Somatic Features of Response and Relapse in Non-muscle-invasive Bladder Cancer Treated with Bacillus Calmette-Guérin Immunotherapy

Exploring the utility of a NGS multigene panel to predict BCG response in patients with non-muscle invasive bladder cancer

Objectives

Intravesical Bacillus Calmette-Guérin (BCG) therapy is a gold standard for patients with high-risk non-muscle invasive bladder cancer (NMIBC). Although a long-lasting therapeutic response is observed in most patients, BCG failure occurs in 30%-50% of patients and a progression to muscle-invasive disease is found in 10%-15%. Therefore, predicting high-risk patients who might not benefit from BCG treatment is critical. The purpose of this study was to identify, whether the presence of specific oncogenic mutations might be indicative of BCG treatment response.

Methods

Nineteen high-grade NMIBC patients who received intravesical BCG were retrospectively enrolled and divided into "responders" and "non-responders" groups. Tissue samples from transurethral resection of bladder cancer were performed before starting therapy and were examined using a multigene sequencing panel.

Results

Mutations in TP53, FGFR3, PIK3CA, KRAS, CTNNB1, ALK and DDR2 genes were detected. TP53 and FGFR3 were found to be the most frequently mutated genes in our cohort (31.6% and 26.3%, respectively), followed by PIK3CA (15.8%). In the BCG-responsive patient group, 90% of samples were found to have mutated genes, with almost 50% of them showing mutations in tyrosine kinase receptors and CTNNB1 genes. On the other hand, in the BCG-unresponsive group, we found mutations in 44.4% of samples, mainly in TP53 gene.

Conclusions

Our findings suggest that a Next-Generation Sequencing (NGS) multigene panel is useful in predicting BCG response in patients with NMIBC.

Molecular biomarkers of progression in non-muscle-invasive bladder cancer - beyond conventional risk stratification

The global incidence of bladder cancer is more than half a million diagnoses each year. Bladder cancer can be categorized into non-muscle-invasive bladder cancer (NMIBC), which accounts for ~75% of diagnoses, and muscle-invasive bladder cancer (MIBC). Up to 45% of patients with NMIBC develop disease progression to MIBC, which is associated with a poor outcome, highlighting a clinical need to identify these patients. Current risk stratification has a prognostic value, but relies solely on clinicopathological parameters that might not fully capture the complexity of disease progression. Molecular research has led to identification of multiple crucial players involved in NMIBC progression. Identified biomarkers of progression are related to cell cycle, MAPK pathways, apoptosis, tumour microenvironment, chromatin stability and DNA-damage response. However, none of these biomarkers has been prospectively validated. Reported gene signatures of progression do not improve NMIBC risk stratification. Molecular subtypes of NMIBC have improved our understanding of NMIBC progression, but these subtypes are currently unsuitable for clinical implementation owing to a lack of prospective validation, limited predictive value as a result of intratumour subtype heterogeneity, technical challenges, costs and turnaround time. Future steps include the development of consensus molecular NMIBC subtypes that might improve conventional clinicopathological risk stratification. Prospective implementation studies of biomarkers and the design of biomarker-guided clinical trials are required for the integration of molecular biomarkers into clinical practice.

The role of TERT C228T and KDM6A alterations and TME in NMIBC treated with BCG

We aimed to investigate the genomic and tumor microenvironmental (TME) profiles in non-muscle invasive bladder cancer (NMIBC) and explore potential predictive markers for Bacillus Calmette-Guérin (BCG) treatment response in high-risk NMIBC patients (according to European Association of Urology (EAU) risk stratification). 40 patients with high-risk NMIBC (cTis-T1N0M0) who underwent en bloc resection followed by BCG instillation were retrospectively enrolled. Surgical samples were subjected to Next Generation Sequencing (NGS) and multiplex immunofluorescence (mIF) assay. Genomic profiling revealed high prevalences of alterations in TERT (55%), KDM6A (32.5%), FGFR3(30%), PIK3CA (30%), TP53(27.5%) and ARID1A (20%). TME analysis showed different proportions of macrophages, NK cells, T cells subsets in tumoral and stromal compartment. Multivariate analysis identified TERT C228T and alteration in KDM6A as two independent factors associated with inferior RFS. The study comprehensively depicted the genomic and TME profiles in NMIBC and identified potential predictive biomarkers for BCG treatment.

Integrating Genetic Alterations and Histopathological Features for Enhanced Risk Stratification in Non-Muscle-Invasive Bladder Cancer

BACKGROUND

Urothelial carcinoma presents as non-muscle-invasive bladder cancer (NMIBC) in ~75% of primary cases. Addressing the limitations of the TNM and WHO04/16 classification systems, this study investigates genetic alterations, the mitotic activity index (MAI), and immunohistochemistry (IHC) markers CK20, p53, and CD25 as better prognostic biomarkers in NMIBC.

METHODS

Using the Oncomine™ Focus Assay for targeted next-generation sequencing (NGS), 409 single-nucleotide variations (SNVs) and 193 copy number variations (CNVs) were identified across 287 patients with TaT1 tumors.

RESULTS

FGFR3 and PIK3CA alterations were significantly more prevalent in Ta tumors, while T1 tumors had significant ERBB2 alterations. Low-grade (LG) tumors were enriched with FGFR3 alterations, while high-grade (HG) tumors were significantly associated with ERBB2 alterations, as well as FGFR1 and CCND1 amplifications. FGFR3 alterations were linked to shorter recurrence-free survival (RFS; p = 0.033) but improved progression-free survival (PFS; p < 0.001). Conversely, ERBB2 alterations (p < 0.001), ERBB3 mutations (p = 0.044), and both MYC (p < 0.001) and MYCN (p = 0.011) amplifications were associated with shorter PFS. Survival analysis of gene sets revealed inverse associations between PIK3CA and ERBB2 (p = 0.003), as well as PIK3CA and MYC (p = 0.005), with PFS.

CONCLUSIONS

In multivariate Cox regression, MAI was the strongest predictor for PFS. Integrating genetic alterations and histopathological features may improve risk stratification in NMIBC.

Relationship between clonal evolution and drug resistance in bladder cancer: A genomic research review

Bladder cancer stands as a prevalent global malignancy, exhibiting notable sex-based variations in both incidence and prognosis. Despite substantial strides in therapeutic approaches, the formidable challenge of drug resistance persists. The genomic landscape of bladder cancer, characterized by intricate clonal heterogeneity, emerges as a pivotal determinant in fostering this resistance. Clonal evolution, encapsulating the dynamic transformations within subpopulations of tumor cells over time, is implicated in the emergence of drug-resistant traits. Within this review, we illuminate contemporary insights into the role of clonal evolution in bladder cancer, elucidating its influence as a driver in tumor initiation, disease progression, and the formidable obstacle of therapy resistance.

Attenuated mutants of Salmonella enterica Typhimurium mediate melanoma regression via an immune response

The lack of effective treatment options for an increasing number of cancer cases highlights the need for new anticancer therapeutic strategies. Immunotherapy mediated by Salmonella enterica Typhimurium is a promising anticancer treatment. Candidate strains for anticancer therapy must be attenuated while retaining their antitumor activity. Here, we investigated the attenuation and antitumor efficacy of two S. enterica Typhimurium mutants, ΔtolRA and ΔihfABpmi, in a murine melanoma model. Results showed high attenuation of ΔtolRA in the Galleria mellonella model, and invasion and survival in tumor cells. However, it showed weak antitumor effects in vitro and in vivo. Contrastingly, lower attenuation of the attenuated ΔihfABpmi strain resulted in regression of tumor mass in all mice, approximately 6 days after the first treatment. The therapeutic response induced by ΔihfABpmi was accompanied with macrophage accumulation of antitumor phenotype (M1) and significant increase in the mRNAs of proinflammatory mediators (TNF-α, IL-6, and iNOS) and an apoptosis inducer (Bax). Our findings indicate that the attenuated ΔihfABpmi exerts its antitumor activity by inducing macrophage infiltration or reprogramming the immunosuppressed tumor microenvironment to an activated state, suggesting that attenuated S. enterica Typhimurium strains based on nucleoid-associated protein genes deletion could be immunotherapeutic against cancer.

Urinary comprehensive genomic profiling predicts urothelial carcinoma recurrence and identifies responders to intravesical therapy

Intravesical therapy (IVT) is the standard of care to decrease risk of recurrence and progression for high-grade nonmuscle-invasive bladder cancer. However, post-IVT recurrence remains common and the ability to risk-stratify patients before or after IVT is limited. In this prospectively designed and accrued cohort study, we examine the utility of urinary comprehensive genomic profiling (uCGP) for predicting recurrence risk following transurethral resection of bladder tumor (TURBT) and evaluating longitudinal IVT response. Urine was collected before and after IVT instillation and uCGP testing was done using the UroAmp™ platform. Baseline uCGP following TURBT identified patients with high (61%) and low (39%) recurrence risk. At 24 months, recurrence-free survival (RFS) was 100% for low-risk and 45% for high-risk patients with a hazard ratio (HR) of 9.3. Longitudinal uCGP classified patients as minimal residual disease (MRD) Negative, IVT Responder, or IVT Refractory with 24-month RFS of 100%, 50%, and 32%, respectively. Compared with MRD Negative patients, IVT Refractory patients had a HR of 10.5. Collectively, uCGP enables noninvasive risk assessment of patients following TURBT and induction IVT. uCGP could inform surveillance cystoscopy schedules and identify high-risk patients in need of additional therapy.

Optimizing outcomes for high-risk, non-muscle-invasive bladder cancer: The evolving role of PD-(L)1 inhibition

Transurethral resection of bladder tumor followed by intravesical Bacillus Calmette-Guérin (BCG) is the standard of care in high-risk, non-muscle-invasive bladder cancer (NMIBC). Although many patients respond, recurrence and progression are common. In addition, patients may be unable to receive induction + maintenance due to intolerance or supply issues. Therefore, alternative treatment options are urgently required. Programmed cell death (ligand) 1 (PD-[L]1) inhibitors show clinical benefit in phase 1/2 trials in BCG-unresponsive NMIBC patients. This review presents the status of PD-(L)1 inhibition in high-risk NMIBC and discusses future directions. PubMed and Google scholar were searched for articles relating to NMIBC immunotherapy and ClinicalTrials.gov for planned and ongoing clinical trials. Preclinical and early clinical studies show that BCG upregulates PD-L1 expression in bladder cancer cells and, when combined with a PD-(L)1 inhibitor, a potent antitumor response is activated. Based on this mechanism, several PD-(L)1 inhibitors are in phase 3 trials in BCG-naïve, high-risk NMIBC in combination with BCG. Whereas PD-(L)1 inhibitors are well characterized in patients with advanced malignancies, the impact of immune-related adverse events (irAE) on the benefit/risk ratio in NMIBC should be determined. Alternative routes to intravenous administration, like subcutaneous and intravesical administration, may facilitate adherence and access. The outcomes of combination of PD-(L)1 inhibitors and BCG in NMIBC are highly anticipated. There will be a need to address treatment resources, optimal management of irAEs and education and training related to use of this therapy in clinical practice.

Somatic Mutation of the Non-Muscle-Invasive Bladder Cancer Associated with Early Recurrence

Next-generation sequencing (NGS) is widely used in muscle-invasive bladder cancer but has limited use in non-muscle-invasive bladder cancer (NMIBC) due to significant heterogeneity and high cancer-specific survival. Therefore, we evaluated the genomic information of NMIBC and identified molecular alterations associated with tumour recurrence. A total of 43 patients with NMIBC who underwent transurethral resection of the bladder were enrolled. We performed NGS using an Oncomine panel of tumour specimens and blood samples corresponding to each specimen. The somatic mutation results were analysed by pairwise comparison and logistic regression according to the recurrence of bladder tumours within 1 year. The median incidence of genetic variations in 43 tumour samples was 56 variations per sample, and a high tumour mutation burden (TMB) was associated with tumour recurrence (median variation 33 vs. 64, p = 0.023). The most mutated gene was adipose tissue macrophages (ATM) (79%), followed by neurofibromatosis-1 (NF1) (79%), and neurogenic locus notch homolog protein 1 (NOTCH1) (79%). In multivariable analysis, mutation of epidermal growth factor receptor (EGFR) (odds ratio [OR], 9.95; 95% confidence interval [CI], 1.40-70.96; p = 0.022) and telomerase reverse transcriptase (TERT) (OR, 7.92; 95% CI, 1.22-51.51; p = 0.030) were significant factors associated with the recurrence of bladder tumour within 1 year. Our results revealed that high TMB, EGFR mutation, and TERT mutation had a significant association with tumour recurrence in NMIBC. In addition, somatic mutations in EGFR and TERT could be useful prognostic biomarkers in NMIBC.

Circulating and urinary tumour DNA in urothelial carcinoma - upper tract, lower tract and metastatic disease

Precision medicine has transformed the way urothelial carcinoma is managed. However, current practices are limited by the availability of tissue samples for genomic profiling and the spatial and temporal molecular heterogeneity observed in many studies. Among rapidly advancing genomic sequencing technologies, non-invasive liquid biopsy has emerged as a promising diagnostic tool to reproduce tumour genomics, and has shown potential to be integrated in several aspects of clinical care. In urothelial carcinoma, liquid biopsies such as plasma circulating tumour DNA (ctDNA) and urinary tumour DNA (utDNA) have been investigated as a surrogates for tumour biopsies and might bridge many shortfalls currently faced by clinicians. Both ctDNA and utDNA seem really promising in urothelial carcinoma diagnosis, staging and prognosis, response to therapy monitoring, detection of minimal residual disease and surveillance. The use of liquid biopsies in patients with urothelial carcinoma could further advance precision medicine in this population, facilitating personalized patient monitoring through non-invasive assays.

Novel sequential treatment strategy for patients with muscle-invasive bladder cancer (MIBC): intravesical recombinant BCG, followed by neoadjuvant chemoimmunotherapy, radical cystectomy plus pelvic lymphadenectomy and adjuvant immunotherapy - protocol of a multicentre, single arm phase 2 trial (SAKK 06/19)

INTRODUCTION

The combination of checkpoint inhibition and cisplatin-based chemotherapy is investigated in muscle invasive bladder cancer (MIBC) and results from phase 2 trials have been presented. Intravesical BCG has been used for non-MIBC (NMIBC) in patients with carcinoma in situ and high-grade Ta/T1 tumours. BCG induces innate and adapted immune response and upregulation of PD-L1 in preclinical models. The proposed trial is intended to implement a new immuno-immuno-chemotherapy induction therapy for MIBC. The combination of BCG and checkpoint inhibition with chemotherapy aims at higher intravesical responses and better local and systemic control of disease.

METHODS AND ANALYSIS

SAKK 06/19 is an open-label single-arm phase II trial for patients with resectable MIBC T2-T4a cN0-1. Intravesical recombinant BCG (rBCG: VPM1002BC) is applied weekly for three instillations followed by four cycles of neoadjuvant cisplatin/gemcitabine every 3 weeks. Atezolizumab 1200 mg every 3 weeks is started together with rBCG and given for four cycles. All patients then undergo restaging and radical cystectomy and pelvic lymphadenectomy. Atezolizumab is continued as maintenance therapy after surgery every 3 weeks for 13 cycles. Pathological complete remission is the primary endpoint. Secondary endpoints include pathological response rate (

TRIAL REGISTRATION NUMBER

NCT04630730.

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Key Words

• CHEMOTHERAPY
• IMMUNOLOGY
• ONCOLOGY
• Urological tumours

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MESH Headings

• Humans
• Cisplatin/therapeutic use
• BCG Vaccine/therapeutic use
• Cystectomy
• Neoadjuvant Therapy
• Urinary Bladder Neoplasms/drug therapy
• Urinary Bladder Neoplasms/pathology
• Immunotherapy
• Administration, Intravesical
• Muscles/pathology
• Lymph Node Excision
• Multicenter Studies as Topic
• Clinical Trials, Phase II as Topic

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Grants

• F. Hoffmann–La Roche Ltd

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Affiliation(s)

Ulf Petrausch OnkoZentrum, Zurich, Switzerland
Martin Spahn Lindenhof Group, Bern, Switzerland
Martina Schneider Competence Center, SAKK, Bern, Switzerland
Stefanie Hayoz Competence Center, SAKK, Bern, Switzerland
Cyrill A Rentsch Department of Urology, University Hospital, Basel, Switzerland
Sacha Rothschild Department of Medical Oncology, Cantonal Hospital, Baden, Switzerland
Aurelius Omlin OnkoZentrum, Zurich, Switzerland
Richard Cathomas Division of Oncology/Hematology, Cantonal Hospital Graubünden, Chur, Switzerland

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Biology of BCG response in non-muscle invasive bladder cancer - 2021 IBCN Updates Part III

Bacillus Calmette-Guerin (BCG) remains the only FDA-approved first-line therapy in patients with high-risk non-muscle invasive bladder cancer. Recurrences, even after adequate BCG therapy, are common and the efficacy of second-line therapies remains modest. Therefore, early identification of patients likely to recur and treatment after recurrence remain critical unmet needs in the clinical care of bladder cancer patients. To address these deficits, a better understanding of the mechanisms of resistance to BCG-therapy is needed. The virtual update of the International Bladder Cancer Network (IBCN) on the biology of response to BCG focused on potential mechanisms and markers of resistance to intravesical BCG therapy. The insights from this meeting will be highlighted and put into context of previously reported mechanisms of resistance to BCG in this review.