Role of Checkpoint Inhibition in Localized Bladder Cancer

Efficacy and safety of neoadjuvant PD-1 inhibitors or PD-L1 inhibitors for muscle invasive bladder cancer: a systematic review and meta-analysis

Introduction

This meta-analysis aims to evaluate the efficacy and safety of neoadjuvant PD-1 inhibitors or PD-L1 inhibitors [PD-(L)1 inhibitors] for muscle-invasive bladder carcinoma (MIBC).

Materials and methods

Four databases (Medline, Embase, Web of Science, and 21 CENTRAL) were searched for articles studying neoadjuvant PD-(L)1 inhibitors for MIBC. The search time period was from the establishment of each database to 21 July 2023. Meta-analyses of pCR, pPR, Grade≥ 3 irAEs rate, RFS, and OS were performed.

Results

In total, 22 studies were included for meta-analysis. The overall pooled pCR of neoadjuvant PD-(L)1 inhibitors was 0.36 (95%CI=0.30-0.42, p=0.00). In subgroup meta-analysis, the pooled PCR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.27 (95%CI=0.19-0.35, p=0.1), 0.41 (95%CI=0.21-0.62, p=0.01), 0.43 (95%CI=0.35-0.50, p=0.06), respectively. The overall pooled pPR of neoadjuvant PD-(L)1 inhibitors was 0.53 (95%CI=0.46-0.60, p=0.00). In subgroup meta-analysis, the pooled pPR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.36 (95%CI=0.22-0.51, p=0.01), 0.51 (95%CI=0.39-0.62, p=0.43), and 0.61 (95%CI=0.53-0.69, p=0.01), respectively. Kaplan-Meier curves for OS and RFS were reconstructed, but there was no significant difference among three groups in terms of OS or RFS. The pooled result of Grade≥ 3 irAEs rate for neoadjuvant PD-(L)1 inhibitors was 0.15 (95%CI=0.09-0.22, p=0.00%). In subgroup analysis, the pooled result of Grade≥ 3 irAEs rate for PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.07 (95%CI=0.04-0.11, p=0.84), 0.31 (95%CI=0.16-0.47, p=0.06), and 0.17 (95%CI=0.06-0.31, I2 = 71.27%, p=0.01), respectively.

Conclusion

Neoadjuvant PD-(L)1 inhibitors were feasible and safe for muscle invasive bladder cancer. Compared with PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI and PD-(L)1 inhibitors plus chemotherapy were associated with higher pCR and pPR, but higher Grade≥3 irAEs. Kaplan-Meier curves for OS and RFS indicated that neoadjuvant PD-(L)1 inhibitors had an acceptable long-term prognostic, but it was not possible to discern statistical differences between the three neoadjuvant subgroups.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023452437, identifier PROSPERO (CRD42023452437).

Molecular classification of urothelial bladder carcinoma

Urothelial bladder carcinoma (UC) ranks among the top ten most commonly diagnosed cancers worldwide on an annual basis. The standardized classification system for urothelial bladder tumors is the Tumor, Node, Metastasis classification, which reflects differences between non-muscle-invasive bladder carcinoma (NMIBC) and muscle-invasive bladder carcinoma (MIBC) and it depends on the extent to which tumor has infiltrated the bladder wall and other tissues and organs. NMIBC and MIBC exhibit great intrinsic heterogeneity regarding different prognoses, survival, progression, and treatment outcomes. In recent years, studies based on mRNA expression profiling revealed the existence of biologically relevant molecular subtypes of UC, which show variant molecular features that can provide more precise stratification of UC patients. Here, we present a complex classification of UC based on mRNA expression studies and molecular subtypes of NMIBC and MIBC in detail with regard to different mRNA expression profiles, mutational signatures, and infiltration by non-tumor cells. The possible impact of molecular subtyping on treatment decisions and patients' outcomes is outlined, too.

Neoadjuvant immunotherapy and chemoimmunotherapy for stage II-III muscle invasive bladder cancer

Objective

Considering the striking evidence revealed by immunotherapy in advanced or metastatic bladder cancer, investigators have explored neoadjuvant immunotherapy and chemoimmunotherapy in muscle-invasive bladder cancer (MIBC). Currently, there have been a large number of studies reporting varied efficacy and safety of these approaches. Herein, we pooled the available evidence in terms of oncological outcomes (pathological complete response [pCR] and pathological partial response [pPR]) and safety outcomes (immune-related adverse events [irAEs], treatment-related adverse events [TRAEs]), through a systematic review and meta-analysis.

Method

We searched PubMed, Embase, Cochrane Library, and American Society of Clinical Oncology meeting abstracts to identify relevant studies up to June 2022. Studies were included if they evaluated the neoadjuvant immunotherapy or chemoimmunotherapy in MIBC and reported at least the pCR.

Results

A total of 22 records involving 843 patients were included. For pCR of immunotherapy, the pooled rate of immune checkpoint inhibitor (ICI) monotherapy and dual-ICIs therapy was 24% (95% confidence interval [CI]: 15.3% - 32.8%) and 32.1% (95%CI: 20.6% - 43.7%), respectively. For pCR of chemoimmunotherapy, the overall pooled rate was 42.6% (95% CI: 34.9% - 50.2%). Subgroup of gemcitabine/cisplatin (GC) plus ICI had a pCR rate of 41.7% (95%CI: 35.8% - 47.5%). In terms of safety, the pooled rate of Grade≥3 irAEs was 11.7% (95% CI: 6.5%-16.9%). In subgroup analysis, the Grade≥3 irAEs rate of ICI monotherapy, dual-ICIs therapy, and GC plus ICI therapy was 7.4% (95% CI: 4.3%-10.5%), 30.3% (95% CI: 15.3%-45.3%), and 14.5% (95% CI: 3.5% - 25.4%), respectively. Besides, the pooled Grade≥3 TRAEs rate for chemoimmunotherapy was 32.4% (95% CI: 13.1% - 51.6%).

Conclusion

Neoadjuvant immunotherapy and chemoimmunotherapy were effective and safe in the treatment of MIBC. Compared to ICI monotherapy, dual-ICIs therapy or chemoimmunotherapy can improve the response rate, while increasing the morbidity of Grade≥ 3 irAEs or Grade≥ 3 TRAEs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD4202233771.

Antitumor Effect and Induced Immune Response Following Exposure of Hexaminolevulinate and Blue Light in Combination with Checkpoint Inhibitor in an Orthotopic Model of Rat Bladder Cancer

Previous studies have found that use of hexaminolevulinate (HAL) and blue light cystoscopy (BLC) during treatment of bladder cancer had a positive impact on overall survival after later cystectomy, indicating a potential treatment effect beyond improved diagnostic accuracy. The aim of our study was to determine whether HAL and BL mimicking clinically relevant doses in an orthotopic rat model could have therapeutic effect by inducing modulation of a tumor-specific immune response. We also assessed whether administration with a checkpoint inhibitor could potentiate any effects observed. Rats were subjected to HAL BL alone and in combination with anti-PD-L1 and assessed for anti-tumor effects and effects on immune markers. Positive anti-tumor effect was observed in 63% and 31% of rats after, respectively, 12 and 30 days after the procedure, together with a localization effect of CD3+ and CD8+ cells after 30 days. Anti-tumor effect at 30 days increases from 31% up to 38% when combined with intravesical anti-PD-L1. In conclusion, our study demonstrated treatment effects with indications of systemic immune activation at diagnostic doses of HAL and blue light. The observed treatment effect seemed to be enhanced when used in combination with intravesically administrated immune checkpoint inhibitor.

Stage-stratified molecular profiling of non-muscle-invasive bladder cancer enhances biological, clinical, and therapeutic insight

Understanding the molecular determinants that underpin the clinical heterogeneity of non-muscle-invasive bladder cancer (NMIBC) is essential for prognostication and therapy development. Stage T1 disease in particular presents a high risk of progression and requires improved understanding. We present a detailed multi-omics study containing gene expression, copy number, and mutational profiles that show relationships to immune infiltration, disease recurrence, and progression to muscle invasion. We compare expression and genomic subtypes derived from all NMIBCs with those derived from the individual disease stages Ta and T1. We show that sufficient molecular heterogeneity exists within the separate stages to allow subclassification and that this is more clinically meaningful for stage T1 disease than that derived from all NMIBCs. This provides improved biological understanding and identifies subtypes of T1 tumors that may benefit from chemo- or immunotherapy.

Evaluation of lymphocyte-specific programmed cell death protein 1 receptor expression and cytokines in blood and urine in canine urothelial carcinoma patients

Urothelial carcinoma (UC) is the most common urinary tumour in dogs. Despite a range of treatment options, prognosis remains poor in dogs. In people, breakthroughs with checkpoint inhibitors have established new standards of care for muscle-invasive bladder cancer patients and elevated levels of programmed cell death protein 1 (PD-1) suggest immune checkpoint blockade may be a novel target for therapy. The goal of this study was to determine if canine UC patients express elevated levels of lymphocyte-specific PD-1 and/or urinary cytokine biomarkers compared to healthy dogs. Paired blood and urine were evaluated in 10 canine UC patients, five cystitis patients and 10 control dogs for lymphocyte-specific PD-1 expression via flow cytometry and relative cytokine expression. In UC patients, PD-1 expression was significantly elevated on CD8⁺ lymphocytes in urine samples. UC patients had a higher CD4:CD8 ratio in their urine compared to healthy dogs, however, there was no significant variation in the CD8:Treg ratio between any group. Cystitis patients had significantly elevated levels of CD4⁺ T cells, CD8⁺ T cells and Tregs in their blood samples compared to UC patients and healthy dogs. Cytokine analysis demonstrated significant elevations in urinary cytokines (granulocyte-macrophage colony-stimulating factor, interferon-gamma [IFN-γ], interleukin (IL)-2, IL-6 IL-7, IL-8 and IL-15, IP-10, KC-like, IL-18, monocyte chemoattractant protein-1 and tumour necrosis factor-alpha). Several of these cytokines have been previously correlated with both lymphocyte-specific PD-1 expression (IFN-γ, IL-2, IL-7 and IL-15) in muscle-invasive urothelial carcinoma in humans. Our results provide evidence of urinary lymphocyte PD-1 expression and future studies could elucidate whether veterinary UC patients will respond favourably to anti-PD-1 immune checkpoint inhibitor therapy.

The emerging role of somatic tumor sequencing in the treatment of urothelial cancer

The development of rapid genome sequencing has greatly enhanced our understanding of the molecular biology underlying many malignancies. Whole exome sequencing has highlighted the individualistic nature of malignancies on a patient-to-patient basis and begun to revolutionize therapeutic approaches. In recent years, whole genome sequencing of urothelial malignancies has identified a host of somatic mutations which contribute to growth, progression, and metastasis of urothelial carcinoma of the bladder and upper tract urothelial carcinoma. As genetic sequencing continues, additional targets will be identified, allowing development of novel therapeutic agents targeting cancer on a molecular level, with the goal of delivering highly individualized care based on the underlying mutational profile of the patient's malignancy. In this review, we aim to discuss known genetic alterations of urothelial malignancy and the implications these mutations carry in terms of prognostication and development of targeted therapeutic agents. We will focus on RNA-expression profiling and genomic DNA profiling, with a focus on comprehensive whole exome and whole genome sequencing relative to selected urothelial carcinoma-associated genes and circulating tumor DNA analysis.

Early PDD Cystoscopy after BCG Induction for High-risk Non-Muscle Invasive Bladder Cancer Significantly Increased the Detection of BCG-refractory Tumors

OBJECTIVES

To compare the detection rate of BCG refractory tumors between white light cystoscopy (WL-C) and Photodynamic Diagnosis cystoscopy (PDD-C).

METHODS

We performed a monocentric retrospective study that included all consecutive patients with high-risk non-muscle-invasive bladder cancer (NMIBC) diagnosed from January 2017 to January 2021. All patients had an initial Transurethral resection of bladder tumor (TURBT) with PDD ± restaging TURBT if needed, followed by full-dose BCG induction. Within 8 weeks following BCG induction all patients had both WL-C and PDD-C under general anesthesia ± TURBT in case of suspicious lesion. The primary endpoint was the detection of bladder cancer (BC) at post-BCG cystoscopy.

RESULTS

A total of 136 consecutive patients met inclusion criteria. Initial BC characteristics were: 35.6% of T1 tumor, 92.6% high-grade and 48.6% associated cis. BC was diagnosed in 33/136 cases (24%) at early PDD-C after BCG induction: 77% Ta, 23% T1, 56% associated cis, 68% high grade and 6% MIBC. Sensibility and Specificity of WL-C and PDD-C: 41 vs 91% (p<0.001) and 86 vs 75% (p=0.001). PDD-C detected 16 additional tumors: 81.3% Ta, 18.7% T1, 75% associated cis and 75% high grade.

CONCLUSIONS

Systematic use of PDD after BCG induction increased the detection of BCG-refractory tumors and lead to significant modification in the treatment of high-risk NMIBC. Future studies are needed to evaluate long-term oncological benefit of early PDD reevaluation and its cost-effectiveness.

The effectiveness and value of nadofaragene firadenovec, oportuzumab monatox, and pembrolizumab for BCG-unresponsive non-muscle-invasive bladder cancer

DISCLOSURES: Funding for this summary was contributed by Arnold Ventures, California Health Care Foundation, The Donaghue Foundation, Harvard Pilgrim Health Care, and Kaiser Foundation Health Plan to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from AbbVie, Aetna, America's Health Insurance Plans, Anthem, Alnylam, AstraZeneca, Biogen, Blue Shield of CA, Boehringer-Ingelheim, Cambia Health Services, CVS, Editas, Evolve Pharmacy, Express Scripts, Genentech/Roche, GlaxoSmithKline, Harvard Pilgrim, Health Care Service Corporation, HealthFirst, Health Partners, Humana, Johnson & Johnson (Janssen), Kaiser Permanente, LEO Pharma, Mallinckrodt, Merck, Novartis, National Pharmaceutical Council, Pfizer, Premera, Prime Therapeutics, Regeneron, Sanofi, Spark Therapeutics, uniQure, and United Healthcare. Beinfeld, McKenna, Rind, and Pearson are employed by ICER. Touchette received funding from ICER for work on this report and has also received fees from Monument Analytics and AstraZeneca, unrelated to this work. The University of Illinois at Chicago (UIC) and Touchette hold a patent for the model described in this report. The model is included in ICER's Interactive Modeler, for which a fee is paid to UIC and Touchette. Atlas also received funding from ICER for work on this report.

Expression of VISTA on tumor-infiltrating immune cells correlated with short intravesical recurrence in non-muscle-invasive bladder cancer

V-domain immunoglobulin suppressor of T cell activation (VISTA) is an immune checkpoint molecule expressed in hematopoietic cells, granulocytes, macrophages, and monocytes. However, few studies to date have investigated VISTA expression, especially its clinical utility, in bladder cancer. The present retrospective study aimed to examine VISTA, programmed death ligand-1 (PD-L1), and CD45 expression by immunohistochemical and immunofluorescence staining of archived pathological tissue samples from 159 patients with primary bladder cancer. The correlation between VISTA expression in immune cells (ICs) and clinicopathologic variables including PD-L1 expression in ICs was examined. Briefly, the rates of VISTA-positive ICs and VISTA-positive tumor cells were 67.9% (108/159) and 30.8% (49/159), respectively. The VISTA expression in ICs of patients with bladder cancer, including those with non-muscle-invasive bladder cancer (NMIBC), was positively correlated with tumor stage, grade, size, and multiplicity. The VISTA expression in ICs was stronger in bladder cancer cases with PD-L1-positive ICs than in those with PD-L1-negative ICs (p < 0.001). The mean intravesical recurrence-free survival was shorter in NMIBC cases with VISTA-positive ICs than in those with VISTA-negative ICs (34.0 vs 39.9 months, p = 0.03, log-rank test). In this first study to investigate VISTA expression in bladder cancer, these results implicate VISTA as a potential immunotherapeutic target and immunologic biomarker in bladder cancer.

Improving Anti-PD-1/PD-L1 Therapy for Localized Bladder Cancer

In high-risk non-muscle invasive bladder cancer (HR-NMIBC), patient outcome is negatively affected by lack of response to Bacillus-Calmette Guérin (BCG) treatment. Lack of response to cisplatin-based neoadjuvant chemotherapy and cisplatin ineligibility reduces successful treatment outcomes in muscle-invasive bladder cancer (MIBC) patients. The effectiveness of PD-1/PD-L1 immune checkpoint inhibitors (ICI) in metastatic disease has stimulated its evaluation as a treatment option in HR-NMIBC and MIBC patients. However, the observed responses, immune-related adverse events and high costs associated with ICI have provided impetus for the development of methods to improve patient stratification, enhance anti-tumorigenic effects and reduce toxicity. Here, we review the challenges and opportunities offered by PD-1/PD-L1 inhibition in HR-NMIBC and MIBC. We highlight the gaps in the field that need to be addressed to improve patient outcome including biomarkers for response stratification and potentially synergistic combination therapy regimens with PD-1/PD-L1 blockade.

Novel Combination Therapies for the Treatment of Bladder Cancer

Bladder cancer is the ninth most frequently diagnosed cancer world-wide and ranks 13th in cancer-related deaths. Two tremendous breakthroughs in bladder cancer therapy over the last decades are the approval of immune checkpoint inhibitors(ICIs)and the fibroblast growth factor receptor tyrosine kinase inhibitor (FGFR-TKI) erdafitinib for treating this deadly disease. Despite the beneficial effects of these approaches, the low response rate and the potential resistance of the cancer are major concerns. Hence, novel combination therapies to overcome these limitations have been investigated. In this context, combining immunotherapy with targeted drugs is an appealing therapeutic option to improve response and reduce the emergence of resistance in the management of bladder cancer. In this review, the rationale of using different therapeutic combinations is discussed according to the mechanistic differences, emphasizing the efficacy and safety based on evidence collected from preclinical and clinical studies. Finally, we highlight the limitations of these combinations and provide suggestions for further efforts in this challenging field.

Diagnosis and Management of Checkpoint Inhibitor Side Effects in Patients with Bladder Cancer: the Urologist’s Perspective

From 2016 through the present day, we have witnessed extraordinarily rapid advances and regulatory approvals of immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway, which has significantly improved survival among patients with advanced and metastatic urothelial carcinoma (mUC). Although these agents usually are well tolerated, their unique mechanism of action may enhance cytotoxic T-cell mediated immunity, evoking unique side effects that differ from conventional chemotherapy or molecularly targeted agents. The most common immune-related adverse events (irAEs) are dermatitis, colitis, pneumonitis, thyroid dysfunction, and transaminitis, but any organ system permeated by the lymphatic vasculature can be affected; also, neuropathies and arthralgias may occur. Immune-mediated events of any grade require prompt recognition and appropriate management to mitigate the risk of irAE exacerbation. Most patients with mild (grade 1) irAEs may continue checkpoint inhibitor treatment with careful monitoring. For grade 2 irAEs, it is appropriate to suspend treatment, initiate corticosteroid therapy, and only resume treatment if the irAE resolves to < grade 1. Events classified as > grade 3 may require permanent treatment cessation and high-dose corticosteroid therapy. In clinical trials of PD-1/PD-L1 inhibitors across multiple cancer types, approximately 15% of patients with mUC developed irAEs requiring corticosteroid therapy. Training physicians and nurse providers and counseling patients regarding the early recognition of irAEs are mandatory to ensure timely irAE detection and optimized patient management. Hence, operationalizing an advanced bladder cancer clinic requires collaboration and coordination amongst urologists, medical and radiation oncologists, and other medical specialists who participate in the increasingly multimodal and multidisciplinary care of patients with bladder cancer.

Rationale and Outcomes for Neoadjuvant Immunotherapy in Urothelial Carcinoma of the Bladder

CONTEXT

Immune therapy has emerged as a powerful treatment of metastatic urothelial carcinoma. Over 20 ongoing studies are exploring this strategy in the neoadjuvant setting in patients with localized muscle-invasive bladder cancer.

OBJECTIVE

To summarize the rationale and the clinical outcomes regarding the use of immune checkpoint blockade in the neoadjuvant setting before radical cystectomy.

EVIDENCE ACQUISITION

A systematic review of the literature in the MEDLINE database was performed. The central search strategy used the terms bladder cancer, urothelial carcinoma, mice, human, immunotherapy, neoadjuvant therapy, atezolizumab, pembrolizumab, durvalumab, nivolumab, avelumab, ipilimumab, and tremelimumab. The search was limited to publications between January 2008 and February 2020. Publicly available relevant abstracts from recent meetings were also included.

EVIDENCE SYNTHESIS

Phase II trials investigating neoadjuvant immune checkpoint blockade as a single agent before radical cystectomy reported a rate of pathological complete response (CR), ranging from 31% with an anti-PD-L1 monoclonal antibody (mAb) atezolizumab (n = 27/88) to 37% with anti-PD-1 mAb pembrolizumab (n = 42/114). Overall, 92% (n = 87/95) and 98% (n = 112/114) of the patients underwent radical cystectomy. Neoadjuvant immune checkpoint blockade did not delay planned surgery. Checkpoint inhibitor monotherapy was well tolerated, with no unexpected toxicity in the presurgical setting. Early phase I/II trials investigating neoadjuvant combination chemotherapy strategies with immune checkpoint blockers reported enhanced antitumor efficacy, with a pathological CR ranging from 33% to 50%.

CONCLUSIONS

Although limited clinical data are available on long-term survival, neoadjuvant immune checkpoint blockade demonstrated effective antitumor efficacy for localized muscle-invasive bladder cancer. Phase III trials are currently investigating this strategy in the presurgical setting.

PATIENT SUMMARY

Immunotherapy prior to surgery has been evaluated for patients with muscle-invasive bladder cancer. Although long-term survival benefit is unknown, such treatment strategy revealed a promising antitumor response rate for patients who underwent radical cystectomy. Ongoing prospective clinical trials will define the potential advantage of this approach over current cisplatin-based chemotherapeutic regimens alone or in combination.

[Immunotherapies in non-muscle invasive bladder cancer: immunotherapies and NMIBC]

Local and systemic immunotherapies are used for the management of bladder cancer in daily practice. BCG has been administered for almost 40 years in patients with non-muscle invasive bladder cancer (NMIBC). Despite its efficacy, disease progression is observed in nearly 30% of patients. Given the antitumor activity of immune checkpoint inhibitors in metastatic setting, these therapies are currently investigated in NMIBC. Pembrolizumab is now approved by the Food and Drug Administration (FDA) for the treatment of patients with BCG-unresponsive, high-risk, NMIBC with carcinoma in situ with or without papillary tumors who are ineligible for or have not elected to undergo cystectomy. Several phase 3 trials are ongoing to investigate the efficacy of PD(L)1 inhibitors combined with BCG such as ALBAN study in France.

Evidence-based Assessment of Current and Emerging Bladder-sparing Therapies for Non-muscle-invasive Bladder Cancer After Bacillus Calmette-Guerin Therapy: A Systematic Review and Meta-analysis

CONTEXT

Currently, there is no standard of care for patients with non-muscle-invasive bladder cancer (NMIBC) who recur despite bacillus Calmette-Guerin (BCG) therapy. Although radical cystectomy is recommended, many patients decline to undergo or are ineligible to receive it. Multiple agents are being investigated for use in this patient population.

OBJECTIVE

To systematically synthesize and describe the efficacy and safety of current and emerging treatments for NMIBC patients after treatment with BCG.

EVIDENCE ACQUISITION

A systematic literature search of MEDLINE, Embase, and the Cochrane Controlled Register of Trials (period limited to January 2007-June 2019) was performed. Abstracts and presentations from major conference proceedings were also reviewed. Randomized controlled trials were assessed using the Cochrane risk of bias tool. Data for single-arm trials were pooled using a random-effect meta-analysis with the proportions approach. Trials were grouped based on the minimum number of prior BCG courses required before enrollment and further stratified based on the proportion of patients with carcinoma in situ (CIS).

EVIDENCE SYNTHESIS

Thirty publications were identified with data from 23 trials for meta-analysis, of which 17 were single arm. Efficacy and safety outcomes varied widely across studies. Heterogeneity across trials was reduced in subgroup analyses. The pooled 12-mo response rates were 24% (95% confidence interval [CI]: 16-32%) for trials with two or more prior BCG courses and 36% (95% CI: 25-47%) for those with one or more prior BCG courses. In a subgroup analysis, inclusion of ≥50% of patients with CIS was associated with a lower response.

CONCLUSIONS

The variability in efficacy and safety outcomes highlights the need for consistent endpoint reporting and patient population definitions. With promising emerging treatments currently in development, efficacious and safe therapeutic options are urgently needed for this difficult-to-treat patient population.

PATIENT SUMMARY

We examined the efficacy and safety outcomes of treatments for non-muscle-invasive bladder cancer after bacillus Calmette-Guerin therapy. Outcomes varied across studies and patient populations, but emerging treatments currently in development show promising efficacy.

Impact of Molecular Subtyping and Immune Infiltration on Pathological Response and Outcome Following Neoadjuvant Pembrolizumab in Muscle-invasive Bladder Cancer

BACKGROUND

The PURE-01 study (NCT02736266) evaluated the use of pembrolizumab before radical cystectomy (RC) in muscle-invasive bladder cancer (MIBC).

OBJECTIVE

To evaluate the ability of molecular signatures to predict the pathological complete response (CR: ypT0N0) and progression-free survival (PFS) after pembrolizumab and RC.

DESIGN, SETTING, AND PARTICIPANTS

We analyzed the expression data from patients with T2-4aN0M0 MIBC enrolled in the PURE-01 study (N=84) and from patients of a retrospective multicenter cohort treated with cisplatin-based neoadjuvant chemotherapy (NAC; N=140).

INTERVENTION

Neoadjuvant pembrolizumab or NAC and RC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Immune signatures and molecular subtyping (The Cancer Genome Atlas, consensus model, and genomic subtyping classifier [GSC]) were evaluated in relation to CR and PFS. Multivariable logistic regression analyses for CR were used, adjusting for gender and clinical T stage.

RESULTS AND LIMITATIONS

The Immune190 signature was significant for CR on multivariable logistic regression analyses (p= 0.02) in PURE-01, but not in the NAC cohort (p= 0.7). Hallmark signatures for interferon gamma (IFNγ; p= 0.004) and IFNα response (p= 0.006) were also associated with CR for PURE-01, but not for NAC (IFNγ: p= 0.9 and IFNα: p= 0.8). In PURE-01, 93% of patients with the highest Immune190 scores (>1st quartile) had 2-yr PFS versus 79% of those with lower scores; no difference was observed in NAC patients, as well as for the other hallmarks in both groups. The neuroendocrine-like subtype had the worst 2-yr PFS in all three subtyping models (33%) and the GSC claudin-low subtype had the best, with no recurrences in 2 yr. Basal subtypes (across classifications) with higher Immune190 scores showed 100% 2-yr PFS after pembrolizumab therapy (p = 0.04, compared with basal-Immune190 low). Statistical analyses are limited by the small number of events and short follow-up.

CONCLUSIONS

Higher RNA-based immune signature scores were significantly associated with CR and numerically improved PFS outcomes after pembrolizumab, but not after NAC. These data emphasize that RNA profiling is a potential tool for personalizing neoadjuvant therapy selection.

PATIENT SUMMARY

We used gene expression profiling to evaluate the association between immune gene expression and response to neoadjuvant immunotherapy, compared with standard chemotherapy, in patients with muscle-invasive bladder cancer (MIBC). We found a significant association between immune gene expression and response to pembrolizumab, but not chemotherapy. We conclude that gene expression profiling has the potential to guide personalized neoadjuvant therapy in MIBC.

Updated Results of PURE-01 with Preliminary Activity of Neoadjuvant Pembrolizumab in Patients with Muscle-invasive Bladder Carcinoma with Variant Histologies

BACKGROUND

Patients with predominant variant histology (VH) of bladder tumors, defined as involving >50 % of the tumor specimens, are typically excluded from clinical trials, and for these patients, the efficacy of standard chemotherapy is limited.

OBJECTIVE

To evaluate the activity of preoperative pembrolizumab in patients with muscle-invasive bladder carcinoma (MIBC) and VH, enrolled in PURE-01 study (NCT02736266).

DESIGN, SETTING, AND PARTICIPANTS

In the open-label, single-arm, phase 2 PURE-01 study, three courses of 200 mg pembrolizumab preceding radical cystectomy (RC) were administered in T2-4aN0M0 MIBC patients. The amended study design included patients with predominant VH.

INTERVENTION

Neoadjuvant pembrolizumab and RC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Pathological complete response (pT0) in intention-to-treat population was the primary endpoint. Biomarker analyses included programmed cell-death ligand-1 (PD-L1) expression using the combined positive score (CPS; Dako 22C3 antibody) and comprehensive genomic profiling (FoundationOne assay). Multivariable logistic regression analyses (MVAs) evaluated the histological category (predominant VH vs nonpredominant VH vs pure urothelial carcinoma), tumor mutational burden (TMB) and CPS in association with the pathological response.

RESULTS AND LIMITATIONS

From February 2017 to June 2019, 114 patients were enrolled; 34 (30%) of them presented with VH, including 19 (17%) with predominant VH. In total, the pT0 rate was 37% (95% confidence interval [CI]: 28-46) and the pT ≤ 1 rate was 55% (95% CI: 46-65). The majority of predominant VH patients presented with squamous-cell carcinoma (SCC; N = 7), and six of seven (86%) had downstaging to pT ≤ 1, with one pT0; two of three lymphoepithelioma-like (LEL) variants had a pT0 response. None of the remaining nine predominant VHs had a response. On MVA, TMB and CPS were associated with both the pT0 and the pT ≤ 1 response, regardless of tumor histology.

CONCLUSIONS

The updated PURE-01 results confirm the activity of neoadjuvant pembrolizumab in MIBC. Patients with SCC and LEL features may be suitable for neoadjuvant immunotherapy trials. CPS and TMB are the key response predictors irrespective of the histological subtypes.

PATIENT SUMMARY

In the PURE-01 study, we have preliminarily evaluated the activity of neoadjuvant pembrolizumab in patients with predominant variant histology (VH). Of these patients, those harboring squamous-cell carcinoma or a lymphoepithelioma-like variant feature had major, although preliminary, pathological responses compared with those with other predominant VHs. Expression of programmed cell-death ligand-1 and tumor mutational burden may predict the pathological response to pembrolizumab, and provide a rationale for selecting patients according to these features instead of the histological bladder cancer subtypes.

Effect of Immunotherapy on Local Treatment of Genitourinary Malignancies

CONTEXT

Management of metastatic genitourinary malignancies has recently been transformed through the use of immune checkpoint inhibitors. The best way to integrate them into local treatment paradigms is still under investigation.

OBJECTIVE

To systematically evaluate evidence regarding the use of immunotherapy in the treatment of local disease, in both the perioperative and the metastatic setting.

EVIDENCE ACQUISITION

We performed a critical review of PubMed and ClinicalTrials.gov according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statement. Prospective and retrospective studies between 2011 and 2018 were included. Twenty-four publications were selected for inclusion, including 10 on urothelial carcinoma, seven on renal cell carcinoma, six on prostate cancer, and one on germ-cell cancer.

EVIDENCE SYNTHESIS

Prospective early-phase trials investigating neoadjuvant immunotherapy prior to cystectomy in urothelial carcinoma suggest a high rate of pathological complete response, from 29% with atezolizumab to 39.5% with pembrolizumab. Several neoadjuvant and adjuvant trials are still ongoing in bladder, renal, and prostate cancers, before or after surgery. The combination of immunotherapy and radiotherapy is being explored and could offer an interesting strategy for definitive treatment modality with curative intent. Finally, in metastatic disease, delayed local treatment could be discussed after immunotherapy in selected patients with an excellent radiographic response.

CONCLUSIONS

Little evidence exists on the oncological impact of immunotherapy on the local treatment of genitourinary malignancies, but preliminary results are encouraging and many prospective trials are ongoing.

PATIENT SUMMARY

In this study, we review recent advances in immunotherapy and its role in local treatment. Immunotherapy is evaluated before or after surgery, or in combination with radiotherapy for localized disease. Ongoing trials will bring clarity on the local downstaging effect of immunotherapy and its association with oncological and functional outcomes.