Second-line systemic therapy and emerging drugs for metastatic transitional-cell carcinoma of the urothelium

Immune Checkpoint Inhibitors and Antibody-Drug Conjugates in Urothelial Carcinoma: Current Landscape and Future Directions

BACKGROUND/OBJECTIVES

Urothelial carcinoma (UC) treatment has been transformed by immunotherapy and antibody-drug conjugates (ADCs). This review evaluates the current evidence for these approaches and identifies future directions.

METHODS

We conducted a structured review of clinical trials, meta-analyses, and guidelines published until early 2025.

RESULTS

Immune checkpoint inhibitors have established benefits across multiple settings: post-platinum therapy (pembrolizumab, nivolumab), maintenance therapy (avelumab), adjuvant settings for high-risk muscle-invasive disease (nivolumab), and BCG-unresponsive non-muscle-invasive disease (pembrolizumab). Enfortumab vedotin (targeting Nectin-4) has proven effective in post-platinum/post-immunotherapy. Most significantly, enfortumab vedotin plus pembrolizumab has redefined first-line treatment with unprecedented survival benefits (median OS 31.5 months vs. 16.1 months with chemotherapy; HR 0.47), and nivolumab plus gemcitabine-cisplatin improved outcomes in cisplatin-eligible patients. Key challenges include managing unique toxicity profiles, optimizing treatment sequencing, and developing reliable biomarkers.

CONCLUSIONS

Combination approaches offer the most promising path forward, with future research needed on resistance mechanisms, biomarker development, and expanding these therapies to earlier disease stages.

Bladder cancer biomarkers: current approaches and future directions

Bladder cancer is a significant health concern worldwide, necessitating effective diagnostic and monitoring strategies. Biomarkers play a crucial role in the early detection, prognosis, and treatment of this disease. This review explores the current landscape of bladder cancer biomarkers, including FDA-approved molecular biomarkers and emerging ones. FDA-approved molecular biomarkers, such as BTA stat, BTA TRAK, and NMP22, have been instrumental in diagnosing and monitoring bladder cancer. These biomarkers are derived from urinary samples and are particularly useful due to their sensitivity and specificity. As we move forward, we should continue to seek ways to optimize our processes and outcomes, these markers remain seriously challenged in the detection of early bladder cancer due to their limited sensitivity and specificity. For instance, sensitivities of BTA stat in bladder tumor detection have varied between 40-72%, while its specificities vary from 29-96%. In the same way, 70% sensitivity and 80% specificity have been recorded for BTA TRAK, while 11-85.7% sensitivity and 77-100% specificity have been documented for NMP22 BladderChek. The given variations, especially the low sensitivity in the diagnosis of bladder cancer at an early stage call for the invention of better diagnostic systems. Moreover, different sample collection and handling procedures applied in different laboratories further contribute to inconsistent results obtained. Extracellular vesicles (EVs) and exosomes, which carry a vast number of proteins, are being considered as potential biomarkers. Although these markers show promise, challenges remain due to non-standardized isolation techniques and lack of reproducibility across studies. Moreover, the discovery of new potential biomarkers is ongoing. For instance, the UBC® Rapid test and UBC ELISA kit, the XPERT BC Monitor, BC UroMark, TaqMan® Arrays, Soluble FAS (sFAS), Bladder tumor fibronectin (BTF), and IGF2 and MAGE-A3 are among the newest biomarkers under investigation. In conclusion, while bladder cancer biomarkers have shown great promise, more research is needed to standardize the testing procedures and validate these biomarkers in a clinical setting. This will pave the way for more accurate and efficient diagnosis and monitoring of bladder cancer, ultimately improving patient outcomes.

Inhibition of KDM4A restricts SQLE transcription and induces oxidative stress imbalance to suppress bladder cancer

In clinical practice, the limited efficacy of standard comprehensive therapy for advanced bladder cancer and the lack of targeted treatment options are well recognized. Targeting abnormal epigenetic modifications in tumors has shown considerable potential in cancer therapy. Through drug screening in tumor organoids, we identified that ML324, a histone lysine demethylase 4A (KDM4A) inhibitor, exhibits potent antitumor effects in both in vitro and in vivo cancer models. Mechanistically, Kdm4a demethylates H3K9me3, leading to chromatin opening and increased accessibility of Gabpa to the squalene epoxidase (Sqle) gene promoter, resulting in transcriptional activation. Inhibition of Kdm4a downregulates Sqle transcription, blocking cholesterol synthesis and causing squalene (SQA) accumulation. This process induces reactive oxygen species (ROS) clearance and suppresses JNK/c-Jun phosphorylation, ultimately inducing apoptosis. Furthermore, ML324 treatment significantly inhibited tumor growth in bladder cancer patient-derived xenograft (PDX) models. Our findings reveal the presence of a Kdm4a-Sqle-ROS-JNK/c-Jun signaling axis that regulates oxidative stress balance, offering a novel strategy for targeted therapy in bladder cancer.

Matching-Adjusted Indirect Comparison of the Efficacy and Safety of Erdafitinib vs Enfortumab Vedotin in Patients with Locally Advanced Metastatic Urothelial Carcinoma

Background: For patients with locally advanced or metastatic urothelial carcinoma (la/mUC), prognosis is poor and effective treatment options are limited. Erdafitinib is an oral fibroblast growth factor receptor (FGFR) kinase inhibitor approved by the FDA for the treatment of adults with la/mUC harboring FGFR alterations whose disease progressed following at least 1 prior line of therapy, including a PD-1 or PD-L(1) inhibitor, based on the phase 3, randomized THOR trial (NCT03390504, Cohort 1). Objective: To compare the efficacy and safety of erdafitinib vs enfortumab vedotin-ejfv (EV) in the absence of head-to-head comparison via an anchored matching-adjusted indirect comparison (MAIC). Methods: An anchored MAIC was conducted according to the National Institute for Health and Care Excellence Decision Support Unit guidance, with physician's choice of chemotherapy (docetaxel/paclitaxel and vinflunine) as the common comparator. Individual patient data from THOR were adjusted to match published key eligibility criteria and average baseline characteristics of EV-301, such as Bellmunt risk score, liver or visceral metastases, primary site, among others. Erdafitinib was then indirectly compared with EV using the relative treatment effects for the reweighted THOR population and those published for EV-301. Results: After matching, the effective sample size for THOR was 126 patients. The MAIC-recalculated hazard ratio (95% credible interval) for erdafitinib vs EV was 0.92 (0.54, 1.57) for overall survival and 0.93 (0.55, 1.56) for progression-free survival, yielding Bayesian probabilities of erdafitinib being better than EV of 62.1% and 60.5%, respectively. For response outcomes, the MAIC-recalculated risk ratio was 1.49 (0.56, 3.90) for confirmed objective response rate and 2.89 (0.27, 30.33) for confirmed complete response with probabilities of 72.6% and 81.3% for erdafitinib being better than EV, respectively. For safety, MAIC-yielded risk ratios of 1.09 (0.99, 1.21) for any treatment-related adverse events, 0.86 (0.57, 1.28) for grade 3+ TRAEs, and 1.02 (0.98, 1.06) for any treatment-emergent adverse events. Conclusion: The MAIC indicates comparable efficacy of erdafitinib vs EV for overall survival and progression-free survival, with erdafitinib showing a higher probability of achieving deep responses. While erdafitinib is associated with slightly more adverse events compared with EV, these events seem to be less severe.

Clinical practice pattern in patients with advanced urothelial cancer who had progressed on pembrolizumab in the pre-enfortumab vedotin era

OBJECTIVES

Pembrolizumab, an anti-PD-1 monoclonal antibody, revolutionized the treatment for advanced urothelial carcinoma. However, the standard treatment for patients after disease progression with pembrolizumab had not been established until the recent approval of enfortumab vedotin. We analyzed the treatment of these patients in the real world, and the patient background and outcomes.

METHODS

We extracted data from 543 patients who experienced progressive disease after pembrolizumab initiation from a Japanese nation-wide cohort of platinum-refractory, metastatic urothelial carcinoma.

RESULTS

The median overall survival of the 543 patients was 3.5 months (95% confidence interval 3.0-4.1). Of these, only 20.6% (n = 112) received chemotherapy as a subsequent systemic treatment after progressive disease. The regimen of chemotherapy was very diverse. The median overall survival was 11.9 months (95% confidence interval 9.2-14.7) for patients who received chemotherapy, compared to 2.4 months for those who did not receive chemotherapy (95% confidence interval 2.1-2.9; P < 0.0001). Patients who received subsequent chemotherapy were more likely to have better performance status, neutrophil-to-lymphocyte ratio <3, hemoglobin >11 mg/dL, and history of a single chemotherapeutic regimen at pembrolizumab initiation.

CONCLUSIONS

This report highlights the real-world practice of the management after pembrolizumab treatment failure in the pre-enfortumab vedotin era, characterized by infrequent use of subsequent anticancer therapy comprising various regimens, reflecting the lack of a standard treatment. Clinical introduction of enfortumab vedotin is expected to improve treatment outcomes in this setting. The present study will provide important baseline data for evaluating the influence of enfortumab vedotin on clinical practices and outcomes.

Efficacy and safety of rucaparib in previously treated, locally advanced or metastatic urothelial carcinoma from a phase 2, open-label trial (ATLAS)

BACKGROUND

ATLAS evaluated the efficacy and safety of the PARP inhibitor rucaparib in patients with previously treated locally advanced/unresectable or metastatic urothelial carcinoma (UC).

METHODS

Patients with UC were enrolled independent of tumor homologous recombination deficiency (HRD) status and received rucaparib 600 mg BID. The primary endpoint was investigator-assessed objective response rate (RECIST v1.1) in the intent-to-treat and HRD-positive (loss of genome-wide heterozygosity ≥10%) populations. Key secondary endpoints were progression-free survival (PFS) and safety. Disease control rate (DCR) was defined post-hoc as the proportion of patients with a confirmed complete or partial response (PR), or stable disease lasting ≥16 weeks.

RESULTS

Of 97 enrolled patients, 20 (20.6%) were HRD-positive, 30 (30.9%) HRD-negative, and 47 (48.5%) HRD-indeterminate. Among 95 evaluable patients, there were no confirmed responses. However, reductions in the sum of target lesions were observed, including 6 (6.3%) patients with unconfirmed PR. DCR was 11.6%; median PFS was 1.8 months (95% CI, 1.6-1.9). No relationship was observed between HRD status and efficacy endpoints. Median treatment duration was 1.8 months (range, 0.1-10.1). Most frequent any-grade treatment-emergent adverse events were asthenia/fatigue (57.7%), nausea (42.3%), and anemia (36.1%). Of 64 patients with data from tumor tissue samples, 10 (15.6%) had a deleterious alteration in a DNA damage repair pathway gene, including four with a deleterious BRCA1 or BRCA2 alteration.

CONCLUSIONS

Rucaparib did not show significant activity in unselected patients with advanced UC regardless of HRD status. The safety profile was consistent with that observed in patients with ovarian or prostate cancer.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov (NCT03397394). Date of registration: 12 January 2018. This trial was registered in EudraCT (2017-004166-10).

Metastases of Urothelium Carcinoma: Differential Diagnosis, Resection, and Survival

BACKGROUND

 Due to its very aggressive nature and low survival chances, the metastasized urothelium carcinoma poses a challenge in regard to therapy. The gold-standard chemotherapy is platinum based. The therapy options are considered controversial, including new systemic therapies. In this respect, surgical therapies, as already established for pulmonary metastases of other tumor entities play an increasingly important role. The consumption of nicotine is a risk factor not only for urothelium carcinoma but also for a pulmonary carcinoma. Thus, we examined the frequency of a second carcinoma in this cohort.

METHODS

 We retrospectively examined patients who had a differential diagnosis of pulmonary metastases, as well as those patients who underwent a surgery due to pulmonary metastases of a urothelium carcinoma between 1999 and 2015.

RESULTS

 A total of 139 patients came to our clinic with the differential diagnosis of pulmonary metastases of a urothelium carcinoma. The most common diagnosis was pulmonary carcinoma (53%). Thirty-one patients underwent surgeries due to pulmonary metastases of a urothelium carcinoma. The median survival was 53 months and the 5-year survival was 51%. With the univariate analysis, only the relapse-free interval of more than 10 months was statistically significant (p < 0.001).

CONCLUSION

 There is a high coincidence of urothelial carcinoma and lung carcinoma. A histological confirmation should be endeavored. Selected patients undergoing a pulmonary metastasis resection have a survival advantage during the multimodal treatment of pulmonary metastasized urothelial carcinomas. For a definitive recommendation, randomized trials including a uniform multimodal therapy regimen and higher numbers of patients are necessary.

Paclitaxel and carboplatin chemotherapy after platinum-based chemotherapy and pembrolizumab for metastatic urothelial carcinoma

Pembrolizumab has been available for the treatment of radical resectable urothelial carcinoma (UC) when it is exacerbated after chemotherapy since December 2017 in Japan. However, the efficacy of chemotherapy for cases progressing after pembrolizumab is unclear. The present study compared the outcomes and toxicities in patients with metastatic UC after failure of platinum-based chemotherapy and pembrolizumab, who were selected to receive paclitaxel and carboplatin (TC) chemotherapy, with those in patients who received the best supportive care (BSC). A total of 36 patients received pembrolizumab for metastatic UC at four institutions between January 2018 and August 2019. Of the 21 patients who progressed after pembrolizumab, 7 received TC chemotherapy (TC group) and 14 selected BSC (BSC group). The median observation period was 4.1 months. The 7 aforementioned patients who received TC chemotherapy (4 male and 3 female; median age, 62 years; range, 57-79 years) were analyzed in the present study. The ECOG performance status was 0 in three patients, 1 in one patient, 2 in two patients and 3 in one patient. Two patients had upper urinary tract UC, two had bladder UC and three had both types of UC. Six patients had visceral metastasis. The number of chemotherapy regimens before pembrolizumab was one in four patients, two in two patients and three in one patient. The objective response rate was 28.6% (partial response, 2 patients; stable disease, 4 patients; progressive disease, 1 patient), the median progression-free survival time was 3.4 months and the median overall survival time was 10.9 months (vs. 2.7 months in BSC group; P=0.0156). Although grade ≥3 adverse events developed in five patients, there were no treatment-associated deaths. The present results suggested that TC chemotherapy may be a preferred option for patients who require aggressive treatment after the failure of platinum-based chemotherapy and pembrolizumab.

Monoclonal Antibodies: A Prospective and Retrospective View

BACKGROUND

Monoclonal Antibodies (mAbs) represent one of the most important classes of biotherapeutic agents. They are used to cure many diseases, including cancer, autoimmune diseases, cardiovascular diseases, angiogenesis-related diseases and, more recently also haemophilia. They can be highly varied in terms of format, source, and specificity to improve efficacy and to obtain more targeted applications. This can be achieved by leaving substantially unchanged the basic structural components for paratope clustering.

OBJECTIVES

The objective was to trace the most relevant findings that have deserved prestigious awards over the years, to report the most important clinical applications and to emphasize their latest emerging therapeutic trends.

RESULTS

We report the most relevant milestones and new technologies adopted for antibody development. Recent efforts in generating new engineered antibody-based formats are briefly reviewed. The most important antibody-based molecules that are (or are going to be) used for pharmacological practice have been collected in useful tables.

CONCLUSION

The topics here discussed prove the undisputed role of mAbs as innovative biopharmaceuticals molecules and as vital components of targeted pharmacological therapies.

Complete Pathological Response to Neoadjuvant Pembrolizumab in a Patient With Chemoresistant Upper Urinary Tract Urothelial Carcinoma: A Case Report

Treatment options as second-line therapy for advanced ureteral carcinoma are limited, and patients experiencing recurrence after first-line cisplatin-based chemotherapy have a poor prognosis. Recently, the programmed death-1 (PD-1) inhibitor pembrolizumab provided a better survival benefit with a complete response rate (9.2%) for chemoresistatant urothelial carcinoma. However, the dynamic changes of the cancer microenvironment about the cases of complete response are still unknown. We herein report a case of a 57-year-old man who had been diagnosed with localized, non-muscle-invasive bladder cancer (pT1N0M0, high grade), for which he underwent transurethral resection of the bladder cancer twice. Given that gemcitabine plus carboplatin as first-line neoadjuvant chemotherapy was unable to control left vesico-ureteral junction recurrence with muscle invasion (T3N0M0, high grade), the patient received the PD-1 inhibitor pembrolizumab as second-line neoadjuvant therapy in an attempt to stop tumor growth, which promoted dramatic tumor shrinkage without serious adverse effects and allowed subsequent nephroureterectomy and lymphadenectomy. To the best of our knowledge, this has been the first study to report that pembrolizumab administration before surgery for chemotherapy-resistant ureteral carcinoma promoted a pathological complete response, providing a better understanding of the cancer microenvironment after immunotherapy.

Activation of Glucocorticoid Receptor Inhibits the Stem-Like Properties of Bladder Cancer via Inactivating the β-Catenin Pathway

Background: Glucocorticoid receptor (GR) signaling pathway has been shown to involve epithelial -to- mesenchymal transition which was implicated in the regulation of bladder cancer stem cells (CSCs) in our previous study. Herein, we aim to figure out how GR affects the stem-like properties of bladder cancer cells.

Methods: We used dexamethasone (DEX) treatment or gene-knockdown/-knockout techniques to activate or silence the GR pathway, respectively. Then we applied immunohistochemical staining and flow cytometry to assess the associations between the expression levels of GR and a stem cell surface marker CD44. Stem-like properties were assessed by reactive oxygen species (ROS), sphere-formation and side population assays. The expression levels of cancer stem cell-associated molecules were assessed by quantitative PCR and Western blotting. Tumor growth was compared using mouse xenograft models.

Results: In GR-positive bladder cancer cells, DEX significantly reduced the expression of CD44 as well as pluripotency transcription factors including β-catenin and its downstream target (C-MYC, Snail, and OCT-4), the rate of sphere formation, and the proportion of side populations, and induced the intracellular levels of ROS. By contrast, GR silencing in bladder cancer cells showed the opposite effects. In xenograft-bearing mice, GR silencing resulted in the enhancement of tumor growth.

Conclusions: These data suggested that GR activity was inversely associated with the stem-like properties of bladder cancer cells, potentially via inactivating the β-catenin pathway.

Single-cell RNA sequencing reveals the tumor microenvironment and facilitates strategic choices to circumvent treatment failure in a chemorefractory bladder cancer patient

BACKGROUND

Tumor cell-intrinsic mechanisms and complex interactions with the tumor microenvironment contribute to therapeutic failure via tumor evolution. It may be possible to overcome treatment resistance by developing a personalized approach against relapsing cancers based on a comprehensive analysis of cell type-specific transcriptomic changes over the clinical course of the disease using single-cell RNA sequencing (scRNA-seq).

METHODS

Here, we used scRNA-seq to depict the tumor landscape of a single case of chemo-resistant metastatic, muscle-invasive urothelial bladder cancer (MIUBC) addicted to an activating Harvey rat sarcoma viral oncogene homolog (HRAS) mutation. In order to analyze tumor evolution and microenvironmental changes upon treatment, we also applied scRNA-seq to the corresponding patient-derived xenograft (PDX) before and after treatment with tipifarnib, a HRAS-targeting agent under clinical evaluation.

RESULTS

In the parallel analysis of the human MIUBC and the PDX, diverse stromal and immune cell populations recapitulated the cellular composition in the human and mouse tumor microenvironment. Treatment with tipifarnib showed dramatic anticancer effects but was unable to achieve a complete response. Importantly, the comparative scRNA-seq analysis between pre- and post-tipifarnib-treated PDX revealed the nature of tipifarnib-refractory tumor cells and the tumor-supporting microenvironment. Based on the upregulation of programmed death-ligand 1 (PD-L1) in surviving tumor cells, and the accumulation of multiple immune-suppressive subsets from post-tipifarnib-treated PDX, a PD-L1 inhibitor, atezolizumab, was clinically applied; this resulted in a favorable response from the patient with acquired resistance to tipifarnib.

CONCLUSION

We presented a single case report demonstrating the power of scRNA-seq for visualizing the tumor microenvironment and identifying molecular and cellular therapeutic targets in a treatment-refractory cancer patient.

Development And In Vitro Characterization Of Bladder Tumor Cell Targeted Lipid-Coated Polyplex For Dual Delivery Of Plasmids And Small Molecules

BACKGROUND

Bladder cancer is the fourth most common cancer in men and eleventh most common in women. Combination therapy using a gene and chemotherapeutic drug is a potentially useful strategy for treating bladder cancer in cases where a synergistic benefit can be achieved successfully. This approach relies on developing drug combinations using carrier systems that can load both hydrophilic genes and hydrophobic drugs. Ideally, the formulation for carrier system should be free of traditional high shear techniques such as sonication and extrusion to reduce shear-induced nucleic acid strand breakage. Moreover, the system should be able to protect the nucleic acid from enzymatic attack and deliver it specifically to the tumor site.

MATERIALS AND METHODS

A dual payload carrier system that was formulated using a simple flow mixing technique to complex anionic plasmid (EGFP-NLS) using a cationic polymer (CD-PEI2.5kD) followed by coating of the polyplex using lipid membranes. The resulting lipid-coated polyplex (LCP) formulations are targeted to bladder cancer cells by employing a bacterial adhesive peptide sequence, RWFV, that targets the LCP to the tumor stroma for efficiently delivering reporter plasmid, EGFP-NLS and a model small molecule drug, pyrene, to the cancer cells.

RESULTS

Encapsulation efficiency of the peptide targeted carrier for the plasmid was 50% ± 0.4% and for pyrene it was 16% ± 0.4%. The ability of the targeted LCP to transfect murine bladder cancer cells was 4-fold higher than LCP bearing a scrambled peptide sequence. Fluorescence of cells due to pyrene delivery was highest after 4 hrs using targeted LCP. Finally, we loaded the peptide targeted LCP with anti-cancer agent, curcumin. The targeted formulation of curcumin resulted in only 45% viable cancer cells at a concentration of 5 µg/mL, whereas the empty and non-targeted formulations did not result any significant cell death.

CONCLUSION

These results demonstrate the specificity of the targeting peptide sequence in engaging tumor cells and the utility of the developed carrier platform to deliver a dual payload to bladder tumor cells.

Epidemiology and unmet needs of bladder cancer in Italy: a critical review

Bladder cancer is one of the most frequent cancers in high-income countries. Information on bladder cancer in Italy is scattered across scientific literature and institutional and educational resources and no attempt has been made yet to organize and summarize this information across various sources of available data. We, therefore, present herein a critical literature review of recent epidemiological and healthcare data, including patients' unmet needs. We undertook a critical review of the scientific and grey literature by exploring several different databases and search browsers. Available official statistics indicate a high burden of bladder cancer in Italy, where this neoplasm has one of the highest incidences worldwide and, in consideration of its relatively high survival, it ranks 4th in cancer prevalence. The limited therapeutic options for muscle-invasive and advanced/metastatic urothelial cancer are one of the major unmet needs for patients with this neoplasm, in Italy and worldwide. Advances in cancer immunotherapy and in understanding molecular biology of bladder cancer are, however, rapidly altering the therapeutic landscape for targeted subgroups of patients with advanced/metastatic disease. Other unmet needs include the low quality of life after radical cystectomy, the lack of widespread clinical pathway schemes to improve and standardize the quality of care and low Italian patients empowerment. Bladder cancer represents a health burden in Italy, with high incidence and prevalence rates, and important unmet needs for patients, including the limited therapeutic options for advanced/metastatic cancers, the low quality of life after radical cystectomy, the lack of widespread clinical pathway schemes, and the low patients empowerment.

Outcomes With First-line PD-1/PD-L1 Inhibition in Advanced Urothelial Cancer: A Single Institution Experience

BACKGROUND

First-line PD-inhibition in cisplatin-ineligible patients with locally advanced or metastatic urothelial cancer represents a novel clinical setting, with uncertainty concerning second-line outcomes. Specifying second-line treatment and outcomes will provide guidance in this new sequence. We performed a retrospective chart review to document the outcomes of these patients treated at our institution.

PATIENTS AND METHODS

Our cohort consisted of 43 patients with advanced urothelial cancer receiving first-line checkpoint inhibition. Baseline factors, programmed death-ligand 1 (PD-L1) status, treatments, and outcomes during and beyond the first line were obtained. Response was scored using Response Evaluation Criteria in Solid Tumors, version 1.1 criteria. Log rank tests were used to compare outcomes in prognostic subgroups, and outcome associations with PD-L1 status were analyzed with Fisher exact tests.

RESULTS

A total of 43 patients received first-line atezolizumab or pembrolizumab from June 2014 until June 2018. The median age was 76.8 years, and the population was 74% male, with 60% having visceral metastases. Reasons for cisplatin ineligibility were Eastern Cooperative Oncology Group performance status 2%, 30%; renal insufficiency, 44%, and both, 21%. First-line objective response rate (ORR) was 30%, and complete response was 14%. The median overall survival was 11.7 months. Of 29 patients progressing, 17 received second-line treatment (most commonly, gemcitabine/carboplatin [10 patients]). The second-line response rate was 33%, and the ORR was 11%. The second-line median overall survival was 6.2 months. No association was found between PD-L1 status and outcomes.

CONCLUSION

Outcomes with first-line immunotherapy are consistent with historical outcomes. The ORR after first-line checkpoint inhibition falls short of historical comparators; however, the response rate compares favorably to those of chemotherapies used in previous second-line regimens. The older age and poorer performance status may have contributed to second-line outcomes.

Special Issue on Molecular Research Efforts in Urothelial Carcinoma: Summary of Included Topics

This Special Issue of International Journal of Molecular Sciences (IJMS) covers one of the most intriguing and emerging fields in terms of molecular oncology and uro-oncologic research efforts over the recent years, namely urothelial carcinoma of the bladder (UCB), as well as urothelial carcinoma of the upper urinary tract (UTUC). A total of 8 articles published in this Special Issue highlight the current progress in molecular oncology and cancer genetics in UCB, including a wide range of research topics, such as FGFR-inhibitors, sarcopenia in UCB, molecular predictors of response following neoadjuvant chemotherapy, exercise cardiac training impacts in the murine UCB model, Obatoclax, tropomyosins as potential biomarkers, immunotherapeutic approaches, as well as a transcriptional analysis of immunohistochemically defined UCB-subgroups. Find a brief summary of the respective articles below.

Second-Line Systemic Treatment for Metastatic Urothelial Carcinoma: A Network Meta-Analysis of Randomized Phase Clinical Trials

Purpose: We aimed to evaluate and compare relative impacts of various second-line treatments on overall survival (OS) in metastatic urothelial carcinoma (mUC). Method: A literature search was conducted in PubMed, Embase, and the Cochrane Library for all articles published prior to December 2018 in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Seven randomized controlled trials with phase III design that met study eligibility criteria were selected for final analysis. A Bayesian framework network meta-analysis (NMA) was applied to indirectly compare the effect of each treatment on OS. Results: In NMA, atezolizumab (HR, 0.90; 95% CI, 0.57-1.40) and pembrolizumab (HR, 0.77, 95% CI, 0.48-1.20) showed no significant effect on OS improvement compared to vinflunine. Gemcitabine/paclitaxel combination (HR, 1.30; 95% CI, 0.80-1.90) and lapatinib (HR, 0.95; 95% CI, 0.57-1.60) was not significantly associated with OS improvement compared to atezolizumab and best supportive care, respectively. However, results of rankograms revealed that pembrolizumab and atezolizumab were the first and second rank therapeutic agents for OS improvement in post-platinum mUC. Conclusions: Our NMA results are inconclusive. The optimal second-line treatment for OS improvement could not be determined because there were no significant OS differences among evaluated therapeutic agents. However, the use of immunotherapeutic agents such as atezolizumab and pembolizumab may have priority for improving OS in second-line setting of mUC.

Molecular and histopathology directed therapy for advanced bladder cancer

Bladder cancer is a heterogeneous group of tumours with at least 40 histological subgroups. Patients with localized disease can be cured with surgical resection or radiotherapy, but such curative options are limited in the setting of recurrent disease or distant spread, in which case systemic therapy is used to control disease and palliate symptoms. Cytotoxic chemotherapy has been the mainstay of treatment for advanced bladder cancer, but high-quality evidence is lacking to inform the management of rare subgroups that are often excluded from studies. Advances in molecular pathology, the development of targeted therapies and the resurgence of immunotherapy have led to the reclassification of bladder cancer subgroups and rigorous efforts to define predictive biomarkers for cancer therapies. In this Review, we present the current evidence for the management of conventional, variant and divergent urothelial cancer subtypes, as well as non-urothelial bladder cancers, and discuss how the integration of genomic, transcriptomic and proteomic characterization of bladder cancer could guide future therapies.

PD-1/PD-L1 Combinations in Advanced Urothelial Cancer: Rationale and Current Clinical Trials

Chemotherapy is no longer the only viable option for patients with locally advanced or metastatic urothelial carcinoma. Immunotherapy, as checkpoint inhibition, has received United States Food and Drug Administration approval in the preceding several years, both in the second-line and first-line for cisplatin-ineligible patients. Those who respond often do so durably; however, response rates in the first line are 23% to 24%, and are lower in the second line. With a focus on urothelial carcinoma, this review discusses the tumor microenvironment and its negative influence on anti-tumor immunity, as well as measures to counteract immune suppression or evasion. The review then describes a range of current clinical trials implementing these measures in the form of programmed death-combination therapy, specifically in advanced bladder and urothelial cancers.

Single-centre Experience of Patients with Metastatic Urothelial Cancer Treated with Chemotherapy Following Immune Checkpoint Inhibition

There are few data on outcomes for patients with metastatic urothelial carcinoma (MUC) who receive chemotherapy (CT) after progression on immune checkpoint inhibitors (ICIs). We carried out a retrospective single-centre analysis of MUC patients who progressed after ICI and then received CT. Patients fell into two groups: CT-naive (no prior-CT) and CT-pretreated (platinum-based CT followed by ICI on progression). The response rate (RR), progression-free survival (PFS), and duration of response (DOR) were assessed. A total of 29 patients received CT following progression on ICI. The median follow-up was 17.0mo (interquartile range 9.1-20.5mo). In the CT-naive group (n=17), 53% had a partial response, 18% had stable disease, and 29% had progressive disease. In the CT-pretreated group (n=12) 17% had a partial response, 67% had stable disease, and 16% had progressive disease. The median PFS was 6.4mo (95% confidence interval [CI] 3.8-9.1) in the CT-naive and 4.4mo (95% CI 1.5-7.3) in the CT-pretreated group. The median DOR was 8.1mo (range 5.1-11.1) among the ten patients with a response to CT after ICI in both groups. Some 38% of patients in the CT-naive and 17% in the CT-pretreated group had dose reductions on post-ICI CT. CT and ICI can be sequenced after previous chemotherapy exposure, although this does not induce long-term durable remissions in most patients. PATIENT SUMMARY: We looked at outcomes for patients with metastatic bladder cancer who received chemotherapy after the cancer got worse while on immunotherapy. We found that patients can be safely treated with further chemotherapy. However, the positive effects of chemotherapy will not be durable in the majority of patients.

Inhibition of EZH2 induces NK cell-mediated differentiation and death in muscle-invasive bladder cancer

Lysine-specific demethylase 6A (KDM6A) and members of the Switch/Sucrose Non-Fermentable (SWI/SNF) family are known to counteract the activity of Enhancer of Zeste Homolog 2 (EZH2), which is often overexpressed and is associated with poor prognosis in muscle-invasive bladder cancer. Here we provide evidence that alterations in chromatin modifying enzymes, including KDM6A and members of the SWI/SNF complex, are frequent in muscle-invasive bladder cancer. We exploit the loss of function mutations in KDM6A and SWI/SNF complex to make bladder cancer cells susceptible to EZH2-based epigenetic therapy that activates an immune response to drive tumor cell differentiation and death. We reveal a novel mechanism of action of EZH2 inhibition, alone and in combination with cisplatin, which induces immune signaling with the largest changes observed in interferon gamma (IFN-γ). This upregulation is a result of activated natural killer (NK) signaling as demonstrated by the increase in NK cell-associated genes MIP-1α, ICAM1, ICAM2, and CD86 in xenografts treated with EZH2 inhibitors. Conversely, EZH2 inhibition results in decreased expression of pluripotency markers, ALDH2 and CK5, and increased cell death. Our results reveal a novel sensitivity of muscle-invasive bladder cancer cells with KMD6A and SWI/SNF mutations to EZH2 inhibition alone and in combination with cisplatin. This sensitivity is mediated through increased NK cell-related signaling resulting in tumor cell differentiation and cell death.

BGJ398, A Pan-FGFR Inhibitor, Overcomes Paclitaxel Resistance in Urothelial Carcinoma with FGFR1 Overexpression

Paclitaxel (PTX) is commonly used to treat urothelial carcinoma (UC) after platinum-based chemotherapy has failed. However, single-agent taxane therapy is not sufficient to inhibit tumor progression and drug resistance in advanced UC. Epithelial-to-mesenchymal transition (EMT) induced by fibroblast growth factor receptor (FGFR)1 signaling has been proposed as a mechanism of PTX resistance, but it is unclear whether this can be overcome by FGFR1 inhibition. The present study investigated whether FGFR1 overexpression contributes to PTX resistance and whether FGFR inhibition can enhance PTX efficacy in UC. The effects of PTX combined with the FGFR inhibitor BGJ398 were evaluated in UC cell lines by flow cytometry; Western blot analysis; cell viability, migration, and colony forming assays; and RNA interference. PTX+BGJ398 induced cell cycle arrest and apoptosis in UC cells with mesenchymal characteristics was accompanied by downregulation of cyclin D1 protein and upregulation of gamma-histone 2A family member X and cleaved poly(ADP-ribose) polymerase. Additionally, PTX+BGJ398 synergistically suppressed UC cell migration and colony formation via regulation of EMT-associated factors, while FGFR1 knockdown enhanced the antitumor effect of PTX. These findings provide a basis for development of effective strategies for overcoming PTX resistance in UC through inhibition of FGFR1 signaling.

Pembrolizumab Combined With Either Docetaxel or Gemcitabine in Patients With Advanced or Metastatic Platinum-Refractory Urothelial Cancer: Results From a Phase I Study

INTRODUCTION

Cytotoxic chemotherapy might prime urothelial cancer (UC) to checkpoint inhibition, prompting a trial of chemotherapy with the programmed death receptor-1 inhibitor pembrolizumab.

PATIENTS AND METHODS

Patients with advanced, platinum-refractory UC received pembrolizumab and either docetaxel (arm A) or gemcitabine (arm B). Primary end points were assessments of maximum tolerated dose and dose-limiting toxicity (DLT). Secondary end points were overall response rate (ORR) and progression-free survival (PFS).

RESULTS

Twelve patients were enrolled in the initial cohorts; 6 in each arm. One DLT was seen in each arm: Grade 3 hypophosphatemia (arm A), Grade 3 diarrhea (arm B). Adverse events of Grade >3 were observed in 7 (54%), the most common being anemia (6; 50%), fatigue (6; 50%), hyponatremia (4; 33%) and neutropenia (3; 25%), with no treatment-related deaths. There were 5 confirmed responses (1 complete, 4 partial), with an ORR of 42% and disease control rate (DCR) of 58%. Arm A had an ORR of 50% and DCR of 67%, whereas arm B had an ORR of 33% and DCR of 50%. Median PFS was 4.8, 5.7, and 3.7 months for the overall cohort, arm A, and arm B, respectively.

CONCLUSION

Pembrolizumab with either docetaxel or gemcitabine is feasible for treatment of platinum-refractory advanced UC patients. Preliminary efficacy was observed. Further examination is warranted.

From Clinical Trials to Real-life Clinical Practice: The Role of Immunotherapy with PD-1/PD-L1 Inhibitors in Advanced Urothelial Carcinoma

CONTEXT

A number of PD-1/PD-L1 inhibitors have recently been approved for use in patients with locally advanced or metastatic urothelial carcinoma (UC) on the basis of results from several clinical trials.

OBJECTIVE

To review the evidence from these trials and consider what it means for the use of these drugs in first-line and post-platinum settings in real-life clinical practice.

EVIDENCE ACQUISITION

PubMed was searched for full reports of clinical trials of single-agent PD-1/PD-L1 inhibitors in advanced UC. Twelve publications were included.

EVIDENCE SYNTHESIS

Responses to PD-1/PD-L1 inhibitors appear to be durable but are only achieved in 17-26% of patients. These drugs offer different toxicity and efficacy profiles to standard chemotherapy regimens. This should be considered when choosing a treatment strategy for each patient.

CONCLUSIONS

PD-1/PD-L1 inhibitors represent a major step forward in the management of advanced UC, although several questions remain regarding their optimal use in routine clinical practice. A validated predictive biomarker of response is yet to be defined, and this is perhaps the most significant unmet need for currently available drugs.

PATIENT SUMMARY

We reviewed the results from clinical trials that investigated how well certain types of anticancer drugs called PD-1/PD-L1 inhibitors worked in patients with bladder cancer. We found that more research is required to identify (1) the factors that might predict which patients with bladder cancer will respond to PD-1/PD-L1 inhibitors and (2) the optimum duration of treatment with these drugs.

Efficacy of BGJ398, a Fibroblast Growth Factor Receptor 1-3 Inhibitor, in Patients with Previously Treated Advanced Urothelial Carcinoma with FGFR3 Alterations

BGJ398, a potent and selective pan-FGFR antagonist, was prospectively evaluated in patients with metastatic urothelial carcinoma bearing a diverse array of FGFR3 alterations. Patients (N = 67) who were unable to receive platinum chemotherapy were enrolled. The majority (70.1%) had received two or more prior antineoplastic therapies. BGJ398 was administered orally at 125 mg/day on a 3 weeks on, 1 week off schedule until unacceptable toxicity or progression. The primary endpoint was the response rate. Among 67 patients treated, an overall response rate of 25.4% was observed and an additional 38.8% of patients had disease stabilization, translating to a disease control rate of 64.2%. The most common treatment-emergent toxicities were hyperphosphatemia, elevated creatinine, fatigue, constipation, and decreased appetite. Further examination of BGJ398 in this disease setting is warranted.Significance: BJG398 is active in patients with alterations in FGFR3, resulting in both reductions in tumor volume and stabilization of disease. Our data highlight putative mechanisms of resistance to the agent, which may be useful in following disease status. Cancer Discov; 8(7); 812-21. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 781.

Decitabine augments cytotoxicity of cisplatin and doxorubicin to bladder cancer cells by activating hippo pathway through RASSF1A

Genetic abnormalities and epigenetic alterations both play vital role in initiation as well as progression of cancer. Whereas genetic mutations cannot be reversed, epigenetic alterations such as DNA methylation can be reversed by the application of DNA methyltransferase inhibitor decitabine. Epigenetic silencing of RASSF1A and involvement of hippo pathway both have been shown to involve in chemo-resistance. Purpose of this study was to observe the effect of combination treatment of decitabine with cisplatin or doxorubicin on bladder cancer cells involving hippo pathway through RASSF1A. Bladder cancer cells (HT1376 & T24) were treated with decitabine and its effect on RASSF1A expression, hippo pathway molecules (MST & YAP), and its downstream targets (CTGF, CYR61 & CTGF) was observed. Effect of decitabine pretreatment on sensitivity of bladder cancer cells towards chemotherapeutic drugs was also studied. Decitabine treatment leads to restoration of RASSF1A, activation of hippo pathway followed by decreased expression of its oncogenic downstream targets (CTGF & CYR61). Further pretreatment of decitabine enhanced cytotoxicity of cisplatin and doxorubicin to bladder cancer cells.

Unwrapping the genomic characteristics of urothelial bladder cancer and successes with immune checkpoint blockade therapy

Urothelial bladder cancer (UBC) is one of the most common lethal cancer worldwide and the 5-year survival rate has not improved significantly with current treatment protocols during the last decade. Intravesical immunotherapy with Bacillus Calmette-Guérin is currently the standard care for non-muscle invasive UBC. Recently, a subset of patients with locally advanced or metastatic UBC have responded to checkpoint blockade immunotherapy against the programmed cell death 1 protein (PD-1) or its ligand (PD-L1) or the cytotoxic T-lymphocyte antigen 4 that releases the inhibition of T cells, the remarkable clinical efficacy on UBC has brought total five checkpoint inhibitors approved by the FDA in the last 2 years, and this is revolutionizing treatment of advanced UBC. We discuss the rationale for immunotherapy in bladder cancer, progress with blocking the PD-1/PD-L1 pathway for UBC treatment, and ongoing clinical trials. We highlight the complexity of the interactions between cancer cells and the immune system, the genomic basis for response to checkpoint blockade immunotherapy, and potential biomarkers for predicting immunotherapeutic response.

IGF1R activation and the in vitro antiproliferative efficacy of IGF1R inhibitor are inversely correlated with IGFBP5 expression in bladder cancer

Background

The insulin growth factor (IGF) pathway has been proposed as a potential therapeutic target in bladder cancer. We characterized the expression of components of the IGF pathway — insulin growth factor receptors (INSR, IGF1R, IGF2R), ligands (INS, IGF1, IGF2), and binding proteins (IGFBP1–7, IGF2BP1–3) — in bladder cancer and its correlation with IGF1R activation, and the anti-proliferative efficacy of an IGF1R kinase inhibitor in this setting.

Methods

We analyzed transcriptomic data from two independent bladder cancer datasets, corresponding to 200 tumoral and five normal urothelium samples. We evaluated the activation status of the IGF pathway in bladder tumors, by assessing IGF1R phosphorylation and evaluating its correlation with mRNA levels for IGF pathway components. We finally evaluated the correlation between inhibition of proliferation by a selective inhibitor of the IGF1R kinase (AEW541), reported in 13 bladder cancer derived cell lines by the Cancer Cell Line Encyclopedia Consortium and mRNA levels for IGF pathway components.

Results

IGF1R expression and activation were stronger in non-muscle-invasive than in muscle-invasive bladder tumors. There was a significant inverse correlation between IGF1R phosphorylation and IGFBP5 expression in tumors. Consistent with this finding, the inhibition of bladder cell line viability by IGF1R inhibitor was also inversely correlated with IGFBP5 expression.

Conclusion

The IGF pathway is activated and therefore a potential therapeutic target for non muscle-invasive bladder tumors and IGFBP5 could be used as a surrogate marker for predicting tumor sensitivity to anti-IGF therapy.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3618-5) contains supplementary material, which is available to authorized users.

Randomized Phase II Study Investigating Pazopanib Versus Weekly Paclitaxel in Relapsed or Progressive Urothelial Cancer

Purpose Two previous single-arm trials have drawn conflicting conclusions regarding the activity of pazopanib in urothelial cancers after failure of platinum-based chemotherapy. Patients and Methods This randomized (1:1) open-label phase II trial compared the efficacy of pazopanib 800 mg orally with paclitaxel (80 mg/m2 days 1, 8, and 15 every 28 days) in the second-line setting. The primary end point was overall survival (OS). Results Between August 2012 and October 2014, 131 patients, out of 140 planned, were randomly assigned. The study was terminated early on the recommendation of the independent data monitoring committee because of futility. Final analysis after the preplanned number of deaths (n = 110) occurred after a median follow-up of 18 months. One hundred fifteen deaths had occurred at the final data extract presented here. Median OS was 8.0 months for paclitaxel (80% CI, 6.9 to 9.7 months) and 4.7 months for pazopanib (80% CI, 4.2 to 6.4 months). The hazard ratio (HR) adjusted for baseline stratification factors was 1.28 (80% CI, 0.99 to 1.67; one-sided P = .89). Median progression-free survival was 4.1 months for paclitaxel (80% CI, 3.0 to 5.6 months) and 3.1 months for pazopanib (80% CI, 2.7 to 4.6 months; HR, 1.09; 80% CI, 0.85 to 1.40; one-sided P = .67). Discontinuations for toxicity occurred in 7.8% and 23.1% for paclitaxel and pazopanib, respectively. Conclusion Pazopanib did not have greater efficacy than paclitaxel in the second-line treatment of urothelial cancers. There was a trend toward superior OS for paclitaxel.

Systemic Immunotherapy for Urothelial Cancer: Current Trends and Future Directions

Urothelial cancer of the bladder, renal pelvis, ureter, and other urinary organs is the fifth most common cancer in the United States, and systemic platinum-based chemotherapy remains the standard of care for first-line treatment of advanced/metastatic urothelial carcinoma (UC). Until recently, there were very limited options for patients who are refractory to chemotherapy, or do not tolerate chemotherapy due to toxicities and overall outcomes have remained very poor. While the role of immunotherapy was first established in non-muscle invasive bladder cancer in the 1970s, no systemic immunotherapy was approved for advanced disease until the recent approval of a programmed death ligand-1 (PD-L1) inhibitor, atezolizumab, in patients with advanced/metastatic UC who have progressed on platinum-containing regimens. This represents a significant milestone in this disease after a void of over 30 years. In addition to atezolizumab, a variety of checkpoint inhibitors have shown a significant activity in advanced/metastatic urothelial carcinoma and are expected to gain Food and Drug Administration (FDA) approval in the near future. The introduction of novel immunotherapy agents has led to rapid changes in the field of urothelial carcinoma. Numerous checkpoint inhibitors are being tested alone or in combination in the first and subsequent-line therapies of metastatic disease, as well as neoadjuvant and adjuvant settings. They are also being studied in combination with radiation therapy and for non-muscle invasive bladder cancer refractory to BCG. Furthermore, immunotherapy is being utilized for those ineligible for firstline platinum-based chemotherapy. This review outlines the novel immunotherapy agents which have either been approved, or are currently being investigated in clinical trials in UC.

Safety and activity of pembrolizumab in patients with locally advanced or metastatic urothelial cancer (KEYNOTE-012): a non-randomised, open-label, phase 1b study

BACKGROUND

PD-1 and its ligands are expressed in urothelial cancer, and findings have shown that inhibition of the PD-1 pathway has clinical benefit. We aimed to assess the safety and activity of an anti-PD-1 antibody pembrolizumab in patients with locally advanced or metastatic urothelial cancer.

METHODS

This study was part of the non-randomised, multi-cohort, open-label, phase 1b KEYNOTE-012 basket trial. We enrolled patients aged 18 years and older with a histologically or cytologically confirmed diagnosis of locally advanced or metastatic urothelial cancer, including cancers of the renal pelvis, ureter, bladder, or urethra, from eight hospitals in the USA and Israel. Patients were required to have at least 1% PD-L1 expression detected on the tumour cells or in tumour stroma, as determined by immunohistochemistry. Patients were given 10 mg/kg intravenous pembrolizumab every 2 weeks until disease progression, unacceptable toxic effects, or the end of the study (ie, 24 months of treatment). Primary endpoints were safety and overall response (defined by Response Evaluation Criteria In Solid Tumors [RECIST] version 1.1), as assessed by a masked, independent central review. Safety was assessed in patients who received one or more doses of pembrolizumab (all-patients-as-treated population); activity was assessed in patients who received pembrolizumab, had measurable disease at baseline, and had one or more post-baseline scans, or discontinued because of progressive disease or treatment-related adverse events (full analysis set). This study is registered with ClinicalTrials.gov, number NCT01848834, and is no longer enrolling patients; follow-up is ongoing.

FINDINGS

Between May 14, 2013, and Dec 10, 2013, 115 patients were tissue pre-screened as part of a two-part consent process. 61 (53%) patients were PD-L1 positive, of whom 33 were enrolled in this study. All enrolled patients received at least one dose of pembrolizumab and were included in the safety analyses. 27 patients comprised the full analysis set and were deemed assessable for activity. Six patients were not assessable: three discontinued study drug because of a non-treatment-related adverse event before the first post-baseline scan, two withdrew before the first post-baseline scan, and one had no measurable disease at baseline. The most common treatment-related adverse events were fatigue (six [18%] of 33 patients) and peripheral oedema (4 [12%]). Five (15%) patients had 11 grade 3 treatment-related adverse events; no single event occurred in more than one patient. Three (9%) patients experienced five serious treatment-related adverse events. After median follow-up of 13 months (range 1-26, IQR 5-23), an overall response was achieved in seven (26% [95% CI 11-46]) of 27 assessable patients, with three (11% [2-29]) complete and four (15% [4-34]) partial responses. Of the four deaths that occurred during the study (cardiac arrest, pneumonia, sepsis, and subarachnoid haemorrhage), none were deemed treatment related.

INTERPRETATION

Pembrolizumab showed anti-tumour activity and acceptable safety in patients with advanced urothelial cancer, supporting ongoing phase 2 and 3 studies of pembrolizumab in this population.

FUNDING

Merck & Co., Inc.

A review of the PD-1/PD-L1 checkpoint in bladder cancer: From mediator of immune escape to target for treatment

PURPOSE

Recent observations have focused attention on the means that human tumors employ to evade host defense systems critical to immune surveillance. The concepts of immunotherapy are familiar to urologists because of the use of bacillus Calmette-Guérin in bladder cancer. Research demonstrating the importance of checkpoint inhibitors in suppressing immune responses against tumors has heightened interest in immunotherapy at a time when there is a need for alternatives to bacillus Calmette-Guérin. We review the literature on the application of immunotherapeutic agents targeting a key checkpoint pathway, programmed death 1 (PD-1) and its ligand (PD-L1), in the field of bladder cancer.

MATERIALS AND METHODS

A comprehensive literature review was performed using Medline/Pubmed and Embase.

RESULTS

The PD-1/PD-L1 pathway may be manipulated by cancer cells to subvert the immune system. PD-1/PD-L1 blockade has been tested in clinical trials for various malignancies including metastatic urothelial carcinoma, with significant response rates and limited side effects. PD-L1 expression has also been proposed as a prognostic marker for bladder cancer with mixed results.

CONCLUSIONS

PD-1 is one of several key receptors mediating immune escape, and agents targeting its ligand PD-L1 have already been successfully applied to patients with metastatic urothelial cancer. More research is needed to standardize criteria for PD-L1 positivity, explore its use as a biomarker, and optimize its use in the treatment for bladder cancer.

Circulating Biomarkers in Bladder Cancer

Bladder cancer is a molecularly heterogeneous disease characterized by multiple unmet needs in the realm of diagnosis, clinical staging, monitoring and therapy. There is an urgent need to develop precision medicine for advanced urothelial carcinoma. Given the difficulty of serial analyses of metastatic tumor tissue to identify resistance and new therapeutic targets, development of non-invasive monitoring using circulating molecular biomarkers is critically important. Although the development of circulating biomarkers for the management of bladder cancer is in its infancy and may currently suffer from lower sensitivity of detection, they have inherent advantages owing to non-invasiveness. Additionally, circulating molecular alterations may capture tumor heterogeneity without the sampling bias of tissue biopsy. This review describes the accumulating data to support further development of circulating biomarkers including circulating tumor cells, cell-free circulating tumor (ct)-DNA, RNA, micro-RNA and proteomics to improve the management of bladder cancer.

Protein Profiling of Bladder Urothelial Cell Carcinoma

This study aimed to detect protein changes that can assist to understand the underlying biology of bladder cancer. The data showed forty five proteins were found to be differentially expressed comparing tumors vs non-tumor tissues, of which EGFR and cdc2p34 were correlated with muscle invasion and histological grade. Ten proteins (ß-catenin, HSP70, autotaxin, Notch4, PSTPIP1, DPYD, ODC, cyclinB1, calretinin and EPO) were able to classify muscle invasive BCa (MIBC) into 2 distinct groups, with group 2 associated with poorer survival. Finally, 3 proteins (P2X7, cdc25B and TFIIH p89) were independent factors for favorable overall survival.

Targeted Therapy for Metastatic Urothelial Cancer: A Work in Progress

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.A 64-year-old man presented to the clinic to discuss treatment options for progressive metastatic urothelial carcinoma (UC). At age 57 years, he underwent cystoprostatectomy for bacillus Calmette-Guérin-refractory, high-grade noninvasive UC. He was well until age 61 years, when he developed a left upper-tract UC. He underwent left nephroureterectomy, revealing locally advanced high-grade UC invading the renal parenchyma (pT3). Postoperatively, his renal function precluded adjuvant cisplatin-based chemotherapy. He enrolled onto a clinical trial of autologous cellular immunotherapy targeting human epidermal growth factor receptor 2, for which he was eligible on the basis of human epidermal growth factor receptor 2 positivity (≥ 1+ by immunohistochemistry) in his nephrectomy tumor specimen. He was randomly assigned to observation. Two years later, he developed a left pelvic mass. Biopsy confirmed metastatic high-grade UC. He was briefly treated with gemcitabine and carboplatin, but this was discontinued as a result of rapid symptomatic and radiographic progression at 8 weeks. He underwent palliative radiation to the left pelvic mass to relieve symptoms of pain and leg edema and subsequently elected to enroll onto a clinical trial of a programmed death 1 inhibitor. Concurrently, his previously obtained pelvic mass biopsy sample was sent for panel-based genomic profiling. He now returns for his first restaging evaluation. Imaging shows marked progression on study with new metastases to the liver as well as progressive edema and pain in the left leg, limiting ambulation. Review of his now-available genomic testing results reveals alterations in HRAS (G12D) and ATR (S296, Q257). He elected to enroll onto a single-arm, open-label trial of a farnesyl transferase inhibitor for patients with HRAS mutations.

Maintenance monotherapy with Gemcitabine following cisplatin-based primary combination chemotherapy in surgically treated advanced urothelial carcinoma: A matched-pair single institution analysis

The role of maintenance therapy with Gemcitabine (GEM) following cisplatin-based combination chemotherapy (CBCC) in patients with surgically treated advanced urothelial carcinoma (UC) remains to be fully elucidated. In the present case control study, a retrospective analysis was performed to evaluate the role of GEM monotherapy following surgical intervention for advanced UC. Between 1999 and 2013, 38 patients were identified with surgically treated advanced UC after having completed CBCC, who were additionally treated quarterly with two consecutive GEM (1,250 mg/m²) infusions as maintenance therapy. This collective was matched by propensity score matching to a control collective (n=38) that received primary CBCC alone, and the overall survival (OS), cancer-specific survival (CSS) and progression-free survival (PFS) rates were determined for the two collectives using Kaplan-Meier estimates and the log-rank test. Regression analysis was performed using the Cox proportional hazards model. The median follow-up time was 37 months (interquartile range: 9-148). Interestingly, patients treated with GEM following primary chemotherapy had a significantly improved outcome with respect to the 5-year OS (46.2 vs. 26.4%, P=0.0314) and 5-year CSS (61.3 vs. 33.4%, P=0.0386) rates. Notably, the 5-year PFS rate did not differ between the two groups (10.3 vs. 16.1%, P=0.134). It is proposed that additional GEM maintenance monotherapy is able to improve survival rates following primary CBCC in surgically treated patients with advanced UC, suggesting a possible treatment option for patients with, e.g., unclear disease status, or those who would require an active maintenance therapy in the future. Prospective studies should further determine the impact of GEM monotherapy with respect to PFS rates in groups comprising larger numbers of patients.

17-DMAG induces heat shock protein 90 functional impairment in human bladder cancer cells: knocking down the hallmark traits of malignancy

Heat shock protein 90 (Hsp90) is a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in multiple oncogenic signaling pathways. Hsp90 holds a prominent role in tumorigenesis, as numerous members of its broad clientele are involved in the generation of the hallmark traits of cancer. 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) specifically targets Hsp90 and interferes with its function as a molecular chaperone, impairing its intrinsic ATPase activity and undermining proper folding of multiple protein clients. In this study, we have examined the effects of 17-DMAG on the regulation of Hsp90-dependent tumorigenic signaling pathways directly implicated in cell cycle progression, survival, and motility of human urinary bladder cancer cell lines. We have used MTT-based assays, FACS analysis, Western blotting, semiquantitative PCR (sqPCR), immunofluorescence, and scratch-wound assays in RT4 (p53(wt)), RT112 (p53(wt)), T24 (p53(mt)), and TCCSUP (p53(mt)) human urinary bladder cancer cell lines. We have demonstrated that, upon exposure to 17-DMAG, bladder cancer cells display prominent cell cycle arrest and commitment to apoptotic and autophagic cell death, in a dose-dependent manner. Furthermore, 17-DMAG administration induced pronounced downregulation of multiple Hsp90 protein clients and other downstream oncogenic effectors, therefore causing inhibition of cell proliferation and decline of cell motility due to the molecular "freezing" of critical cytoskeletal components. In toto, we have clearly demonstrated the dose-dependent and cell type-specific effects of 17-DMAG on the hallmark traits of cancer, appointing Hsp90 as a key molecular component in bladder cancer targeted therapy.

Docetaxel for the treatment of bladder cancer

INTRODUCTION

Docetaxel has had a significant impact on the management of urothelial carcinoma (UC). Multiple phase II trials have been conducted to evaluate the efficacy of docetaxel in the treatment of metastatic UC. Docetaxel is an accepted community standard for the therapy of platinum-treated patients with metastatic UC.

AREAS COVERED

This review focuses on the data supporting a role for docetaxel in the therapy of advanced UC. It also explores the future development of docetaxel and describes the ongoing clinical trials in the treatment of UC.

EXPERT OPINION

Docetaxel plays an important role as one of the standard agents used in the comparator arms of randomized trials evaluating new agents as salvage therapy for metastatic UC. Furthermore, biologic agents are being developed in chemo-biologic regimens using docetaxel as the platform. In the context of emerging novel agents such as T-cell checkpoint inhibitors, docetaxel may continue to play a role as a salvage therapy in select patients ineligible for immunotherapy or following checkpoint inhibitors.

Pharmacogenomics: Biomarker-Directed Therapy for Bladder Cancer

The clinical management of bladder cancer has seen little change over the last three decades and there is pressing need to identify more effective treatments for advanced disease. Low clinical use of neoadjuvant therapies stems from historical limitations in the ability to predict patients most likely to respond to combination chemotherapies. This article focuses on recent molecular and genetic studies, highlighting promising clinical trials and retrospective studies, and discusses emerging trials that use predictive biomarkers to match patients with therapies to which they are most likely to respond. The implementation of predictive genomic and molecular biomarkers will revolutionize urologic oncology and the clinical management of bladder cancer.

Predicting the response of patients with advanced urothelial cancer to methotrexate, vinblastine, Adriamycin, and cisplatin (MVAC) after the failure of gemcitabine and platinum (GP)

BACKGROUND

Platinum-based systemic chemotherapy is the treatment of choice for patients with advanced urothelial carcinoma (UC). Although no chemotherapeutic regimen is established as a second-line therapy, recent studies reported that methotrexate, vinblastine, Adriamycin and cisplatin (MVAC) elicited a significant response in patients who failed gemcitabine and platinum (GP) chemotherapy. We investigated the clinical factors useful for predicting a favourable response to MVAC in UC patients who failed GP.

METHODS

Forty-five patients with advanced UC who received second-line MVAC chemotherapy after failure with first-line GP chemotherapy were enrolled in this study. Univariate and multivariate analyses based on Cox's regression were performed to identify independent prognostic factors for progression-free survival (PFS) after second-line MVAC chemotherapy.

RESULTS

The median follow-up period after the first MVAC administration was 10.0 months. The median PFS and overall survival (OS) were 6.5 months (95% confidence interval [CI]: 5.1-7.9) and 14.5 months (95% CI, 7.4-21.4), respectively. The overall response rate was 57.8%. The response to first-line GP chemotherapy (hazard ratio [HR], 2.500; p = 0.012) and patient age (HR, 1.047; p = 0.033) were predictors of PFS after MVAC chemotherapy.

CONCLUSIONS

The response to first-line GP chemotherapy and age were independent predictors of PFS in patients who received second-line MVAC chemotherapy. This report is the first to describe independent predictors of PFS after MVAC chemotherapy.