Mepolizumab in Severe Eosinophilic Asthma: A 2-Year Follow-Up in Specialized Asthma Clinics in Greece: An Interim Analysis

INTRODUCTION

Mepolizumab is a monoclonal antibody against IL-5 for the treatment of severe eosinophilic asthma. The aim of the current study was to present a predesigned interim analysis of the data of patients who have completed 1 year of therapy with mepolizumab.

METHODS

This study is a prospective multicenter, noninterventional 2-year observational study and aims to describe the clinical benefit and safety profile of mepolizumab in patients with severe eosinophilic asthma.

RESULTS

Compared to the year preceding the initiation of treatment, the annual rate of exacerbations decreased significantly, from 4.3 ± 2.3 to 1.3 ± 1.8; p < 0.0001. Forty-two patients received maintenance dose of oral corticosteroids (OCS) at baseline. From these patients at the end of 1 year of therapy with mepolizumab, 17 patients (40%) had achieved OCS discontinuation. A reduction in the median dose of OCS was also achieved. After 1 year of treatment with mepolizumab, the asthma control test score significantly increased from 16.3 ± 3.7 to 21.2 ± 3.8 (p < 0.0001). This marked clinical improvement was paralleled by a significant reduction of blood eosinophil count. All patients showed a considerable improvement of airflow limitation. In respect to adverse events of treatment with mepolizumab, 19 patients (27%) were recorded to have at least one such occurrence during their 1-year treatment.

CONCLUSIONS

We have shown that in patients with severe eosinophilic asthma, 1 year of treatment with mepolizumab was safe, resulted in significant reduction of the annual exacerbation rate, reduction (or even discontinuation) of the needed dose of OCS, and improvements of asthma control and lung function.

Cigarette Smoke-Induced Emphysema Exhausts Early Cytotoxic CD8+ T Cell Responses against Nascent Lung Cancer Cells

Chronic obstructive pulmonary disease is a chronic inflammatory disorder with an increased incidence of lung cancer. The emphysema component of chronic obstructive pulmonary disease confers the greatest proportion to lung cancer risk. Although tumors create inflammatory conditions to escape immunity, the immunological responses that control growth of nascent cancer cells in pre-established inflammatory microenvironments are unknown. In this study, we addressed this issue by implanting OVA-expressing cancer cells in the lungs of mice with cigarette smoke-induced emphysema. Emphysema augmented the growth of cancer cells, an effect that was dependent on T cytotoxic cells. OVA-specific OTI T cells showed early signs of exhaustion upon transfer in emphysema tumor hosts that was largely irreversible because sorting, expansion, and adoptive transfer failed to restore their antitumor activity. Increased numbers of PD-L1- and IDO-positive CD11c⁺ myeloid dendritic cells (DCs) infiltrated emphysema tumors, whereas sorted emphysema tumor DCs poorly stimulated OTI T cells. Upon adoptive transfer in immunocompetent hosts, T cells primed by emphysema tumor DCs were unable to halt tumor growth. DCs exposed to the emphysema tumor microenvironment downregulated MHC class II and costimulatory molecules, whereas they upregulated PD-L1/IDO via oxidative stress-dependent mechanisms. T cell activation increased upon PD-L1 blockade in emphysema DC-T cell cocultures and in emphysema tumor hosts in vivo. Analysis of the transcriptome of primary human lung tumors showed a strong association between computed tomography-based emphysema scoring and downregulation of immunogenic processes. Thus, suppression of adaptive immunity against lung cancer cells links a chronic inflammatory disorder, emphysema, to cancer, with clinical implications for emphysema patients to be considered optimal candidates for cancer immunotherapies.

Angiopoietin-1 inhibits endothelial permeability, neutrophil adherence and IL-8 production

1 Angiopoietin-1 (Ang1) is an angiogenic growth factor that binds to the Tie2 receptor on vascular endothelium, promoting blood vessel maturation and integrity. In the present study, we have investigated whether Ang1 also possesses anti-inflammatory properties by determining its effects on endothelial barrier function, neutrophil (PMN) adherence to endothelial cells (EC) and production of the PMN chemotactic factor interleukin-8 (IL-8). 2 Pretreatment of endothelial monolayers with Ang1 attenuated the permeability increase induced by thrombin in both lung microvascular cells and a human endothelial cell line. Similarly, Ang1 prevented the permeability-inducing effects of platelet-activating factor, bradykinin and histamine. 3 Pretreatment of EC with Ang1 also reduced the adherence of PMN to EC stimulated by thrombin. In contrast to its ability to counteract the increase in monolayer permeability brought about by various inflammatory agents, Ang1 did not affect the ability of histamine, PAF, or tumor necrosis factor-alpha to stimulate PMN adherence to EC. 4 In addition to its ability to inhibit PMN adherence, Ang1 diminished IL-8 production from EC challenged with thrombin in a concentration-dependent manner. 5 When EC were preincubated with the specific Rho kinase (ROCK) inhibitor Y-27632, we observed a reduction in PMN adherence in response to thrombin, as well as a decrease in thrombin-stimulated IL-8 production. Coincubation of monolayers with Y-27632 and Ang1 did not further attenuate the above-mentioned responses. However, Ang-1 failed to inhibit the activation of RhoA in response to thrombin, suggesting that inhibition of EC adhesiveness for PMN and IL-8 production by Ang1 does not result from reduced ROCK activation. 6 We conclude that Ang1 can counteract several aspects of the inflammatory response, including endothelial permeability, PMN adherence to EC as well as inhibition of IL-8 production by EC.