Emerging role of immunotherapy in urothelial carcinoma-Future directions and novel therapies

High Pretreatment Serum PD-L1 Levels Are Associated with Muscle Invasion and Shorter Survival in Upper Tract Urothelial Carcinoma

Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule and a widely used therapeutic target in urothelial cancer. Its circulating, soluble levels (sPD-L1) were recently suggested to be associated with the presence and prognosis of various malignancies but have not yet been investigated in upper tract urothelial carcinoma (UTUC). In this study, we assessed sPD-L1 levels in 97 prospectively collected serum samples from 61 UTUC patients who underwent radical nephroureterectomy (RNU), chemotherapy (CTX), or immune checkpoint inhibitor (ICI) therapy. In addition to pretreatment samples, postoperative and on-treatment sPD-L1 levels were determined in some patients by using ELISA. In the RNU group, elevated preoperative sPD-L1 was associated with a higher tumor grade (p = 0.019), stage (p < 0.001) and the presence of metastasis (p = 0.002). High sPD-L1 levels were significantly associated with worse survival in both the RNU and CTX cohorts. sPD-L1 levels were significantly elevated in postoperative samples (p = 0.011), while they remained unchanged during CTX. Interestingly, ICI treatment caused a strong, 25-fold increase in sPD-L1 (p < 0.001). Our results suggest that elevated preoperative sPD-L1 level is a predictor of higher pathological tumor stage and worse survival in UTUC, which therefore may help to optimize therapeutic decision-making. The observed characteristic sPD-L1 flare during immune checkpoint inhibitor therapy may have clinical significance.

The Multiple Potential Biomarkers for Predicting Immunotherapy Response-Finding the Needle in the Haystack

Immune checkpoint inhibitors (ICIs) are being increasingly utilised in a variety of advanced malignancies. Despite promising outcomes in certain patients, the majority will not derive benefit and are at risk of potentially serious immune-related adverse events (irAEs). The development of predictive biomarkers is therefore critical to personalise treatments and improve outcomes. A number of biomarkers have shown promising results, including from tumour (programmed cell death ligand 1 (PD-L1), tumour mutational burden (TMB), stimulator of interferon genes (STING) and apoptosis-associated speck-like protein containing a CARD (ASC)), from blood (peripheral blood mononuclear cells (PBMCs), circulating tumour DNA (ctDNA), exosomes, cytokines and metal chelators) and finally the microbiome.

Pembrolizumab monotherapy versus chemotherapy for treatment of advanced urothelial carcinoma with disease progression during or following platinum-containing chemotherapy. A Cochrane Rapid Review

BACKGROUND

The use of systemic immunotherapy targets is emerging as an important treatment option for metastatic urothelial carcinoma, particularly for patients who cannot tolerate or who fail cisplatin-based chemotherapy. One such target is the inhibition of the checkpoint protein programmed cell death-1 (PD-1) receptor and its ligand (PD-L1) by monoclonal antibodies.

OBJECTIVES

To assess the effects of pembrolizumab monotherapy versus chemotherapy for treatment of advanced urothelial carcinoma with disease progression during or following platinum-containing chemotherapy.

SEARCH METHODS

We performed a Cochrane Rapid Review, limiting our search to published studies in the English language. We searched databases of the medical literature, including the Cochrane Central Register of Controlled Trials and MEDLINE, as well as trial registries including ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP). Our search extended from January 2000 to June 2018.

SELECTION CRITERIA

We included randomised controlled trials except cross-over trials and cluster randomised trials. We excluded all other study designs. Participants included had locally advanced or metastatic urothelial carcinoma of the bladder, with disease progression during or following platinum-containing chemotherapy (synonymous with second-/third-/fourth-line therapy). This review focused on pembrolizumab (synonyms: MK-3475, lambrolizumab, Keytruda).

DATA COLLECTION AND ANALYSIS

Two review authors independently classified and abstracted data from the included study. The certainty of evidence was rated according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified one randomised controlled trial that included 542 participants, which compared the use of pembrolizumab monotherapy versus chemotherapy for the treatment of advanced urothelial carcinoma with disease progression during or following platinum-containing chemotherapy. Results were reported after a median follow-up of 14.1 months (range 9.9 to 22.1 months).Primary outcomesPembrolizumab probably reduces the risk of death from any cause (hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.59 to 0.90; moderate certainty evidence). This corresponds to 115 fewer deaths (191 fewer to 38 fewer) per 1000 participants with pembrolizumab at 12 months. We downgraded the certainty of evidence one level for imprecision.Pembrolizumab may slightly improve quality of life (change from baseline to week 15 assessed with the Core Quality of Life Questionnaire; higher value reflects better quality of life; scale 0 to 100) with a mean difference (MD) of 9.05, 95% CI 4.61 to 13.50; low certainty evidence). We downgraded the certainty of evidence two levels for study limitations and imprecision.Secondary outcomesPembrolizumab may have little or no effect on disease progression (HR 0.98, 95% CI 0.81 to 1.19; low certainty evidence). This corresponds to three fewer patients (42 fewer to 24 more) whose disease progressed per 1000 participants at 12 months. We downgraded the certainty of evidence two levels for study limitations and imprecision.Pembrolizumab probably improves treatment response (based on complete or partial radiologic response) with a risk ratio (RR) of 1.85, 95% CI 1.24 to 2.77; moderate certainty evidence). This corresponds to 97 more respondents (27 more to 202 more) per 1000 participants with pembrolizumab. We downgraded the certainty of evidence one level for imprecision.Pembrolizumab may have little or no effect on treatment-related mortality (RR 0.96, 95% CI 0.24 to 3.79; low certainty evidence). This corresponds to one fewer (12 fewer to 44 more) treatment-related deaths per 1000 participants with pembrolizumab. We downgraded the certainty of evidence two levels for study limitations and imprecision.Pembrolizumab may have little or no effect on discontinuations due to adverse events (RR 0.66, 95% CI 0.39 to 1.10). This corresponds to 54 fewer discontinuations per 1000 participants (95% CI 79 fewer to 7 more). We downgraded the certainty of evidence for study limitations and imprecision.Pembrolizumab may reduce serious adverse events (RR 0.83, 95 CI 0.72 to 0.97; low certainty evidence). This corresponds to 107 fewer serious averse events per 1000 participants (95% CI 19 fewer to 176 fewer). We downgraded two levels for study limitations and imprecision.

AUTHORS' CONCLUSIONS

The use of pembrolizumab in men with advanced urothelial carcinoma with disease progression during or following platinum-containing chemotherapy probably improves overall survival when compared with chemotherapy alone. At 12 months follow-up about 70% of those in the chemotherapy group had died, compared with 59% of those treated with pembrolizumab. We are very uncertain about the effects of pembolizumab on quality of life. Pembolizumab may also improve treatment response rates, and reduce the risk of serious adverse events, but may make little or no difference to discontinuations of treatment due to adverse events. These conclusions are based on a single trial that was sponsored by the producer of pembrolizumab.

A Comprehensive Review of US FDA-Approved Immune Checkpoint Inhibitors in Urothelial Carcinoma

Few effective treatment options are available for patients with advanced or metastatic urothelial carcinoma (UC) after unsuccessful first-line platinum-based chemotherapy. To date, immune checkpoint inhibitors are novel therapeutic agents for UC treatment. From May 2016 to May 2017, five anti-PD-1/PD-L1 monoclonal antibodies received accelerated or regular approval from the US Food and Drug Administration (FDA) for the treatment of patients with locally advanced or metastatic UC. The present comprehensive review presents the background information of these five US FDA-approved anticancer agents to provide a basic but concise understanding of these agents for advanced studies. We summarize their immune checkpoint mechanisms, clinical efficacy, recommended usage protocols, adverse events, and the limitations of the PD-L1 biomarker assays.

[Immunotherapy in uropathology]

The algorithms for treatment of metastatic cancers are evolving due to positive results obtained with immunotherapy. Therapeutics approaches to stimulate the immune system have already been used in the treatment of kidney and bladder cancer, such as the administration of cytokines and BCG therapy, confirming the immunogenicity of these tumors. The aim of immunotherapies is not only to activate the immune system against tumor cells, but also to take into account the tumor-induced suppressive microenvironment, in particular by removing the anergy of T-cell lymphocytes, and by targeting the co-stimulation inhibitors molecules. Among the genito-urinary cancers, second-line clinical trials have clearly shown that kidney and bladder cancers are sensitive to the inhibition of PD-1/PD-L1 axis and have already achieved FDA approvals for some molecules. Numerous other clinical trials are underway, particularly in first-line treatment in bladder and renal cancers. Refractory testicular cancer could also benefit from these treatments. Other approaches using vaccine therapy especially in castration-resistant prostate cancer are also of interest. We will see, in this chapter dedicated to the urogenital cancers, the benefit of the immunotherapy by resituating it in the genetic and immunological context of each organ. We will also present briefly the therapeutic outlines and the place of biomarkers.

Making urothelial carcinomas less immune to immunotherapy

The success of immune checkpoint inhibitors in advanced urothelial carcinoma provides patients with the prospect for durable objective responses. However, the majority of patients do not respond to immune checkpoint blockade. Several potential predictive biomarkers of response have been evaluated in hopes of better identifying likely responders, though each has been shown to have limitations. Going forward, development of reliable predictive biomarkers is imperative. Likewise, innovative treatment combination approaches to convert non-responders to responders are essential to continue making progress in the field.