Predictive and Prognostic Biomarkers and Tumor Antigens for Targeted Therapy in Urothelial Carcinoma

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of immuno-oncology in various hematologic and solid malignancies offers new targets with tremendous therapeutic potential in UC. Historically, there were no predictive biomarkers to guide the clinical management and treatment of UC, and biomarker development was an unmet need. However, recent and ongoing clinical trials have identified several promising tumor biomarkers that have the potential to serve as predictive or prognostic tools in UC. This review provides a comprehensive summary of emerging biomarkers and molecular tumor targets including programmed death ligand 1 (PD-L1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor (FGFR), DNA damage response and repair (DDR) mutations, poly (ADP-ribose) polymerase (PARP) expression and circulating tumor DNA (ctDNA), as well as their clinical utility in UC. We also evaluate recent advancements in precision oncology in UC, while illustrating limiting factors and challenges related to the clinical application of these biomarkers in clinical practice.

Advances in diagnosis and treatment of bladder cancer

Bladder cancer remains a leading cause of cancer death worldwide and is associated with substantial impacts on patient quality of life, morbidity, mortality, and cost to the healthcare system. Gross hematuria frequently precedes the diagnosis of bladder cancer. Non-muscle-invasive bladder cancer (NMIBC) is managed initially with transurethral resection of a bladder tumor (TURBT), followed by a risk stratified approach to adjuvant intravesical therapy (IVe), and is associated with an overall survival of 90%. However, cure rates remain lower for muscle invasive bladder cancer (MIBC) owing to a variety of factors. NMIBC and MIBC groupings are heterogeneous and have unique pathological and molecular characteristics. Indeed, The Cancer Genome Atlas project identified genetic drivers and luminal and basal molecular subtypes of MIBC with distinct treatment responses. For NMIBC, IVe immunotherapy (primarily BCG) is the gold standard treatment for high grade and high risk NMIBC to reduce or prevent both recurrence and progression after initial TURBT; novel trials incorporate immune checkpoint inhibitors. IVe gene therapy and combination IVe chemotherapy have recently been completed, with promising results. For localized MIBC, essential goals are improving care and reducing morbidity following cystectomy or bladder preserving strategies. In metastatic disease, advances in understanding of the genomic landscape and tumor microenvironment have led to the implementation of immune checkpoint inhibitors, targeted treatments, and antibody-drug conjugates. Defining better selection criteria to identify the patients most likely to benefit from a specific treatment is an urgent need.

Predictors of response to neoadjuvant therapy in urothelial cancer

Neoadjuvant cisplatin-based chemotherapy (NACC) followed by radical cystectomy is the standard treatment for localized muscle-invasive bladder cancer (MIBC). Patients who achieve a complete pathological response following NACC have better overall survival than those with residual disease. However, a subset of patients does not derive benefit from NACC while experiencing chemotherapy-related side effects that may delay cystectomy, which can be detrimental. There is a need for predictive and prognostic biomarkers to better stratify patients who will derive benefits from NACC. This review summarizes the currently available literature on various predictors of response to neoadjuvant chemotherapy. Covered predictors include clinical factors, treatment regimens (including chemotherapy and immunotherapy), histological predictors, and molecular predictors such as DNA repair genes, p53, FGFR3, ERBB2, Bcl-2, EMMPRIN, survivin, choline-phosphate cytidylyltransferase-α, epigenetic markers, immunological markers, other molecular predictors and gene expression profiling. Further, we elaborate on the potential role of neoadjuvant immunotherapy and the correlative biomarkers of response.

Genitourinary cancer neoadjuvant therapies: current and future approaches

Neoadjuvant therapies can improve tolerability, reduce tumor volume to facilitate surgery, and assess subsequent treatment response. Therefore, there is much enthusiasm for expanding the benefits of cancer therapies to the neoadjuvant setting to reduce recurrence and improve survival in patients with localized or locally advanced genitourinary (GU) cancer. This approach is clinically pertinent because these treatments are administered primarily to treatment-naive patients and can elicit the greatest drug response. In addition, the results are not impacted by other anticancer treatments. While neoadjuvant therapies have been the standard treatment for bladder cancer in the past, they are presently restricted to clinical trials for renal and prostate cancer (PCa); however, changes are imminent. Precision neoadjuvant therapies will be ushered in by biomarker-stratified neoadjuvant trials with appropriate survival endpoints and comprehensive correlative and imaging studies. This review discusses neoadjuvant studies in GU malignancies and how they inform future study design considerations.

ATM deficiency confers specific therapeutic vulnerabilities in bladder cancer

Ataxia-telangiectasia mutated (ATM) plays a central role in the cellular response to DNA damage and ATM alterations are common in several tumor types including bladder cancer. However, the specific impact of ATM alterations on therapy response in bladder cancer is uncertain. Here, we combine preclinical modeling and clinical analyses to comprehensively define the impact of ATM alterations on bladder cancer. We show that ATM loss is sufficient to increase sensitivity to DNA-damaging agents including cisplatin and radiation. Furthermore, ATM loss drives sensitivity to DNA repair-targeted agents including poly(ADP-ribose) polymerase (PARP) and Ataxia telangiectasia and Rad3 related (ATR) inhibitors. ATM loss alters the immune microenvironment and improves anti-PD1 response in preclinical bladder models but is not associated with improved anti-PD1/PD-L1 response in clinical cohorts. Last, we show that ATM expression by immunohistochemistry is strongly correlated with response to chemoradiotherapy. Together, these data define a potential role for ATM as a predictive biomarker in bladder cancer.

Current and Emerging Strategies to Treat Urothelial Carcinoma

Urothelial cell carcinoma (UCC, bladder cancer, BC) remains a difficult-to-treat malignancy with a rising incidence worldwide. In the U.S., UCC is the sixth most incident neoplasm and ~90% of diagnoses are made in those >55 years of age; it is ~four times more commonly observed in men than women. The most important risk factor for developing BC is tobacco smoking, which accounts for ~50% of cases, followed by occupational exposure to aromatic amines and ionizing radiation. The standard of care for advanced UCC includes platinum-based chemotherapy and programmed cell death (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors, administered as frontline, second-line, or maintenance therapy. UCC remains generally incurable and is associated with intrinsic and acquired drug and immune resistance. UCC is lethal in the metastatic state and characterized by genomic instability, high PD-L1 expression, DNA damage-response mutations, and a high tumor mutational burden. Although immune checkpoint inhibitors (ICIs) achieve long-term durable responses in other cancers, their ability to achieve similar results with metastatic UCC (mUCC) is not as well-defined. Here, we discuss therapies to improve UCC management and how comprehensive tumor profiling can identify actionable biomarkers and eventually fulfill the promise of precision medicine for UCC patients.

Bladder preservation after neoadjuvant therapy - 2021 IBCN updates part 1

The morbidity associated with radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC) has fueled investigations into the feasibility of bladder preservation strategies after a favorable clinical response to neoadjuvant therapy (NAT). Identifying optimal candidates for bladder preservation is predicated on our ability to identify tumors with inherent cisplatin sensitivity and accurately stage patients before and after NAT. In the present review, we evaluate the accuracy and limitations of contemporary staging modalities and investigate clinical outcomes in patients with MIBC who were managed with bladder preservation after NAT. Lastly, we discuss the predictive role of cisplatin-sensitizing DNA damage response (DDR) gene alterations as a foundational component to current prospective clinical trials evaluating bladder preservation in the setting of MIBC.

Current Status of Perioperative Therapy in Muscle-Invasive Bladder Cancer and Future Directions

PURPOSE OF REVIEW

Cisplatin-based combination chemotherapy has been a standard of care in the perioperative management of muscle-invasive bladder cancer for years, but several novel therapies are under active investigation. This review aims to provide an update on recent relevant literature and a forward look at the future landscape of adjuvant and neoadjuvant therapy in muscle-invasive bladder cancer patients who opt for radical cystectomy.

RECENT FINDINGS

The recent approval of nivolumab as adjuvant therapy established a new treatment option for high-risk patients with muscle-invasive bladder cancer after radical cystectomy. Several phase II studies of chemo-immunotherapy combinations and immunotherapy alone have reported pathological complete responses in the 26-46% range, including studies in cisplatin-ineligible patients. Randomized studies of perioperative chemo-immunotherapy, immunotherapy alone, and enfortumab vedotin are ongoing. Muscle-invasive bladder cancer remains a challenging disease associated with significant morbidity and mortality; however, increasing options in systemic therapy and an increasingly personalized approach to cancer treatment suggest continued future improvements in patient care.

Actionable genomic landscapes from a real-world cohort of urothelial carcinoma patients

BACKGROUND

Recent targeted therapies for advanced and metastatic urothelial cancer have generated enthusiasm, but the actionable genomic landscape of early-stage disease remains largely unknown. Here, we utilized a large, real-world cohort to comprehensively investigate the incidence of genetic alterations with potential therapeutic implications at all stages of bladder cancer.

MATERIALS AND METHODS

We retrospectively analyzed next-generation sequencing (NGS) data from 1,562 bladder cancer patients (stages I-IV) with formalin-fixed, paraffin-embedded tumor biopsies sequenced using the Tempus xT solid tumor assay. Incidence of genetic alterations, tumor mutational burden (TMB), microsatellite instability (MSI), and PD-L1 status were assessed and stratified by bladder cancer stage. For patients with tumor-normal match sequencing (n=966), incidental germline alterations in 50 genes were assessed.

RESULTS

The cohort was composed of 165 stage I-II, 211 stage III, and 1,186 stage IV tumors. TMB-high, PD-L1 positive, and MSI-high status were noted in 14%, 33%, and 0.7% of tumors, respectively, and were similar across stages. Alterations in fibroblast growth factor receptor (FGFR)2/3, homologous recombination repair genes, additional DNA repair gene mutations (ERCC2, RB1, FANCC), and NTRK fusions were detected at similar frequencies across disease stages. We identified a low rate of incidental germline mutations in all tumors (5.2%) and in specific genes: MUTYH (1.9%), BRCA2 (0.5%), and ATM (0.8%).

CONCLUSIONS

Important subsets of patients demonstrate genetic alterations in potentially actionable molecular pathways at all stages. This analysis found minimal variability in these alterations across stages, providing rationale for early identification of genetic alterations and personalization of therapies at all stages for patients with bladder cancer.

Approaches to Clinical Complete Response after Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: Possibilities and Limitations

In the surgical oncology field, the change from a past radical surgery to an organ preserving surgery is a big trend. In muscle-invasive bladder cancer treatment, neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the standard of care for muscle-invasive bladder cancer (MIBC) patients eligible for cisplatin. There is a growing interest in bladder preserving strategies after NAC because good oncologic outcome has been reported for pathologic complete response (pCR) patients after NAC, and many studies have continued to discuss whether bladder preservation treatment is possible for these patients. However, in actual clinical practice, decision-making should be determined according to clinical staging and there is a gap that cannot be ignored between clinical complete response (cCR) and pCR. Currently, there is a lack in a uniform approach to post-NAC restaging of MIBC and a standardized cCR definition. In this review, we clarify the gap between cCR and pCR at the current situation and focus on emerging strategies in bladder preservation in selected patients with MIBC who achieve cCR following NAC.

Concurrent durvalumab and radiation therapy (DUART) followed by adjuvant durvalumab in patients with localized urothelial cancer of bladder: results from phase II study, BTCRC-GU15-023

BACKGROUND

Patients with bladder cancer (BC) who are cisplatin ineligible or have unresectable disease have limited treatment options. Previously, we showed targeting programmed death-ligand 1 (PD-L1) with durvalumab (durva) and radiation therapy (RT) combination was safe in BC. We now report results from a phase II study evaluating the toxicity and efficacy of durva and RT in localized BC.

METHODS

This is a single-arm, multi-institutional phase II study; N=26. Enrolled patients had pure or mixed urothelial BC (T2-4 N0-2 M0) with unresectable tumors and were unfit for surgery or cisplatin ineligible. Patients received durva concurrently with RT ×7 weeks, followed by adjuvant durva × 1 year.

PRIMARY ENDPOINTS

(A) progression-free survival (PFS) at 1 year and (B) disease control rate (DCR) post adjuvant durva. Key secondary endpoints: (A) complete response (CR) post durvaRT (8 weeks), (B) overall survival (OS), (C) PFS and (D) toxicity. Correlative studies included evaluation of baseline tumor and blood (baseline, post durvaRT) for biomarkers.

RESULTS

Median follow-up was 27 months. Evaluable patients: 24/26 post durvaRT, 22/26 for DCR post adjuvant durva, all patients for PFS and OS. Post adjuvant durva, DCR was seen in 72.7%, CR of 54.5%. 1-year PFS was 71.5%, median PFS was 21.8 months. 1-year OS was 83.8%, median OS was 30.8 months. CR at 8 weeks post durvaRT was 62.5%. Node positive (N+) patients had similar median PFS and OS. DurvaRT was well tolerated. Grade ≥3 treatment-related adverse events: anemia, high lipase/amylase, immune-nephritis, transaminitis, dyspnea (grade 4-COPD/immune), fatigue, rash, diarrhea and scleritis. No difference in outcome was observed with PD-L1 status of baseline tumor. Patients with CR/PR or SD had an increase in naïve CD4 T cells, a decrease in PD-1+CD4 T cells at baseline and an increase in cytokine-producing CD8 T cells, including interferon gamma (IFNγ) producing cells, in the peripheral blood.

CONCLUSION

Durva with RT followed by adjuvant durva was safe with promising efficacy in localized BC patients with comorbidities, including N+ patients. Larger randomized studies, like S1806 and EA8185, are needed to evaluate the efficacy of combining immunotherapy and RT in BC.

TRIAL REGISTRATION NUMBER

NCT02891161.

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.

["Surgery only" is not enough: potential of multimodal therapy in urothelial bladder carcinoma]

Radical cystectomy is the standard treatment for muscle invasive bladder cancer. Using perioperative cisplatin-based chemotherapy, 5‑year overall survival rates are 5% higher with neoadjuvant chemotherapy compared to local therapy alone. New multimodal concepts have been developed to improve oncologic efficacy and to reduce treatment-related morbidity. Perioperative use of checkpoint inhibitors aims at improving efficacy, while bladder-preserving concepts try to avoid cystectomy in good responders. This article reviews new developments in radioimmunotherapy and perioperative combination therapies as well as bladder-preserving concepts like trimodal bladder therapy.

Adjuvant Systemic Therapy for High-risk Muscle-invasive Bladder Cancer After Radical Cystectomy: Current Options and Future Opportunities

We describe the case of a 71-yr-old woman with locally advanced muscle-invasive bladder cancer and stage III chronic kidney disease due to an obstructed nonfunctional left kidney. She was started on neoadjuvant immunotherapy, but had to stop treatment because of acute worsening of renal function. Radical cystectomy was then performed uneventfully, revealing pT3aN1 urothelial carcinoma of the bladder. Adjuvant chemotherapy in high-risk locally advanced bladder cancer after radical cystectomy currently poses several challenges, especially for cisplatin-ineligible candidates. Recent data on adjuvant immunotherapy trials suggest a disease-free survival advantage for this subgroup of patients. The current and future role of immuno-oncology agents in this setting is discussed. PATIENT SUMMARY: Patients with advanced bladder cancer might benefit from further chemotherapy or immunotherapy following bladder removal, but it is still unclear which patients benefit the most from this strategy. Measurement of biomarkers and scans to show urinary function will probably help in optimising patient selection for this treatment in the near future.

Neoadjuvant immunotherapy, chemotherapy, and combination therapy in muscle-invasive bladder cancer: A multi-center real-world retrospective study

To parallelly compare the efficacy of neoadjuvant immunotherapy (tislelizumab), neoadjuvant chemotherapy (gemcitabine and cisplatin), and neoadjuvant combination therapy (tislelizumab + GC) in patients with muscle-invasive bladder cancer (MIBC) and explore the efficacy predictors, we perform a multi-center, real-world cohort study that enrolls 253 patients treated with neoadjuvant treatments (combination therapy: 98, chemotherapy: 107, and immunotherapy: 48) from 15 tertiary hospitals. We demonstrate that neoadjuvant combination therapy achieves the highest complete response rate and pathological downstaging rate compared with neoadjuvant immunotherapy or chemotherapy. We develop and validate an efficacy prediction model consisting of pretreatment clinical characteristics, which can pinpoint candidates to receive neoadjuvant combination therapy. We also preliminarily reveal that patients who achieve pathological complete response after neoadjuvant treatments plus maximal transurethral resection of the bladder tumor may be safe to receive bladder preservation therapy. Overall, this study highlights the benefit of neoadjuvant combination therapy based on tislelizumab for MIBC.

Which Biomarkers are Useful in the Management of Muscle-invasive Bladder Cancer in 2022?

In current clinical practice, the use of biomarkers remains largely experimental for patients with localized disease. However, with continued commitment to prospective trials and collaborative efforts, we are on the horizon of incorporating biomarker use to guide personalized treatment decisions.

The past, present, and future of pT0 in bladder cancer clinical trials

PURPOSE OF REVIEW

Since the establishment of neoadjuvant chemotherapy as the standard of care for patients with muscle invasive bladder cancer, the pathologic absence of disease, denoted pT0, was found to be predictive of improved overall survival. Accordingly, it has been used in clinical trials as an optimal surrogate outcome measure, even in contemporary nonchemotherapeutic interventions. We review the role of pT0 as a catalyst for change in trial design and its suitability to facilitate more efficient and timely results. In addition, we explore the present and future of cT0, the clinical absence of disease, in defining treatment response and enabling bladder-sparing management options.

RECENT FINDINGS

The use of pT0 as a surrogate has provided initial results for the efficacy of immunotherapy in the neoadjuvant space. In combination with molecular markers, pT0 has improved our ability to identify treatment responders and its clinical counterpart, cT0, has been integrated into multiple trials to redefine postneoadjuvant chemotherapy management algorithms.

SUMMARY

The use of pT0 as a surrogate endpoint in bladder cancer trials has improved clinical trial design, defined efficacy of emerging therapeutics, and has the potential to redefine the postneoadjuvant treatment management for patients seeking bladder-sparing options.

Neoadjuvant Atezolizumab With Gemcitabine and Cisplatin in Patients With Muscle-Invasive Bladder Cancer: A Multicenter, Single-Arm, Phase II Trial

PURPOSE

Neoadjuvant gemcitabine and cisplatin (GC) followed by radical cystectomy (RC) is standard for patients with muscle-invasive bladder cancer (MIBC). On the basis of the activity of atezolizumab (A) in metastatic BC, we tested neoadjuvant GC plus A for MIBC.

METHODS

Eligible patients with MIBC (cT2-T4aN0M0) received a dose of A, followed 2 weeks later by GC plus A every 21 days for four cycles followed 3 weeks later by a dose of A before RC. The primary end point was non-muscle-invasive downstaging to < pT2N0.

RESULTS

Of 44 enrolled patients, 39 were evaluable. The primary end point was met, with 27 of 39 patients (69%) < pT2N0, including 16 (41%) pT0N0. No patient with < pT2N0 relapsed and four (11%) with ≥ pT2N0 relapsed with a median follow-up of 16.5 months (range: 7.0-33.7 months). One patient refused RC and two developed metastatic disease before RC; all were considered nonresponders. The most common grade 3-4 adverse event (AE) was neutropenia (n = 16; 36%). Grade 3 immune-related AEs occurred in five (11%) patients with two (5%) requiring systemic steroids. The median time from last dose of chemotherapy to surgery was 7.8 weeks (range: 5.1-17 weeks), and no patient failed to undergo RC because of AEs. Four of 39 (10%) patients had programmed death-ligand 1 (PD-L1)-positive tumors and were all < pT2N0. Of the patients with PD-L1 low or negative tumors, 23 of 34 (68%) achieved < pT2N0 and 11 of 34 (32%) were ≥ pT2N0 (P = .3 for association between PD-L1 and < pT2N0).

CONCLUSION

Neoadjuvant GC plus A is a promising regimen for MIBC and warrants further study. Patients with < pT2N0 experienced improved relapse-free survival. The PD-L1 positivity rate was low compared with published data, which limits conclusions regarding PD-L1 as a predictive biomarker.

Therapy for Muscle-Invasive Urothelial Carcinoma: Controversies and Dilemmas

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Phase II Study of Gemcitabine and Split-Dose Cisplatin Plus Pembrolizumab as Neoadjuvant Therapy Before Radical Cystectomy in Patients With Muscle-Invasive Bladder Cancer

PURPOSE

To evaluate the safety and efficacy of gemcitabine and cisplatin in combination with the immune checkpoint inhibitor pembrolizumab as neoadjuvant therapy before radical cystectomy (RC) in muscle-invasive bladder cancer.

METHODS

Patients with clinical T2-4aN0/XM0 muscle-invasive bladder cancer eligible for RC were enrolled. The initial six patients received lead-in pembrolizumab 200 mg once 2 weeks prior to pembrolizumab 200 mg once on day 1, cisplatin 70 mg/m² once on day 1, and gemcitabine 1,000 mg/m² once on days 1 and 8 every 21 days for four cycles. This schedule was discontinued for toxicity and subsequent patients received cisplatin 35 mg/m² once on days 1 and 8 without lead-in pembrolizumab. The primary end point was pathologic downstaging (< pT2N0) with null and alternative hypothesis rates of 35% and 55%, respectively. Secondary end points were toxicity including patient-reported outcomes, complete pathologic response (pT0N0), event-free survival, and overall survival. Association of pathologic downstaging with programmed cell death ligand 1 staining was explored.

RESULTS

Thirty-nine patients were enrolled between June 2016 and March 2020 (72% cT2, 23% cT3, and 5% cT4a). Patients received a median of four cycles of therapy. All patients underwent RC except one who declined. Twenty-two of 39 patients (56% [95% CI, 40 to 72]) achieved < pT2N0 and 14 of 39 (36% [95% CI, 21 to 53]) achieved pT0N0. Most common adverse events (AEs) of any grade were thrombocytopenia (74%), anemia (69%), neutropenia (67%), and hypomagnesemia (67%). One patient had new-onset type 1 diabetes mellitus with ketoacidosis related to pembrolizumab and no patients required steroids for immune-related AEs. Clinicians consistently under-reported AEs when compared with patients.

CONCLUSION

Neoadjuvant gemcitabine and cisplatin plus pembrolizumab met its primary end point for improved pathologic downstaging and was generally safe. A global study of perioperative chemotherapy plus pembrolizumab or placebo is ongoing.