Efficacy and Safety of Durvalumab in Locally Advanced or Metastatic Urothelial Carcinoma: Updated Results From a Phase 1/2 Open-label Study

Everolimus and pazopanib (E/P) benefit genomically selected patients with metastatic urothelial carcinoma

BACKGROUND

Metastatic urothelial carcinoma (mUC) is a genomically diverse disease with known alterations in the mTOR pathway and tyrosine kinases including FGFR. We investigated the efficacy and safety of combination treatment with everolimus and pazopanib (E/P) in genomically profiled patients with mUC.

METHODS

mUC patients enrolled on a Phase I dose escalation study and an expansion cohort treated with E/P were included. The primary end point was objective response rate (ORR); secondary end points were safety, duration of response (DOR), progression-free survival (PFS) and overall survival (OS). Patients were assessed for mutations and copy number alterations in 300 relevant cancer-associated genes using next-generation sequencing and findings were correlated with outcomes. Time-to-event data were estimated with Kaplan-Meier methods.

RESULTS

Of the 23 patients enrolled overall, 19 had mUC. ORR was 21% (one complete response (CR), three partial responses (PR), eight with stable disease (SD). DOR, PFS and OS were 6.5, 3.6, and 9.1 months, respectively. Four patients with clinical benefit (one CR, two PR, one SD) had mutations in TSC1/TSC2 or mTOR and a 5th patient with PR had a FGFR3-TACC3 fusion.

CONCLUSIONS

Combination therapy with E/P is safe in mUC and select patients with alterations in mTOR or FGFR pathways derive significant clinical benefit.

'DURVIT': a phase-I trial of single low-dose durvalumab (Medi4736) IntraTumourally injected in cervical cancer: safety, toxicity and effect on the primary tumour- and lymph node microenvironment

Background

Treatment with programmed cell death receptor (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors is a promising strategy to lift tumour-induced immune response suppression. However, the current systemic treatment often causes autoimmune side effects. In more than 50% of squamous cell cervical cancer, PD-L1 expression is detected. Moreover, we observed high and interrelated rates of PD-L1 positive macrophages and regulatory T cells in metastatic lymph nodes of cervical cancer patients. As cervical cancer in general initially metastasizes to regional lymph nodes, local administration of durvalumab (a PD-L1 checkpoint inhibitor) at an early stage will deliver these antibodies exactly where they are needed, facilitating immune protection. This may result in a clinical benefit while reducing undesirable side effects.

Methods

DURVIT is a non-randomized, single-arm, open-label, phase I study. Three escalating dose levels of intratumourally (i.t.) injected durvalumab will be tested, i.e. 5, 10 and 20 mg (three patients per dose level, with an additional three at the highest tolerated dose). The primary endpoint of this phase-I study is safety. Immune monitoring will consist of flow cytometric, immunohistochemical and functional T cell reactivity testing. The first patient has been included in this trial in November 2017.

Discussion

Evidence of safety and biological efficacy of this locally administered checkpoint blockade may expand adjuvant therapy options for cervical cancer patients. Early metastatic spread of cervical cancer cells may thus be controlled in the draining lymph node basin, and beyond, and hopefully delay or even prevent the onset of disease recurrence.

Trial registration

NTR6119, 1-nov-2016.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4764-0) contains supplementary material, which is available to authorized users.

Clinical Development and Initial Approval of Novel Immune Checkpoint Inhibitors in Oncology: Insights From a Global Regulatory Perspective

Immune checkpoint inhibitors (ICI) have demonstrated meaningful patterns of clinical efficacy across various cancers. During their development, novel regulatory strategies and clinical design approaches were explored. This metrics-based narrative review examines submission strategies and clinical evidence expectations of the US, European, and Japanese drug agencies, as well as their impact on approval and overall development times. Also discussed is the role of emerging clinical science and biomarker evaluation to get the first six ICI initially approved.

Impact of the Number of Cycles of Platinum Based First Line Chemotherapy for Advanced Urothelial Carcinoma

PURPOSE

We evaluated the impact of the number of cycles of platinum based, first line chemotherapy (fewer than 6 cycles vs the conventional 6 cycles or more) on the survival of patients with metastatic urothelial carcinoma.

MATERIALS AND METHODS

We used the RISC (Retrospective International Study of Invasive/Advanced Cancer of the Urothelium) database. The association of the number of cycles of chemotherapy with overall survival was investigated by Cox multiple regression analysis after controlling for recognized prognostic factors. We excluded patients who received fewer than 3 or more than 9 platinum chemotherapy cycles to reduce confounding factors. The primary analysis was a comparison of overall survival for 3 to 5 vs 6 to 9 cycles using 6-month landmark analysis when 281 death events were observed.

RESULTS

Of the 1,020 patients in the RISC 472 received cisplatin or carboplatin, of whom 338 and 134, respectively, were evaluable. A total of 157 patients received 3 to 5 cycles (median 4) and 315 received 6 to 9 cycles (median 6). There was no significant difference in overall survival between 3 to 5 and 6 to 9 cycles (HR 1.02, 95% CI 0.78-1.33, p = 0.91). No significant interactions were observed for the type of platinum (p = 0.09) and completed planned chemotherapy (p = 0.56). The limitations of a hypothesis generating, retrospective analysis applied.

CONCLUSIONS

Four cycles of platinum based, first line chemotherapy appeared adequate and did not significantly compromise the survival of patients with advanced urothelial carcinoma. The omission of excessive cycles may avoid unnecessary cumulative toxicity and facilitate a better transition to second line therapy and investigational switch maintenance therapy strategies. These results require prospective validation but they may impact practice in select patients.

Outcome and prognostic factors in metastatic urothelial carcinoma patients receiving second-line chemotherapy: an analysis of real-world clinical practice data in Japan

Objectives

The objective of the present study was to investigate the survival outcome and prognostic factors of metastatic urothelial carcinoma patients treated with second-line systemic chemotherapy in real-world clinical practice.

Methods

Overall, 114 patients with metastatic urothelial carcinoma undergoing second-line systemic chemotherapy were included in this retrospective analysis. The dominant second-line chemotherapy was a paclitaxel-based combination regimen (60%, 68/114). We assessed the progression-free survival and overall survival times using the Kaplan–Meier method. The Cox proportional hazards model was applied to identify the factors affecting overall survival.

Results

The median progression-free survival and overall survival times were 4 and 9 months, respectively. In the multivariate analysis, an Eastern Cooperative Oncology Group performance status score greater than 0 at presentation, C-reactive protein level ≧1 mg/dl and poor response to prior chemotherapy were adverse prognostic indicators. Patients with 0, 1, 2 and 3 of those risk factors had a median overall survival of 17, 12, 7 and 3 months, respectively.

Conclusions

The Eastern Cooperative Oncology Group performance status at presentation, C-reactive protein level and response to prior chemotherapy were prognostic factors for metastatic urothelial carcinoma patients undergoing second-line chemotherapy. In the future, this information might help guide the choice of salvage treatment, such as second-line chemotherapy or immune checkpoint inhibitors, after the failure of first-line chemotherapy.

Immune checkpoint inhibitors for urothelial carcinoma

Urothelial carcinoma (UC), originating in the bladder or upper urinary tract, is the most common histological type of cancer. Currently, platinum-based cytotoxic chemotherapy is the standard treatment for metastatic UC (mUC) and the preferred treatment option in the perioperative (neoadjuvant and/or adjuvant) setting of muscle invasive bladder cancer (MIBC). In addition, intravesical bacillus Calmette-Guerin immunotherapy or chemotherapy is applied as the adjuvant therapeutic option in non-muscle invasive bladder cancer (NMIBC) after transurethral resection, to prevent recurrence and progression. In recent years, with an increased understanding of cancer immunobiology, systemic immunotherapies targeting immune checkpoint inhibition has been explored and clinically used in the area of UC. The programmed cell death 1 receptor (PD-1) and its ligand (PD-L1) are important negative regulators of immune activity, preventing the destruction of normal tissues and autoimmunity. To date, five immune checkpoint inhibitors blocking PD-1 (pembrolizumab, nivolumab) or PD-L1 (atezolizumab, durvalumab, and avelumab) have been approved by the United States Food and Drug Administration (US-FDA) for first- or second-line use in mUC, based on durable therapeutic response and manageable safety profiles observed in relevant clinical trials. In addition, the clinical use of several immune checkpoint inhibitors is currently being tested for MIBC and NMIBC. In this article, we review the current and ongoing clinical trials, regarding immune checkpoint inhibitors, being conducted in various clinical settings of UC, including mUC, MIBC, and NMIBC.

The molecular limitations of biomarker research in bladder cancer

PURPOSE

Urothelial carcinoma of the bladder (UCB) is a common malignancy with limited systemic treatment options in advanced stages. Despite recent advances in immunotherapy, the majority of patients do not respond to these treatments. There is an unmet need for developing robust biomarkers to inform treatment decisions and identify patients who are likely to respond.

METHODS

A MEDLINE/PubMed literature search was performed, focusing on tissue-based and circulating biomarkers, and their potential in muscle-invasive UCB.

RESULTS

UCB is a heterogeneous disease that consists of several clonal and subclonal populations, each with a mix of truncal and private genomic alterations. This inter- and intra-tumoral heterogeneous landscape results in the development of treatment resistance. Tumor heterogeneity also constitutes a barrier to the development of robust markers of response and resistance to chemotherapy and immunotherapy. Defects in DNA repair genes and a high tumor mutational burden independently confer sensitivity to cisplatin-based chemotherapy and checkpoint inhibitors. Oncogenic alterations such as FGFR3 mutations and fusions are associated with response to FGFR3 inhibitors. Several emerging potential biomarkers, including gene expression-based molecular subtypes, T-cell receptor clonality, and tissue- or blood-based immune-gene profiling, require prospective testing and validation. Tissue-based biomarkers such as PD-L1 immunohistochemistry have several limitations due to discordance in assay methodology and trial designs. Novel liquid-biopsy techniques are promising as potential biomarkers.

CONCLUSIONS

Validated biomarkers that capture the complexity of the biology of both the tumor and the tumor microenvironment are needed in muscle-invasive UCB. Standardization of methods is critical to developing reliable biomarkers to guide clinical management.

Biomarkers for predicting efficacy of PD-1/PD-L1 inhibitors

Programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) is a negative modulatory signaling pathway for activation of T cell. It is acknowledged that PD-1/PD-L1 axis plays a crucial role in the progression of tumor by altering status of immune surveillance. As one of the most promising immune therapy strategies, PD-1/PD-L1 inhibitor is a breakthrough for the therapy of some refractory tumors. However, response rate of PD-1/PD-L1 inhibitors in overall patients is unsatisfactory, which limits the application in clinical practice. Therefore, biomarkers which could effectively predict the efficacy of PD-1/PD-L1 inhibitors are crucial for patient selection. Biomarkers reflecting tumor immune microenvironment and tumor cell intrinsic features, such as PD-L1 expression, density of tumor infiltrating lymphocyte (TIL), tumor mutational burden, and mismatch-repair (MMR) deficiency, have been noticed to associate with treatment effect of anti-PD-1/anti-PD-L1 therapy. Furthermore, gut microbiota, circulating biomarkers, and patient previous history have been found as valuable predictors as well. Therefore establishing a comprehensive assessment framework involving multiple biomarkers would be meaningful to interrogate tumor immune landscape and select sensitive patients.

Interventional therapy combined with immune checkpoint inhibitors: Emerging opportunities for cancer treatment in the era of immunotherapy

Immune checkpoint inhibitors-based immunotherapy offers a new effective modality in the treatment of advanced malignancies. Considering the remarkable efficacy of immune checkpoint inhibitors in clinical trials, the FDA has approved a variety of immune checkpoint inhibitors for the treatment of advanced tumors. However, only limited patients with certain cancers can benefit from monotherapy of immune checkpoint inhibitors. Interventional therapy for cancer can not only destroy the primary tumors, but also regulate the immune system through different mechanisms, which provides a potential possibility for the combination of immune checkpoint inhibitors and interventional modalities in cancer treatment. This article reviews the possible synergistic mechanisms of interventional therapy combined with immune checkpoint inhibitors and summarizes the research progress of the combined therapy in cancer treatment.

Management of Brain Metastases in the New Era of Checkpoint Inhibition

PURPOSE OF THE REVIEW

Brain metastasis is a common complication of advanced malignancies, especially, lung cancer, breast cancer, renal cell carcinoma, and melanoma. Traditionally surgery, when indicated, and radiation therapy, either as whole-brain radiation therapy or stereotactic radiosurgery, constituted the major treatment options for brain metastases. Until recently, most of the systemic chemotherapy agents had limited activity for brain metastases. However, with the advent of small molecule tyrosine kinase inhibitors and immunotherapy agents, there has been renewed interest in using these agents in the management of brain metastases.

RECENT FINDINGS

Immune checkpoint inhibitors have revolutionized the treatment of metastatic melanoma, lung cancer, kidney cancer, and bladder cancer among others. They modulate the immune system to recognize tumor antigens as "non-self" antigens and mount an immune response against them. Initial studies of using immune checkpoint inhibitors in brain metastases have shown promising activity, and several clinical trials are currently underway. Studies are also assessing the combination of radiation therapy and immunotherapy in brain metastases. The results of these ongoing clinical trials have the potential to change the therapeutic paradigm in patients with brain metastases.

Immune Checkpoint Inhibition for Pancreatic Ductal Adenocarcinoma: Current Limitations and Future Options

Pancreatic ductal adenocarcinoma (PDAC), as the most frequent form of pancreatic malignancy, still is associated with a dismal prognosis. Due to its late detection, most patients are ineligible for surgery, and chemotherapeutic options are limited. Tumor heterogeneity and a characteristic structure with crosstalk between the cancer/malignant cells and an abundant tumor microenvironment (TME) make PDAC a very challenging puzzle to solve. Thus far, targeted therapies have failed to substantially improve the overall survival of PDAC patients. Immune checkpoint inhibition, as an emerging therapeutic option in cancer treatment, shows promising results in different solid tumor types and hematological malignancies. However, PDAC does not respond well to immune checkpoint inhibitors anti-programmed cell death protein 1 (PD-1) or anti-cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) alone or in combination. PDAC with its immune-privileged nature, starting from the early pre-neoplastic state, appears to escape from the antitumor immune response unlike other neoplastic entities. Different mechanisms how cancer cells achieve immune-privileged status have been hypothesized. Among them are decreased antigenicity and impaired immunogenicity via both cancer cell-intrinsic mechanisms and an augmented immunosuppressive TME. Here, we seek to shed light on the recent advances in both bench and bedside investigation of immunotherapeutic options for PDAC. Furthermore, we aim to compile recent data about how PDAC adopts immune escape mechanisms, and how these mechanisms might be exploited therapeutically in combination with immune checkpoint inhibitors, such as PD-1 or CTLA-4 antibodies.

Therapeutic Vaccines for Genitourinary Malignancies

The field of genitourinary malignancies has been a showcase for therapeutic cancer vaccine success since the application of intravesicular Bacillus Calmette-Guerin (BCG) for bladder cancer in the 1970s and enjoyed a renaissance in 2010 with the US Food and Drug Administration (FDA) approval of sipuleucel-T for prostate cancer. Several vaccine strategies have emerged, such as autologous or allogeneic whole-tumor vaccines, DNA vaccines, use of viral vectors, and peptides as immunostimulatory adjuvants. Despite impressive early trials, vaccine monotherapy has achieved limited success in the clinical world; however, combinations of vaccine and immune checkpoint inhibition or vaccine and cytokine stimulation are expected to move the field forward. This article reviews pivotal trials of cancer vaccines in prostate, renal, and bladder cancer and ongoing trials combining vaccines with other immune therapy agents.

Drug response to PD-1/PD-L1 blockade: based on biomarkers

In recent years, immunotherapies targeting programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) have provided great hopes for patients with cancer. A successful anti-PD-1/PD-L1 therapy includes not only the elimination of immunosuppressive tumor cells but also the rejuvenation of exhausted T cells. Nevertheless, the efficacy of therapy is still low, so that biomarker-driven therapy has attracted more and more attention to identify patients who are likely to benefit from therapy and to reduce unnecessary disease progression. While many studies have focused on characteristics of tumor biopsies, biomarkers linked to T cell exhaustion and rejuvenation have just become new hot spots in drug response studies. However, no biomarker is perfect in drug response prediction currently, so there is an urgent need for other biomarkers to compensate for the deficiency. In this review, we summarize some approved and candidate biomarkers predictive of drug response before and during PD-1/PD-L1 blockade, including those characterizing responsive or suppressive tumor cells and those evaluating the T cell rejuvenation. Overall, we set up a comprehensive network of biomarkers of tumor characteristics and T cell rejuvenation, predicting drug response before and during anti-PD-1/PD-L1 therapies.

Reproducibility of PD-L1 immunohistochemistry interpretation across various types of genitourinary and head/neck carcinomas, antibody clones, and tissue types

Programmed death-ligand 1 (PD-L1) expression by tumor cells is a mechanism for down-regulation of antitumor T-cell responses and is a target for immunotherapy in various cancers. PD-L1 status as a predictor of treatment response has led to the development of multiple platforms with different reference cutoffs. We studied 128 cases of genitourinary and head/neck carcinomas, aiming to assess the frequency of PD-L1 positivity, interobserver reliability of PD-L1 interpretation, and the concordance of PD-L1 scoring between small samples from tissue microarray and whole sections using SP263 and SP142 clones. No prostatic carcinoma (0/21) was PD-L1 positive compared with 15% to 24% PD-L1 positivity in urothelial carcinoma (UC), hypopharyngeal squamous cell carcinoma (HP-SCC), and high-grade salivary gland carcinoma. There was substantial interobserver agreement in determining overall PD-L1 positivity in UC and HP-SCC using SP263 (κ = 0.702) and SP142 (κ = 0.757) antibodies. Subgroup analysis for both antibodies showed excellent agreement in UC (κ = 0.812 and 0.827) and moderate agreement in HP-SCC (κ = 0.469 and 0.591). Moderate to substantial agreement between tissue microarray and whole sections was achieved using SP263 (overall, κ = 0.573; UC, κ = 0.424; and HP-SCC, κ = 0.667) and SP142 (UC, κ = 0.493). PD-L1 interpretation in genitourinary and head/neck carcinomas is reliable and reproducible among pathologists and across different tissue preparations. Tumor PD-L1 staining heterogeneity may lead to discrepant PD-L1 results between small biopsies and large sections from surgical resection in a subset of tumors (19% of UC and 15% of HP-SCC). Retesting in such cases may be required to determine patient suitability for anti-PD-1/PD-L1 therapy.

Immune Checkpoint Inhibitors for Urothelial Cancer: An Update on New Therapies

Ongoing trials are evaluating immune checkpoint inhibitors-used alone, in combination with cytotoxic, targeted, radiation therapies, or with other such inhibitors-for therapy in patients with advanced bladder cancer.

Antibody-Drug Conjugates in Bladder Cancer

Urothelial carcinoma (UC) is characterized by expression of a plethora of cell surface antigens, thus offering opportunities for specific therapeutic targeting with use of antibody-drug conjugates (ADCs). ADCs are structured from two major constituents, a monoclonal antibody (mAb) against a specific target and a cytotoxic drug connected via a linker molecule. Several ADCs are developed against different UC surface markers, but the ones at most advanced stages of development include sacituzumab govitecan (IMMU-132), enfortumab vedotin (ASG-22CE/ASG-22ME), ASG-15ME for advanced UC, and oportuzumab monatox (VB4-845) for early UC. Several new targets are identified and utilized for novel or existing ADC testing. The most promising ones include human epidermal growth factor receptor 2 (HER2) and members of the fibroblast growth factor receptor axis (FGF/FGFR). Positive preclinical and early clinical results are reported in many cases, thus the next step involves further improving efficacy and reducing toxicity as well as testing combination strategies with approved agents.

Approved checkpoint inhibitors in bladder cancer: which drug should be used when?

The treatment of advanced metastatic urothelial carcinoma has recently evolved with the approval of five checkpoint inhibitors. In the second-line setting, in patients who have progressed on cisplatin-based chemotherapy, pembrolizumab, atezolizumab, durvalumab, nivolumab and avelumab are United States Food and Drug Administration (FDA) approved. In cisplatin-ineligible patients, atezolizumab and pembrolizumab are the FDA-approved checkpoint inhibitors. Here we describe the updated clinical efficacy of these checkpoint inhibitors in the treatment of advanced urothelial carcinoma and then suggest how they can be sequenced in the context of available chemotherapeutic options. For cisplatin-eligible patients, platinum-based chemotherapy remains the standard first-line treatment. For patients progressing on platinum-based therapy, phase III trials have been performed comparing pembrolizumab and atezolizumab separately with standard chemotherapy, and results favor the use of pembrolizumab.

Consistency of tumor and immune cell programmed cell death ligand-1 expression within and between tumor blocks using the VENTANA SP263 assay

Background

Several anti-programmed cell death-1 (PD-1) and anti-programmed cell death ligand-1 (PD-L1) therapies have shown encouraging safety and clinical activity in a variety of tumor types. A potential role for PD-L1 testing in identifying patients that are more likely to respond to treatment is emerging. PD-L1 expression in clinical practice is determined by testing one tumor section per patient. Therefore, it is critical to understand the impact of tissue sampling variability on patients’ PD-L1 classification.

Methods

Resected non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) and urothelial carcinoma (UC) tissue samples (five samples per tumor type) were obtained from commercial sources and two tumor blocks were taken from each. Three sections from each block (~ 100 μm apart) were stained using the VENTANA PD-L1 (SP263) assay, and scored based on the percentage of PD-L1-staining tumor cells (TCs) or tumor-infiltrating immune cells (ICs) present. Each section was categorized as PD-L1 high or low/negative using a variety of cut-off values, and intra-block and intra-case (between blocks of the same tumor) concordance (overall percentage agreement [OPA]) were evaluated. An additional 200 commercial NSCLC samples were also analyzed, and intra-block concordance determined by scoring two sections per sample (≥70 μm apart).

Results

Concordance in TC PD-L1 classification was high at all applied cut-offs. Intra-block and intra-case OPA for the 15 NSCLC, HNSCC or UC samples were 100% and 80–100%, respectively, across all cut-offs; intra-block OPA for the 200 NSCLC samples was 91.0–98.5% across all cut-offs. IC PD-L1 classification was less consistent; intra-block and intra-case OPA for the 15 NSCLC, HNSCC or UC samples ranged between 70 and 100% and between 60 and 100%, respectively, with similar observations in the intra-block analysis of the 200 NSCLC samples.

Conclusions

These results show the reproducibility of TC PD-L1 classification across the depth of the tumor using the VENTANA PD-L1 (SP263) assay. Practically, this means that treatment decisions based on TC PD-L1 classification can be made confidently, following analysis of one tumor section. Although more variable than TC staining, consistent IC PD-L1 classification was also observed within and between blocks and across cut-offs.

Electronic supplementary material

The online version of this article (10.1186/s13000-018-0725-9) contains supplementary material, which is available to authorized users.

Immune check point inhibitors for metastatic urothelial carcinoma: current evidence-based approach for urology daily practice

INTRODUCTION

Treatment strategy for inoperable and metastatic urothelial carcinoma (mUC) has been revolutionized by the introduction of programmed cell death protein 1 (PD-1) and programmed cell death protein ligand (PD-L1) antibodies. During the last 3 decades treatment options were limited to chemotherapy, making further treatment of patients whose disease progressed under ongoing therapy or who were ineligible to receive cytotoxic therapy in the first place, nearly impossible.

EVIDENCE ACQUISITION

Five antibodies including pembrolizumab (PD-L1 antibody), atezolizumab (PD-1 antibody), nivolumab (PD-1 antibody), avelumab and durvalumab (PD-L1 antibodies) have been approved in the treatment of advanced urothelial carcinoma in first- and second-line treatment setting. The objective of this review was to examine and compare the different cohorts and to discuss the quality of the respective studies in order to set up selection criteria for clinical decision making.

EVIDENCE SYNTHESIS

So far pembrolizumab and atezolizumab have demonstrated overall survival (OS) benefit in phase II studies and have shown superiority over standard chemotherapy in phase III studies which has granted them approval in first and second-line treatment setting. Improved OS and durable responses were also seen in phase Ib/II non-randomized, single-arm trials conducted with nivolumab, avelumab and durvalumab and granting accelerated approval for second-line treatment. The huge advantage of immunotherapy and one of the reasons for its overall recognition is its good tolerability profile especially in comparison to chemotherapy.

CONCLUSIONS

Pembrolizumab has to be recommended in second-line therapy due to reporting in a phase III trial and OS survival benefit compared to chemotherapy control group. In cisplatin-eligible and treatment-naïve patients with visceral or liver metastases data also slightly favors pembrolizumab rather than atezolizumab.

Immune-checkpoint inhibitors in previously treated patients with advanced or metastatic urothelial carcinoma: A systematic review and meta-analysis

Immunotherapy represents a new hope for patients with advanced urothelial carcinoma (UC). However, to date, only one of two randomized studies showed a clear survival advantage with these treatments. Aimed to investigate the role of immune-checkpoint inhibitors in patients with platinum progressed metastatic UC we performed a systematic review and meta-analysis of clinical trials to evaluate the efficacy and activity, in terms of Overall Survival (OS) and Objective Response Rate (ORR). Immune checkpoint inhibitors have showed to improve OS compared to chemotherapy in unselected patients (HR 0.80, 95% CI 0.69-0.93, p = 0.003), while the difference was not significant in patients selected for PD-L1 expression (HR 0.72, 95% CI 0.48-1.09, p = 0.12). Pooled probability of response was 0.18 (95% CI 0.16-0.20) in unselected patients and 0.27 (95% CI 0.25-0.32) in PD-L1 selected patients. Immunotherapy results in a significant survival advantage in PD-L1 unselected patients suggesting that PD-L1 expression may not be a reliable marker in previously platinum treated patients.

Pembrolizumab Combined With Either Docetaxel or Gemcitabine in Patients With Advanced or Metastatic Platinum-Refractory Urothelial Cancer: Results From a Phase I Study

INTRODUCTION

Cytotoxic chemotherapy might prime urothelial cancer (UC) to checkpoint inhibition, prompting a trial of chemotherapy with the programmed death receptor-1 inhibitor pembrolizumab.

PATIENTS AND METHODS

Patients with advanced, platinum-refractory UC received pembrolizumab and either docetaxel (arm A) or gemcitabine (arm B). Primary end points were assessments of maximum tolerated dose and dose-limiting toxicity (DLT). Secondary end points were overall response rate (ORR) and progression-free survival (PFS).

RESULTS

Twelve patients were enrolled in the initial cohorts; 6 in each arm. One DLT was seen in each arm: Grade 3 hypophosphatemia (arm A), Grade 3 diarrhea (arm B). Adverse events of Grade >3 were observed in 7 (54%), the most common being anemia (6; 50%), fatigue (6; 50%), hyponatremia (4; 33%) and neutropenia (3; 25%), with no treatment-related deaths. There were 5 confirmed responses (1 complete, 4 partial), with an ORR of 42% and disease control rate (DCR) of 58%. Arm A had an ORR of 50% and DCR of 67%, whereas arm B had an ORR of 33% and DCR of 50%. Median PFS was 4.8, 5.7, and 3.7 months for the overall cohort, arm A, and arm B, respectively.

CONCLUSION

Pembrolizumab with either docetaxel or gemcitabine is feasible for treatment of platinum-refractory advanced UC patients. Preliminary efficacy was observed. Further examination is warranted.

The evolving immunotherapeutic landscape in advanced oesophagogastric cancer

Improvements in median overall survival in the advanced oesophagogastric (OG) setting have plateaued, underlining the need for improved therapeutic approaches in this patient population. Immunotherapeutics are inducing unexpected durable responses in an expanding list of advanced disease indications. Although OG cancers have traditionally been considered to be more challenging to treat with immunotherapy than some other malignancies because of their variable tumour mutational burden and relative scarcity of infiltrating T cells, immune checkpoint inhibitor (ICPI) trials conducted over the last few years suggest there is an important role for these treatments. ICPI efficacy may be demonstrated in specific molecular subtypes of OG cancer. This review outlines the improvements in defining predictive biomarkers of responsiveness to ICPIs. Increasingly, identification of an expanding list of ICPI resistance mechanisms will drive biomarker-directed research. In addition, the specific rationale to combine ICPIs with chemotherapies, radiotherapies, targeted therapies and other novel immunotherapeutic drugs will be discussed.

Safety and efficacy of durvalumab (MEDI4736) in various solid tumors

Introduction

The prominent immune checkpoint molecule, programmed cell death ligand-1 (PD-L1), is the object of increasing attention. Here, we report a meta-analysis investigating the safety and efficacy of durvalumab (MEDI4736), an inhibitor of PD-L1, in various solid tumors.

Methods

A systematic search of PubMed, Embase, and related articles was performed. Safety data were analyzed using Comprehensive Meta-Analysis software program version 2. Ultimately, 17 studies with 1,529 patients were included in our analysis.

Results

The major adverse events associated with durvalumab were pruritus and fatigue, while pruritus, increased alanine transaminase, and increased aspartate aminotransferase were common among patients treated with a combination of durvalumab and tremelimumab. Higher PD-L1 expression was associated with a superior objective response rate.

Conclusion

Durvalumab is safe in patients with many solid cancers and, in combination with tremelimumab, it has a tolerable safety profile and is associated with improved prognosis. PD-L1 expression is a biomarker of the efficacy of durvalumab.

Tumor matrix remodeling and novel immunotherapies: the promise of matrix-derived immune biomarkers

Recent advances in our understanding of the dynamics of cellular cross-talk have highlighted the significance of host-versus-tumor effect that can be harnessed with immune therapies. Tumors exploit immune checkpoints to evade adaptive immune responses. Cancer immunotherapy has witnessed a revolution in the past decade with the development of immune checkpoint inhibitors (ICIs), monoclonal antibodies against cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or their ligands, such as PD1 ligand 1 (PD-L1). ICIs have been reported to have activity against a broad range of tumor types, in both solid organ and hematologic malignancy contexts. However, less than one-third of the patients achieve a durable and meaningful treatment response. Expression of immune checkpoint ligands (e.g., PD-L1), mutational burden and tumor-infiltrating lymphocytes are currently used as biomarkers for predicting response to ICIs. However, they do not reliably predict which patients will benefit from these therapies. There is dire need to discover novel biomarkers to predict treatment efficacy and to identify areas for development of combination strategies to improve response rates. Emerging evidence suggests key roles of tumor extracellular matrix (ECM) components and their proteolytic remodeling products in regulating each step of the cancer-immunity cycle. Here we review tumor matrix dynamics and matrix remodeling in context of anti-tumor immune responses and immunotherapy and propose the exploration of matrix-based biomarkers to identify candidates for immune therapy.

From Clinical Trials to Real-life Clinical Practice: The Role of Immunotherapy with PD-1/PD-L1 Inhibitors in Advanced Urothelial Carcinoma

CONTEXT

A number of PD-1/PD-L1 inhibitors have recently been approved for use in patients with locally advanced or metastatic urothelial carcinoma (UC) on the basis of results from several clinical trials.

OBJECTIVE

To review the evidence from these trials and consider what it means for the use of these drugs in first-line and post-platinum settings in real-life clinical practice.

EVIDENCE ACQUISITION

PubMed was searched for full reports of clinical trials of single-agent PD-1/PD-L1 inhibitors in advanced UC. Twelve publications were included.

EVIDENCE SYNTHESIS

Responses to PD-1/PD-L1 inhibitors appear to be durable but are only achieved in 17-26% of patients. These drugs offer different toxicity and efficacy profiles to standard chemotherapy regimens. This should be considered when choosing a treatment strategy for each patient.

CONCLUSIONS

PD-1/PD-L1 inhibitors represent a major step forward in the management of advanced UC, although several questions remain regarding their optimal use in routine clinical practice. A validated predictive biomarker of response is yet to be defined, and this is perhaps the most significant unmet need for currently available drugs.

PATIENT SUMMARY

We reviewed the results from clinical trials that investigated how well certain types of anticancer drugs called PD-1/PD-L1 inhibitors worked in patients with bladder cancer. We found that more research is required to identify (1) the factors that might predict which patients with bladder cancer will respond to PD-1/PD-L1 inhibitors and (2) the optimum duration of treatment with these drugs.

Acquired resistance to cancer immunotherapy

In recent times, advances in cancer immunotherapy have yielded impressive, durable clinical responses in patients with varied subtypes of cancer. However, a significant proportion of patients who initially demonstrate encouraging tumor regression develop resistance and progress over time. The identification of novel therapeutic approaches to overcome resistance may result in significantly improved clinical outcomes and remains an area of high scientific priority. This review aims to summarize the current knowledge regarding the role of both tumor-intrinsic and tumor-extrinsic factors in the development of resistance to cancer immunotherapy and to discuss current and possible future therapeutic strategies targeting these mechanisms.

Pharmacologic Modulation of Human Immunity in the Era of Immuno-oncology: Something Old, Something New

The concept of exploiting the immune system to treat cancer forms the basis of immuno-oncology. Since its birth in the late 1800s, immuno-oncology, or cancer immunotherapy, has come a long way. With better understanding of the complex relationship between tumor and the immune system, we have been able to explore and develop various modalities of anticancer therapies. In this review, we summarize the main strategies of immunotherapy that are available today: monoclonal antibodies, anticancer vaccines, cytokines, and adoptive T-cell therapy. We also highlight the unique set of adverse effects associated with modern immunotherapy and propose nonsteroidal immunomodulators and anticytokine antibodies as treatment options for toxicities. The future of immuno-oncology is discussed, including combination therapy, drug-antibody conjugates, epigenetic drugs, using nanoparticles for drug delivery, new antigen discovery, and developing biomarkers to assess treatment responses. A data search was conducted using PubMed and included studies published through November 1, 2017. Search terms used include cancer immunotherapy, pembrolizumab, ipilimumab, nivolumab, PD-1 inhibitors, PD-L1 inhibitors, checkpoint inhibitors, anticancer vaccines, TVEC, and adoptive cell therapy.

Biological effects of radiation on cancer cells

With the development of radiotherapeutic oncology, computer technology and medical imaging technology, radiation therapy has made great progress. Research on the impact and the specific mechanism of radiation on tumors has become a central topic in cancer therapy. According to the traditional view, radiation can directly affect the structure of the DNA double helix, which in turn activates DNA damage sensors to induce apoptosis, necrosis, and aging or affects normal mitosis events and ultimately rewires various biological characteristics of neoplasm cells. In addition, irradiation damages subcellular structures, such as the cytoplasmic membrane, endoplasmic reticulum, ribosome, mitochondria, and lysosome of cancer cells to regulate various biological activities of tumor cells. Recent studies have shown that radiation can also change the tumor cell phenotype, immunogenicity and microenvironment, thereby globally altering the biological behavior of cancer cells. In this review, we focus on the effects of therapeutic radiation on the biological features of tumor cells to provide a theoretical basis for combinational therapy and inaugurate a new era in oncology.

Nivolumab and its use in the second-line treatment of metastatic urothelial cancer

Nivolumab is a fully human monoclonal antibody blocking PD-1 with demonstrated effectiveness against metastatic urothelial carcinoma. In this review, we describe the pharmacological properties of nivolumab and the treatment of metastatic urothelial carcinoma with this checkpoint inhibitor after the failure of first-line platinum-based chemotherapy. Cancer immunotherapy by checkpoint inhibition offers potential to prolong patient survival with well manageable toxicity although serious immune-related adverse events may occur. The overall response rate to nivolumab after first-line chemotherapy is about 20%. Patients unfit for cisplatin may benefit from first-line cancer immunotherapy. It remains unclear which patient will respond and PD-1/PD-L1 expression alone is not a sufficiently reliable predictive biomarker.

Pan-cancer adaptive immune resistance as defined by the Tumor Inflammation Signature (TIS): results from The Cancer Genome Atlas (TCGA)

The Tumor Inflammation Signature (TIS) is an investigational use only (IUO) 18-gene signature that measures a pre-existing but suppressed adaptive immune response within tumors. The TIS has been shown to enrich for patients who respond to the anti-PD1 agent pembrolizumab. To explore this immune phenotype within and across tumor types, we applied the TIS algorithm to over 9000 tumor gene expression profiles downloaded from The Cancer Genome Atlas (TCGA). As expected based on prior evidence, tumors with known clinical sensitivity to anti-programmed cell death protein 1 (PD-1) blockade had higher average TIS scores. Furthermore, TIS scores were more variable within than between tumor types, and within each tumor type a subset of patients with elevated scores was identifiable although with different prevalence associated with each tumor type, the latter consistent with the observed clinical responsiveness to anti PD-1 blockade. Notably, TIS scores only minimally correlated with mutation load in most tumors and ranking tumors by median TIS score showed differing association to clinical sensitivity to PD-1/PD-1 ligand 1 (PD-L1) blockade than ranking of the same tumors by mutation load. The expression patterns of the TIS algorithm genes were conserved across tumor types yet appeared to be minimally prognostic in most cancers, consistent with the TIS score serving as a pan-cancer measurement of the inflamed tumor phenotype. Characterization of the prevalence and variability of TIS will lead to increased understanding of the immune status of untreated tumors and may lead to improved indication selection for testing immunotherapy agents.

Transcriptional changes associated with in vivo growth of muscle-invasive bladder cancer cell lines in nude mice

Cancer cells set in motion transcriptomic programs allowing for adaptation and growth in immunocompromised mice to form xenografts, a frequently used tool in cancer research. 2D cultures may not be representative of tumors growing in a complex host microenvironment. This can result in different responses to the same agent tested in vitro and in vivo which impedes the process of developing novel therapeutics. Understanding the transition cells undergo from 2D cell culture to a 3D host microenvironment will help in developing and choosing appropriate models for pre-clinical studies. Our study characterized the transcriptome of a three frequently used muscle-invasive bladder cancer cell lines HT1376, T24 and UM-UC-3 grown in culture and xenografts in nude mice. We found that bladder cancer cells undergo few transcriptomic changes when transitioned from 2D cell culture to xenografts in nude mice. UM-UC-3 cells have the least transcriptomic alterations followed by T24 and HT1376 cells. Respective xenografts cluster with their parental cell lines rather than other xenografts or cell lines. We applied established bladder cancer molecular subtypes to our data and found that UM-UC-3, containing the least transcriptomic alterations, most closely resembled the basal-like molecular subtype of bladder cancer. HT1376 and T24 have mixed basal and luminal molecular signatures. Our studies suggest this subset of bladder cancer cell lines and derived xenografts maintain similar transcriptomic profiles in both 2D culture and 3D xenografts and can be used interchangeably in pre-clinical studies.

Immune checkpoint inhibitors in urothelial cancer: recent updates and future outlook

Bladder cancer is the sixth most common cancer in the US and most tumors have urothelial (transitional cell) histology. Platinum-based chemotherapy has long been the standard of care in advanced disease, but long-term outcomes have largely remained poor. Since the peak incidence of bladder cancer is in the eighth decade of life and beyond, medical comorbidities may often limit the use of chemotherapy. Immune checkpoint inhibitors with their favorable toxicity profiles and notable antitumor activity have ushered in a new era in the treatment of advanced urothelial cancer (UC) with five agents targeting the PD-1/PD-L1 pathway being recently approved by the US Food and Drug administration. A plethora of clinical trials are ongoing in diverse disease settings, employing agents targeting PD-1/PD-L1 and related immune checkpoint pathways. While reactivating anti-tumor immunity, these agents may lead to a unique constellation of immune-related adverse events, which may warrant discontinuation of therapy and potential use of immunosuppression. Novel combinations with various treatment modalities and optimal sequencing of active therapies are being investigated in prospective clinical trials and retrospective registries. At the era of precision molecular medicine, and since patients do not respond uniformly to these agents, there is a growing need for identification and validation of biomarkers that can accurately predict treatment response and assist in patient selection. This review discusses current updates and future directions of immunotherapy in advanced UC.

Development of immunotherapy in bladder cancer: present and future on targeting PD(L)1 and CTLA-4 pathways

PURPOSE

Over the past 3 decades, no major treatment breakthrough has been reported for advanced bladder cancer. Recent Food and Drug Administration (FDA) approval of five immune checkpoint inhibitors in the management of advanced bladder cancer represent new therapeutic opportunities. This review examines the available data of the clinical trials leading to the approval of ICIs in the management of metastatic bladder cancer and the ongoing trials in advanced and localized settings.

METHODS

A literature search was performed on PubMed and ClinicalTrials.gov combining the MeSH terms: 'urothelial carcinoma' OR 'bladder cancer', and 'immunotherapy' OR 'CTLA-4' OR 'PD-1' OR 'PD-L1' OR 'atezolizumab' OR 'nivolumab' OR 'ipilimumab' OR 'pembrolizumab' OR 'avelumab' OR 'durvalumab' OR 'tremelimumab'. Prospectives studies evaluating anti-PD(L)1 and anti-CTLA-4 monoclonal antibodies were included.

RESULTS

Evidence-data related to early phase and phase III trials evaluating the 5 ICIs in the advanced urothelial carcinoma are detailed in this review. Anti-tumour activity of the 5 ICIs supporting the FDA approval in the second-line setting are reported. The activity of PD(L)1 inhibitors in the first-line setting in cisplatin-ineligible patients are also presented. Ongoing trials in earlier disease-states including non-muscle-invasive and muscle-invasive bladder cancer are discussed.

CONCLUSIONS

Blocking the PD-1 negative immune receptor or its ligand, PD-L1, results in unprecedented rates of anti-tumour activity in patients with metastatic urothelial cancer. However, a large majority of patients do not respond to anti-PD(L)1 drugs monotherapy. Investigations exploring the potential value of predictive biomarkers, optimal combination and sequences are ongoing to improve such treatment strategies.

Emerging biomarkers and targeted therapies in urothelial carcinoma

The use of immunotherapy has revolutionized the management of patients with locally advanced, unresectable, and metastatic urothelial carcinoma (UC); however, platinum-based chemotherapy remains a therapeutic cornerstone both in localized muscle-invasive and advanced UC. There is still no predictive molecular biomarker with clinical utility to help guide treatment and select patients most likely to derive benefit from a particular therapeutic modality or regimen. However, recent research has further characterized the inherent biology and immunology landscapes of UC leading to the development of potential biomarkers and therapeutic targets that could be used upon further validation. Emerging interrogation of The Cancer Genome Atlas (TCGA) and other molecular profiling datasets has led to the identification of distinct molecular subtypes with diverse clinical behaviors with potential sensitivity to various therapies. It has also led to the discovery of multiple frequently altered genes and proteins that could lead to perturbation of intracellular signaling pathways and of the dynamic interactions between tumor cells, their "microenvironment", and the host "macro-environment". The advent of molecular profiling and deeper next-generation sequencing has the potential to change biomarker and "real time" drug sensitivity assessment, introducing and testing the premise of "precision oncology" and personalized medicine. Within this review, we summarize emerging biomarkers that may predict response to cisplatin-based chemotherapy, immunotherapy, emerging targeted therapies, and promising combination strategies. We also highlight a few examples of 'precision medicine' trials aiming to improve outcomes in UC. Since our review is not exhaustive we strongly recommend the readers to follow the continuously changing literature in the very interesting and dynamic field of UC.

PD-L2 amplification and durable disease stabilization in patient with urothelial carcinoma receiving pembrolizumab

We report the immunological profile of a patient with upper-tract urothelial carcinoma experiencing stable disease on pembrolizumab for 20 months. The tumor exhibited extensive infiltration by CD8⁺ cytotoxic T lymphocytes, low-to-moderate mutational burden, no PD-L1 staining by commercially available immunohistochemical assays, but amplification of CD274 (coding for PD-L1) and/or PDCD1LG2 (encoding PD-L2) by fluorescence in situ hybridization. RNA-seq revealed multiple biomarkers of an ongoing immune response and compensatory immune evasion, including moderate PD-L1 levels coupled with robust PD-L2 expression. Pending validation in additional patients, these findings suggest that PD-L2 expression levels may constitute a biomarker of response to immune checkpoint blockade in urothelial carcinoma.

Systemic Therapy for Advanced Urothelial Carcinoma: Current Standards and Treatment Considerations

Urothelial carcinoma is the sixth most common malignancy in the United States. Although most are diagnosed with non-muscle-invasive malignancy, many patients will develop recurrent disease within 5 years, with 10% to 20% developing advanced muscle-invasive or more distant incurable disease. For such patients, clinical outcomes have remained suboptimal, although recent therapeutic advances have brought new hope to the field. Here, we discuss the main systemic treatment options available for the treatment of patients with advanced disease. This review begins with traditional chemotherapy, which remains a first-line treatment option for many patients. The second section focuses on the evolving landscape of immunotherapy, specifically on approved checkpoint inhibitors and future challenges. Last, we address advances in targeted treatments, including angiogenesis and fibroblast growth factor receptor (FGFR) inhibitors as well as antibody-drug conjugates. As the number of available treatment options continues to expand, ongoing trials to investigate the best sequence and combination strategies to incorporate these drugs into clinical practice will help delineate the future.

Defining and Understanding Adaptive Resistance in Cancer Immunotherapy

Despite the unprecedented tumor regression and long-term survival benefit observed with anti-programmed death (PD) [anti-PD-1 or anti-B7-homolog 1 (B7-H1)] therapy in patients with advanced cancers, a large portion of patients do not benefit from such treatment and a fraction of responders relapse. Current efforts to overcome resistance and improve efficacy of anti-PD therapy require a clear understanding of resistance and should precede current avenues using random combinations with available treatment regimens. Here, we categorized three types of resistance, namely target-missing, primary, and acquired resistance. This categorization requires reliable, accurate tissue sampling and appropriate interpretation of results based on the four classifications of tumor immunity in the microenvironment (TIME). We believe that fundamental understanding of these complex tumor-immune interactions and of the cellular and molecular mechanisms underlying these types of true resistance is the key for targeting the right targets in combination with or beyond anti-PD therapy in the future.

Apatorsen plus docetaxel versus docetaxel alone in platinum-resistant metastatic urothelial carcinoma (Borealis-2)

BACKGROUND

A randomised study to assess the addition of apatorsen, an antisense oligonucleotide that inhibits Hsp27 expression, to docetaxel in patients with metastatic urothelial carcinoma (mUC) relapsed after prior platinum-based chemotherapy.

METHODS

Multicentre, phase II study with 1:1 randomisation to apatorsen (three loading doses at 600 mg intravenous followed by weekly doses) plus docetaxel (75 mg/m² intravenous every 21 days) (A/D) or docetaxel alone. Overall survival (OS) was the primary end point with a P value <0.1 (one-sided) being positive. Progression-free survival (PFS), objective response rate (ORR), safety, and effect of Hsp27 levels on outcomes were secondary end points.

RESULTS

Patients randomised to A/D (n = 99) had improved OS compared to docetaxel alone (n = 101): HR: 0.80, 80% CI: 0.65-0.98, P = 0.0784, median 6.4 vs 5.9 months. PFS and ORR were similar in both arms. A/D had more incidence of sepsis and urinary tract infections. Patients with baseline Hsp27 levels <5.7 ng/mL had improved OS compared to those with levels ≥5.7 ng/mL. Patients with a decline or ≤20.5% increase in Hsp27 from baseline benefited more from A/D than those with >20.5% increase.

CONCLUSIONS

A/D met its predefined OS end point in patients with platinum-refractory mUC in this phase II trial. This trial is hypothesis generating requiring further study before informing practice.

Durvalumab: a potential maintenance therapy in surgery-ineligible non-small-cell lung cancer

Lung cancer is the most common cancer worldwide and the most common cause of cancer-related death. Non-small-cell lung cancer comprises ~87% of newly diagnosed cases of lung cancer, and nearly one-third of these patients have stage III disease. Despite improvements in the treatment of stage IV lung cancer, particularly with the introduction and dissemination of checkpoint inhibitors, very little progress has been made in the treatment of stage III lung cancer. In this article, we discuss the general staging criteria and treatment options for stage III lung cancer. We review how concurrent radiation and chemotherapy can have immunomodulatory effects, supporting the rationale for incorporating immunotherapy into existing treatment paradigms. Finally, we discuss the results of the PACIFIC trial and implications for the treatment of stage III lung cancer. In the PACIFIC trial, adding durvalumab as a maintenance therapy following the completion of chemoradiotherapy improved progression-free survival in patients with locally advanced unresectable stage III lung cancer. On the strength of these results, durvalumab has been approved by the US Food and Drug Administration for use in this setting, representing the first advance in the treatment of stage III lung cancer in nearly a decade.

Programmed cell death-1 and programmed cell death ligand-1 antibodies-induced dysthyroidism

BACKGROUND

Monoclonal antibodies blocking the programmed cell death-1 (PD-1) or its ligand (PD-L1) are a group of immune checkpoints inhibitors (ICIs) with proven antitumor efficacy. However, their use is complicated by immune-related adverse events (irAEs), including endocrine adverse events (eAEs).

PURPOSE

We review the incidence, time to onset and resolution rate of dysthyroidism induced by PD-1/PD-L1 Ab, and the clinical, biological and radiological findings. We aim to discuss the potential mechanisms of PD-1/PD-L1 Ab-induced dysthyroidism, and to propose a management algorithm.

METHODS

We performed a literature search of available clinical trials regarding PD-1/PD-L1 Ab in the PubMed database. We selected all English language clinical trials that included at least 100 patients. We also present selected case series or reports, retrospective studies and reviews related to this issue.

FINDINGS

In patients treated with PD-1 Ab, hypothyroidism occurred in 2-10.1% and hyperthyroidism occurred in 0.9-7.8%. When thyroiditis was reported separately, it occurred in 0.34-2.6%. Higher rates were reported when PD-1 Ab were associated with other ICI or chemotherapy. The median time to onset of hyperthyroidism and hypothyroidism after PD-1 Ab initiation was 23-45 days and 2-3.5 months, respectively. Regarding PD-L1 Ab, hypothyroidism occurred in 0-10% and hyperthyroidism in 0.5-2% of treated patients. The average time to onset of dysthyroidism after PD-L1 Ab was variable and ranged from 1 day after treatment initiation to 31 months.

CONCLUSION

Dysthyroidism occurs in up to 10% of patients treated with PD-1/PD-L1 Ab. Hypothyroidism and reversible destructive thyroiditis are the most frequent endocrine adverse events (eAE) in PD-1/PD-L1 treated patients. Immune and non-immune mechanisms are potentially involved, independently of the presence of thyroid antibodies.

PD-1/PD-L1 pathway inhibitors in advanced prostate cancer

INTRODUCTION

Pharmacological inhibition of immune checkpoint receptors or their ligands represents a transformative breakthrough in the management of multiple cancers. However, immune checkpoint inhibitors have yet to be FDA-approved for the management of metastatic prostate cancer (PCa), the commonest non-cutaneous malignancy in men. Areas covered: We review our current understanding of the PD-1/PD-L1 pathway in cancer, the use of anti-PD-1/PD-L1 therapeutics in PCa, and potential subgroups of PCa patients who may derive the greatest benefit from these agents (such as men with tumors that have expression of PD-L1 and/or high mutational load). We also review the prior and current clinical trials evaluating the blockade of PD-1/PD-L1 in PCa, highlighting some of the key ongoing studies of greatest relevance to the field. Expert commentary: Clinical trials investigating PD-1/PD-L1 inhibitors should be encouraged in patients with PCa. While it is unlikely that immune checkpoint monotherapies will produce long-lasting responses in a substantial proportion of patients, there is early evidence of activity in some patient subsets. These subgroups may include those with high PD-L1 expression, those with hypermutated or microsatellite-unstable tumors, and those enriched for germline and/or somatic DNA-repair gene mutations (e.g. intraductal/ductal histology, primary Gleason pattern 5, and perhaps AR-V7-positive tumors).

Immuno-Oncology Biomarkers for Gastric and Gastroesophageal Junction Adenocarcinoma: Why PD-L1 Testing May Not Be Enough

PURPOSE

The treatment of patients with advanced gastric and gastroesophageal junction (G/GEJ) adenocarcinomas has been transformed by the U.S. Food and Drug Administration approval of pembrolizumab. Tumor and adjacent tissue must stain positively for the programmed cell death ligand 1 (PD-L1) protein by companion diagnostic testing. However, some patients with PD-L1-negative tumors also benefit from pembrolizumab. High microsatellite instability (MSI) and tumor mutational load (TML) are positive predictive biomarkers for immune checkpoint inhibition (ICI) in other tumors. We sought to identify more patients who could benefit from ICI using alternative PD-L1 thresholds, MSI, and TML.

METHODS

Tumor specimens underwent next-generation sequencing (NGS) and PD-L1 testing using immunohistochemistry. NGS was used to determine TML and MSI.

RESULTS

We profiled 581 G/GEJ adenocarcinoma specimens. PD-L1 staining was scored for intensity (0, none; 1+, weak; 2+, moderate; 3+, strong). Using 2+ staining at a 5% threshold, 9.3% of tumors were PD-L1 positive, and using 1+ staining at 1%, 16.2% were PD-L1 positive. 6.9% of tumors had high MSI. High TML (≥17 mutations per megabase) was seen in 6.9%, and medium TML (≥7) was seen in 56.5% of tumors. Thirty (5.2%) PD-L1-negative tumors at the 1+, 1% threshold had high TML or high MSI. Primary tumors had higher rates of high TML (8.8% vs. 3.9%; p = .0377) and high MSI (8.5% vs. 3.9%; p = .0471) than metastases.

CONCLUSION

PD-L1 testing alone fails to detect patients who may benefit from ICI. Lower PD-L1 thresholds and TML testing should be considered in future clinical trials.

IMPLICATIONS FOR PRACTICE

Pembrolizumab is approved by the U.S. Food and Drug Administration for patients with refractory gastric and gastroesophageal cancers if the tumor and adjacent tissue stain positively for the programmed cell death ligand 1 (PD-L1) protein by companion diagnostic testing. Tumor mutational load, microsatellite instability (MSI), and alternative PD-L1 testing thresholds may serve as predictive biomarkers for response to immune checkpoint inhibition, and standard PD-L1 testing will not identify all patients who may benefit from this therapy.

CD8 lymphocytes in tumors and nonsynonymous mutational load correlate with prognosis of bladder cancer patients treated with immune checkpoint inhibitors

Background

Anti–programed cell death 1 checkpoint inhibitors have recently demonstrated effectiveness against metastatic cancers including urothelial carcinoma.

Aims

To identify biomarkers/factors that correlate with the clinical response in advanced bladder cancer patients who received immune checkpoint inhibitor treatment.

Methods and results

We investigated tumors from 18 bladder cancer patients who had received anti–programed cell death 1 (pembrolizumab) or anti–programmed death‐ligand 1 therapy (atezolizumab or durvalumab) and performed exome analysis, T‐cell receptor sequencing of the tumor‐infiltrating lymphocytes (TILs), and immunohistochemical analysis of CD8 and programmed death‐ligand 1 in cancer tissues. Immunohistochemical analysis of bladder cancer tissues demonstrated that a higher number of CD8 T‐cell infiltration into cancer tissues was significantly associated with longer cancer‐specific survival of the patients (P = .0012). T‐cell receptor beta sequencing of TILs using genomic DNAs extracted from the tissues of 15 cases revealed that patients with higher clonal expansion of TILs had some tendency of longer cancer‐specific survival (P = .055), than those with lower clonal expansion. We performed whole exome sequencing of 14 cases and found that patients carrying higher numbers of somatic mutations received greater benefit from immunotherapy (P = .034) and one patient who had high microsatellite instability has survived for 1034 days.

Conclusion

CD8 infiltration in tumors and nonsynonymous mutation load might be useful predictive markers for immune checkpoint inhibitors for bladder cancer patients.