Final Results of Neoadjuvant Atezolizumab in Cisplatin-ineligible Patients with Muscle-invasive Urothelial Cancer of the Bladder

Neo-Adjuvant immunotherapies: Bladder cancer as a platform for drug development targeting mucosal immunity

Bacillus Calmette-Guerin (BCG) is a live attenuated Mycobacterium bovis strain, originally developed as a vaccine against tuberculosis. It is also the only bacterial cancer therapy approved by the US Food & Drug Administration for clinical use. BCG is delivered in the bladder, shortly after tumour resection, for patients with high-risk non-muscle invasive bladder cancer (NMIBC). Modulating mucosal immunity by exposing the urothelium to intravesical BCG has been the main therapeutic strategy for high-risk NMIBC over the last three decades. Thus, BCG provides a benchmark for the clinical development of bacteria-or other live attenuated pathogens-as cancer therapy. Currently, a myriad of immuno-oncology compounds is under clinical evaluation in BCG-unresponsive and BCG-naïve patients as an alternative therapy in the context of worldwide BCG shortages. For patients with non-metastatic muscle-invasive bladder cancer (MIBC), studies investigating neoadjuvant immunotherapy with either anti-PD-1/PD-L1 monoclonal antibodies in monotherapy or in combination with anti-CTLA-4 monoclonal antibodies have shown overall efficacy and acceptable safety profiles prior to radical cystectomy. Emerging clinical investigations are testing synergistic approaches by combining intravesical delivery of drugs with systemic immune checkpoint blockades in the neoadjuvant setting for patients with MIBC. Such novel strategy aims to prime a local anti-tumour immunity and reduce distant metastatic relapses by enhancing a systemic adaptive anti-tumour immune response. Here, we present and discuss some of the most promising clinical trials developing such novel therapeutic approaches.

Adaptive Immunity in Genitourinary Cancers

CONTEXT

While urothelial and renal cell cancers have exhibited modest responses to novel immune checkpoint inhibitors targeting the programmed death ligand 1 and its receptor, response rates in patients with prostate cancer have remained poor. The factors underlying suboptimal outcomes observed in patients treated with novel immunotherapies are still to be resolved.

OBJECTIVE

To review the literature and describe the key adaptive immune physiological events associated with cancer progression and therapeutic response in genitourinary (GU) cancers.

EVIDENCE ACQUISITION

We performed a nonsystematic, collaborative narrative review to highlight recent advancements leading to the current state of knowledge on the critical mediators of antitumor adaptive immunity to GU cancers. Further, we discuss the findings on the pre- and post-treatment immunological events that either are unique to each of the three cancer types or exhibit overlapping clinical associations.

EVIDENCE SYNTHESIS

Aging-associated immune function decline is a major factor underlying poor outcomes observed in patients treated with both conventional and novel immunotherapies. Other cancer immunobiological aspects associated with suboptimal responses in GU cancers include the overall tumor mutational burden, mutations in specific tumor suppressor/DNA damage repair genes (KDM6A, PTEN, STAG2, TP53, ATM, and BRCA2), and abundance of multiple functional states of adaptive immune cells and their spatiotemporal localization within the tumor immune microenvironment. Understanding these mechanisms may potentially lead to the development of prognostic and predictive biomarkers such as immune cell infiltration profiles and tertiary lymphoid structures (TLSs) that associate with variable clinical outcomes depending on the nature of the novel immunotherapeutic approach. Implementation of newer immune-monitoring technologies and improved preclinical modeling systems will augment our understanding of the host and tumor intrinsic factors contributing to the variability of responses to immunotherapies.

CONCLUSIONS

Despite the tremendous progress made in the understanding of dynamic and static adaptive immune elements within the tumor immune landscape, several knowledge gaps remain. A comprehensive knowledge thus gained will lead to precision immunotherapy, improved drug sequencing, and a therapeutic response.

PATIENT SUMMARY

We performed a collaborative review by a diverse group of experts in the field to examine our understanding of the events and crosstalk between cancer cells and the patient's immune system that are associated with responses to novel immunotherapies. An evolving understanding of tumor-intrinsic and host-related immune alterations, both before and after therapy, will aid in the discovery of promising markers of responses to immunotherapy as well as the development of unique therapeutic approaches for the management of genitourinary cancers.

Gender-specific outcomes in immune checkpoint inhibitor therapy for advanced or metastatic urothelial cancer: a systematic review and meta-analysis

PURPOSE

To analyze gender-specific differences in survival parameters in advanced or metastatic urothelial cancer patients undergoing immune checkpoint inhibition.

METHODS

The primary aim of this systematic review and meta-analysis was to evaluate gender-specific differences in disease-free (DFS), progression-free (PFS), cancer-specific survival (CSS), event-free survival (EFS), overall survival (OS) and objective response rate (ORR). The sources MEDLINE, Embase and Cochrane Library were systematically searched from January 2010 to June 2022. No restrictions were made concerning language, study region or publication type. A comparison of gender-specific differences in survival parameters was performed using a random-effects meta-analysis. A risk of bias assessment was done using the ROBINS-I tool.

RESULTS

Five studies were included. In a random-effect meta-analysis of the studies, PCD4989g and IMvigor 211 with both using atezolizumab, females were more likely to have better objective response rate (ORR) than men (OR 2.24; 95% CI 1.20-4.16; p = 0.0110). In addition, females had a comparable median OS to men (MD 1.16; 95% CI - 3.15-5.46; p = 0.598). In summary, comparing all results, a tendency was seen toward better response rates and survival parameters in female patients. The risk of bias assessment yielded an overall low risk of bias.

CONCLUSIONS

There is a tendency toward better outcomes in women for immunotherapy in advanced or metastatic urothelial cancer, but only for the antibody atezolizumab women have a significantly better ORR. Unfortunately, many studies fail to report gender-specific outcomes. Therefore, further research is essential when aiming for individualized medicine. This research should address immunological confounders.

Tumour microenvironment as a predictive factor for immunotherapy in non-muscle-invasive bladder cancer

Bladder cancer (BC) can be divided into two subgroups depending on invasion of the muscular layer: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Its aggressiveness is associated, inter alia, with genetic aberrations like losses of 1p, 6q, 9p, 9q and 13q; gain of 5p; or alterations in the p53 and p16 pathways. Moreover, there are reported metabolic disturbances connected with poor diagnosis-for example, enhanced aerobic glycolysis, gluconeogenesis or haem catabolism.Currently, the primary way of treatment method is transurethral resection of the bladder tumour (TURBT) with adjuvant Bacillus Calmette-Guérin (BCG) therapy for NMIBC or radical cystectomy for MIBC combined with chemotherapy or immunotherapy. However, intravesical BCG immunotherapy and immune checkpoint inhibitors are not efficient in every case, so appropriate biomarkers are needed in order to select the proper treatment options. It seems that the success of immunotherapy depends mainly on the tumour microenvironment (TME), which reflects the molecular disturbances in the tumour. TME consists of specific conditions like hypoxia or local acidosis and different populations of immune cells including tumour-infiltrating lymphocytes, natural killer cells, neutrophils and B lymphocytes, which are responsible for shaping the response against tumour neoantigens and crucial pathways like the PD-L1/PD-1 axis.In this review, we summarise holistically the impact of the immune system, genetic alterations and metabolic changes that are key factors in immunotherapy success. These findings should enable better understanding of the TME complexity in case of NMIBC and causes of failures of current therapies.

Cancer-associated Fibroblasts in Bladder Cancer: Origin, Biology, and Therapeutic Opportunities

CONTEXT

Bladder cancer (BLCA) is a highly prevalent tumour and a health problem worldwide, especially among men. Recent work has highlighted the relevance of the tumour microenvironment (TME) in cancer biology with translational implications. Cancer-associated fibroblasts (CAFs) are a prominent, heterogeneous population of cells in the TME. CAFs have been associated with tumour development, progression, and poor prognosis in several neoplasms. However, their role in BLCA has not yet been exploited deeply.

OBJECTIVE

To review the role of CAFs in BLCA biology and provide an understanding of CAF origin, subtypes, markers, and phenotypic and functional characteristics to improve patient management.

EVIDENCE ACQUISITION

A PubMed search was performed to review manuscripts published using the terms "cancer associated fibroblast" and "bladder cancer" or "urothelial cancer". All abstracts were reviewed, and the full content of all relevant manuscripts was analysed. In addition, selected manuscripts on CAFs in other tumours were considered.

EVIDENCE SYNTHESIS

CAFs have been studied less extensively in BLCA than in other tumours. Thanks to new techniques, such as single-cell RNA-seq and spatial transcriptomics, it is now possible to accurately map and molecularly define the phenotype of fibroblasts in normal bladder and BLCA. Bulk transcriptomic analyses have revealed the existence of subtypes among both non-muscle-invasive and muscle-invasive BLCA; these subtypes display distinct features regarding their CAF content. We provide a higher-resolution map of the phenotypic diversity of CAFs in these tumour subtypes. Preclinical studies and recent promising clinical trials leverage on this knowledge through the combined targeting of CAFs or their effectors and the immune microenvironment.

CONCLUSIONS

Current knowledge of BLCA CAFs and the TME is being increasingly applied to improve BLCA therapy. There is a need to acquire a deeper understanding of CAF biology in BLCA.

PATIENT SUMMARY

Tumour cells are surrounded by nontumoural cells that contribute to the determination of the behaviour of cancers. Among them are cancer-associated fibroblasts. The "neighbourhoods" established through these cellular interactions can now be studied with much greater resolution. Understanding these features of tumours will contribute to the designing of more effective therapies, especially in relationship to bladder cancer immunotherapy.

High- or low-dose preoperative ipilimumab plus nivolumab in stage III urothelial cancer: the phase 1B NABUCCO trial

Cohort 1 of the phase 1B NABUCCO trial showed high pathological complete response (pCR) rates with preoperative ipilimumab plus nivolumab in stage III urothelial cancer (UC). In cohort 2, the aim was dose adjustment to optimize responses. Additionally, we report secondary endpoints, including efficacy and tolerability, in cohort 2 and the association of presurgical absence of circulating tumor DNA (ctDNA) in urine and plasma with clinical outcome in both cohorts. Thirty patients received two cycles of either ipilimumab 3 mg kg-1 plus nivolumab 1 mg kg-1 (cohort 2A) or ipilimumab 1 mg kg-1 plus nivolumab 3 mg kg-1 (cohort 2B), both followed by nivolumab 3 mg kg-1. We observed a pCR in six (43%) patients in cohort 2A and a pCR in one (7%) patient in cohort 2B. Absence of urinary ctDNA correlated with pCR in the bladder (ypT0Nx) but not with progression-free survival (PFS). Absence of plasma ctDNA correlated with pCR (odds ratio: 45.0; 95% confidence interval (CI): 4.9-416.5) and PFS (hazard ratio: 10.4; 95% CI: 2.9-37.5). Our data suggest that high-dose ipilimumab plus nivolumab is required in stage III UC and that absence of ctDNA in plasma can predict PFS. ClinicalTrials.gov registration: NCT03387761 .

Predictive value of radiological response, pathological response and relapse-free survival for overall survival in neoadjuvant immunotherapy trials: pooled analysis of 29 clinical trials

BACKGROUND

An increasing number of clinical trials are being conducted exploring the efficacy of neoadjuvant immune checkpoint inhibitors. Surrogate end-points for overall survival (OS) are urgently needed.

METHODS

Phase II or III trials of neoadjuvant immunotherapy that reported data on OS and surrogate end-points were identified from January 1, 2000, to November 25, 2022. Individual patient data, and trial-level data were requested from corresponding authors or extracted from eligible trials. At the individual level, correlations between radiological and pathological response and OS were measured by the Cox model and quantified by hazard ratio (HR). C-statistic was used to quantify the predictive performance of radiological and pathological response for OS. The coefficient of determination (R²) between RFS and OS was evaluated by a bivariate survival model.

RESULTS

A total of 29 trials reporting 2901 patients were included. ORR correlated with improved OS (3-year OS: 87.0% versus 70.4% for ORR versus non-ORR, respectively; HR, 0.34, 95% confidence interval [CI], 0.17-0.68). The HRs for OS in patients achieving MPR and pCR were 0.24 (95% CI, 0.12-0.46) and 0.13 (95% CI, 0.05-0.36). The survival benefit maintained after adjusting tumour type. C-statistics of ORR, MPR and pCR were 0.63, 0.63 and 0.65, respectively. The strength of association between RFS and OS was strong (R² = 0.88, 95% CI, 0.79-0.94).

CONCLUSIONS

These findings suggest that ORR, MPR, pCR and RFS are valid predictors for OS when using neoadjuvant immune checkpoint inhibitors. Moreover, MPR, pCR and RFS may be the most optimal surrogates for OS.

Contemporary Systemic Therapies in Urothelial Carcinoma

Prior to the past decade, systemic therapy options for muscle-invasive bladder cancer (MIBC) or locally advanced/metastatic urothelial carcinoma (la/mUC) were dismal for cisplatin-ineligible patients and after progression on chemotherapy. Although the bulk of available evidence for novel systemic therapies exists in the la/mUC setting, emerging data suggests an important role in the neoadjuvant and adjuvant spaces as well. In this narrative review, we examine the application of contemporary systemic therapies to urothelial carcinoma (UC) including immune checkpoint inhibitors (ICIs), antibody-drug conjugates (ADCs), and targeted therapies. We additionally acknowledge the potential of combination therapies to further potentiate a durable synergistic response.

Current and Future Landscape of Perioperative Treatment for Muscle-Invasive Bladder Cancer

Cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy is the current standard of care for muscle-invasive bladder cancer (MIBC). However, less than half of patients are candidates for this treatment, and 50% will develop metastatic disease. Adjuvant chemotherapy could be offered if neoadjuvant treatment has not been administered for suitable patients. It is important to reduce the risk of systemic recurrence and improve the prognosis of localized MIBC. Systemic therapy for metastatic urothelial carcinoma has evolved in recent years. Immune checkpoint inhibitors and targeted agents, such as antibody-drug conjugates or FGFR inhibitors, are new therapeutic alternatives and have shown their benefit in advanced disease. Currently, several clinical trials are investigating the role of these drugs, as monotherapy and in combination with chemotherapy, in the neoadjuvant and adjuvant settings with promising outcomes. In addition, the development of predictive biomarkers could predict responses to neoadjuvant therapies.

Predictive Biomarkers of Response to Neoadjuvant Therapy in Muscle Invasive Bladder Cancer

Neoadjuvant cisplatin-based chemotherapy is recommended prior to surgical removal of the bladder for patients with non-metastatic muscle invasive bladder cancer. Despite a survival benefit, approximately half of patients do not respond to chemotherapy and are exposed potentially unnecessarily to substantial toxicity and delay in surgery. Therefore, biomarkers to identify likely responders before initiating chemotherapy would be a helpful clinical tool. Furthermore, biomarkers may be able to identify patients who do not need subsequent surgery after clinical complete response to chemotherapy. To date, there are no clinically approved predictive biomarkers of response to neoadjuvant therapy. Recent advances in the molecular characterization of bladder cancer have shown the potential role for DNA damage repair (DDR) gene alterations and molecular subtypes to guide therapy, but these need validation from prospective clinical trials. This chapter reviews candidate predictive biomarkers of response to neoadjuvant therapy in muscle invasive bladder cancer.

Feasibility of Longitudinal ctDNA Assessment in Patients with Uterine and Extra-Uterine Leiomyosarcoma

Background: Leiomyosarcomas (LMS) are aggressive malignancies with a propensity for early relapse. Current surveillance modalities include physical exam and imaging; however, radiological response to therapy may only manifest after 4-6 cycles of treatment. Herein, we evaluated the feasibility of longitudinal circulating tumor DNA (ctDNA) assessment in LMS patients to identify disease progression. Methods: We performed a retrospective review of patients with LMS who underwent treatment at Stanford Cancer Center between September 2019 and May 2022. ctDNA detection was performed using a personalized, tumor-informed ctDNA assay. Genomic analysis was conducted to characterize tumor mutation burden (TMB) and known driver mutations. Results: A total of 148 plasma samples were obtained from 34 patients with uterine (N = 21) and extrauterine (N = 13) LMS (median follow-up: 67.2 (19-346.3) weeks] and analyzed for ctDNA presence. Nineteen patients had metastatic disease. The most frequently mutated driver genes across sub-cohorts were TP53, RB1, and PTEN. Patients were stratified into four sub-cohorts (A-D) based on ctDNA kinetics. ctDNA levels tracked longitudinally with progression of disease and response to therapy. Conclusion: Our results indicate that while undetectable ctDNA may suggest a lower likelihood of relapse, ctDNA positivity may indicate progressive disease, enabling closer monitoring of patients for early clinical intervention.