Recent developments in the management of bladder cancer: Introduction

An upsurge of advances in the management of bladder cancer has rapidly occurred over the past 2 years. In this issue, recent developments in the management of bladder cancer will be discussed, including the emerging role of immunotherapy, biomarkers, and advanced imaging.     

Regulation of alloantigen-mediated T-cell proliferation by endogenous interferon-gamma: implications for long-term allograft acceptance.

BACKGROUND: Recent data suggest that interferon (IFN)-gamma is not an essential mediator of acute rejection but, instead, is critical for the induction of long-term allograft acceptance. The in vivo mechanisms by which endogenous IFN-gamma regulates the alloimmune response and thus facilitates the induction of long-term allograft survival are not known. METHODS: We examined long-term cardiac and skin allograft survival, alloantigen-induced T-cell proliferation, and alloantigen-induced T-cell apoptosis in wild-type (IFN-gamma+/+) and IFN-gamma gene-knockout (IFN-gamma-/-) mice treated with either B7-CD28 T-cell costimulation blockade alone or B7-CD28 T-cell costimulation blockade combined with donor splenocyte transfusion. RESULTS: We found that IFN-gamma is essential for long-term allograft survival induced by treating mice with either B7-CD28 T-cell costimulation blockade alone or B7-CD28 T-cell costimulation blockade combined with donor splenocyte transfusion. Alloantigen-induced T-cell proliferation in vivo was significantly greater in IFN-gamma-/- mice than in IFN-gamma+/+ mice, and T-cell costimulation blockade abrogated alloantigen-induced T-cell proliferation in wild-type mice but failed to do so in mice that lack IFN-gamma. In contrast, alloantigen-induced T lymphocyte apoptosis in vivo did not differ between IFN-gamma+/+ and IFN-gamma-/- mice, and T-cell costimulation blockade enhanced alloantigen-induced T-cell apoptosis in both mouse strains. CONCLUSIONS: These data suggest that endogenous IFN-gamma facilitates the induction of long-term allograft survival by limiting the proliferation of alloactivated T lymphocytes. The data also suggest that B7-CD28 T-cell costimulation blockade exerts immunosuppressive actions by inhibiting the proliferation of activated T lymphocytes and by promoting their apoptosis.     

A review of the PD-1/PD-L1 checkpoint in bladder cancer: From mediator of immune escape to target for treatment

Purpose

Recent observations have focused attention on the means that human tumors employ to evade host defense systems critical to immune surveillance. The concepts of immunotherapy are familiar to urologists because of the use of bacillus Calmette-Guérin in bladder cancer. Research demonstrating the importance of checkpoint inhibitors in suppressing immune responses against tumors has heightened interest in immunotherapy at a time when there is a need for alternatives to bacillus Calmette-Guérin. We review the literature on the application of immunotherapeutic agents targeting a key checkpoint pathway, programmed death 1 (PD-1) and its ligand (PD-L1), in the field of bladder cancer.

Clinical development of immunotherapy for prostate cancer

Prostate cancer is the most common cancer in men, and the second leading cause of cancer‐related death in Western countries. Prostate cancer‐related death occurs in patients with metastatic castration‐resistant prostate cancer. Although several new drugs for castration‐resistant prostate cancer have been approved, each of these has prolonged survival by just a few months. Consequently, new therapies are sorely needed. Recently, it has been recognized that immunotherapy is an effective treatment for prostate cancer patients. Several strategies, such as cancer vaccines and immune checkpoint inhibitors, have been investigated in clinical studies for prostate cancer patients. In the present review, the results of the most recent clinical studies investigating immunotherapy in prostate cancer patients are reported, and the future clinical development of immunotherapy for prostate cancer is discussed.     

Interaction Between ICOS-B7RP1 and B7-CD28 Costimulatory Pathways in Alloimmune Responses In Vivo

The B7-CD28 pathway is one of the foremost costimulatory pathways involved in T-cell activation. Recently, a number of additional costimulatory pathways have been described and preliminary data suggest that they play important roles in alloimmunity. However, the interactions between these different pathways are not well understood. We studied the effect of targeting ICOS ligand, B7RP1, in a rat cardiac transplant model, with and without concomitant blockade of the B7 pathway using CTLA4Ig. In a fully mismatched WF to LEW vascularized cardiac allograft model, without therapy, grafts were acutely rejected (MST 10.8 +/- 1.6 days). Early (day of transplant) B7RP1 blockade with ICOSIg alone had little effect on graft survival and rather than being additive with B7 blockade, ICOSIg abrogated the prolonged graft survival induced by CTLA4Ig treatment. By contrast, delayed (day 2 post-transplant) blockade of B7RP1 did not have such an effect. These findings were not related to cytokine deviation but may be in part related to the pattern of down-regulation of B7.2 expression following early B7RP1 blockade. This is the first report describing the complex interactions between ICOS-B7RP1 and B7-CD28 costimulatory pathways in alloimmunity in vivo.     

Lymphocyte costimulatory receptors in renal disease and transplantation

Cell-to-cell signal exchange during antigen presentation deeply influences the profile and extent of the immune response. Together with the TCR/MHC-mediated signal, accessory signals are provided to the T cell by the antigen-presenting cell (APC), through specific receptor-ligand interactions that represent indispensable costimulation for T-cell activation and survival. The main costimulatory pathways are the B7 family members and the CD40-CD154 receptor-ligand pair. B7-1 and B7-2 costimulate T-cells by binding to CD28. Their binding is prevented by the neoexpression of CTLA4, a CD28 homologue that can deliver a negative signal. Another CD28-like molecule, called ICOS (inducible costimulator), has been described and binds B7RP-1, a third member of the B7 family, but not B7-1 and B7-2. The CD40-CD154 interaction works as a two way costimulatory system by triggering activation signals to both T-cell and APCs. Its importance is highlighted by the discovery that mutations of the CD154 gene are responsible for a severe human immunodeficiency. Disruption of the natural costimulatory interaction was highly effective for prevention and treatment in several experimental models of autoimmune disease and transplant rejection. This review focuses on the most significant advances in understanding the physiopathological events involving costimulatory molecules, and their impact on renal diseases and transplantation.     

In Vivo Function of Immune Inhibitory Molecule B7‐H4 in Alloimmune Responses

B7 ligands deliver both costimulatory and coinhibitory signals to the CD28 family of receptors on T lymphocytes, the balance between which determines the ultimate immune response. Although B7‐H4, a recently discovered member of the B7 family, is known to negatively regulate T cell immunity in autoimmunity and cancer, its role in solid organ allograft rejection and tolerance has not been established. Targeting the B7‐H4 molecule by a blocking antibody or use of B7‐H4^?/? mice as recipients of fully MHC‐mismatched cardiac allografts did not affect graft survival. However, B7‐H4 blockade resulted in accelerated allograft rejection in CD28‐deficient recipients. B7‐1/B7‐2‐double‐deficient recipients are truly independent of CD28/CTLA‐4:B7 signals and usually accept MHC‐mismatched heart allografts. Blockade of B7‐H4 in these mice also precipitated rejection, demonstrating regulatory function of this molecule independent of an intact CD28/CTLA‐4:B7 costimulatory pathway. Accelerated allograft rejection was always accompanied by increased frequencies of alloreactive IFN‐γ‐, IL‐4‐ and Granzyme B‐producing splenocytes. Finally, intact recipient, but not donor, B7‐H4 is essential for prolongation of allograft survival by blocking CD28/CTLA4:B7 pathway using CTLA4‐Ig. These data are the first to provide evidence of the regulatory effects of B7‐H4 in alloimmune responses in a murine model of solid organ transplantation.     

阻断B7诱导大鼠心脏移植免疫耐受的实验研究

目的　研究阻断B7方法诱导大鼠心脏异位移植的免疫耐受。　方法　采用Ono法建立大鼠异位心脏移植模型 ,实验组腹腔注射B7阻断剂CTLA 4Ig,观察大鼠移植的心脏存活天数 ,病理改变和术后IL 2 ,IgG以及IgM含量的变化。　结果　实验组移植的心脏存活时间为 :(31 6 0± 1 82 )d ,对照组 (7 2 5± 0 71)d ,差异有显著性意义 (P <0 0 1)。组织学改变 :实验组见局灶性血管周围或间质内淋巴细胞浸润和局灶性心肌损伤 ,病理分级Ⅰ～Ⅱ级。对照组可见大量淋巴细胞浸润 ,心肌细胞损伤和坏死 ,间质内出血水肿 ,病理分级Ⅳ级。术后IL 2含量实验组比对照组明显下降 ,有显著性差异 ,P <0 0 1。IgG和IgM含量差异无显著性意义 (P >0 0 5 )。　结论　阻断B7能诱导大鼠心脏移植免疫耐受 ,为移植排斥反应提供了新的治疗方法     

Immunotherapy for genitourinary tumors

The present review provides an update about the major achievements and recent advances of immunotherapy in renal cell carcinoma, urothelial carcinoma, and prostate cancer. Although the treatment strategy for renal cell carcinoma and urothelial carcinoma includes traditional cancer immunotherapies, such as interleukin‐2 and interferon‐alfa, the clinical outcomes of these therapies are unsatisfactory. In recent years, the development of immune checkpoint inhibitors has drastically changed the treatment strategy for various cancers, including genitourinary cancer. The present review summarizes the approved cancer immunotherapies for renal cell carcinoma, urothelial carcinoma and prostate cancer. Furthermore, we review the response evaluation and biomarkers for immune checkpoint inhibitors with a distinctive mode of action that is different from cytotoxic agents. Finally, future perspectives for cancer immunotherapy are discussed.     

Updated European Association of Urology Guidelines on Renal Cell Carcinoma: Nivolumab plus Cabozantinib Joins Immune Checkpoint Inhibition Combination Therapies for Treatment-naïve Metastatic Clear-Cell Renal Cell Carcinoma

Longer follow-up and new trial data from phase 3 randomised controlled trials investigating immune checkpoint blockade (PD-1 or its ligand PD-L1) in advanced clear-cell renal cell carcinoma (RCC) have recently become available. The CheckMate 9ER trial demonstrated an improved progression-free survival (PFS) and overall survival (OS) benefit for the combination of cabozantinib plus nivolumab. A Keynote-426 update demonstrated an ongoing OS benefit for pembrolizumab plus axitinib in the intention-to-treat population, with a PFS benefit seen across all International Metastatic Database Consortium (IMDC) subgroups, while an update of CheckMate 214 confirmed the long-term benefit of ipilimumab plus nivolumab in IMDC intermediate and poor risk patients. The RCC Guidelines Panel continues to recommend these tyrosine kinase inhibitors + immunotherapy (IO) combination across IMDC risk groups in advanced first-line RCC and dual immunotherapy of ipilimumab and nivolumab in IMDC intermediate and poor risk.Patient summaryNew data from trials of immune checkpoint inhibitors for advanced kidney cancer confirm a survival benefit with the combination of cabozantinib plus nivolumab and pembrolizumab plus axitinib and ipilimumab plus nivolumab. These combination therapies are recommended as first-line treatment for advanced kidney cancer.     

免疫检查点抑制剂在乳腺癌免疫治疗中应用进展

乳腺癌已成为全球发病率最高的癌症，其异质性使得乳腺癌分类治疗进入了精准治疗时代。随着肿瘤免疫治疗的成功，既往被认为“弱免疫原性”的乳腺癌也跨入了免疫治疗阶段。目前，免疫检查点抑制剂在乳腺癌免疫治疗的临床应用中取得了重大进展，但乳腺癌免疫治疗单药的获益人群有限，联合方案成为新的研究热点。随着免疫检查点抑制剂在乳腺癌中的研究进展，有效联合免疫治疗和化疗可能提高乳腺癌病人的生存率，但用药时机和适用人群仍需合理评估。免疫治疗在乳腺癌中既有应用前景，也存在挑战。     

Epidemiologic perspectives on immunosuppressed populations and the immunosurveillance and immunocontainment of cancer

The advent in the last several years of effective immunotherapy for cancer has renewed interest in the role of the immune system in controlling cancer. The idea that the immune system can help control cancer has a long history. Solid organ transplant recipients (SOTRs) as well as human immunodeficiency virus (HIV)–infected people are affected by cell‐mediated immune dysfunction. Epidemiologic studies of these populations reveal a pattern characterized by a strongly increased incidence of virus‐related cancers (eg, Kaposi sarcoma, non‐Hodgkin lymphoma, and anogenital cancers). In addition, recent epidemiologic studies have evaluated cancer‐specific mortality among SOTRs and HIV‐infected people following a cancer diagnosis. For a wider range of cancers—not limited to those caused by viruses, and including melanoma and cancers of the colorectum, lung, and breast— these immunosuppressed cancer patients have higher cancer‐specific mortality than other cancer patients. This latter group of cancers somewhat mirrors those for which immunotherapy with checkpoint inhibitors is approved. These epidemiologic observations suggest that there are 2 distinct immune selection processes in humans: immunosurveillance directed against premalignant cells before cancer diagnosis (most relevant for preventing virus‐related cancers), and “immunocontainment” directed against established cancers. These processes thus appear relevant for different groups of malignancies and may have different mechanisms.     

Tumor-infiltrating lymphocytes in breast cancer according to tumor subtype: Current state of the art

The recent success of the immune checkpoint blockade in cancer immunotherapy has modified the treatment algorithms in a variety of aggressive neoplastic diseases. Nevertheless, optimal selection of ideal candidates to these drugs remains a challenge. The presence, location and composition of a pre-existing tumor immune infiltrate seem to impact on the benefit from these treatments. The association between the presence of baseline tumor-infiltrating lymphocytes (TIL) and patients' outcomes has been widely investigated in breast cancer, although immunotherapeutic strategies have historically been less successful with respect to other neoplastic diseases such as melanoma and kidney cancer. TIL extent varies and has different associations with outcomes in the various breast cancer subtypes. Furthermore, the presence of baseline high TIL has been associated with an increased benefit from some chemotherapeutic and targeted agents even though some conflicting results have been observed on this regard. This review aims to summarize the state of the art of TIL in breast cancer with a focus on their assessment, prevalence and clinical implications in the different subtypes.     

Allogeneic Parenchymal and Hematopoietic Tissues Differ in Their Ability to Induce Deletion of Donor-Reactive T Cells

The establishment of immune tolerance to self antigen expressed exclusively in the periphery is a crucial yet incompletely understood feature of the immune system. A dominant concept of peripheral tolerance has been that exposure of T cells to signal one, the TCR-MHC interaction, in the absence of signal two, or costimulation, is a major mechanism of peripheral tolerance. This model suggests that any cell type that expresses MHC-peptide complexes, be they of self or foreign origin, should have the capacity to tolerize antigen-specific T cells when critical costimulatory interactions are interrupted. However, a spectrum of responses, from permanent engraftment to rapid rejection, has been observed in various transplantation models utilizing costimulatory blockade. Therefore we undertook a series experiments to directly assess the tolerogenic potential of donor hematopoietic and parenchymal cells. We find that allogeneic tissues differ profoundly in their ability to promote peripheral tolerance concurrent with combined blockade of B7-CD28 and CD40-CD40L pathways. Non-vascularized and vascularized parenchymal grafts as well as donor-specific transfusions promote varying degrees of donor-specific hyporesponsiveness, but fail to induce donor-reactive T-cell deletion; whereas establishment of stable hematopoietic chimerism promotes specific tolerance mediated by deletion of donor-reactive cells in the periphery.     

Immunotherapy for castration-resistant prostate cancer: Progress and new paradigms

BackgroundThe approval of sipuleucel-T in conjunction with data from other immunotherapeutic trials for prostate cancer and other solid tumors demonstrates the potential of harnessing the patient׳s immune system for long-term survival. Thus, a range of therapeutic approaches are under evaluation. This review describes the rationale for immunotherapy for prostate cancer, summarizes the approaches under evaluation, and discusses sequencing options for immunotherapy in the current treatment paradigm.DesignReferences for this review were identified through searches of PubMed with the search terms “prostate cancer,” “immune system,” “vaccine,” “immunotherapy,” and “T cells.” Articles were also identified through searches of the authors׳ own files. The final reference list was generated based on originality and relevance.ResultsThe immune system can recognize and respond to prostate tumor antigens, effected through tumor-associated antigens and tumor infiltration of immune effector cells. However, evidence also suggests that prostate tumors are adept at escaping immunological recognition, thus hypothesizing multiple therapeutic strategies. Therapeutic approaches could include vaccination and modulation of T-cell function via the blockade of checkpoint receptors such as cytotoxic T-lymphocyte antigen-4 and programmed death 1. In phase III trials, sipuleucel-T improved overall survival for an M1 patient population with castration-resistant prostate cancer and ipilimumab also did so when given after radiotherapy in a subset of better risk patients. In randomized phase II trials, prostate-specific antigen-TRICOM improved overall survival and tasquinimod improved progression-free survival.ConclusionAlthough immunotherapy has the potential to affect advanced prostate cancer, additional research is needed to (1) identify predictive or surrogate markers of activity, (2) understand which agents are clinically effective alone or in combination with other therapies, and (3) define the optimal timing for an immunotherapy to achieve maximal benefit.     

Immunotherapy and therapeutic vaccines in prostate cancer： an update on current strategies and clinical implications

In recent years, immunotherapy has emerged as a viable and attractive strategy for the treatment of prostate cancer. While there are multiple ways to target the immune system, therapeutic cancer vaccines and immune checkpoint inhibitors have been most successful in late-stage clinical trials. The landmark Food and Drug Administration approval of sipuleuceI-T for asymptomatic or minimally symptomatic metastatic prostate cancer set the stage for ongoing phase III trials with the cancer vaccine PSA-TRICOM and the immune checkpoint inhibitor ipilimumab. A common feature of these immune-based therapies is the appearance of improved overall survival without short-term changes in disease progression. This class effect appears to be due to modulation of tumor growth rate kinetics, in which the activated immune system exerts constant immunologic pressure that slows net tumor growth. Emerging data suggest that the ideal population for clinical trials of cancer vaccines is patients with lower tumor volume and less aggressive disease. Combination strategies that combine immunotherapy with standard therapies have been shown to augment both immune response and clinical benefit.     

基于肿瘤免疫微环境的免疫治疗策略在晚期肾透明细胞癌中的应用进展

近期的临床研究结果显示,仍有大量晚期肾透明细胞癌(ccRCC)患者对免疫检查点抑制剂(ICIs)无反应。提高ccRCC患者免疫治疗反应是当前迫切的临床需求。靶向不同的肿瘤免疫微环境成分成为克服晚期ccRCC免疫治疗耐药性和优化治疗策略的突破点。本文概述晚期ccRCC免疫治疗面临的挑战,并总结基于肿瘤免疫微环境的新型免疫治疗策略,包括靶向其他共抑制分子和共刺激分子、改良细胞因子疗法、小分子免疫调节剂、靶向免疫代谢和癌症疫苗等。     

The Rationale and Emerging Use of Neoadjuvant Immune Checkpoint Blockade for Solid Malignancies

Unprecedented advances in the treatment of cancer have occurred through the use of immunotherapy, with several agents currently approved by the Food and Drug Administration (FDA) for the treatment of widespread metastatic disease across cancer types. Immune checkpoint blockade represents a particularly promising class of agents that block inhibitory molecules on the surface of T cells, resulting in their activation and propagation of an immune response. Treatment with these agents may re-invigorate anti-tumor immunity, resulting in therapeutic responses, and use of these agents currently is being studied in the adjuvant setting. Additionally, a strong rationale exists for their use in the neoadjuvant setting for high-risk resectable disease (e.g., regional nodal disease in the case of melanoma). This rationale is based on the relatively high risk of relapse for these patients, as well as on scientific evidence suggesting that long-term immunologic memory and tumor control may be superior in the setting of treatment for an intact tumor (i.e., neoadjuvant therapy) as opposed to treatment in the setting of micrometastatic disease (e.g., adjuvant treatment). The potential advantages of this approach and the current landscape for neoadjuvant immune checkpoint blockade is discussed in this report, as well as caveats that should be considered by clinicians contemplating this strategy.     

Efficacy and tolerance of immune checkpoint inhibitors in transplant patients with cancer: A systematic review

Solid organ transplant (SOT) is frequently complicated by cancers, which render immunosuppression challenging. Immune checkpoint inhibitors have emerged as treatments for many cancers. Data are lacking regarding efficacy and rejection risk in the SOT population. We conducted a systematic literature review and analyzed 83 cases of immune checkpoint inhibitor use for cancer in SOT. Two thirds of these patients received anti–programmed death ligand 1 therapy, 15.7% received anti–cytotoxic T lymphocyte–associated protein 4 therapy, and 10.8% received a combination. Allograft rejection occurred in 39.8% of patients, leading to end‐stage organ failure in 71.0% of cases. Outcomes were similar across organs and immunotherapy regimens. The use of immunosuppressants other than steroids, time since transplant, and prior episodes of rejection were associated with the risk of rejection. The median overall survival of patients was 36 weeks. Most of the deaths were related to cancer progression. In nonkidney recipients, graft rejection was strongly associated with worse survival. At the end of the study, 19.3% of the patients were alive, free from rejection and tumor progression. This study highlights the difficult tradeoff facing oncologists and transplant specialists managing transplant recipients with cancer, and the need for prospective data and novel biomarkers for identifying the patients likely to benefit from immunotherapy in the SOT setting.     

Intratumoral immunotherapy with anti-PD-1 and TLR9 agonist induces systemic antitumor immunity without accelerating rejection of cardiac allografts

Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) blockades, have revolutionized the field of cancer immunotherapy. However, there is a growing concern whether PD-1 inhibitors can be administered safely to transplant recipients with advanced cancer, as the T cells activated by checkpoint inhibitors may become reactive not only toward tumor antigens but also toward donor alloantigen, thereby resulting in allograft rejection. Here, immunotherapy with anti-PD-1/toll like receptor 9 agonist was administered to C57BL/6 mice bearing a cardiac allograft that were receiving maintenance immunosuppression or a PI4KIIIβ inhibitor-based tolerogenic regimen. Intratumoral (i.t.), but not systemic, immunotherapy promoted potent anti-tumor responses, but did not accelerate allograft rejection. This effect was associated with a pro-immunogenic effect induced by i.t. immunotherapy resulting in systemic cellular and humoral immune anti-tumor responses. Furthermore, when the tumor and cardiac allograft shared major histocompatibility complex (MHC) antigens, i.t. immunotherapy promoted immune responses directed against tumor and the cardiac allograft resulting in allograft rejection. The anti-tumor effect was compromised by maintenance immunosuppression with cyclosporin A, indicating that an optimal balance between enhanced anti-tumor immunity and decreased transplant immunoreactivity is critical. A clinically relevant approach could be to temporarily withdraw maintenance immunosuppression and/or replace it with a PI4KIIIβ inhibitor–based tolerance-inducing regimen to allow for effective immunotherapy to take place.