Imatinib in patients with severe COVID-19: a randomised, double-blind, placebo-controlled, clinical trial.

BACKGROUND: The major complication of COVID-19 is hypoxaemic respiratory failure from capillary leak and alveolar oedema. Experimental and early clinical data suggest that the tyrosine-kinase inhibitor imatinib reverses pulmonary capillary leak. METHODS: This randomised, double-blind, placebo-controlled, clinical trial was done at 13 academic and non-academic teaching hospitals in the Netherlands. Hospitalised patients (aged ≥18 years) with COVID-19, as confirmed by an RT-PCR test for SARS-CoV-2, requiring supplemental oxygen to maintain a peripheral oxygen saturation of greater than 94% were eligible. Patients were excluded if they had severe pre-existing pulmonary disease, had pre-existing heart failure, had undergone active treatment of a haematological or non-haematological malignancy in the previous 12 months, had cytopenia, or were receiving concomitant treatment with medication known to strongly interact with imatinib. Patients were randomly assigned (1:1) to receive either oral imatinib, given as a loading dose of 800 mg on day 0 followed by 400 mg daily on days 1-9, or placebo. Randomisation was done with a computer-based clinical data management platform with variable block sizes (containing two, four, or six patients), stratified by study site. The primary outcome was time to discontinuation of mechanical ventilation and supplemental oxygen for more than 48 consecutive hours, while being alive during a 28-day period. Secondary outcomes included safety, mortality at 28 days, and the need for invasive mechanical ventilation. All efficacy and safety analyses were done in all randomised patients who had received at least one dose of study medication (modified intention-to-treat population). This study is registered with the EU Clinical Trials Register (EudraCT 2020-001236-10). FINDINGS: Between March 31, 2020, and Jan 4, 2021, 805 patients were screened, of whom 400 were eligible and randomly assigned to the imatinib group (n=204) or the placebo group (n=196). A total of 385 (96%) patients (median age 64 years [IQR 56-73]) received at least one dose of study medication and were included in the modified intention-to-treat population. Time to discontinuation of ventilation and supplemental oxygen for more than 48 h was not significantly different between the two groups (unadjusted hazard ratio [HR] 0·95 [95% CI 0·76-1·20]). At day 28, 15 (8%) of 197 patients had died in the imatinib group compared with 27 (14%) of 188 patients in the placebo group (unadjusted HR 0·51 [0·27-0·95]). After adjusting for baseline imbalances between the two groups (sex, obesity, diabetes, and cardiovascular disease) the HR for mortality was 0·52 (95% CI 0·26-1·05). The HR for mechanical ventilation in the imatinib group compared with the placebo group was 1·07 (0·63-1·80; p=0·81). The median duration of invasive mechanical ventilation was 7 days (IQR 3-13) in the imatinib group compared with 12 days (6-20) in the placebo group (p=0·0080). 91 (46%) of 197 patients in the imatinib group and 82 (44%) of 188 patients in the placebo group had at least one grade 3 or higher adverse event. The safety evaluation revealed no imatinib-associated adverse events. INTERPRETATION: The study failed to meet its primary outcome, as imatinib did not reduce the time to discontinuation of ventilation and supplemental oxygen for more than 48 consecutive hours in patients with COVID-19 requiring supplemental oxygen. The observed effects on survival (although attenuated after adjustment for baseline imbalances) and duration of mechanical ventilation suggest that imatinib might confer clinical benefit in hospitalised patients with COVID-19, but further studies are required to validate these findings. FUNDING: Amsterdam Medical Center Foundation, Nederlandse Organisatie voor Wetenschappelijk Onderzoek/ZonMW, and the European Union Innovative Medicines Initiative 2.

Oestrogen-mediated upregulation of the Mas receptor contributes to sex differences in acute lung injury and lung vascular barrier regulation.

Epidemiological data from the SARS-CoV-2 outbreak suggest sex differences in mortality and vulnerability; however, sex-dependent incidence of acute respiratory distress syndrome (ARDS) remains controversial and the sex-dependent mechanisms of endothelial barrier regulation are unknown. In premenopausal women, increased signalling of angiotensin (Ang)(1-7) via the Mas receptor has been linked to lower cardiovascular risk. Since stimulation of the Ang(1-7)/Mas axis protects the endothelial barrier in acute lung injury (ALI), we hypothesised that increased Ang(1-7)/Mas signalling may protect females over males in ALI/ARDS.Clinical data were collected from Charité inpatients (Berlin) and sex differences in ALI were assessed in wild-type (WT) and Mas-receptor deficient (Mas-/- ) mice. Endothelial permeability was assessed as weight change in isolated lungs and as transendothelial electrical resistance (TEER) in vitroIn 734 090 Charité inpatients (2005-2016), ARDS had a higher incidence in men as compared to women. In murine ALI, male WT mice had more lung oedema, protein leaks and histological evidence of injury than female WT mice. Lung weight change in response to platelet-activating factor (PAF) was more pronounced in male WT and female Mas-/- mice than in female WT mice, whereas Mas-receptor expression was higher in female WT lungs. Ovariectomy attenuated protection in female WT mice and reduced Mas-receptor expression. Oestrogen increased Mas-receptor expression and attenuated endothelial leakage in response to thrombin in vitro This effect was alleviated by Mas-receptor blockade.Improved lung endothelial barrier function protects female mice from ALI-induced lung oedema. This effect is partially mediated via enhanced Ang(1-7)/Mas signalling as a result of oestrogen-dependent Mas expression.

Tocilizumab improves oxidative stress and endothelial glycocalyx: A mechanism that may explain the effects of biological treatment on COVID-19.

We investigated the effects of tocilizumab on endothelial glycocalyx, a determinant of vascular permeability, and myocardial function in rheumatoid arthritis (RA). Eighty RA patients were randomized to tocilizumab (n = 40) or conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and glucocorticoids (GC) (n = 40) for 3 months. Forty healthy subjects with similar age and sex served as controls. We measured: (a)perfused boundary region (PBR) of the sublingual arterial microvessels (increased PBR indicates reduced glycocalyx thickness), (b)pulse wave velocity (PWV), (c)global LV longitudinal strain (GLS), (d)global work index (GWI) using speckle tracking echocardiography and e)C-reactive protein (CRP), malondialdehyde (MDA) and protein carbonyls (PCs) as oxidative stress markers at baseline and post-treatment. Compared to controls, RA patients had impaired glycocalyx and myocardial deformation markers (P < 0.05). Compared with baseline, tocilizumab reduced PBR(2.14 ± 0.2 versus 1.97 ± 0.2 µm; P < 0.05) while no significant differences were observed post-csDMARDs + GC(P > 0.05). Compared with csDMARDs + GC, tocilizumab achieved a greater increase of GLS, GWI and reduction of MDA, PCs and CRP(P < 0.05). The percent improvement of glycocalyx thickness (PBR) was associated with the percent decrease of PWV, MDA, PCs and the percent improvement of GLS and GWI(P < 0.05). Tocilizumab improves endothelial function leading to a greater increase of effective myocardial work than csDMARDs + GC through a profound reduction of inflammatory burden and oxidative stress. This mechanism may explain the effects of tocilizumab on COVID-19. CLINICAL TRIAL REGISTRATION: url: https://www.clinicaltrials.gov. Unique identifier: NCT03288584.

The SARS-CoV-2 spike protein alters barrier function in 2D static and 3D microfluidic in-vitro models of the human blood-brain barrier.

As researchers across the globe have focused their attention on understanding SARS-CoV-2, the picture that is emerging is that of a virus that has serious effects on the vasculature in multiple organ systems including the cerebral vasculature. Observed effects on the central nervous system include neurological symptoms (headache, nausea, dizziness), fatal microclot formation and in rare cases encephalitis. However, our understanding of how the virus causes these mild to severe neurological symptoms and how the cerebral vasculature is impacted remains unclear. Thus, the results presented in this report explored whether deleterious outcomes from the SARS-CoV-2 viral spike protein on primary human brain microvascular endothelial cells (hBMVECs) could be observed. The spike protein, which plays a key role in receptor recognition, is formed by the S1 subunit containing a receptor binding domain (RBD) and the S2 subunit. First, using postmortem brain tissue, we show that the angiotensin converting enzyme 2 or ACE2 (a known binding target for the SARS-CoV-2 spike protein), is ubiquitously expressed throughout various vessel calibers in the frontal cortex. Moreover, ACE2 expression was upregulated in cases of hypertension and dementia. ACE2 was also detectable in primary hBMVECs maintained under cell culture conditions. Analysis of cell viability revealed that neither the S1, S2 or a truncated form of the S1 containing only the RBD had minimal effects on hBMVEC viability within a 48 h exposure window. Introduction of spike proteins to invitro models of the blood-brain barrier (BBB) showed significant changes to barrier properties. Key to our findings is the demonstration that S1 promotes loss of barrier integrity in an advanced 3D microfluidic model of the human BBB, a platform that more closely resembles the physiological conditions at this CNS interface. Evidence provided suggests that the SARS-CoV-2 spike proteins trigger a pro-inflammatory response on brain endothelial cells that may contribute to an altered state of BBB function. Together, these results are the first to show the direct impact that the SARS-CoV-2 spike protein could have on brain endothelial cells; thereby offering a plausible explanation for the neurological consequences seen in COVID-19 patients.