Directing the Future Breakthroughs in Immunotherapy: The Importance of a Holistic Approach to the Tumour Microenvironment

Simple Summary

Immunotherapies have changed the way we treat cancer and, while some patients have benefitted greatly, there are still those that do not respond to therapy. Understanding why some patients respond to therapy and others do not is critical in developing new immunotherapeutic strategies. The increasing awareness of the importance of investigating the tumour in its entirety, including the surrounding tissue and role of various immune cells is helping to differentiate responders and non-responders. In addition, the resolution gained by the development of sophisticated bioinformatic technologies allows for a deeper understanding of the complex roles of individual cells in the tumour. This advancement will be critical for the development of novel therapies to treat cancer.

Abstract

Immunotherapy has revolutionised the treatment of cancers by exploiting the immune system to eliminate tumour cells. Despite the impressive response in a proportion of patients, clinical benefit has been limited thus far. A significant focus to date has been the identification of specific markers associated with response to immunotherapy. Unfortunately, the heterogeneity between patients and cancer types means identifying markers of response to therapy is inherently complex. There is a growing appreciation for the role of the tumour microenvironment (TME) in directing response to immunotherapy. The TME is highly heterogeneous and contains immune, stromal, vascular and tumour cells that all communicate and interact with one another to form solid tumours. This review analyses major cell populations present within the TME with a focus on their diverse and often contradictory roles in cancer and how this informs our understanding of immunotherapy. Furthermore, we discuss the role of integrated omics in providing a comprehensive view of the TME and demonstrate the potential of leveraging multi-omics to decipher the underlying mechanisms of anti-tumour immunity for the development of novel immunotherapeutic strategies.

Long-term outcomes of patients with active melanoma brain metastases treated with combination nivolumab plus ipilimumab (CheckMate 204): final results of an open-label, multicentre, phase 2 study

BACKGROUND

Combination nivolumab plus ipilimumab was efficacious in patients with asymptomatic melanoma brain metastases (MBM) in CheckMate 204, but showed low efficacy in patients with symptomatic MBM. Here, we provide final 3-year follow-up data from the trial.

METHODS

This open-label, multicentre, phase 2 study (CheckMate 204) included adults (aged ≥18 years) with measurable MBM (0·5-3·0 cm in diameter). Asymptomatic patients (cohort A) had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and no neurological symptoms or baseline corticosteroid use; symptomatic patients (cohort B) had an ECOG performance status of 0-2 with stable neurological symptoms and could be receiving low-dose dexamethasone. Nivolumab 1 mg/kg plus ipilimumab 3 mg/kg was given intravenously every 3 weeks for four doses, followed by nivolumab 3 mg/kg every 2 weeks for up to 2 years, until disease progression or unacceptable toxicity. The primary endpoint was intracranial clinical benefit rate (complete responses, partial responses, or stable disease lasting ≥6 months) assessed in all treated patients. Intracranial progression-free survival and overall survival were key secondary endpoints. This study is registered with ClinicalTrials.gov, NCT02320058.

FINDINGS

Between Feb 19, 2015, and Nov 1, 2017, 119 (72%) of 165 screened patients were enrolled and treated: 101 patients were asymptomatic (cohort A; median follow-up 34·3 months [IQR 14·7-36·4]) and 18 were symptomatic (cohort B; median follow-up 7·5 months [1·2-35·2]). Investigator-assessed intracranial clinical benefit was observed in 58 (57·4% [95% CI 47·2-67·2]) of 101 patients in cohort A and three (16·7% [3·6-41·4]) of 18 patients in cohort B; investigator-assessed objective response was observed in 54 (53·5% [43·3-63·5]) patients in cohort A and three (16·7% [3·6-41·4]) patients in cohort B. 33 (33%) patients in cohort A and three (17%) patients in cohort B had an investigator-assessed intracranial complete response. For patients in cohort A, 36-month intracranial progression-free survival was 54·1% (95% CI 42·7-64·1) and overall survival was 71·9% (61·8-79·8). For patients in cohort B, 36-month intracranial progression-free survival was 18·9% (95% CI 4·6-40·5) and overall survival was 36·6% (14·0-59·8). The most common grade 3-4 treatment-related adverse events (TRAEs) were increased alanine aminotransferase and aspartate aminotransferase (15 [15%] of 101 patients each) in cohort A; no grade 3 TRAEs occurred in more than one patient each in cohort B, and no grade 4 events occurred. The most common serious TRAEs were colitis, diarrhoea, hypophysitis, and increased alanine aminotransferase (five [5%] of each among the 101 patients in cohort A); no serious TRAE occurred in more than one patient each in cohort B. There was one treatment-related death (myocarditis in cohort A).

INTERPRETATION

The durable 3-year response, overall survival, and progression-free survival rates for asymptomatic patients support first-line use of nivolumab plus ipilimumab. Symptomatic disease in patients with MBM remains difficult to treat, but some patients achieve a long-term response with the combination.

FUNDING

Bristol Myers Squibb.

Evaluation of single domain antibodies as nuclear tracers for imaging of the immune checkpoint receptor human lymphocyte activation gene-3 in cancer

Recent advancements in the field of immune-oncology have led to a significant increase in life expectancy of patients with diverse forms of cancer, such as hematologic malignancies, melanoma and lung cancer. Unfortunately, these encouraging results are not observed in the majority of patients, who remain unresponsive and/or encounter adverse events. Currently, researchers are collecting more insight into the cellular and molecular mechanisms that underlie these variable responses. As an example, the human lymphocyte activation gene-3 (huLAG-3), an inhibitory immune checkpoint receptor, is increasingly studied as a therapeutic target in immune-oncology. Noninvasive molecular imaging of the immune checkpoint programmed death protein-1 (PD-1) or its ligand PD-L1 has shown its value as a strategy to guide and monitor PD-1/PD-L1-targeted immune checkpoint therapy. Yet, radiotracers that allow dynamic, whole body imaging of huLAG-3 expression are not yet described. We here developed single-domain antibodies (sdAbs) that bind huLAG-3 and showed that these sdAbs can image huLAG-3 in tumors, therefore representing promising tools for further development into clinically applicable radiotracers.

CD8+ T Lymphocytes Immune Depletion and LAG-3 Overexpression in Hodgkin Lymphoma Tumor Microenvironment Exposed to Anti-PD-1 Immunotherapy

Background: Resistance to anti-PD-1 remains a considerable clinical challenge for the treatment of patients with classical Hodgkin lymphoma (cHL), and mechanisms of anti-PD-1 resistance remain unknown. This pilot study aims to investigate the tumor microenvironment in patients with cHL relapsing after anti-PD-1. Methods: This study investigated tumor samples of eight patients with cHL, including four patients exposed to anti-PD-1 with a paired longitudinal histological analysis before and after anti-PD-1, and four patients not exposed to anti-PD-1 who served as control for the cellular biological investigations. Fresh cells tumor microenvironment analysis included phenotypic characterization of their T cell surfaces immune checkpoint markers PD-1, PD-L1, ICOS, TIM-3, LAG-3, 41-BB and BTLA. Tumor tissues immunohistochemistry staining included CD30, CD4, CD8, CD68, CD163, PD-L1, PD-1, LAG-3 and TIM-3. Findings: Paired longitudinal tumor tissues analysis in the tumor microenvironment found a CD8+ lymphocytes tumor depletion and an increase of LAG-3 staining after anti-PD-1 exposure. The fresh cells analysis of the tumor microenvironment in patients exposed to anti-PD-1 found CD8+ lymphocyte depletion, with an elevated CD4+/CD8+ lymphocytes ratio (median ratio 9.77 in exposed anti-PD-1 versus 2.39 in not-exposed anti-PD-1 patients; p = 0.0943). On the cell surfaces of CD4+ lymphocytes, the median positive expression of LAG-3 was significantly higher in the samples exposed to anti-PD-1 compared to the controls (15.05 [IQR:17.91-10.65] versus 3.84 [IQR 1.87-6.57]; p = 0.0376). Interpretation: This pilot study proposes hypotheses for understanding the resistance to immunotherapies in patients with Hodgkin lymphoma. Hodgkin lymphoma exposed to anti-PD-1 correlated in tumor microenvironment with an immune depletion of CD8+ T lymphocytes and overexpression of LAG-3 on CD4+ helper T lymphocytes.

Investigational immunomodulatory drugs for enhancement of triple negative breast cancer (TNBC) immunotherapy: early phase development

INTRODUCTION

Immunotherapy through the blockade of PD1-PDL1 axis has shown to improve outcomes in advanced and early triple negative breast cancer (TNBC). To further enhance immune-stimulation, and ultimately improve patient outcomes, a wide variety of next-generation immunotherapies (NGIO) is being developed for this disease.

AREAS COVERED

In the present article, we discuss the immune landscape of TNBC and recapitulate the rationale and available clinical evidence of NGIO under early phase development for TNBC, highlighting challenges and opportunities in this emerging field of research.

EXPERT OPINION

Multiple immunotherapeutic strategies beyond PD-(L)1 blockade have been tested for TNBC, including the targeting of further inhibitory checkpoints, the agonism of costimulatory molecules, the intratumoral administration of immunotherapies and cancer vaccines. Most of these strategies have demonstrated to be safe in early clinical trials, with some exhibiting early signs of antitumor activity. To optimally harness the potential of NGIO, a refined patient selection based on emerging immune biomarkers will be required, through an adaptation of immunotherapeutic strategies based on patient and tumor characteristics. More mature data from ongoing clinical trials, added to the progressively increasing knowledge on breast cancer immune landscape, will hopefully clarify the role of NGIO for the treatment of TNBC.

Second-Line Treatment Options for Hepatocellular Carcinoma: Current Landscape and Future Direction

Hepatocellular carcinoma is a leading cause of mortality worldwide, and its incidence is rising. The last few years have witnessed a proliferation of available systemic therapeutic options, with the approval of multiple agents, including immune checkpoint inhibitors and drugs targeting vascular endothelial growth factor, such as cabozantinib, regorafenib, and ramucirumab. Most recently, the combination of atezolizumab plus bevacizumab has resulted in the longest overall survival yet known in hepatocellular carcinoma, therefore changing the preferred first-line treatment from the previous options of sorafenib and lenvatinib. The aim of this review is to summarize the available clinical data for the current second-line systemic treatment options and the future perspectives in the treatment landscape of hepatocellular carcinoma.

Immune checkpoint inhibitors and cardiotoxicity: possible mechanisms, manifestations, diagnosis and management

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are a new class of anticancer drugs that enhance the immune system function and activate T cells against cancerous cells. Although cardiac complications are not common, they could be accompanied with high morbidity and mortality.

AREAS COVERED

Regarding the importance of cardiac complications and their subsequent burden on individuals and the healthcare system, this review attempts to discuss the mechanism, diagnosis, and management of myocarditis, besides recapitulating the possible mechanism of other cardiac adverse events. Moreover, we briefly discuss the concurrent administration of other chemotherapeutic agents.

EXPERT OPINION

Due to insufficient knowledge concerning the physiopathology of immune-related adverse events (irAEs) and their potential further complications, cardiovascular complications in particular and in the context of this paper's focus, cooperation of oncologists, immunologists, and cardiologists is necessary for the management of patients. Experimental approaches such as using corticosteroids are becoming a part of guidelines for managing cardiac irAEs. However, a unique algorithm for diagnosis and management is necessary, especially in myocarditis cases. Furthermore, more studies are required to resolve current challenges, including prevention of myocarditis, concurrent administration of other chemotherapeutic agents, and re-introducing patients with ICIs.

Toward personalized treatment approaches for non-small-cell lung cancer

Worldwide, lung cancer is the most common cause of cancer-related deaths. Molecular targeted therapies and immunotherapies for non-small-cell lung cancer (NSCLC) have improved outcomes markedly over the past two decades. However, the vast majority of advanced NSCLCs become resistant to current treatments and eventually progress. In this Perspective, we discuss some of the recent breakthrough therapies developed for NSCLC, focusing on immunotherapies and targeted therapies. We highlight our current understanding of mechanisms of resistance and the importance of incorporating genomic analyses into clinical studies to decipher these further. We underscore the future role of neoadjuvant and maintenance combination therapy approaches to potentially cure early disease. A major challenge to successful development of rational combination therapies will be the application of robust predictive biomarkers for clear-cut patient stratification, and we provide our views on clinical research areas that could influence how NSCLC will be managed over the coming decade.

Development of a Metastatic Uveal Melanoma Prognostic Score (MUMPS) for Use in Patients Receiving Immune Checkpoint Inhibitors

Simple Summary

This is a retrospective cohort study of metastatic uveal melanoma patients. This study undertook to identify clinical characteristics that were predictive and prognostics of benefit to immune checkpoint inhibitors in patients with metastatic uveal melanoma. We developed a Metastatic Uveal Melanoma Prognostic risk Score based on retrospective data that is comprised of 3 readily available clinical variables (time to metastatic diagnosis, presence of bone metastases, and LDH). Our findings demonstrated that the Metastatic Uveal Melanoma Prognostic risk Score was associated with a statistically significant association with overall survival outcomes in patients with metastatic uveal melanoma treated with ICI. There was a significant predictive association with disease control to ICI for patients with a ‘good risk’ Metastatic Uveal Melanoma Prognostic risk score. This is one of the larger analysis of clinical outcomes in metastatic uveal melanoma patients to date and could inform clinical decision-making.

Abstract

Metastatic uveal melanoma (mUM) is a rare disease. There are limited data on prognostic clinical factors for overall survival (OS) in patients with mUM treated with immune checkpoint inhibitors (ICI). Retrospective and non-randomized prospective studies have reported response rates of 0–17% for anti-PD1/L1 ± anti-CTLA4 ICI in mUM, indicating a potential benefit only in a subset of patients. This study evaluates the characteristics associated with ICI benefit in patients with mUM. We performed a single-center retrospective cohort study of patients with mUM who received anti-PD1/L1 ± anti-CTLA4 ICI between 2014–2019. Clinical and genomic characteristics were collected from a chart review. Treatment response and clinical progression were determined by physician assessment. Multivariable Cox regression models and Kaplan–Meier log-rank tests were used to assess differences in clinical progression-free survival (cPFS) and OS between groups and identify clinical variables associated with ICI outcomes. We identified 71 mUM patients who received 75 lines of ICI therapy. Of these, 54 received anti-PD1/L1 alone, and 21 received anti-PD1/L1 + anti-CTLA4. Patient characteristics were: 53% female, 48% were 65 or older, 72% received one or fewer lines of prior therapy. Within our cohort, 53% of patients had developed metastatic disease <2 years after their initial diagnosis. Bone metastases were present in 12% of patients. The median cPFS was 2.7 months, and the median OS was 10.0 months. In multivariable analyses for both cPFS and OS, the following variables were associated with a good prognosis: ≥2 years from the initial diagnosis to metastatic disease (n = 25), LDH < 1.5 × ULN (n = 45), and absence of bone metastases (n = 66). We developed a Metastatic Uveal Melanoma Prognostic Score (MUMPS). Patients were divided into 3 MUMPS groups based on the number of the above-mentioned prognostic variables: Poor prognosis (0–1), Intermediate prognosis (2) and Good prognosis (3). Good prognosis patients experienced longer cPFS (6.0 months) and OS (34.5 months) than patients with intermediate (2.3 months cPFS, 9.4 months OS) and poor prognosis disease (1.8 months cPFS, 3.9 months OS); p < 0.0001. We developed MUMPS—a prognostic score based on retrospective data that is comprised of 3 readily available clinical variables (time to metastatic diagnosis, presence of bone metastases, and LDH). This MUMPS score has a potential prognostic value. Further validation in independent datasets is warranted to determine the role of this MUMPS score in selecting ICI treatment management for mUM.

GSK-3β in Pancreatic Cancer: Spotlight on 9-ING-41, Its Therapeutic Potential and Immune Modulatory Properties

Simple Summary

Glycogen synthase kinase-3 beta is a protein kinase implicated in the promotion and development of various cancers, including pancreatic cancer. In cell culture and animal studies, drugs targeting the inhibition of this protein show treatment potential in pancreatic cancer. Studies show targeting this protein for treatment may overcome resistance to conventional chemotherapy in pancreatic tumors. Early-stage clinical trials are currently studying small molecule inhibitors targeting glycogen synthase kinase-3 beta and interim results show favorable results. Recent studies also suggest that targeting this protein will create synergy with immunotherapy, such as checkpoint inhibitors. Future studies should aim to study new combination treatments involving glycogen synthase kinase-3 beta targeting drugs with chemotherapy and immunotherapy in pancreatic cancer.

Abstract

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.

Gene of the month: lymphocyte-activation gene 3 (LAG-3)

Lymphocyte-activation gene 3 (LAG-3) is a coreceptor found on activated T-lymphocytes activated B-lymphocytes and natural killer (NK) cells. It is closely related to CD4 where it shares multiple common and divergent features. It contains specific binding sites with high affinity to major histocompatibility complex (MHC) Class II and functions as an inhibitor of T-cell signalling. Tumour-infiltrating lymphocytes with high LAG-3 expression have been found in many solid tumours including ovarian cancer, melanoma, colorectal cancer and haematological malignancies including Hodgkin and diffuse large B-cell lymphoma. LAG-3 antagonism has been demonstrated to restore the anti-tumourigenic function of T-cells in vivo, however, mechanistic knowledge remains relatively poorly defined. As other immune checkpoint inhibitors have transformed the management of difficult to treat cancers, such as melanoma, it is hoped that LAG-3 might have the same potential. This review will explore LAG-3 modulation as an anticancer therapy, highlighting recent clinical developments.