges and opportunities.

Targeting HER2 with Trastuzumab Deruxtecan: A Dose-Expansion, Phase I Study in Multiple Advanced Solid Tumors

HER2-targeted therapies are approved only for HER2-positive breast and gastric cancers. We assessed the safety/tolerability and activity of the novel HER2-targeted antibody-drug conjugate trastuzumab deruxtecan (T-DXd) in 60 patients with pretreated, HER2-expressing (IHC ≥ 1+), non-breast/non-gastric or HER2-mutant solid tumors from a phase I trial (NCT02564900). Most common (>50%) treatment-emergent adverse events (TEAE) were nausea, decreased appetite, and vomiting. Two drug-related TEAEs were associated with fatal outcomes. The confirmed objective response rate (ORR) was 28.3% (17/60). Median progression-free survival (PFS) was 7.2 [95% confidence interval (CI), 4.8-11.1] months. In HER2-mutant non-small cell lung cancer (NSCLC), ORR was 72.7% (8/11), and median PFS was 11.3 (95% CI, 8.1-14.3) months. Confirmed responses were observed in six tumor types, including HER2-expressing NSCLC, colorectal cancer, salivary gland cancer, biliary tract cancer, endometrial cancer, and HER2-mutant NSCLC and breast cancer. Results suggest T-DXd holds promise for HER2-expressing/mutant solid tumors. SIGNIFICANCE: T-DXd demonstrated promising activity in a heterogeneous patient population with heavily pretreated HER2-expressing or HER2-mutant solid tumors, especially HER2-mutant NSCLC. The safety profile was generally acceptable. Interstitial lung disease can be severe and requires prompt monitoring and intervention. Further research of T-DXd is warranted to address these unmet medical needs.See related commentary by Rolfo and Russo, p. 643.This article is highlighted in the In This Issue feature, p. 627.

Precision oncology in urothelial cancer

Genomics-driven, precision medicine has been adopted in virtually every tumour type and underlies the significant advances in cancer management to date. The paradigm shift from the indiscriminate use of chemotherapeutics, to strategies that harness our mechanistic knowledge of cancer biology has led to profound clinical benefit for patients, and will continue to mould present and future treatment approaches. In the realm of urothelial cancer, the present status of precision medicine includes a rich landscape that encompasses molecularly-matched therapy, predictive biomarkers that could help inform response to chemotherapy and immunotherapy, as well as novel strategies such as antibody drug conjugates that exploit the use of target proteins for enhanced tumour killing. Here, we present an overview on these clinically-impactful discoveries in urothelial cancer, discuss the limitations and challenges in the implementation of precision oncology, and offer our vision for its future.

The Landscape of Long Non-Coding RNA Dysregulation and Clinical Relevance in Muscle Invasive Bladder Urothelial Carcinoma

Bladder cancer is one of the most common cancers in the United States, but few advancements in treatment options have occurred in the past few decades. This study aims to identify the most clinically relevant long non-coding RNAs (lncRNAs) to serve as potential biomarkers and treatment targets for muscle invasive bladder cancer (MIBC). Using RNA-sequencing data from 406 patients in The Cancer Genome Atlas (TCGA) database, we identified differentially expressed lncRNAs in MIBC vs. normal tissues. We then associated lncRNA expression with patient survival, clinical variables, oncogenic signatures, cancer- and immune-associated pathways, and genomic alterations. We identified a panel of 20 key lncRNAs that were most implicated in MIBC prognosis after differential expression analysis and prognostic correlations. Almost all lncRNAs we identified are correlated significantly with oncogenic processes. In conclusion, we discovered previously undescribed lncRNAs strongly implicated in the MIBC disease course that may be leveraged for diagnostic and treatment purposes in the future. Functional analysis of these lncRNAs may also reveal distinct mechanisms of bladder cancer carcinogenesis.

HER2-targeted therapies - a role beyond breast cancer

HER2 is an established therapeutic target in a large subset of women with breast cancer; a variety of agents including trastuzumab, pertuzumab, lapatinib, neratinib and trastuzumab emtansine (T-DM1) have been approved for the treatment of HER2-positive breast cancer. HER2 is also overexpressed in subsets of patients with other solid tumours. Notably, the addition of trastuzumab to first-line chemotherapy has improved the overall survival of patients with HER2-positive gastric cancer, and has become the standard-of-care treatment for this group of patients. However, trials involving pertuzumab, lapatinib and T-DM1 have failed to provide significant improvements in the outcomes of patients with HER2-positive gastric cancer. HER2-targeted therapies are also being tested in patients with other solid tumours harbouring HER2 overexpression, and/or amplifications or other mutations of the gene encoding HER2 (ERBB2), including biliary tract, colorectal, non-small-cell lung and bladder cancers. The experience with gastric cancer suggests that the successes observed in HER2-positive breast cancer might not be replicated in these other tumour types, owing to differences in the level of HER2 overexpression and other aspects of disease biology. In this Review, we describe the current role of HER2-targeted therapies beyond breast cancer and also highlight the potential of novel HER2-targeted agents that are currently in clinical development.

Exosomes containing ErbB2/CRK induce vascular growth in premetastatic niches and promote metastasis of bladder cancer

Locally advanced and metastatic invasive bladder cancer (BC) has a poor prognosis, and no advanced therapies beyond cisplatin‐based combination chemotherapy have been developed. Therefore, it is an urgent issue to elucidate the underlying mechanisms of tumor progression and metastasis of invasive BC for the development of new therapeutic strategies. Here, we clarified a novel role of exosomes containing ErbB2 and CRK in a formation of premetastatic niches and subsequent metastases. CRK adaptors were overexpressed in invasive UM‐UC‐3 BC cells. In an orthotopic xenograft model, metastases to lung, liver, and bone of UM‐UC‐3 cells were completely abolished by CRK elimination. Mass spectrometry analysis identified that ErbB2 was contained in UM‐UC‐3‐derived exosomes in a CRK‐dependent manner; the exosomes significantly increased proliferation and invasion properties of low‐grade 5637 BC cells and HUVECs through FAK and PI3K/AKT signaling pathways. In athymic mice educated with UM‐UC‐3‐derived exosomes, i.v. implanted UM‐UC‐3 cells were trapped with surrounding PKH67‐labeled exosomes in lung and led to development of lung metastasis with disordered vascular proliferation. In contrast, exosomes derived from CRK‐depleted BC cells failed to induce these malignant features. Taken together, we showed that CRK adaptors elevated the expression of ErbB2/3 in BC cells, and these tyrosine kinase/adaptor units were transferred from host BC cells to metastatic recipient cells by exosomes, leading to vascular leakiness and proliferation and contributing to the formation of distant metastasis. Thus, CRK intervention with ErbB2/3 blockade might be a potent therapeutic strategy for patients with ErbB2 overexpressing advanced and metastatic BC.

Targeted therapies in urothelial bladder cancer: a disappointing past preceding a bright future?

Bladder cancer (BC) is the most frequent cancer affecting the urinary tract. With the growing era of targeted therapies around the 2000s, many trials evaluated the efficacy of targeted therapy in advanced BC. However, no approval was given yet to any form of targeted therapy when it comes to BC. The aim of this paper was to report the most pivotal trials that evaluated different families of targeted therapy in the treatment of BC, according to their biomarkers (FGFR3, EGFR, HER2, VEGF and PI3K/AKT/mTOR). The ongoing trials testing targeted therapies in advanced BC were then summarized. Finally, the different immunotherapies approved for this disease and their potential combination with targeted therapy were addressed.

Prevalence and role of HER2 mutations in cancer

HER2 activating mutations act as oncogenic drivers in various cancer types. In the clinic, they can be identified by next generation sequencing (NGS) in either tumor biopsies or circulating cell-free DNA (cfDNA). Preclinical data indicate that HER2 "hot spot" mutations are constitutively active, have transforming capacity in vitro and in vivo and show variable sensitivity to anti-HER2 based therapies. Recent clinical trials also revealed activity of HER2-targeted drugs against a variety of tumors harboring HER2 mutations. Here, we review the prevalence and type of HER2 mutations identified in different human cancers, their biochemical and biological characterization, and their sensitivity to anti HER2-based therapies in both preclinical and clinical settings.

Pertuzumab plus trastuzumab for HER2-amplified metastatic colorectal cancer (MyPathway): an updated report from a multicentre, open-label, phase 2a, multiple basket study

BACKGROUND

Therapies targeting HER2 have improved clinical outcomes in HER2-positive breast and gastric cancers, and are emerging as potential treatments for HER2-positive metastatic colorectal cancer. MyPathway evaluates the activity of targeted therapies in non-indicated tumour types with potentially predictive molecular alterations. We aimed to assess the activity of pertuzumab and trastuzumab in patients with HER2-amplified metastatic colorectal cancer.

METHODS

MyPathway is an ongoing, phase 2a, multiple basket study. Patients in this subset analysis were aged 18 years or older and had treatment-refractory, histologically confirmed HER2-amplified metastatic colorectal cancer with measurable or evaluable disease and an Eastern Cooperative Oncology Group performance status score of 2 or less, enrolled from 25 hospitals or clinics in 16 states of the USA. Patients received pertuzumab (840 mg loading dose, then 420 mg every 3 weeks, intravenously) and trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks, intravenously). The primary endpoint was the proportion of patients who achieved an objective response based on investigator-reported tumour responses. Analyses were done per protocol. This ongoing trial is registered with ClinicalTrials.gov, number NCT02091141.

FINDINGS

Between Oct 20, 2014, and June 22, 2017, 57 patients with HER2-amplified metastatic colorectal cancer were enrolled in the MyPathway study and deemed eligible for inclusionin this cohort analysis. Among these 57 evaluable patients, as of Aug 1, 2017, one (2%) patient had a complete response and 17 (30%) had partial responses; thus overall 18 of 57 patients achieved an objective response (32%, 95% CI 20-45). The most common treatment-emergent adverse events were diarrhoea (19 [33%] of 57 patients), fatigue (18 [32%] patients), and nausea (17 [30%] patients). Grade 3-4 treatment-emergent adverse events were recorded in 21 (37%) of 57 patients, most commonly hypokalaemia and abdominal pain (each three [5%] patients). Serious treatment-emergent adverse events were reported in ten (18%) patients and two (4%) of these adverse events (ie, chills and infusion-related reaction) were considered treatment related. There were no treatment-related deaths.

INTERPRETATION

Dual HER2-targeted therapy with pertuzumab plus trastuzumab is well tolerated and could represent a therapeutic opportunity for patients with heavily pretreated, HER2-amplified metastatic colorectal cancer.

FUNDING

F Hoffmann-La Roche/Genentech.

Targeting Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER2) Expressing Bladder Cancer Using Combination Photoimmunotherapy (PIT)

Bladder cancer (BC) is heterogeneous and expresses various cell surface targets. Photoimmunotherapy (PIT) involves monoclonal antibodies (MAbs) conjugated to a photoabsorber (PA), IR Dye 700Dx, and then activated by near infra-red light (NIR) to specifically target tumors. We have demonstrated that tumors expressing EGFR can be targeted with PIT. However, PIT may be less effective when a tumor lacks "overwhelming" expression of a single target such as EGFR. We present a combinatorial PIT approach for targeting BC expressing EGFR and HER2, using PA- labeled panitumumab (pan) and trastuzumab (tra), respectively. Human BC tissues and cell lines were analyzed for EGFR and HER2 expression. Efficacy of PA-labeled MAbs singly and in combination was analyzed. About 45% of BC tissues stain for both EGFR and HER2. In vitro, the combination of pan IR700 and tra IR700 with NIR was more efficacious than either agent alone. Tumor xenografts treated with combination PIT showed significant tumor growth retardation. Combination PIT is a promising approach for treating BC with low/moderate expression of surface receptors. In addition, given the molecular heterogeneity of bladder cancer, targeting more than one surface receptor may allow for more effective cell death across different bladder tumors.

Prognostic and therapeutic role of HER2 expression in micropapillary carcinoma of the bladder

Micropapillary carcinoma of the bladder (MPBC) is a variant type of infiltrating urothelial carcinoma, which portends a poor biological behavior in terms of disease stage at first diagnosis and clinical outcome; its peculiar morphology raises issues concerning the ability of tumor detection by imaging techniques and proper biopsy procedure, and the appropriate treatment for non-muscle infiltrating and muscle-infiltrating MPBC remains a matter of debate. On the basis of its established prognostic and therapeutic role in breast and gastro-esophageal cancer in the first instance, the human epidermal growth factor receptor-2 (HER2) has been investigated in selected case series of MPBC over the last 10 years. The aim of the present review was to summarize the existing evidence on HER2 status in MPBC, and to discuss its present and future utility in risk assessment and treatment choice of this uncommon, yet aggressive, disease.

Conceptual Framework for Therapeutic Development Beyond Anti-PD-1/PD-L1 in Urothelial Cancer

Platinum-based chemotherapy has been the standard of care in advanced urothelial cancer, but long-term outcomes have remained poor. Immune checkpoint inhibitors, with their favorable toxicity profiles and noteworthy efficacy, have steered a new era in advanced urothelial cancer, with five agents targeting the PD-1/PD-L1 pathway approved by the U.S. Food and Drug Administration (FDA). However, most patients do not achieve response, whereas immunotherapy-related adverse events may cause morbidity, increased health care use, and-rarely-mortality. Therefore, there is an urgent need for additional therapeutic modalities across the disease spectrum. A plethora of clinical trials are ongoing in various disease settings, including chemotherapy regimens, radiotherapy, antibody-drug conjugates, agents targeting additional immune checkpoint pathways, vaccine, cytokines, adoptive cell therapies, as well as targeted and anti-angiogenic agents. Two agents, enfortumab vedotin and erdafitinib, have breakthrough designation by the FDA but are not approved yet (at the time of this paper's preparation). Novel combinations with various treatment modalities and optimal sequencing of active therapies are being investigated in prospective clinical trials. Evaluation of new treatments has met with substantial challenges for many reasons, for example, molecular heterogeneity, clonal evolution, and genomic instability. In the era of precision molecular medicine, and because patients do not respond uniformly to current therapies, there is a growing need for identification and validation of biomarkers that can accurately predict treatment response and assist in patient selection. Here, we review current updates and future directions of experimental therapeutics in urothelial cancer, including examples (but not an exhaustive list) of ongoing clinical trials.

Contemporary best practice in the management of urothelial carcinomas of the renal pelvis and ureter

Upper tract urothelial carcinoma (UTUC) accounts for 5% of urothelial carcinomas (UCs), the estimated annual incidence being 1-2 cases per 100,000 inhabitants. Similarly to bladder UC, divergent differentiations and histologic variants confer an adverse risk factor in comparison with pure UTUC. Molecular and genomic characterization studies on UTUC have shown changes occurring at differing frequencies from bladder cancer, with unique molecular and clinical subtypes, potentially with different responses to treatment. Systemic chemotherapy is the standard approach for patients with inoperable locally advanced or metastatic UCs. Although initial response rates are high, the median survival with combination chemotherapy is about 15 months. In first-line chemotherapy several cisplatin-based regimens have been proposed. For patients with advanced UC who progress to first-line treatment, the only product licensed in Europe is vinflunine, a third-generation, semisynthetic, vinca alkaloid. Better response rates (15-60%), with higher toxicity rates and no overall survival (OS) benefit, are generally achieved in multidrug combinations, which often include taxanes and gemcitabine. The US FDA has recently approved five agents targeting the programmed death-1 and programmed death ligand-1 pathway as a second-line therapy in patients with locally advanced or metastatic UC with disease progression during or following platinum-containing chemotherapy. Potential therapeutic targets are present in 69% of tumours analyzed. Specific molecular alterations include those involved in the RTK/Ras/PI(3)K, cell-cycle regulation and chromatin-remodeling pathways, many of them have either targeted therapies approved or under investigation. Angiogenic agents, anti-epidermal growth factor receptor therapy, phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) pathway inhibitors and immunotherapeutic drugs are being successfully investigated.

Anti-CD137 monoclonal antibody enhances trastuzumab-induced, natural killer cell-mediated cytotoxicity against pancreatic cancer cell lines with low human epidermal growth factor-like receptor 2 expression

Because human epidermal growth factor-like receptor (HER) 2 is expressed on the surface of human pancreatic carcinoma cells to varying degrees, trastuzumab, an anti-HER2 monoclonal antibody (mAb), is expected to exert antibody-dependent, natural killer (NK) cell-mediated cytotoxicity (ADCC) against the cells. However, some reports found that the effect of trastuzumab against human pancreatic carcinoma cells was limited because most express only limited HER2. We examined whether anti-CD137 stimulating mAb could enhance trastuzumab-mediated ADCC against Panc-1, a human pancreatic cancer cell line with low HER2 expression, in vitro. Supplementation of anti-CD137 mAb could improve trastuzumab-mediated ADCC against Panc-1 which was insufficient without this stimulating antibody. The ADCC differed in individual cells, and this was related to the expression of CD137 on the surface of NK cells after trastuzumab stimulation in association with the Fcγ-RIIIA polymorphism. NK cells with Fcγ-RIIIA-VV/VF showed high levels of ADCC against Panc-1, but those with Fcγ-RIIIA-FF did not show optimal ADCC. In addition, trastuzumab-mediated ADCC against the human pancreatic cancer cell line Capan-1 with high HER2 expression was generally high and not affected by the Fcγ-RIIIA polymorphism. These results demonstrated that in Fcγ-RIIIA-VV/VF-carrying healthy individuals, trastuzumab plus αCD137 mAb could induce effective ADCC against HER2-low-expressing pancreatic cancer cell lines, and that such an approach may result in similar findings in patients with pancreatic cancer.

The molecular limitations of biomarker research in bladder cancer

PURPOSE

Urothelial carcinoma of the bladder (UCB) is a common malignancy with limited systemic treatment options in advanced stages. Despite recent advances in immunotherapy, the majority of patients do not respond to these treatments. There is an unmet need for developing robust biomarkers to inform treatment decisions and identify patients who are likely to respond.

METHODS

A MEDLINE/PubMed literature search was performed, focusing on tissue-based and circulating biomarkers, and their potential in muscle-invasive UCB.

RESULTS

UCB is a heterogeneous disease that consists of several clonal and subclonal populations, each with a mix of truncal and private genomic alterations. This inter- and intra-tumoral heterogeneous landscape results in the development of treatment resistance. Tumor heterogeneity also constitutes a barrier to the development of robust markers of response and resistance to chemotherapy and immunotherapy. Defects in DNA repair genes and a high tumor mutational burden independently confer sensitivity to cisplatin-based chemotherapy and checkpoint inhibitors. Oncogenic alterations such as FGFR3 mutations and fusions are associated with response to FGFR3 inhibitors. Several emerging potential biomarkers, including gene expression-based molecular subtypes, T-cell receptor clonality, and tissue- or blood-based immune-gene profiling, require prospective testing and validation. Tissue-based biomarkers such as PD-L1 immunohistochemistry have several limitations due to discordance in assay methodology and trial designs. Novel liquid-biopsy techniques are promising as potential biomarkers.

CONCLUSIONS

Validated biomarkers that capture the complexity of the biology of both the tumor and the tumor microenvironment are needed in muscle-invasive UCB. Standardization of methods is critical to developing reliable biomarkers to guide clinical management.

Reappraisal of HER2 status in the spectrum of advanced urothelial carcinoma: a need of guidelines for treatment eligibility

Although human epidermal growth factor receptor 2 (HER2) may represent a therapeutic target, its evaluation in urothelial carcinoma of the bladder does not rely on a standardized scoring system by immunohistochemistry or fluorescent in situ hybridization (FISH), as reflected by various methodology in the literature and clinical trials. Our aim was to improve and standardize HER2 amplification detection in bladder cancer. We assessed immunohistochemical criteria derived from 2013 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAPs) guidelines for breast cancer and investigated intratumoral heterogeneity in a retrospective multicentric cohort of 188 patients with locally advanced urothelial carcinoma of the bladder. Immunohistochemistry was performed on 178 primary tumors and 126 lymph node metastases, eligible cases (moderate/strong, complete/incomplete membrane staining) were assessed by FISH. HER2 overexpression was more frequent with 2013 ASCO/CAP than 2007 ASCO/CAP guidelines (p < 0.0001). The rate of positive HER2 FISH was similar between primary tumor and lymph node metastases (8%). Among positive FISH cases, 48% were associated with moderate/strong incomplete membrane staining that were not scored eligible for FISH by 2007 ASCO/CAP criteria. Among 3+ immunohistochemistry score cases, 67% were associated with HER2-positive FISH. Concordance between primary tumors and matched lymph node metastases was moderate for immunohistochemistry (κ = 0.54 (CI 95%, 0.41-0.67)) and FISH (κ = 0.50 (CI 95%, 0.20-0.79)). HER2-positive FISH was more frequent in micropapillary carcinomas (12%) and carcinoma with squamous differentiation (11%) than in pure conventional carcinoma (6%). Intratumoral heterogeneity for HER2 immunohistochemistry was observed in 7% primary tumor and 6% lymph node metastases; 24% positive HER2 FISH presented intratumoral heterogeneity. Our study suggests that HER2 evaluation should include an immunohistochemistry screening step with eligibility for FISH including incomplete/complete and moderate/strong membrane staining. Spatial or temporal intratumoral heterogeneity prompts to perform evaluation on both tumor and lymph node, and for each histological variant observed.

Emerging biomarkers and targeted therapies in urothelial carcinoma

The use of immunotherapy has revolutionized the management of patients with locally advanced, unresectable, and metastatic urothelial carcinoma (UC); however, platinum-based chemotherapy remains a therapeutic cornerstone both in localized muscle-invasive and advanced UC. There is still no predictive molecular biomarker with clinical utility to help guide treatment and select patients most likely to derive benefit from a particular therapeutic modality or regimen. However, recent research has further characterized the inherent biology and immunology landscapes of UC leading to the development of potential biomarkers and therapeutic targets that could be used upon further validation. Emerging interrogation of The Cancer Genome Atlas (TCGA) and other molecular profiling datasets has led to the identification of distinct molecular subtypes with diverse clinical behaviors with potential sensitivity to various therapies. It has also led to the discovery of multiple frequently altered genes and proteins that could lead to perturbation of intracellular signaling pathways and of the dynamic interactions between tumor cells, their "microenvironment", and the host "macro-environment". The advent of molecular profiling and deeper next-generation sequencing has the potential to change biomarker and "real time" drug sensitivity assessment, introducing and testing the premise of "precision oncology" and personalized medicine. Within this review, we summarize emerging biomarkers that may predict response to cisplatin-based chemotherapy, immunotherapy, emerging targeted therapies, and promising combination strategies. We also highlight a few examples of 'precision medicine' trials aiming to improve outcomes in UC. Since our review is not exhaustive we strongly recommend the readers to follow the continuously changing literature in the very interesting and dynamic field of UC.

Characterization of metastatic urothelial carcinoma via comprehensive genomic profiling of circulating tumor DNA

BACKGROUND

Biomarker-guided clinical trials are increasingly common in metastatic urothelial carcinoma (mUC), yet patients for whom contemporary tumor tissue is not available are not eligible. Technological advancements in sequencing have made cell-free circulating DNA (cfDNA) next-generation sequencing (NGS) readily available in the clinic. The objective of the current study was to determine whether the genomic profile of mUC detected by NGS of cfDNA is similar to historical tumor tissue NGS studies. A secondary objective was to determine whether the frequency of genomic alterations (GAs) differed between lower tract mUC (mLTUC) and upper tract mUC (mUTUC).

METHODS

Patients from 13 academic medical centers in the United States who had a diagnosis of mUC between 2014 and 2017 and for whom cfDNA NGS results were available were included. cfDNA profiling was performed using a commercially available platform (Guardant360) targeting 73 genes.

RESULTS

Of 369 patients with mUC, 294 were diagnosed with mLTUC and 75 with mUTUC. A total of 2130 GAs were identified in the overall mUC cohort: 1610 and 520, respectively, in the mLTUC and mUTUC cohorts. In the mLTUC cohort, frequently observed GAs were similar between cfDNA NGS and historical tumor tissue studies, including tumor protein p53 (TP53) (P = 1.000 and .115, respectively), AT-rich interaction domain 1A (ARID1A) (P = .058 and .058, respectively), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) (P = .058 and .067, respectively), erb-b2 receptor tyrosine kinase 2 (ERBB2) (P = .565 and .074, respectively), and fibroblast growth factor receptor 3 (FGFR3) (P = .164 and .014, respectively). No significant difference was observed with regard to the frequency of GAs between patients with mLTUC and mUTUC.

CONCLUSIONS

Among patients with mUC for whom no tumor tissue was available, cfDNA NGS was able to identify a similar profile of GAs for biomarker-driven clinical trials compared with tumor tissue. Despite the more aggressive clinical course, cases of mUTUC demonstrated a circulating tumor DNA genomic landscape that was similar to that of mLTUC. Cancer 2018;124:2115-24. © 2018 American Cancer Society.

Prognostic Value of Molecular Breast Cancer Subtypes based on Her2, ESR1, PGR and Ki67 mRNA-Expression in Muscle Invasive Bladder Cancer

INTRODUCTION: Gene expression analyses have identified similarities between bladder and breast cancer, where clinical risk stratification is based on Her2, ESR1, PGR and Ki67 expression. The aim of the study was to assess the respective marker gene expression in patients treated with radical cystectomy for muscle-invasive bladder cancer (MIBC) and to evaluate the applicability of breast cancer subtypes for MIBC risk stratification. MATERIALS & METHODS: 102 patients treated with radical cystectomy for MIBC were assessed. Using routine FFPE tissue and an IVD validated kit, mRNA expression was measured by single step RT-qPCR. Partition test were employed to define cut-off values for high or low marker gene expression. Association of expression with outcome was assessed using Kaplan-Meier analysis and multivariate cox regression analysis. Finally, we performed validation of our results in the MD-Anderson cohort (n = 57). RESULTS: Cancer specific survival (CSS) was impaired in patients with high gene expression of Her2 (P = 0.0009) and ESR1 (P = 0.04). In the multivariate regression model Her2 expression remained significant for the prediction of CSS (HR = 2.11, CI 1.11-4.21, P = 0.024). Furthermore, molecular stratification by breast cancer subgroups was significant (P = 0.023) for CSS prediction. Especially the differentiation between Her2-positive and Luminal A (HR = 4.41, CI 1.53-18.71, P = 0.004) and Luminal B (HR = 1.96, CI 0.99-4.08, P = 0.053) respectively was an independent prognostic parameter for CSS. External validation resulted in comparable risk stratification with differences in fractional subgroups distribution. CONCLUSION: Gene expression of Her2, ESR1, PGR, Ki67 and corresponding breast cancer subtypes allow a risk-stratification in MIBC, whereby Her2 overexpressing tumors reveal a particularly poor prognosis.

Molecular Correlates of In Vitro Responses to Dacomitinib and Afatinib in Bladder Cancer

Background:

The HER family of proteins (EGFR, HER2, HER3 and HER4) have long been thought to be therapeutic targets for bladder cancer, but previous clinical trials targeting these proteins have been disappointing. Second generation agents may be more effective.

Objective:

The aim of this study was to evaluate responses to two second-generation irreversible tyrosine kinase inhibitors, dacomitinib and afatinib, in bladder cancer cell lines.

Methods:

Cell lines were characterized by targeted next generation DNA sequencing, RNA sequencing, western blotting and flow cytometry. Cell survival responses to dacomitinib or afatinib were determined using (3-[4,5-dimethylthioazol-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT) or [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and phenazine methosylfate (PMS) cell survival assays.

Results:

Only two cell lines of 12 tested were sensitive to afatinib. Sensitivity to afatinib was significantly associated with mutation in either HER2 or HER3 (p < 0.05). The two cell lines sensitive to afatinib were also responsive to dacomitinib ralong with an additional 4 other cell lines out of 16 tested. No characteristic was associated with dacomitinib sensitivity. Molecular profiling demonstrated that only two genes were high in both afatinib and dacomitinib sensitive cells. Further rhigher expression of RAS pathway genes was noted for dacomitinib responsive cells.

Conclusions:

This study confirms that cell line screening can be useful in pre-clinical evaluation of targeted small molecule inhibitors and suggests that compounds with similar structure(s) and target(s) may have distinct sensitivity profiles. Further rcombinational targeting of additional molecularly relevant pathways may be important in enhancing responses to HER targeted agents in bladder cancer.

Therapeutic Antibodies in Cancer Therapy

The therapeutic arsenal in solid tumors comprises different anticancer strategies with diverse chemotherapeutic agents and a growing number of biological substances. Large clinical study-based chemotherapeutic protocols combined with biologicals have become an important component in (neo-) adjuvant therapy alongside surgery in solid cancers as well as radiation therapy in some instances. In recent years, monoclonal antibodies have entered the mainstream of cancer therapy. Their first use was as antagonists of oncogenic receptor tyrosine kinases, but today monoclonal antibodies have emerged as long-sought vehicles for the targeted delivery of potent chemotherapeutic agents and as powerful tools to manipulate anticancer immune responses. There is a growing number of FDA approved monoclonal antibodies and small molecules targeting specific types of cancer suggestive of the clinical relevance of this approach.Targeted cancer therapies , also referred to as personalized medicine, are being studied for use alone, in combination with other targeted therapies, and in combination with chemotherapy. The use of monoclonal antibodies in colorectal and gastric cancer for example have shown best outcome when combined with chemotherapy, even though single agent anti-EGFR antibodies seem to be active in particular setting of metastatic colorectal cancer patients. However, it is not well defined whether the addition of anti-VEGF - and anti-EGFR strategies to chemotherapy could improve outcome in those patients susceptible to colorectal cancer-related metastases resection. Among the most promising approaches to activating therapeutic antitumor immunity is the blockade of immune checkpoints, exemplified by the recently FDA-approved agent, Ipilimumab, an antibody that blocks the coinhibitory receptor CTLA-4. Capitalizing on the success of Ipilimumab, agents that target a second coinhibitory receptor, PD-1, or its ligand, PD-L1, are in clinical development. This section attempts to discuss recent progress of targeted agents and in tackling a more general target applicable to gastrointestinal cancer .

Different stages in drug development for muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is a highly aggressive disease. Despite optimal therapy, half of the patients will succumb to disease. This prognosis could not be improved over the last three decades. Therefore, MIBC is left behind from other cancers such as prostate, where novel treatment options were discovered and improve patient outcomes. While being aware of the recent emerging evidence of checkpoint inhibition in MIBC, we aim to describe different stages of drug development in MIBC by using three specific targets. On the example of Her2 targeting, we aimed to indicate, that either a target is ineffective in MIBC or that the patient selection is insufficient. The first clinical trials using a pan fibroblast growth factor receptor (panFGFR) inhibitor to target the FGFR pathway showed promising results. Data of further trials are to be awaited before implementing these drugs into daily clinical practice. A large variety of novel agents are investigated in vitro and in vivo. On the example of a malaria protein, we aimed to discuss a treatment paradigm that is not dependent on pathway signaling and the genomic landscape of MIBC. The ultimate question still remains to be answered: How do we select the optimal treatment for the right patient?

The Emerging Molecular Landscape of Urothelial Carcinoma

Although there have been many recent discoveries in the molecular alterations associated with urothelial carcinoma, current understanding of this disease lags behind many other malignancies. Historically, a two-pathway model had been applied to distinguish low- and high-grade urothelial carcinoma, although significant overlap and increasing complexity of molecular alterations has been recently described. In many cases, mutations in HRAS and FGFR3 that affect the MAPK and PI3K pathways seem to be associated with noninvasive low-grade papillary tumors, whereas mutations in TP53 and RB that affect the G1-S transition of the cell cycle are associated with high-grade in situ and invasive carcinoma. However, recent large-scale analyses have identified overlap in these pathways relative to morphology, and in addition, many other variants in a wide variety of oncogenes and tumor-suppressor genes have been identified. New technologies including next-generation sequencing have enabled more detailed analysis of urothelial carcinoma, and several groups have proposed molecular classification systems based on these data, although consensus is elusive. This article reviews the current understanding of alterations affecting oncogenes and tumor-suppressor genes associated with urothelial carcinoma, and their application in the context of morphology and classification schema.

Emerging drugs for urothelial (bladder) cancer

INTRODUCTION

Metastatic urothelial carcinoma has been associated with poor prognosis and a median survival of approximately 12-14 months with standard therapy. Treatment options for decades have been limited to platinum based chemotherapy as first line with few therapeutic options available to the majority who will ultimately progress beyond platinum. Areas covered: This review focuses on the various targeted, antiangiogenic, chemotherapeutic and immunotherapeutic agents currently being developed for the treatment of urothelial carcinoma. Expert opinion: Incorporation of systemic immunotherapy into the treatment of urothelial carcinoma has already fundamentally changed the treatment of this disease. The landscape is rapidly changing and it is likely that immunotherapy will be incorporated into therapy in earlier disease states and in novel combinations. Outcomes in urothelial carcinoma have improved and likely to improve further with ongoing and future clinical research that is discussed in this review.

Toward personalized management in bladder cancer: the promise of novel molecular taxonomy

Empowered by the recent advances in next generation sequencing and bioinformatics technology, an unprecedented wave of integrated transcriptomic and genomic studies have impacted the field of bladder cancer. These studies not only have confirmed previously charted genetic pathways in bladder cancer development but also have led to the discovery of numerous additional crucial driver genetic alterations. As a result, a novel genomic-based taxonomy is emerging that promises to better define clinically relevant intrinsic subtypes of bladder cancer. The current review is an update on the above advances and their significant implications on the future of bladder cancer patient management.

Systemic therapy in bladder cancer

Systemic chemotherapy is essential for the management of muscle-invasive bladder cancer (MIBC) and metastatic bladder cancer (BCa). Neoadjuvant chemotherapy is key to the management of MIBC with many cisplatin-based regimens. Adjuvant chemotherapy may be considered for selected patients who did not receive neoadjuvant therapy. Systemic chemotherapy with radiotherapy is a critical component of a trimodal bladder-preserving approach and is superior to radiotherapy alone. Cisplatin-based chemotherapy has been the mainstay for metastatic BCa. Immunotherapy in the form of checkpoint inhibitors is a promising new drug for the treatment of BCa. Molecular characterization of each individual BCa is likely to lead to a target-directed therapeutic revolution.

Targeted therapies in the treatment of urothelial cancers

Progress has been slow in systemic management of locally advanced and metastatic bladder cancer over the past 20 years. However, the recent approval of immunotherapy with atezolizumab and nivolumab for second-line salvage therapy may usher in an era of more rapid improvement. Systemic treatment is suboptimal and is an area of substantial unmet medical need. The recent findings from The Cancer Genome Atlas project revealed promising pathways that may be amenable to targeted therapies. Promising results with treatment using vascular endothelial growth factor inhibitors such as ramucirumab, sunitinib or bevacizumab, and human epidermal growth factor receptor 2 targeted therapies, epidermal growth factor receptor inhibitors, and fibroblast growth factor receptor inhibitors, are undergoing clinical trials and are discussed later.

Her2 alterations in muscle-invasive bladder cancer: Patient selection beyond protein expression for targeted therapy

Although the introduction of novel targeted agents has improved patient outcomes in several human cancers, no such advance has been achieved in muscle-invasive bladder cancer (MIBC). However, recent sequencing efforts have begun to dissect the complex genomic landscape of MIBC, revealing distinct molecular subtypes and offering hope for implementation of targeted therapies. Her2 (ERBB2) is one of the most established therapeutic targets in breast and gastric cancer but agents targeting Her2 have not yet demonstrated anti-tumor activity in MIBC. Through an integrated analysis of 127 patients from three centers, we identified alterations of Her2 at the DNA, RNA and protein level, and demonstrate that Her2 relevance as a tumor driver likely may vary even within ERBB2 amplified cases. Importantly, tumors with a luminal molecular subtype have a significantly higher rate of Her2 alterations than those of the basal subtype, suggesting that Her2 activity is also associated with subtype status. Although some of our findings present rare events in bladder cancer, our study suggests that comprehensively assessing Her2 status in the context of tumor molecular subtype may help select MIBC patients most likely to respond to Her2 targeted therapy.

The evolving genomic landscape of urothelial carcinoma

Survival of patients with urothelial carcinoma (including bladder cancer and upper tract urothelial carcinoma) is limited by our current approaches to staging, surgery, and chemotherapy. Large-scale, next-generation sequencing collaborations, such as The Cancer Genome Atlas, have already identified drivers and vulnerabilities of urothelial carcinoma. This disease has a high degree of mutational heterogeneity and a high frequency of somatic mutations compared with other solid tumours, potentially resulting in an increased neoantigen burden. Mutational heterogeneity is mediated by multiple factors including the apolipoprotein B mRNA editing enzyme catalytic polypeptide family of enzymes, smoking exposure, viral integrations, and intragene and intergene fusion proteins. The mutational landscape of urothelial carcinoma, including specific mutations in pathways and driver genes, such as FGFR3, ERBB2, PIK3CA, TP53, and STAG2, affects tumour aggressiveness and response to therapy. The next generation of therapies for urothelial carcinoma will be based on patient-specific targetable mutations found in individual tumours. This personalized-medicine approach to urothelial carcinoma has already resulted in unique clinical trial design and has the potential to improve patient outcomes and survival.

Bladder Sparing Approaches for Muscle-Invasive Bladder Cancers

Organ preservation has been increasingly utilised in the management of muscle-invasive bladder cancer. Multiple bladder preservation options exist, although the approach of maximal TURBT performed along with chemoradiation is the most favoured. Phase III trials have shown superiority of chemoradiotherapy compared to radiotherapy alone. Concurrent chemoradiotherapy gives local control outcomes comparable to those of radical surgery, but seemingly more superior when considering quality of life. Bladder-preserving techniques represent an alternative for patients who are unfit for cystectomy or decline major surgical intervention; however, these patients will need lifelong rigorous surveillance. It is important to emphasise to the patients opting for organ preservation the need for lifelong bladder surveillance as risk of recurrence remains even years after radical chemoradiotherapy treatment. No randomised control trials have yet directly compared radical cystectomy with bladder-preserving chemoradiation, leaving the age-old question of superiority of one modality over another unanswered. Radical cystectomy and chemoradiation, however, must be seen as complimentary treatments rather than competing treatments. Meticulous patient selection is vital in treatment modality selection with the success of recent trials within the field of bladder preservation only being possible through this application of meticulous selection criteria compared to previous decades. A multidisciplinary approach with radiation oncologists, medical oncologists, and urologists is needed to closely monitor patients who undergo bladder preservation in order to optimise outcomes.

Phase III, Double-Blind, Randomized Trial That Compared Maintenance Lapatinib Versus Placebo After First-Line Chemotherapy in Patients With Human Epidermal Growth Factor Receptor 1/2-Positive Metastatic Bladder Cancer

Purpose To establish whether maintenance lapatinib after first-line chemotherapy is beneficial in human epidermal growth factor receptor (HER) 1/HER2-positive metastatic urothelial bladder cancer (UBC). Methods Patients with metastatic UBC were screened centrally for HER1/HER2 overexpression. Patients who screened positive for HER1/2 and who did not have progressive disease during chemotherapy (four to eight cycles) were randomly assigned one to one to lapatinib or placebo after completion of first-line/initial chemotherapy for metastatic disease. The primary end point was progression-free survival (PFS). Results Between 2007 and 2013, 446 patients with UBC were screened, and 232 with HER1- or HER2-positive disease were randomly assigned. The median PFS for lapatinib and placebo was 4.5 (95% CI, 2.8 to 5.4) and 5.1 (95% CI, 3.0 to 5.8) months, respectively (hazard ratio, 1.07; 95% CI, 0.81 to 1.43; P = .63). The overall survival for lapatinib and placebo was 12.6 (95% CI, 9.0 to 16.2) and 12.0 (95% CI, 10.5 to 14.9) months, respectively (hazard ratio, 0.96; 95% CI, 0.70 to 1.31; P = .80). Discontinuation due to adverse events were similar in both arms (6% lapatinib and 5% placebo). The rate of grade 3 to 4 adverse events for lapatinib and placebo was 8.6% versus 8.1% ( P = .82). Preplanned subset analysis of patients strongly positive for HER1/HER2 (3+ on immunohistochemistry; n = 111), patients positive for only HER1 (n = 102), and patients positive for only HER2 (n = 42) showed no significant benefit with lapatinib in terms of PFS and overall survival ( P > .05 for each). Conclusion This trial did not find significant improvements in outcome by the addition of maintenance lapatinib to standard of care.

Circulating biomarkers to guide systemic therapy for urothelial carcinoma

There are very few biomarkers used to diagnose bladder cancer and no clinically approved biomarkers for prediction or prognostication of this disease. All currently available biomarkers are based on urine tests, and thus, they may not be applicable to patients with extravesical tumors. Biopsy of metastatic sites requires an invasive procedure, whereas serum-based markers, which can be easily obtained and serially measured, thus have obvious merit. These deficiencies may be overcome with advances in genome sequencing, identification of circulating tumor cells, and RNA-, protein-, and DNA-based biomarkers. Here, progress in circulating biomarkers in both superficial and invasive bladder cancer is described.

Aldo-keto reductase 1C1 induced by interleukin-1β mediates the invasive potential and drug resistance of metastatic bladder cancer cells

In treating bladder cancer, determining the molecular mechanisms of tumor invasion, metastasis, and drug resistance are urgent to improving long-term patient survival. One of the metabolic enzymes, aldo-keto reductase 1C1 (AKR1C1), plays an essential role in cancer invasion/metastasis and chemoresistance. In orthotopic xenograft models of a human bladder cancer cell line, UM-UC-3, metastatic sublines were established from tumors in the liver, lung, and bone. These cells possessed elevated levels of EMT-associated markers, such as Snail, Slug, or CD44, and exhibited enhanced invasion. By microarray analysis, AKR1C1 was found to be up-regulated in metastatic lesions, which was verified in metastatic human bladder cancer specimens. Decreased invasion caused by AKR1C1 knockdown suggests a novel role of AKR1C1 in cancer invasion, which is probably due to the regulation of Rac1, Src, or Akt. An inflammatory cytokine, interleukin-1β, was found to increase AKR1C1 in bladder cancer cell lines. One particular non-steroidal anti-inflammatory drug, flufenamic acid, antagonized AKR1C1 and decreased the cisplatin-resistance and invasion potential of metastatic sublines. These data uncover the crucial role of AKR1C1 in regulating both metastasis and drug resistance; as a result, AKR1C1 should be a potent molecular target in invasive bladder cancer treatment.