Focus on Biochemical and Clinical Predictors of Response to Immune Checkpoint Inhibitors in Metastatic Urothelial Carcinoma: Where Do We Stand?

The evolving treatment landscape of metastatic urothelial cancer

Cisplatin-based chemotherapy is currently the first-line standard of care for patients with metastatic urothelial cancer (mUC); however, up to 50% of patients are ineligible for cisplatin, necessitating alternative treatment options. Immune checkpoint inhibitors have been shown to be effective in cisplatin-ineligible patients. However, despite advances in the first-line setting, the prognosis remains poor, and challenges persist in selecting optimal therapies, treatment sequences and combination regimens. Maintenance therapy with avelumab revealed improved overall (OS) and progression-free survival (PFS) compared with best supportive care alone in patients with platinum-responsive mUC. Antibody-drug conjugates and targeted therapy with fibroblast growth factor receptor (FGFR) inhibitors have shown promise in selected patients, particularly in patients with metastatic disease that has progressed despite platinum-based chemotherapy. At the European Society of Medical Oncology Congress in 2023, groundbreaking results were presented from two phase III trials, EV-302/KEYNOTE-A39 and CheckMate 901, focusing on previously untreated mUC. In the former, the combination of enfortumab vedotin and pembrolizumab showed significant improvements in OS, PFS and overall response rate compared with chemotherapy alone; the combination of nivolumab with gemcitabine-cisplatin chemotherapy demonstrated a significant extension in median OS, PFS and overall response rate compared with chemotherapy alone. In addition, erdafitinib therapy resulted in significantly longer OS than chemotherapy among patients with mUC and FGFR alterations after previous treatment with immune checkpoint inhibitors. This comprehensive summary of the current treatment landscape for mUC incorporates clinical trial evidence and discussion of agents that are currently under investigation to provide support for clinical decision making and understanding of future therapeutic approaches.

Prognostic value of KRAS mutations, TP53 mutations and PD-L1 expression among lung adenocarcinomas treated with immunotherapy

AIMS

The aim of this study was to investigate the association between oncogenic alterations and programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinomas, as well as the prognostic value of KRAS and/or TP53 mutations in patients treated with immunotherapy.

METHODS

This study is a retrospective cohort study of 519 patients with lung adenocarcinomas analysed for mutations and PD-L1 expression. Data were collected from electronic pathology record system, next-generation sequencing system, and clinical databases. Association between mutations and PD-L1 expression was investigated, as well as survival statistics of the 65 patients treated with immunotherapy.

RESULTS

41% of the samples contained a KRAS mutation, predominantly together with mutations in TP53 (41%) or STK11 (10%). Higher expression of PD-L1 was seen among patients with KRAS mutations (p=0.002) and EGFR wild type (p=0.006). For patients treated with immunotherapy, there was no statistically significant difference for overall survival (OS) and progression-free survival (PFS) according to KRAS mutation status, TP53 mutation status or PD-L1 expression. The HR for concomitant mutations in TP53 and KRAS was 0.78 (95% CI 0.62 to 0.99) for OS and 0.43 (0.21 to 0.88) for PFS. Furthermore, concomitant TP53 and KRAS mutations predicted a better PFS (p=0.015) and OS (p=0.029) compared with no mutations or a single mutation in either TP53 or KRAS.

CONCLUSION

Mutations in TP53 together with KRAS may serve as a potential biomarker for survival benefits with immunotherapy.

Endothelial cells are a key target of IFN-g during response to combined PD-1/CTLA-4 ICB treatment in a mouse model of bladder cancer

To explore mechanisms of response to combined PD-1/CTLA-4 immune checkpoint blockade (ICB) treatment in individual cell types, we generated scRNA-seq using a mouse model of invasive urothelial carcinoma with three conditions: untreated tumor, treated tumor, and tumor treated after CD4+ T cell depletion. After classifying tumor cells based on detection of somatic variants and assigning non-tumor cell types using SingleR, we performed differential expression analysis, overrepresentation analysis, and gene set enrichment analysis (GSEA) within each cell type. GSEA revealed that endothelial cells were enriched for upregulated IFN-g response genes when comparing treated cells to both untreated cells and cells treated after CD4+ T cell depletion. Functional analysis showed that knocking out IFNgR1 in endothelial cells inhibited treatment response. Together, these results indicated that IFN-g signaling in endothelial cells is a key mediator of ICB induced anti-tumor activity.

Cancer immunotherapy with immune checkpoint inhibitors (ICIs): potential, mechanisms of resistance, and strategies for reinvigorating T cell responsiveness when resistance is acquired

Cancer is still the leading cause of death globally. The approval of the therapeutic use of monoclonal antibodies against immune checkpoint molecules, notably those that target the proteins PD-1 and PD-L1, has changed the landscape of cancer treatment. In particular, first-line PD-1/PD-L1 inhibitor drugs are increasingly common for the treatment of metastatic cancer, significantly prolonging patient survival. Despite the benefits brought by immune checkpoint inhibitors (ICIs)-based therapy, the majority of patients had their diseases worsen following a promising initial response. To increase the effectiveness of ICIs and advance our understanding of the mechanisms causing cancer resistance, it is crucial to find new, effective, and tolerable combination treatments. In this article, we addressed the potential of ICIs for the treatment of solid tumors and offer some insight into the molecular pathways behind therapeutic resistance to ICIs. We also discuss cutting-edge therapeutic methods for reactivating T-cell responsiveness after resistance has been established.

Endothelial cells are a key target of IFN-g during response to combined PD-1/CTLA-4 ICB treatment in a mouse model of bladder cancer

To explore mechanisms of response to combined PD-1/CTLA-4 immune checkpoint blockade (ICB) treatment in individual cell types, we generated scRNA-seq using a mouse model of invasive urothelial carcinoma with three conditions: untreated tumor, treated tumor, and tumor treated after CD4+ T cell depletion. After classifying tumor cells based on detection of somatic variants and assigning non-tumor cell types using SingleR, we performed differential expression analysis, overrepresentation analysis, and gene set enrichment analysis (GSEA) within each cell type. GSEA revealed that endothelial cells were enriched for upregulated IFN-g response genes when comparing treated cells to both untreated cells and cells treated after CD4+ T cell depletion. Functional analysis showed that knocking out IFNgR1 in endothelial cells inhibited treatment response. Together, these results indicated that IFN-g signaling in endothelial cells is a key mediator of ICB induced anti-tumor activity.

A Novel m7G-Related Genes-Based Signature with Prognostic Value and Predictive Ability to Select Patients Responsive to Personalized Treatment Strategies in Bladder Cancer

Although N7-methylguanosine (m7G) modification serves as a tumor promoter in bladder cancer (BLCA), the comprehensive role of m7G-related characterization in BLCA remains unclear. In this study, we systematically evaluated the m7G-related clusters of 760 BLCA patients through consensus unsupervised clustering analysis. Next, we investigated the underlying m7G-related genes among these m7G-related clusters. Univariate Cox and LASSO regressions were used for screening out prognostic genes and for reducing the dimension, respectively. Finally, we developed a novel m7G-related scoring system via the GSVA algorithm. The correlation between tumor microenvironment, prediction of personalized therapies and this m7G-related signature was gradually revealed. We first identified three m7G-related clusters and 1108 differentially expressed genes relevant to the three clusters. Based on the profile of 1108 genes, we divided BLCA patients into two clusters, which were quantified by our established m7G-related scoring system. Patients with higher m7G-related scores tended to have a better OS and more chances to benefit from immunotherapy. A significantly negative connection between sensitivity to classic chemotherapeutic drugs and m7G-related signature was uncovered. In summary, our data show that m7G-related characterization of BLCA patients can be of value for prognostic stratification and for patient-oriented therapeutic options, designing personalized treatment strategies in the preclinical setting.

Neoadjuvant Treatment in Muscle-Invasive Bladder Cancer: From the Beginning to the Latest Developments

Urothelial carcinoma of the bladder is one of the most prevalent cancers worldwide, diagnosed as muscle invasive in 25% of cases. Although several studies have demonstrated an overall 5% absolute survival benefit at 5 years with cisplatin-based combination neoadjuvant treatment, administration of chemotherapy prior to radical cystectomy (RC) in muscle-invasive bladder cancer (MIBC) patients is still a matter of debate. This may be due to the perceived modest survival benefit, cisplatin-based chemotherapy ineligibility, or fear of delaying potentially curative surgery in non-responders. However, immunotherapy and novel targeted therapies have shown to prolong survival in advanced disease and are under investigation in the neoadjuvant and adjuvant settings to reduce systemic relapse and improve cure rates. Genomic characterization of MIBC could help select the most effective chemotherapeutic regimen for the individual patient. Large cohort studies on neoadjuvant treatments with immune checkpoint inhibitors (ICIs) and molecular therapies, alone or combined with chemotherapy, are ongoing. In this review, we trace the development of neoadjuvant therapy in MIBC and explore recent advances that may soon change clinical practice.

Immunotherapy in Genitourinary Malignancy: Evolution in Revolution or Revolution in Evolution

Immunotherapy, the 5th pillar of cancer care after surgery, radiotherapy, cytotoxic chemotherapy, and precision therapy (molecular targeted therapy), is revolutionizing the standard of care in certain patients with genitourinary malignancies. As modest clinical benefits of IL-2 for metastatic renal cell carcinoma and Bacillus Calmette-Guerin therapy for early-stage bladder cancers in the past years, immune checkpoint inhibitors therapies demonstrate meaningful survival benefit and durable clinical response in renal cell carcinoma, urothelial carcinoma, and some prostate cancer. Despite best efforts, the benefits are limited to a minority of unselected patients due to the complexities of biomarker development. Now come the next hurdles: figuring out which patients best respond to immune checkpoint inhibitors and which patients won't respond to immune checkpoint inhibitors? How best to approach immune checkpoint inhibitors therapies to extend/maximize the treatment response as long as possible? How to overcome therapeutic resistance by specific concurrent immunomodulators or targeted therapy or chemotherapy? The role of immune checkpoint inhibitors in combination or sequencing with chemotherapy or other targeted therapies or other immunomodulating therapeutics in the early disease, neoadjuvant, adjuvant, and metastatic setting is actively under exploration. Ideal strategy for cancer care is to provide not just more time, but more quality time: there remain unmet needs for novel therapies that exploit molecular or genetic pathways to extend survival without compromising health-related quality of life for patients with advanced genitourinary malignancies. Further research is needed to discover new therapeutic strategies, and validate efficacy and effectiveness in real-world settings.

Management of Advanced Urothelial Carcinoma in Older and Frail Patients: Have Novel Treatment Approaches Improved Their Care?

Patients with urothelial carcinoma tend to be older and frailer with a large number of chronic medical conditions. This is particularly pronounced in those with unresectable locally advanced and metastatic urothelial carcinoma. Prior to 2016, treatment options in advanced urothelial carcinoma were limited to chemotherapy, and as a result, a large number of patients were not receiving disease-directed management. Over the last 6 years, multiple alternative modalities including immune checkpoint inhibitors and targeted therapies have been introduced. They are being utilized clinically in older and frail patients, but there are limited studies investigating outcomes in these specific populations. Based upon current evidence, age does not impact the efficacy and tolerance of immune checkpoint inhibitors if patients are fit enough to receive therapy. In frailer patients, immune checkpoint inhibitors appear to be safe, but outcomes from largely retrospective studies demonstrate mixed data regarding their efficacy. Although there are indications from clinical trials that enfortumab vedotin, sacituzumab govitecan, and erdafitinib are also efficacious irrespective of age, there is still not enough evidence to draw definitive conclusions about their use in older and frail patients. Regardless, in all older patients with advanced urothelial carcinoma, it is critical to evaluate for frailty through geriatric screening tools and comprehensive assessments. Combining these evaluations with consideration of an individual patient's goals should be the foundation upon which therapeutic decisions are made in this population of patients.

Checkpoint Inhibition in Bladder Cancer: Clinical Expectations, Current Evidence, and Proposal of Future Strategies Based on a Tumor-Specific Immunobiological Approach

Simple Summary

In contrast with other strategies, immunotherapy is a treatment aimed at empowering the patient’s immune system in order to increase immunity and the response against cancer. Recently, a new class of drugs, immune checkpoint inhibitors, has shown potential in increasing treatment chances for patients with bladder cancers, improving their survival. However, predicting the response to immune checkpoint inhibition is important, since only a group of patients develop a good response. Biomarkers to predict the response to checkpoint inhibition must identify tumors’ and patients’ specific profiles. This study reviews the current knowledge on this most relevant clinical topic, focusing on bladder cancer, going from basic science to ongoing clinical trials and available clinical evidence. Finally, a critical analysis of published data is provided, and an original panel of biomarkers, able to select the right patients for treatments, based on patient-specific immune profiling, is proposed.

Abstract

In contrast with other strategies, immunotherapy is the only treatment aimed at empowering the immune system to increase the response against tumor growth. Immunotherapy has a role in the treatment of bladder cancer (BC) due to these tumors’ high tumor mutational burden (TMB) and mostly prominent immune infiltrate. The therapy or combination has to be adjusted to the tumor’s immunobiology. Recently, a new class of immunotherapeutic agents, immune checkpoint inhibitors (ICI), has shown potential in increasing treatment chances for patients with genitourinary cancers, improving their oncological outcomes. The clinical efficacy of ICI has been shown in both the first-line treatment of cisplatin-ineligible patients, with programmed death ligand 1 (PD-L1)-positive tumors (atezolizumab, pembrolizumab), and in second-line settings, for progression after platinum-based chemotherapy (atezolizumab, pembrolizumab, and nivolumab for FDA and EMA; durvalumab and avelumab for FDA alone). Predicting the response to ICI is important since only a subset of patients undergoing ICI therapy develop a concrete and lasting response. Most of the patients require a different therapy or therapy combination to achieve tumor control. The cancer immunity cycle provides a conceptual framework to assist therapy selection. Biomarkers to predict response to ICI must identify where the cancer immunity cycle is disrupted. We reviewed the current knowledge on ICI treatment in BC, going from basic science to current data and available clinical evidence. Secondly, a critical analysis of published data is provided, and an original panel of biomarkers able to predict response to ICI treatment, based on tumor-specific immune profiling, is proposed.

Immune Checkpoint Inhibitors in Urothelial Bladder Cancer: State of the Art and Future Perspectives

Simple Summary

Urothelial bladder cancer (BC) is one of the most fatal cancers, with a dismal five-year survival rate of 5% in patients with metastatic disease. Clinically relevant benefits of immunotherapy in advanced or metastatic bladder cancer have led to Food and Drug Administration (FDA) approval of immune checkpoint inhibitors (ICIs) as second- or first-line therapy in patients unresponsive to or ineligible for standard treatment. The advantage of ICIs is being investigated in various stages of BC, either as monotherapy or in combination with other drugs. In this review we discuss the role of ICIs in BC, highlighting their current clinical application and outlining future therapeutic perspectives.

Abstract

Bladder cancer (BC) is the most common malignancy of the genitourinary tract, with high morbidity and mortality rates. Until recently, the treatment of locally advanced or metastatic urothelial BC was based on the use of chemotherapy alone. Since 2016, five immune checkpoint inhibitors (ICIs) have been approved by the Food and Drug Administration (FDA) in different settings, i.e., first-line, maintenance and second-line treatment, while several trials are still ongoing in the perioperative context. Lately, pembrolizumab, a programmed death-1 (PD-1) inhibitor, has been approved for Bacillus Calmette–Guérin (BCG)-unresponsive high-risk non-muscle invasive bladder cancer (NMIBC), using immunotherapy at an early stage of the disease. This review investigates the current state and future perspectives of immunotherapy in BC, focusing on the rationale and results of combining immunotherapy with other therapeutic strategies.

Current status and future perspectives of immunotherapy against urothelial and kidney cancer

Much attention has been paid to immune checkpoint inhibitors to various cancer treatments. In urothelial cancer, pembrolizumab was initially approved for patients who either recurred or progressed following platinum-based chemotherapy. For the platinum-fit population, although the standard first-line treatment is still platinum-based systemic chemotherapy, avelumab has been recently approved as a maintenance therapy for patients who have not had disease progression with four to six cycles of first-line chemotherapy. In addition, adjuvant nivolumab has just prolonged disease-free survival (DFS) by ~10 months, compared with placebo in patients with muscle-invasive bladder urothelial cancer or upper tract urothelial cancer at high-risk of recurrence after radical surgical resection. On the other hand, in kidney cancer, nivolumab was initially approved for advanced renal cell carcinoma patients after one or two prior anti-angiogenic therapies. Next, combinations of two immune checkpoint inhibitors (nivolumab + ipilimumab) and immune checkpoint inhibitor + tyrosine kinase inhibitors (pembrolizumab + axitinib and avelumab + axitinib) were approved for the first-line treatment for patients with advanced renal cell carcinoma. Recently, new generation tyrosine kinase inhibitors, such as cabozantinib and lenvatinib have been combined with immune checkpoint inhibitors. Both nivolumab + cabozantinib and pembrolizumab + lenvatinib have demonstrated superior progression-free survival and objective response rate, compared with sunitinib. So far, no prospective trials have demonstrated the duration of immune checkpoint inhibitor treatments. We are now doing the Japan Clinical Oncology Group 1905 trial, where patients with advanced renal cell carcinoma who have received an immune checkpoint inhibitor for 24 weeks are divided into two groups: those who continue immune checkpoint inhibitor treatment and those who discontinue immune checkpoint inhibitor treatment.

Urothelial carcinoma in the era of immune checkpoint inhibitors

Bladder cancer is the seventh most frequent cancer worldwide. The majority of patients present with nonmuscle invasive disease, while 20% of the patients are diagnosed with muscle-invasive bladder cancer. The treatment of nonmuscle invasive disease is endoscopic resection followed by intravesical adjuvant treatment for high risk patients. The standard treatment of localized muscle-invasive disease is neoadjuvant chemotherapy followed by radical cystectomy. Platinum-based chemotherapy is the first-line treatment in locally advanced or metastatic urothelial carcinoma. Immune checkpoint inhibitors have been approved for the treatment of metastatic urothelial carcinoma as second-line treatment or first-line in platinum-ineligible patients. Recently, pembrolizumab have been approved in bacillus Calmette-Guérin (BCG)-refractory nonmuscle invasive bladder cancer. This review summarizes the current evidence concerning immunotherapy in the treatment of urothelial carcinoma.

Immunotherapy in the Treatment of Urothelial Bladder Cancer: Insights From Single-Cell Analysis

Urothelial bladder cancer (UBC) is a global challenge of public health with limited therapeutic options. Although the emergence of cancer immunotherapy, most notably immune checkpoint inhibitors, represents a major breakthrough in the past decade, many patients still suffer from unsatisfactory clinical outcome. A thorough understanding of the fundamental cellular and molecular mechanisms responsible for antitumor immunity may lead to optimized treatment guidelines and new immunotherapeutic strategies. With technological developments and protocol refinements, single-cell approaches have become powerful tools that provide unprecedented insights into the kaleidoscopic tumor microenvironment and intricate cell-cell communications. In this review, we summarize recent applications of single-cell analysis in characterizing the UBC multicellular ecosystem, and discuss how to leverage the high-resolution information for more effective immune-based therapies.

Immune Checkpoint Inhibitors for the Treatment of Bladder Cancer

A number of immune checkpoint inhibitors (ICIs) have been approved as first-line therapy in case of cisplatin-ineligible patients or as second-line therapy for patients with metastatic urothelial carcinoma (mUC) of the bladder. About 30% of patients with mUC will respond to ICIs immunotherapy. Programmed death-ligand 1 (PD-L1) expression detected by immunohistochemistry seems to predict response to immune checkpoint inhibitors in patients with mUC as supported by the objective response rate (ORR) and overall survival (OS) associated with the response observed in most clinical trials. Pembrolizumab, an anti-PD-1 antibody, demonstrated better OS respective to chemotherapy in a randomized phase 3 study for second-line treatment of mUC. Nivolumab, a PD-1 antibody, also demonstrated an OS benefit when compared to controls. Atezolizumab, Durvalumab, and Avelumab antibodies targeting PD-L1 have also received approval as second-line treatments for mUC with durable response for more than 1 year in selected patients. Atezolizumab and Pembrolizumab also received approval for first-line treatment of patients that are ineligible for cisplatin. A focus on the utility of ICIs in the adjuvant or neoadjuvant setting, or as combination with chemotherapy, is the basis of some ongoing trials. The identification of a clinically useful biomarker, single or in association, to determine the optimal ICIs treatment for patients with mUC is very much needed as emphasized by the current literature. In this review, we examined relevant clinical trial results with ICIs in patients with mUC alone or as part of drug combinations; emphasis is also placed on the adjuvant and neoadjuvant setting. The current landscape of selected biomarkers of response to ICIs including anti-PD-L1 immunohistochemistry is also briefly reviewed.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer

Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.