Pembrolizumab with Chemoradiation as Treatment for Muscle-invasive Bladder Cancer: Analysis of Safety and Efficacy of the PCR-MIB Phase 2 Clinical Trial (ANZUP 1502)

BACKGROUND

Radiation may improve the efficacy of immune checkpoint inhibition. This study investigates the combination of pembrolizumab and chemoradiation (CRT) for muscle-invasive bladder cancer (MIBC).

OBJECTIVE

To assess the feasibility and safety of pembrolizumab combined with CRT for MIBC.

DESIGN, SETTING, AND PARTICIPANTS

A single-arm phase 2 trial was performed with 28 participants having cT2-T4aN0M0 MIBC (Eastern Cooperative Oncology Group performance status 0-1; estimated glomerular filtration rate ≥40 ml/min; no contraindications to pembrolizumab) suitable for CRT.

INTERVENTION

Whole bladder radiation therapy (RT; 64 Gy in 32 daily fractions, over 6.5 wk, combined with cisplatin (35 mg/m2 intravenously [IV] weekly, six doses) and pembrolizumab (200 mg IV q3 weeks, seven doses), both starting with RT. Surveillance cystoscopy/biopsy and computerised tomography scans performed 12 and 24 wk after CRT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was feasibility, determined by a prespecified satisfactory low rate of grade 3 or worse nonurinary toxicity or completion of planned CRT according to defined parameters. Secondary endpoints were complete cystoscopic response, locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS), and overall survival (OS).

RESULTS AND LIMITATIONS

Twenty-eight patients were enrolled with a 31-mo median follow-up. Six had Grade >3 nonurinary adverse events during/within 12 wk after treatment; three had more than one cisplatin dose reduction. The 24-wk post-CRT complete response (CR) rate was 88%. Eight patients developed metastatic disease, and three had nonmetastatic progression. The DMFS at 2 yr is 78% (95% confidence interval [CI] 54-90%), with LRPFS at 2 yr of 87% (95% CI 64-96%) and median OS of 39 mo (95% CI 17.1-not evaluable). Limitations are the single-arm design and sample size.

CONCLUSIONS

Combining pembrolizumab with CRT for MIBC was feasible, with manageable toxicity and promising CR rates.

PATIENT SUMMARY

Immunotherapy treats nonmetastatic/metastatic bladder cancer effectively. We combined pembrolizumab with chemotherapy and radiation to assess its safety and impact on treatment delivery. The combination was feasible with encouraging early activity. Further larger trials are warranted.

Neoadjuvant immunochemotherapy in the treatment of nonmetastatic muscle-invasive bladder cancer: a systematic review

Introduction: Multiple trials are currently studying the additional effect of immunotherapy on neoadjuvant chemotherapy (NAC) in nonmetastatic muscle-invasive bladder cancer. Methods: We performed a systematic review of the literature that summarizes all ongoing trials, with their results when available. Results: From an initial 269 trials identified, 17 were included. Pathological response and pathological complete response rates of the immunotherapy + NAC combination in the cisplatin-eligible population varied between 56.6-75% and 34.0-66.7%, respectively. Two studies published their results in the cisplatin-ineligible population, with pathological complete response rates of 18 and 45.2%. Conclusion: Neoadjuvant immunochemotherapy in platinum-eligible patients results in response rates higher than those reported for NAC alone. Strong preliminary results are still lacking in the platinum-ineligible population.

Neoadjuvant Immunotherapy in Gastrointestinal Cancers - The New Standard of Care?

The development of immune checkpoint inhibitors (ICI) offers novel treatment possibilities for solid cancers, with the crucial benefit of providing higher cure rates. These agents have become part of standard treatments in the metastatic and adjuvant setting for select cancers, such as melanoma, non-small cell lung cancer (NSCLC) or urological malignancies. Currently, there is ample clinical interest in employing ICI in a neoadjuvant setting with a curative intent. This approach is especially supported by the scientific rationale that ICI primarily stimulate the host immune system to eradicate tumor cells, rather than being inherently cytotoxic. Aside from tumor downstaging, neoadjuvant immunotherapy offers the potential of an in situ cancer vaccination, leading to a systemic adjuvant immunological effect after tumor resection. Moreover, preclinical data clearly demonstrate a synergistic effect of ICI with radiotherapy (RT), chemoradiotherapy (CRT) or chemotherapy (ChT). This review harmonizes preclinical concepts with real world data (RWD) in the field of neoadjuvant ICI in gastrointestinal (GI) cancers and discusses their limitations. We believe this is a crucial approach, since up to now, neoadjuvant strategies have been primarily developed by clinicians, whereas the advances in immunotherapy primarily originate from preclinical research. Currently there is limited published data on neoadjuvant ICI in GI cancers, even though neoadjuvant treatments including RT, CRT or ChT are frequently employed in locally advanced/oligometastatic GI cancers (i.e. rectal, pancreatic, esophagus, stomach, etc.). Utilizing established therapies in combination with ICI provides an abundance of opportunities for innovative treatment regimens to further improve survival rates.

Adjuvant immunotherapy for muscle-invasive urothelial carcinoma of the bladder

INTRODUCTION

There are substantial unmet needs with regards to adjuvant therapy for muscle-invasive urothelial carcinoma (UC) of the bladder, including patients with persistent disease histologically following neoadjuvant platinum-based therapy and radical resection, as well as patients who are not eligible for or refuse cytotoxic chemotherapy. As such, increased interest has been developed in advancing the use of systemic immunotherapy in the postoperative setting.

AREAS COVERED

We begin by examining current uses of systemic immunotherapy in the treatment of advanced UC. We also review emerging neoadjuvant data and describe current adjuvant approaches. We then report and analyze data on adjuvant immunotherapy, including the recent randomized trials on adjuvant nivolumab and atezolizumab, and conclude with a discussion on the available evidence and likely directions of the field.

EXPERT OPINION

Systemic immunotherapy can serve to enhance postoperative therapies for muscle-invasive bladder UC, as exemplified by the recent approval of nivolumab. Further research will serve to define optimal immunotherapy timing and combinations with other systemic therapies, as well as identify predictive biomarkers to allow effective tailoring of therapy for each patient.

Cost-Effectiveness of Immune Checkpoint Inhibitors in Urothelial Carcinoma-A Review

Simple Summary

Urothelial carcinoma is a malignancy that originates in the genitourinary tract. It is a heterogeneous disease that can present at different stages, and the treatment options vary in efficacy. Advances in immunotherapy stimulated adoption in urothelial carcinoma, and published trials have shown promising results when compared to conventional therapies. However, oncologic drugs are historically costly, and immunotherapy is no exception. A cost-effectiveness analysis is a standardized method of weighing the clinical benefits of an intervention against the financial burden to obtain a composite proposed value. Multiple investigators have assessed immunotherapy in urothelial carcinoma, but no consensus has been reached. Here, we aim to review the literature of the available cost-effectiveness studies to summarize the results and determine the current value of systemic immunotherapy compared to standard treatment. Positive findings will support continued efforts to adopt immunotherapy, whereas negative findings will identify potential gaps for improvement in cost-effectiveness.

Abstract

Over the last decade, an increasing number of immune checkpoint inhibitors (ICIs) have been assessed for therapeutic efficacy in urothelial carcinoma (UC). The high cost has prompted multiple cost-effectiveness analyses for the various disease stages, with no established consensus. We reviewed the literature to assess the available cost-effectiveness studies and summarize their findings. Studies were filtered for a calculated incremental cost-effectiveness ratio (ICER) to standardize comparison. Over 2600 articles were narrowed to eight primary investigations: one for BCG-refractory non-muscle invasive (NMI), one for neoadjuvant therapy in muscle-invasive (MI), and six for advanced disease. Cost-effectiveness was not achieved for NMI disease. Atezolizumab met the willingness-to-pay (WTP) threshold as neoadjuvant therapy for MI disease compared to chemotherapy, but with multiple limitations on the interpretation. Of the six studies on advanced disease, the results were mixed. This was at least partially attributable to varied methodologies including extrapolated time horizons, inconsistent cost inputs, and different WTP thresholds. Overall, the aggregate results were not compelling enough to establish ICIs as cost-effective compared to conventional chemotherapy. Value may improve with continued investigation into long-term outcomes, refined patient selection, and pricing discounts.

Perioperative Systemic Treatment for Muscle-Invasive Bladder Cancer: Current Evidence and Future Perspectives

Radical cystectomy is the primary treatment for muscle-invasive bladder cancer; however, approximately 50% of patients develop metastatic disease within 2 years of diagnosis, which results in dismal prognosis. Therefore, systemic treatment is important to improve the prognosis of muscle-invasive bladder cancer. Currently, several guidelines recommend cisplatin-based neoadjuvant chemotherapy before radical cystectomy, and adjuvant chemotherapy is recommended in patients who have not received neoadjuvant chemotherapy. Immune checkpoint inhibitors have recently become the standard treatment option for metastatic urothelial carcinoma. Owing to their clinical benefits, several immune checkpoint inhibitors, with or without other agents (including other immunotherapy, cytotoxic chemotherapy, and emerging agents such as antibody drug conjugates), are being extensively investigated in perioperative settings. Several studies for perioperative immunotherapy have shown that immune checkpoint inhibitors have promising efficacy with relatively low toxicity, and have explored the predictive molecular biomarkers. Herein, we review the current evidence and discuss the future perspectives of perioperative systemic treatment for muscle-invasive bladder cancer.

Checkpoint inhibitors in BCG-unresponsive nonmuscle invasive bladder cancer: can they help spare the bladder?

Intravesical BCG therapy has been for years, the standard of care in nonmuscle-invasive bladder cancer. But upon recurrence/relapse, radical cystectomy is imposed, due to the paucity of other therapeutic options. Immunotherapy has been revolutionizing cancer treatment, and its indications continue to broaden. It has been approved for the treatment of advanced urothelial cancer of the bladder, mainly as a second-line therapy. Its activity is being studied in nonmuscle-invasive bladder cancer that is not responsive to BCG; we herein report the trials investigating these checkpoint inhibitors (pembrolizumab, nivolumab, atezolizumab, durvalumab and avelumab) in this particular setting.

Comparison of Oncologic Outcomes of Dose-Dense Methotrexate, Vinblastine, Doxorubicin, and Cisplatin (ddMVAC) with Gemcitabine and Cisplatin (GC) as Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer: Systematic Review and Meta-Analysis

Simple Summary

Currently, platinum-based neoadjuvant chemotherapy (NAC) is becoming a standard treatment for use in patients with muscle-invasive bladder cancer. However, comparisons of oncologic outcomes for the two most commonly used NAC regimens, ddMVAC (dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin) and GC (gemcitabine and cisplatin), are controversial. We sought to compare the oncologic outcomes of these two regimens via a systematic review and meta-analysis of all the available studies published to date. Through this, we aimed to provide evidence on the optimal NAC regimen for use in muscle-invasive bladder cancer.

Abstract

Platinum-based neoadjuvant chemotherapy (NAC) is widely used for treating muscle-invasive bladder cancer (MIBC). A systematic review was performed following PRISMA guidelines. PubMed, Embase, and the Cochrane Library were searched up to December 2020. We conducted a meta-analysis to compare the oncologic outcomes of ddMVAC (dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin) and GC (gemcitabine and cisplatin), which are the most widely used NAC regimens. Endpoints included pathologic complete response (pCR), pathologic downstaging (pDS), overall survival (OS), and cancer-specific survival (CSS). Five studies, with a total of 1206 patients, were included for meta-analysis. pCR was observed in 35.2% of the ddMVAC arm and in 25.1% of the GC arm, and pCR was significantly higher in ddMVAC than in GC (odds ratio (OR), 1.45; 95% confidence interval (CI), 1.11–1.89; p = 0.006). There was no significant difference in pDS (OR, 1.37; CI, 0.84–2.21; p = 0.20). OS was significantly higher in ddMVAC than in GC (hazard ratio, 2.16; CI, 1.42–3.29; p = 0.0004). Only one study reported CSS outcomes. The results of this analysis indicate that ddMVAC is superior to GC in terms of pCR and OS, suggesting that ddMVAC is more effective than GC in NAC for MIBC. However, this should be interpreted with caution because of the inherent limitations of retrospective studies.

Neoadjuvant Therapy for Cisplatin Ineligible Muscle Invasive Bladder Cancer Patients: A Review of Available Evidence

Neoadjuvant chemotherapy followed by radical cystectomy is the standard of care for muscle invasive non-metastatic bladder cancer patients. While cisplatin based neoadjuvant chemotherapy has been recommended, systemic therapy in a neoadjuvant setting for cisplatin ineligible patients still needs to be addressed. Various strategies like split dosing cisplatin chemotherapy, carboplatin based chemotherapy and taxanes based chemotherapy have been tried as neoadjuvant therapy for cisplatin ineligible patients. Immunotherapy is a promising tool in this regard with a need for the development of predictive and prognostic biomarkers which can bring out the true potential of these immunotherapeutic agents.

PRIME-HCC: phase Ib study of neoadjuvant ipilimumab and nivolumab prior to liver resection for hepatocellular carcinoma

Background

After liver resection (LR), patients with hepatocellular cancer (HCC) are at high risk of recurrence. There are no approved anti-cancer therapies known to affect such risk, highlighting the acute need for novel systemic therapies to control the probability of disease relapse. Immunotherapy is expanding as a novel treatment option for HCC. Emerging data from cohort 4 of the CA209–040 study, which investigated the safety and preliminary efficacy of nivolumab/ipilimumab co-administration in advanced HCC, suggest that the combination can be delivered safely with an acceptable proportion of reversible grade 3–4 toxicities (27.1%) and a low discontinuation rate (2%) in patients with HCC. Here, we describe the design and rationale of PRIME-HCC, a two-part, multi-centre, phase Ib study to assess safety and bioactivity of the nivolumab/ipilimumab combination prior to LR in early-stage HCC.

Methods

The study involves an initial safety run-in phase (Part 1) to allow for preliminary safety characterisation within the first 6 patients enrolled and a subsequent expansion (Part 2). Ipilimumab will be administered once only on Day 1. Nivolumab will be administered on Day 1 and Day 22 (± 3 days) for a total of two 21-day cycles (i.e. 6 weeks of treatment). The primary objective of the study is to determine the safety and tolerability of the nivolumab/ipilimumab combination prior to LR. The secondary objective is to preliminarily characterize the efficacy of the combination prior to LR, including objective response rate (ORR) and pathologic response rates. Additional exploratory objectives include preliminary evidence of long-term disease control and to identify predictive correlates of response to the nivolumab/ipilimumab combination in HCC.

Discussion

The results of this study will help define the positioning of neoadjuvant nivolumab/ipilimumab combination in the perioperative management of HCC, with potential to improve survival outcomes in this patient population.

Trial registration

EudraCT Number: 2018–000987-27 Clinical trial registry & ID: ClinicalTrials.gov: NCT03682276.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08033-x.

Neoadjuvant immunotherapy in resectable head and neck cancer: oral cavity carcinoma as a potential research model

Squamous cell carcinoma of oral cavity (OCSCC) accounts for approximately 25% of cases of head and neck squamous cell carcinoma (HNSCC). Tobacco and alcohol consumption are the main risk factors for both cancers. Surgical resection, combined with adjuvant radiotherapy or radiochemotherapy in patients with high risk of relapse, is the key element in management in the initial stages. However, despite the availability of aggressive multidisciplinary treatments, advanced resectable OCSCC carries poor prognosis; only half of the patients are disease-free 5 years after the surgery. Immunotherapy based on the use of immune checkpoint inhibitors has been proven to be effective in a wide variety of tumours, including recurrent and metastatic HNSCC. These positive results resulted in investigations into its effectiveness in earlier stages of the disease with OCSCC emerging as an interesting research model because of the accessible location of the tumours. This article reviews the potential advantages of emerging immunotherapeutic agents [mainly monoclonal antibodies against programmed cell death-1 (PD-1) immune checkpoint inhibitors] as neoadjuvant treatment for OCSCC at locoregional stages as well as the ongoing clinical trials, challenges in evaluating tumour response, and possible predictive biomarkers of response with highlights regarding the role of oral microbiota as modulators of immune response. The efficacy and safety of anti-PD-1 drugs in these patients have been proven in preliminary trials. If there is a decrease in the relapse rate and an improvement in the overall survival after surgical resection in ongoing trials, preoperative immunotherapy may be established as a treatment option for patients with early stages of the disease.

A Single-arm Phase II Trial of Neoadjuvant Cabazitaxel and Cisplatin Chemotherapy for Muscle-Invasive Transitional Cell Carcinoma of the Urinary Bladder

INTRODUCTION

Neoadjuvant cisplatin-based combination chemotherapy improves survival in muscle-invasive bladder cancer. However, response rates and survival remain suboptimal. We evaluated the efficacy, safety, and tolerability of cisplatin plus cabazitaxel.

METHODS

A phase II single-arm trial was designed to recruit at least 26 evaluable patients. This would give 80% power to detect the primary endpoint, an objective response rate defined as a pathologic complete response plus partial response (pathologic downstaging), measured by pathologic staging at cystectomy (p₀ = 0.35 and p₁ = 0.60, α = 0.05).

RESULTS

Objective response was seen in 15 of 26 evaluable patients (57.7%) and more than one- third of patients achieved a pathologic complete response (9/26; 34.6%). Seventy-eight percent of the patients (21/27) completed all cycles of treatment, with only 6.7% of the reported adverse events being graded 3 or 4. There were 6 treatment-related serious adverse event reported, but no suspected unexpected serious adverse reactions. In the patients who achieved an objective response, the median progression-free survival and overall survival were not reached (median follow-up of 41.5 months). In contrast, the median progression-free survival (7.2 months) and overall survival (16.9 months) were significantly worse (P = .001, log-rank) in patients who did not achieve an objective response.

CONCLUSION

Cabazitaxel plus cisplatin for neoadjuvant treatment of muscle-invasive bladder cancer can be considered a well-tolerated and effective regimen before definitive therapy with higher rates (57.7%) of objective response, comparing favorably to that with of cisplatin/gemcitabine (23%-26%). These results warrant further evaluation in a phase III study.

Defining cisplatin eligibility in patients with muscle-invasive bladder cancer

The current treatment paradigm for muscle-invasive bladder cancer (MIBC) consists of cisplatin-based neoadjuvant chemotherapy followed by local definitive therapy, or local definitive therapy alone for cisplatin-ineligible patients. Given that MIBC has a high propensity for distant relapse and is a chemotherapy-sensitive disease, under-utilization of chemotherapy is associated with suboptimal cure rates. Cisplatin eligibility criteria are defined for patients with metastatic bladder cancer by the Galsky criteria, which include creatinine clearance ≥60 ml/min. However, consensus is still lacking regarding cisplatin eligibility criteria in the neoadjuvant, curative MIBC setting, which continues to represent a substantial barrier to the standardization of patient care and clinical trial design. Jiang and colleagues accordingly suggest an algorithm for assessing cisplatin eligibility in patients with MIBC. Instead of relying on an absolute renal function threshold, their algorithm emphasizes a multidisciplinary and patient-centred approach. They also propose mitigation strategies to minimize the risk of cisplatin-induced nephrotoxicity in selected patients with impaired renal function. This new framework is aimed at reducing the inappropriate exclusion of some patients from cisplatin-based neoadjuvant chemotherapy (which leads to under-treatment) and harmonizing clinical trial design, which could lead to improved overall outcomes in patients with MIBC.

Recent advances in neoadjuvant immunotherapy for urothelial bladder cancer: What to expect in the near future

Urothelial bladder cancer (UC) is the most common malignancy involving the urinary system and represents a significant health problem. Immunotherapy has been used for decades for UC with intravesical bacillus Calmette-Guérin (BCG) set as the standard of care for non-muscle-invasive bladder cancer (NMIBC). The advent of immune checkpoint inhibitors (ICIs) has completely transformed the treatment landscape of bladder cancer enabling to expand the treatment strategies. Novel ICIs have successfully shown improved outcomes on metastatic disease to such an extent that the standard of care paradigm has changed leading to the development of different trials with the aim of determining whether ICIs may have a role in early disease. The localized muscle-invasive bladder cancer (MIBC) scenario remains challenging since the recurrence rate continues to be high despite all therapeutic efforts. This article will review the current experience of ICIs in the neoadjuvant setting of UC, the clinical trials landscape and finally, an insight of what to expect in the immediate and mid-term future.

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.

Novel therapies for advanced urologic cancers

PURPOSE OF REVIEW

Systemic treatment of advanced urogenital malignancies has changed significantly in recent years and it will continue to change rapidly in upcoming years. It is the scope of this review article to providing the reader with the most recently approved treatment strategies to be used in daily routine for the individualized and most optimal treatment of our patients.

RECENT FINDINGS

Immunooncological therapy (IOT) has emerged as the treatment of choice in metastatic renal cell carcinoma and we describe the most relevant clinical trials and we will give some differential therapeutic recommendation who might be best treated with which combination therapy considering both oncological efficacy and treatment-related toxicity. New neoadjuvant treatment options for muscle-invasive bladder cancer are reported. With regard to metastatic prostate cancer, the landscape of medical therapy is continuously evolving and the new, and most relevant therapeutic strategies for metastatic hormone-naive and castration-resistant PCA are described. Last, but not least, we highlight latest developments in the management of advanced testis cancer.

SUMMARY

The novel treatment options reported in this article are ready for use in daily routine and already represent or will shortly represent new guideline-recommended therapies.

Current status and future directions of the use of novel immunotherapeutic agents in bladder cancer

PURPOSE OF REVIEW

To report the available information on the current status and future direction of the use of checkpoint inhibitors as novel immunotherapeutic agents in bladder cancer.

RECENT FINDINGS

In the past 3 years, five immunotherapies targeting programmed cell death 1 (Pembrolizumab and Durvalumab) or programmed cell death-ligand 1 (PD-L1) (Atezolizumab, nivolumab and Avelumab) pathways have been approved in second-line setting for patients who progressed during or after cisplatin-based chemotherapy. According to the most recent update, these patients should be PD-L1-positive to be eligible for immunotherapy. The use of novel checkpoint inhibitors was also very promising in other settings: Metastatic urothelial carcinoma without prior systemic treatment (IMvigor-130), as neoadjuvant treatment before radical cystectomy in patients with muscle invasive disease (PURE-01), and in Bacillus Calmette-Guérin (BCG) refractory nonmuscle invasive bladder cancer (KEYNOTE 057).

SUMMARY

Ongoing trials on the role of checkpoint inhibitors in bladder cancer may change our approach to different stages of bladder cancer. For metastatic urothelial carcinoma, the role of combined immune and chemotherapy may improve survival. For localized bladder cancer, immunotherapy as neoadjuvant therapy may be associated with less toxicity and better tolerability. Finally, in the setting of a BCG-refractory or BCG-naïve nonmuscle invasive disease checkpoint inhibitors may reduce/delay the risk of progression and subsequent cystectomy.

Immune checkpoints and their inhibitors: Reappraisal of a novel diagnostic and therapeutic dimension in the urologic malignancies

Advances in molecular immunology have unveiled some of the complexity of the mechanisms regulating cellular immune responses and led to the successful targeting of immune checkpoints in attempts to enhance antitumor T cell responses. Surgery, chemotherapy, and radiation therapy have been the mainstay of treatment in urologic malignancies. Immune checkpoint molecules such as cytotoxic T-lymphocyte associated protein-4, programmed cell death protein-1, and programmed death-ligand 1 have been shown to play central roles in evading cancer immunity. Thus these molecules have been targeted by inhibitors for the management of cancers forming the basis of immunotherapy. Immunotherapy is now among the first line therapeutic options for metastatic renal cell carcinomas. In advanced bladder cancer, immunotherapy is the standard of care in the second line and the first line for cisplatin ineligible patients. There continues to be ongoing research to identify the role if any of immunotherapy in testicular, prostatic, and penile cancers. The ideal biomarker for response to immunotherapy is still elusive. Although programmed death-ligand 1 immunohistochemical testing has been widely used across the globe as a biomarker for immunotherapy, companion diagnostic tests have inherent issues with testing and reporting and cannot have universal applicability. Additional biomarkers including, tumor mutational burden, deficient mismatch repair, high microsatellite instability, and immune gene expression profiling are being evaluated in various clinical trials. This review appraises the data of immunotherapy in the management of urologic malignancies.

Immunotherapy for urothelial carcinoma: Metastatic disease and beyond

For advanced and metastatic urothelial carcinomas (UCs), platinum (preferably cisplatin)-based chemotherapy has been the standard treatment for many years. However, many patients are ineligible for cisplatin-based chemotherapy because of poor performance status and/or other age-related conditions. At the other end of the spectrum, patients with localized non-muscle-invasive bladder cancer who are unresponsive to intravesical Bacillus Calmette-Guérin (BCG) treatment often face radical cystectomy as the only option. In recent years, the application of immunotherapy in the form of immune-checkpoint inhibitors has provided viable alternatives in the second-line postplatinum and first-line cisplatin-ineligible settings. Recent and ongoing clinical trials are also assessing the safety and efficacy of immunotherapy for neoadjuvant and adjuvant uses before/after cystectomy, for BCG-unresponsive cases, and for combination treatments that include the newer indoleamine 2,3-dioxygenase-1 inhibitors and/or BCG. This review summarizes recent developments in immunotherapy for UCs.

Prognostic and Predictive Value of Tumor-Infiltrating Immune Cells in Urothelial Cancer of the Bladder

The prognosis and responsiveness to chemotherapy and checkpoint inhibitors differs substantially among patients with bladder cancer (BC). There is an unmet need for biomarkers that can accurately predict prognosis and treatment outcome. Here, we describe the available literature on the prognostic and predictive value of tumor-infiltrating immune cells in BC. Current evidence indicates that a high density of tumor-infiltrating CD8+ T cells is a favorable prognostic factor, whereas PD-L1 expression and tumor-associated macrophages are unfavorable prognostic features. While PD-L1 expression appears unsuccessful as a biomarker for the response to checkpoint inhibitors, there are some indications that high CD8+ T cell infiltration, low transforming growth factor-beta signaling and low densities of myeloid-derived suppressor cells are associated with response. Future studies should focus on combinations of biomarkers to accurately predict survival and response to treatment.

Neoadjuvant Therapies for Bladder Cancer in Cisplatin-ineligible Patients: What Options Do We Have?

Neoadjuvant chemotherapy has proven clinical benefit in muscle- invasive bladder cancer. Cisplatin is the likely driver of this benefit. Textbook definitions of cisplatin ineligibility may restrict almost 50% of patients from therapy. Checkpoint inhibitors (anti- PD-1 antibodies and anti- CTLA-4 antibodies) are currently in clinical trials for neoadjuvant use. Initial data from these studies appear promising.

Latest progress in molecular biology and treatment in genitourinary tumours

The management of genitourinary cancer, including bladder, prostate, renal and testicular cancer, has evolved dramatically in recent years due to a better understanding of tumour genetic mutations, alterations in molecular pathways, and to the development of new kinds of drugs such as targeted therapies and immunotherapies. In the field of immunotherapy, new drugs focused on stimulating, enhancing and modulating the immune system to detect and destroy cancer, have been recently discovered. Research in oncology moves quickly and new data of great relevance for clinical practice are communicated every year. For this reason, a group of experts, focused exclusively on the treatment of genitourinary tumours and who get together every year in the BestGU conference to assess the latest progress in this field have summarized the most important advances in a single review, along with a critical assessment of whether these results should alter daily clinical practice.

Programmed Death 1 and Programmed Death Ligand 1 Inhibitors in Advanced and Recurrent Urothelial Carcinoma: Meta-analysis of Single-Agent Studies

We performed a systematic review and meta-analysis on the response rates of patients with treatment-refractory urothelial carcinoma treated with programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors. We reviewed the literature for prospective studies evaluating PD-1/PD-L1 inhibitors in refractory urothelial carcinoma patients, which formed the basis for US Food and Drug Administration approval of 5 different antagonistic antibodies targeting PD-1 or PD-L1 (atezolizumab, durvalumab, avelumab, nivolumab, and pembrolizumab). We considered studies examining PD-1/PD-L1-treated patients, which we identified using the following key terms in the Pubmed, Scopus, Web of Science, ClinicalTrial.gov, and Cochrane Library databases. Eligible studies had ≥ 20 patients each and reported response rates, duration of response, and overall survival (OS). We performed fixed and random-effects meta-analyses to model the point estimates for objective response rate and complete response. The median progression-free survival (PFS) and OS for studies reporting these statistics were evaluated. We found 10 eligible studies that met our inclusion criteria, providing extractable numerators and denominators for response rates, PFS, and OS for 1934 patients with metastatic urothelial carcinoma. The objective response rate was 18% (95% confidence interval, 15-22) for second-line or later therapies. The random-effects estimate for complete response was 4% (95% confidence interval, 3-5), including all disease locations and all PD-1 and PD-L1 inhibitors. Median OS and PFS were < 13 months and 3 months, respectively, across all studies, irrespective of PD-L1 expression. We found that the estimated response rates of agents included in this meta-analysis seem to be more favorable than other salvage therapies.

The Challenge of Managing Bladder Cancer and Upper Tract Urothelial Carcinoma: A Review with Treatment Recommendations from the Spanish Oncology Genitourinary Group (SOGUG)

Bladder cancer is the fourth most common cancer in men and the ninth most common in women in the Western world. The management of bladder carcinoma requires a multidisciplinary approach. Optimal treatment depends on several factors, including histology, stage, patient status, and possible comorbidities. Here we review recent findings on the treatment of muscle-invasive bladder carcinoma, advanced urothelial carcinoma, upper tract urothelial carcinoma, non-urothelial carcinoma, and urologic complications arising from the disease or treatment. In addition, we present the recommendations of the Spanish Oncology Genitourinary Group for the treatment of these diseases, based on a focused analysis of clinical management and the potential of current research, including recent findings on the potential benefit of immunotherapy. In recent years, whole-genome approaches have provided new predictive biomarkers and promising molecular targets that could lead to precision medicine in bladder cancer. Moreover, the involvement of other specialists in addition to urologists will ensure not only appropriate therapeutic decisions but also adequate follow-up for response evaluation and management of complications. It is crucial, however, to apply recent molecular findings and implement clinical guidelines as soon as possible in order to maximize therapeutic gains and improve patient prognosis.

Radiation therapy before radical cystectomy combined with immunotherapy in locally advanced bladder cancer - study protocol of a prospective, single arm, multicenter phase II trial (RACE IT)

Background

Patients with locally advanced bladder cancer (cT3/4 cN0/N+ cM0) have a poor prognosis despite radical surgical therapy and perioperative chemotherapy. Preliminary data suggest that the combination of radiation and immunotherapy does not lead to excess toxicity and may have synergistic (abscopal) anti-tumor effects. We hypothesize that the combined preoperative application of the PD-1 checkpoint-inhibitor Nivolumab with concomitant radiation therapy of the bladder and pelvic region followed by radical cystectomy with standardized lymphadenectomy is safe and feasible and might improve outcome for patients with locally advanced bladder cancer.

Methods

Study design: “RACE IT” (AUO AB 65/18) is an investigator initiated, prospective, multicenter, open, single arm phase II trial sponsored by Technical University Munich. Study drug and funding are provided by the company Bristol-Myers Squibb.

Study treatment: Patients will receive Nivolumab 240 mg i.v. every 2 weeks for 4 cycles preoperatively with concomitant radiation therapy of bladder and pelvic region (max. 50.4 Gy). Radical cystectomy with standardized bilateral pelvic lymphadenectomy will be performed between week 11–15.

Primary endpoint: Rate of patients with completed treatment consisting of radio-immunotherapy and radical cystectomy at the end of week 15.

Secondary endpoints: Acute and late toxicity, therapy response and survival (1 year follow up).

Main inclusion criteria: Patients with histologically confirmed, locally advanced bladder cancer (cT3/4, cN0/N+), who are ineligible for neoadjuvant, cisplatin-based chemotherapy or who refuse neoadjuvant chemotherapy.

Main exclusion criteria: Patients with metastatic disease (lymph node metastasis outside pelvis or distant metastasis) or previous chemo-, immune- or radiation therapy.

Planned sample size: 33 patients, interim analysis after 11 patients.

Discussion

This trial aims to evaluate the safety and feasibility of the combined approach of preoperative PD-1 checkpoint-inhibitor therapy with concomitant radiation of bladder and pelvic region followed by radical cystectomy. The secondary objectives of therapy response and survival are thought to provide preliminary data for further clinical evaluation after successful completion of this trial. Recruitment has started in February 2019.

Trial registration

Protocol Code RACE IT: AB 65/18; EudraCT: 2018–001823-38; Clinicaltrials.gov: NCT03529890; Date of registration: 27 June 2018.

Immunotherapy and urothelial carcinoma: An overview and future prospectives

BACKGROUND

Urothelial carcinoma (UC) is a common malignancy with a high mortality rate when metastatic. Traditionally, systemic therapy consisted in platinum-based regimens as first-line, with Taxanes or Vinflunine as further lines. Recently, checkpoint inhibitors (CPIs) immunotherapy has emerged as a new therapeutic option.

METHODS

We searched in Medline, Pubmed and ClinicalTrial.gov databases for the relevant literature, reviewing the results of published trials and the design of ongoing studies involving CPIs in UC.

RESULT

Strong evidence supports the use of CPIs after failure of Cisplatin-based chemotherapy, although no predictive parameter is available so far. Expression of Programmed-Death-1-Ligand has given conflicting results, and is currently indicated only for the selection of Cisplatin-ineligible patients who should receive CPIs.

CONCLUSION

The therapeutic landscape of UC is rapidly changing due to the availability of CPIs. Neoadjuvant trials with CPIs and trials combining two CPIs are promising and will further expand the use of immunotherapy.

Molecular Biomarkers of Response to PD-1/ PD-L1 Immune Checkpoint Blockade in Advanced Bladder Cancer

BACKGROUND

The activity of PD-1/PD-L1 inhibitors in the treatment of advanced bladder cancer (BC) is promising for many patients. However, a subset of patients do not benefit from treatment, thus leading to an effort to better identify predictive molecular biomarkers of response.

OBJECTIVE

To conduct a systematic review of the literature on predictive molecular biomarkers associated with response to PD-1 and PD-L1 inhibitors in advanced bladder cancer, defined as locally-advanced, unresectable, or metastatic (mBC) disease.

METHODS

A search of the literature was performed using Embase (1947 - January 2019), Medline (1946 - January 2019), and EBM Reviews for Cochrane Central Register of Controlled Trials (as of December 2018). Studies examining the association of molecular biomarkers with clinical outcome in BC treated with PD-1 or PD-L1 monotherapy were included. Outcomes of interest were overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), duration of response, and objective response rate (ORR).

RESULTS

Using the study search criteria, 899 unique abstract citations were found, of which 834 did not meet the eligibility criteria. Full text of the remaining 65 citations were screened, and 50 studies excluded, including 18 review articles. Eight additional studies from the bibliography of the review papers were included, making a total of 23 studies. Five PD-1 / PD-L1 antibodies have been tested in BC immunohistochemistry (IHC). These studies used different expression scoring criteria and generally had poor ability to discriminate likelihood for response. Overall, the data suggests CD8⁺ T cell infiltration is necessary to mediate an antitumor immune response, but other immune cell populations, such as neutrophils may suppress T cell-mediated immunity and efficacy of PD-1/PD-L1 blockade. An IFNγ signature is a promising predictor, but there needs to be consensus on the optimal gene panel composition, and prospective validation. Tumor mutation burden (TMB) is a promising predictor in six studies reporting on 1200 patients, but there is not a consensus on the optimal definition of "high TMB". Detection of T cell receptor (TCR) clonal expansion has only been conducted in small studies and so its predictive value remains inconclusive. Epithelial-mesenchymal transformation (EMT) and transforming growth factor β (TGFβ) are associated with poor prognosis and possibly intrinsic resistance to PD-1/PD-L1 checkpoint blockade, but more work needs to be done to build upon and confirm the initial findings.

CONCLUSIONS

Currently no molecular biomarker is sufficiently mature for routine clinical use, while some candidates, or a combination show great promise and need further study.

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.

Delayed immune-related events (DIRE) after discontinuation of immunotherapy: diagnostic hazard of autoimmunity at a distance

BACKGROUND

The risk of delayed autoimmunity occurring months or years after discontinuation of immunotherapy is frequently asserted in the literature. However, specific cases were rarely described until 2018, when a wave of reports surfaced. With expanding I-O indications in the adjuvant/neoadjuvant curative setting, growing numbers of patients will receive limited courses of immunotherapy before entering routine surveillance. In this context, under-recognition of DIRE could pose a growing clinical hazard.

METHODS

The aim of this study was to characterize DIRE through identification of existing reports of delayed post-treatment irAE in cancer patients treated with immunotherapy. We performed a PubMed literature review from 2008 through 2018 to determine the median data safety reporting window from existing I-O clinical trials, which we then applied to define the DIRE cutoff, and collated all qualifying reports over the same time span. DIRE was defined as new immune-related adverse events (irAE) manifesting ≥90 days after discontinuation of immunotherapy.

RESULTS

Median duration of I-O clinical trials data safety reporting was 90 days (82% ≤ 90 days). DIRE cutoff was thus set as ≥90 days post-immunotherapy. We identified 23 qualifying cases; 21 by literature review and 2 from our institution. Median off-treatment interval to DIRE was 6 months (range: 3 to 28). Median cumulative immunotherapy exposure was 4 doses (range: 3 to 42). Involvement included endocrine, neurologic, GI, pulmonary, cardiac, rheumatologic and dermatologic irAE.

CONCLUSIONS

As immunotherapy indications expand into the curative setting, often with brief exposure and potentially sequenced with multimodality treatments, it will be necessary to recognize an emerging diagnostic complex, which we have termed delayed immune-related events (DIRE). Clinical vigilance has the potential to reduce morbidity from diagnostic delay, as irAE are generally manageable with prompt initiation of treatment - or from misdiagnosis - as misattribution can lead to unnecessary or harmful interventions as we describe. DIRE should therefore figure prominently in the differential diagnosis of patients presenting with illnesses of unclear etiology, irrespective of intervening treatments or interval post-immunotherapy, both of which can confound diagnosis. Increased recognition will rest on delineation of DIRE as a clinical diagnostic entity.

Formidable Scenarios in Urothelial and Variant Cancers of the Urinary Tract

Diagnostic and therapeutic challenges in the field of bladder and upper tract cancers provide opportunities for multidisciplinary care. Urothelial cancers make up the majority of the histologic subtype of bladder and upper tract cancers. Although the existence of variant histology, nonurothelial cancers, and urethral cancers is rare, these cancers pose a challenging clinical dilemma given the lack of well-defined consensus treatment guidelines. This review focuses on key issues of treatment: cisplatin ineligibility with emphasis on the definition, nuances of chemotherapy and frontline immune checkpoint inhibitor therapy, use of radiation in bladder-preservation strategies, upper tract urothelial cancer management, and highlights of urothelial variants and nonurothelial tumors and management.

Drug strategies for bladder cancer in the elderly: is there promise for the future?

INTRODUCTION

Bladder cancer (BCa) is a disease that predominantly affects adult and elderly populations. As people live longer, it will become even more frequent and consequently represents a big health problem for health-care providers and is a challenging clinical dilemma. In the elderly, the treatment of BCa presents some peculiarities due to its more aggressive behavior and reduced patient reserves, impacting their response to medical and surgical therapies.

AREAS COVERED

The authors provide a non-systematic review of the literature using PubMed to obtain an overview of the therapeutic options for BCa in the elderly, from the low-risk non-muscle-invasive setting to muscle-invasive and advanced/metastatic disease.

EXPERT OPINION

The main challenge in the treatment of BCa in the elderly is represented by the need to find a compromise between the risk of under- and overtreatment. The wide spectrum of disease prognoses between low-risk non-muscle invasive BCa and invasive metastatic disease represents a perfect setting for a personalized approach. To pursue this aim, older patients need a multidisciplinary approach and clinical management, in order to optimize oncological outcomes as well as to face and support their frailty during cancer therapies.

Retrospective analysis of the efficacy and safety of neoadjuvant gemcitabine and cisplatin in muscle-invasive bladder cancer

Background

Neoadjuvant cisplatin-based combination chemotherapy for muscle-invasive bladder cancer (MIBC) improves overall and disease-free survival. However, there is much debate over the optimal neoadjuvant regimen. Gemcitabine plus cisplatin (GC) has been the neoadjuvant regimen of choice for many institutions for patients with MIBC based on data extrapolated from the metastatic setting. Based on recent data, many institutions are transitioning to variations of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) as the neoadjuvant regimen of choice.

Objective

To assess the effectiveness and safety of neoadjuvant chemotherapy with gemcitabine plus cisplatin in patients with muscle-invasive bladder cancer prior to cystectomy.

Methods

This is a single-center, retrospective, cohort study at Duke University Hospital (DUH). Patients included had MIBC and received gemcitabine plus cisplatin chemotherapy prior to a cystectomy. The primary endpoint was to assess the pathologic complete response (pCR) rate in MIBC after treatment with gemcitabine and cisplatin. Patients were split into two groups, those who received their chemotherapy at DUH, and those who received their chemotherapy at an outside facility.

Results

Overall pCR rate for all patients (n = 36) was 14%. The pCR rates for patients in the Duke Chemotherapy Group (n = 17) and in the Community Chemotherapy Group (n = 19) were 24% and 5%, respectively. GC was overall well tolerated in most patients with few adverse events ≥ grade 3.

Conclusions

This retrospective study demonstrates a consistent pCR rate (24% in Duke Chemotherapy Group) for neoadjuvant GC in MIBC compared with other literature. The overall pCR rate for all patients was 14%.

Efficacy of Split Schedule Versus Conventional Schedule Neoadjuvant Cisplatin-Based Chemotherapy for Muscle-Invasive Bladder Cancer

Neoadjuvant cisplatin-based chemotherapy (NAC; 70 mg/m2) is standard of care for muscle-invasive bladder carcinoma (MIBC). Many patients (pts) cannot receive cisplatin because of renal impairment, and administration of cisplatin 35 mg/m2 on day 1 + 8 or 1 + 2 (i.e., split schedule) is a commonly used alternative. In this retrospective analysis, we compared complete (pT0) and partial ( Collapse

Key Words

• Cisplatin
• Muscle‐invasive bladder cancer
• Neoadjuvant chemotherapy
• Nephrotoxicity

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MESH Headings

• Aged
• Antineoplastic Combined Chemotherapy Protocols/administration & dosage
• Antineoplastic Combined Chemotherapy Protocols/adverse effects
• Carcinoma, Transitional Cell/pathology
• Carcinoma, Transitional Cell/therapy
• Cisplatin/administration & dosage
• Cisplatin/adverse effects
• Cystectomy
• Female
• Humans
• Kidney/drug effects
• Male
• Neoadjuvant Therapy/adverse effects
• Neoadjuvant Therapy/methods
• Neoplasm Invasiveness/pathology
• Neoplasm Staging
• Renal Insufficiency/chemically induced
• Renal Insufficiency/epidemiology
• Renal Insufficiency/prevention & control
• Retrospective Studies
• Treatment Outcome
• Urinary Bladder Neoplasms/pathology
• Urinary Bladder Neoplasms/therapy

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Grants

• K23 CA187185 NCI NIH HHS

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Affiliation(s)

Chelsea K Osterman University of North Carolina Medical Center, Chapel Hill, North Carolina, USA
Dilip S Babu University of Rochester Medical Center, Rochester, New York, USA
Daniel M Geynisman Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
Bianca Lewis Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
Robert A Somer MD Anderson Cancer Center at Cooper, Camden, New Jersey, USA
Arjun V Balar Langone Medical Center, New York University, New York City, New York, USA
Matthew R Zibelman Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
Elizabeth A Guancial Florida Cancer Specialists and Research Institute, Sarasota, Florida, USA
Gianna Antinori MD Anderson Cancer Center at Cooper, Camden, New Jersey, USA
Shun Yu Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA
Vivek Narayan Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA
Thomas J Guzzo Department of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
Elizabeth R Plimack Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA
David J Vaughn Department of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
Chunkit Fung University of Rochester Medical Center, Rochester, New York, USA
Ronac Mamtani Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA

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Current Status and Future Direction of Immunotherapy in Urothelial Carcinoma

PURPOSE OF REVIEW

Since 2016, five new programmed cell death protein 1/ligand 1 (PD-1/L1) checkpoint inhibitors have been approved for metastatic urothelial carcinoma. This review will summarize the data supporting the widespread use of these agents and highlight areas of ongoing clinical development.

RECENT FINDINGS

PD-1/L1 axis inhibition has demonstrated clear superiority to chemotherapy for the treatment of metastatic urothelial cancer in the second-line setting. A multitude of ongoing studies are investigating the feasibility and efficacy of incorporating established and novel immunotherapies into earlier lines of therapy, including non-metastatic muscle-invasive bladder cancer and even non-muscle-invasive disease. Early-phase clinical trials have begun to explore the safety and activity of novel immune-oncology combinations across a range of clinical settings. Immunotherapy has a clearly defined role in the treatment of metastatic urothelial cancer both in the platinum-refractory setting and in the first-line cisplatin-ineligible setting. Ongoing clinical trials will dictate how to best incorporate immunotherapy into earlier lines of therapy and define the safety and activity of novel immunotherapy agents and combinations.

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

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

Immunotherapy for Urothelial Carcinoma: Current Evidence and Future Directions

PURPOSE OF REVIEW

Until recently, effective treatment options for patients with advanced urothelial carcinoma were limited to platinum-based chemotherapy. In the post-platinum setting and for patients ineligible for cisplatin, minimally effective second-line chemotherapy was used and outcomes were poor. The approval of immune checkpoint inhibitors has significantly changed the treatment landscape of urothelial carcinoma. Here, we review current data demonstrating their efficacy in advanced disease and ongoing trials investigating novel combination strategies.

RECENT FINDINGS

Since May 2016, five agents targeting the programmed cell death 1 (PD-1) pathways have been approved for use after progression on platinum-based chemotherapy. Further, atezolizumab and pembrolizumab are approved for use in cisplatin-ineligible patients with high programmed death-ligand 1 (PD-L1) expression. Preliminary studies have shown their safety and efficacy as neoadjuvant therapy in muscle-invasive bladder cancer. Several ongoing trials are investigating these agents in combination with radiation therapy, platinum-based chemotherapy, other immune checkpoint inhibitors, and targeted agents. Immune checkpoint inhibitors have demonstrated durable efficacy in patients with advanced urothelial carcinoma as first- and second-line therapy. Ongoing studies will help define the optimal sequence, combination strategies, and predictive biomarkers of response.