Tocilizumab Improves the Prognosis of COVID-19 in Patients with High IL-6

Tocilizumab for the treatment of COVID-19

INTRODUCTION

Since the beginning of the COVID-19 pandemic, the repurposing of medicines has been pursued to find interventions effective in preventing fatal outcome of the disease. One of these drugs was tocilizumab, an interleukin-6 inhibiting monoclonal antibody, previously used to treat several immune-related disorders.

AREAS COVERED

In this article, we present the results of the initial observational studies and subsequent randomized clinical trials on the efficacy and safety of tocilizumab in the treatment of COVID-19. Despite conflicting results, possibly due to the heterogeneity of the studied populations, large studies have ultimately proven that preventing IL-6 from attaching to its receptors can effectively reverse the fatal course of the disease. We also discuss the meta-analyses, which mostly supported the validity of tocilizumab therapy. We show how tocilizumab found its place in the most important recommendations on COVID-19 treatment and obtained authorization from the major regulatory authorities.

EXPERT OPINION

The criteria for optimizing tocilizumab therapy in COVID-19 still need to be established. They are also important considering the existing risks of future zoonotic spillovers and epidemics that may trigger hyperinflammation that could be efficiently blocked. The experience gained with tocilizumab shall be perceived as preparedness for future challenges.

The Effect of Reduced Oxygen Saturation on Retinal Microvascularization in COVID-19 Patients with Bilateral Pneumonia Based on Optical Coherence Tomography Study

The aim of the study was to evaluate changes in the retinal thickness and microvasculature based on optical coherence tomography (OCT) depending on baseline oxygen saturation (SpO2) in patients hospitalized due to COVID-19 bilateral pneumonia. The prospective study was carried out among 62 patients with COVID-19 pneumonia who underwent ophthalmic examination after hospital discharge. They were divided into three groups depending on the oxygen saturation (SpO2) on admission: ≤90% (group 1), >90% and ≤95% (group 2), and >95% (group 3). The following parameters were assessed in the ophthalmological examination and correlated with the baseline SpO2: ganglion cell layer (GCL), the retinal nerve fiber layer (RNFL) in the macular area, RNFL in the peripapillary area, the foveal avascular zone (FAZ) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), vessel density (VD) in SCP, in DCP, and in the choriocapillaris plexus (CC). Baseline saturation ≤90% in COVID-19 patients caused a decrease of VD in some areas of SCP and DCP and an increase in FAZ area in SCP and DCP. In the group of patients with SpO2 ≤ 90% statistically significant thinning of the retina in the inner superior ring (ISR) (p = 0.029), the inner temporal ring (ITR) (p = 0.34), the outer superior ring (OSR) (p = 0.012), and the outer temporal ring (OTR) (p= 0.004)] was observed. The statistically significant thickening of RNFL optic disc and thinning of RNFL retina in some macular areas in patients with SpO2 ≤ 90% were reported. The size of FAZ area in SCP and vessel density were significantly greater in some areas of SCP, DCP, and CC in patients with SpO2 ≤ 90% (p = 0.025). Baseline oxygen saturation ≤90% has been found to influence the ocular parameters of OCT in COVID-19 patients. We noticed a widened FAZ zone in SCP and increased VD in some regions of the retina and choroid as a response to systemic hypoxia.

The association of airborne particulate matter and benzo[a]pyrene with the clinical course of COVID-19 in patients hospitalized in Poland

Air pollution can adversely affect the immune response and increase the severity of the viral disease. The present study aimed to explore the relationship between symptomatology, clinical course, and inflammation markers of adult patients with coronavirus disease 2019 (COVID-19) hospitalized in Poland (n = 4432) and air pollution levels, i.e., mean 24 h and max 24 h level of benzo(a)pyrene (B(a)P) and particulate matter <10 μm (PM₁₀) and <2.5 μm (PM_2.5) during a week before their hospitalization. Exposures to PM_2.5 and B(a)P exceeding the limits were associated with higher odds of early respiratory symptoms of COVID-19 and hyperinflammatory state: interleukin-6 > 100 pg/mL, procalcitonin >0.25 ng/mL, and white blood cells count >11 × 10³/mL. Except for the mean 24 h PM₁₀ level, the exceedance of other air pollution parameters was associated with increased odds for oxygen saturation <90%. Exposure to elevated PM_2.5 and B(a)P levels increased the odds of oxygen therapy and death. This study evidences that worse air quality is related to increased severity of COVID-19 and worse outcome in hospitalized patients. Mitigating air pollution shall be an integral part of measures undertaken to decrease the disease burden during a pandemic of viral respiratory illness.

Lack of Difference in Tocilizumab Efficacy in the Treatment of Severe COVID-19 Caused by Different SARS-CoV-2 Variants

Tocilizumab (TOC) is presumed to be an effective and safe treatment for severe COVID-19, but its usefulness has not been yet investigated for different SARS-CoV-2 variants. This study aimed to evaluate the influence of TOC on mortality in patients with severe COVID-19 caused by Delta and non-Delta SARS-CoV-2 variants. In a retrospective analysis, we compared the medical records of 78 and 224 patients with severe COVID-19 due to Delta and non-Delta variants, respectively. A total of 30 patients with Delta and 84 with non-Delta variants were treated with TOC in addition to standard therapy. There were no statistically significant differences in mortality rate when comparing Delta vs. non-Delta patients nor when comparing those treated with TOC vs. not treated with TOC in both variants. Using a logistic regression model, in the examined population as a whole, we found an increased (p < 0.05) risk of death as leukocyte and erythrocyte counts decreased and as procalcitonin increased. Increased procalcitonin was significant for mortality in the Delta group, while decreased IL-6, leukocytes, and platelets and increased fibrinogen and procalcitonin were significant in the non-Delta group. Tocilizumab efficacy in severe COVID-19 does not differ between Delta or non-Delta virus variants. The Delta variant of SARS-CoV-2 does not increase mortality when compared to other virus strains.

Tocilizumab effectiveness in mechanically ventilated COVID-19 patients (T-MVC-19 Study): a multicenter real-world evidence

BACKGROUND

This study aimed to evaluate the effectiveness of tocilizumab in mechanically ventilated patients with coronavirus disease 2019 (COVID-19).

RESEARCH DESIGN AND METHODS

This retrospective multicenter study included adults (≥18 years) diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time polymerase chain reaction (RT-PCR) from nasopharyngeal swab, and requiring invasive mechanical ventilation during admission. Survival analyses with inverse propensity score treatment weighting (IPTW) and propensity score matching (PSM) were conducted. To account for immortal bias, we used Cox proportional modeling with time-dependent covariance. Competing risk analysis was performed for the extubation endpoint.

RESULTS

A total of 556 (tocilizumab = 193, control = 363) patients were included. Males constituted the majority of the participants (69.2% in tocilizumab arm,74.1% in control arm). Tocilizumab was not associated with a reduction in mortality with hazard ratio [(HR) = 0.82,95% confidence interval (95%CI): 0.62-1.10] in the Inverse propensity score weighting (IPTW) analysis and (HR = 0.86,95% CI: 0.64-1.16) in the PSM analysis. However, tocilizumab was associated with an increased rate of extubation (33.6%) compared to the control arm (11.9%); subdistributional hazards (SHR) = 3.1, 95% CI: 1.86-5.16).

CONCLUSIONS

Although tocilizumab was not found to be effective in reducing mortality, extubation rate while on mechanical ventilation was higher among tocilizumab treated group.

Passive Immunotherapy Against SARS-CoV-2: From Plasma-Based Therapy to Single Potent Antibodies in the Race to Stay Ahead of the Variants

The COVID-19 pandemic is now approaching 2 years old, with more than 440 million people infected and nearly six million dead worldwide, making it the most significant pandemic since the 1918 influenza pandemic. The severity and significance of SARS-CoV-2 was recognized immediately upon discovery, leading to innumerable companies and institutes designing and generating vaccines and therapeutic antibodies literally as soon as recombinant SARS-CoV-2 spike protein sequence was available. Within months of the pandemic start, several antibodies had been generated, tested, and moved into clinical trials, including Eli Lilly's bamlanivimab and etesevimab, Regeneron's mixture of imdevimab and casirivimab, Vir's sotrovimab, Celltrion's regdanvimab, and Lilly's bebtelovimab. These antibodies all have now received at least Emergency Use Authorizations (EUAs) and some have received full approval in select countries. To date, more than three dozen antibodies or antibody combinations have been forwarded into clinical trials. These antibodies to SARS-CoV-2 all target the receptor-binding domain (RBD), with some blocking the ability of the RBD to bind human ACE2, while others bind core regions of the RBD to modulate spike stability or ability to fuse to host cell membranes. While these antibodies were being discovered and developed, new variants of SARS-CoV-2 have cropped up in real time, altering the antibody landscape on a moving basis. Over the past year, the search has widened to find antibodies capable of neutralizing the wide array of variants that have arisen, including Alpha, Beta, Gamma, Delta, and Omicron. The recent rise and dominance of the Omicron family of variants, including the rather disparate BA.1 and BA.2 variants, demonstrate the need to continue to find new approaches to neutralize the rapidly evolving SARS-CoV-2 virus. This review highlights both convalescent plasma- and polyclonal antibody-based approaches as well as the top approximately 50 antibodies to SARS-CoV-2, their epitopes, their ability to bind to SARS-CoV-2 variants, and how they are delivered. New approaches to antibody constructs, including single domain antibodies, bispecific antibodies, IgA- and IgM-based antibodies, and modified ACE2-Fc fusion proteins, are also described. Finally, antibodies being developed for palliative care of COVID-19 disease, including the ramifications of cytokine release syndrome (CRS) and acute respiratory distress syndrome (ARDS), are described.

Effectiveness of Tocilizumab in Patients with Severe or Critical Lung Involvement in COVID-19: A Retrospective Study

Introduction: Acute lung injury is associated with dysfunctional immune response to SARS-CoV-2. This leads to CRS, which require immunomodulatory treatments aiming to limit the excessive production of cytokines. The literature so far indicates the effectiveness of tocilizumab in patients with COVID-19-associated pneumonia, but there is no clear evidence of its effectiveness in patients with at least 50% lung involvement; therefore, we aimed to bridge this gap in knowledge. Materials and methods: Longitudinal data for 4287 patients with confirmed COVID-19 infection were collected between 1st March 2020 and 16th of January 2022. In total, 182 cases with lung involvement >50% and biochemical indicators of cytokine release storm (Il-6 >100 pg/mL) were selected and analyzed using non-parametric statistics and multivariate Cox models. Results: Among the 182 included patients, 100 (55%) were treated with TCZ, while 82 (45%) did not receive TCZ. The groups were balanced regarding demographics, lung involvement and biochemical markers. Overall mortality in the group was 63.1%. Mortality in the TCZ group was 58.0% compared to 69.5% (n = 57) in the non-TCZ group (p = 0.023). In multivariate Cox proportional hazards models, intravenous administration of tocilizumab was associated with lower probability of ICU admission (HR: 0333 (CI: 0.159−0.700, p = 0.004)) and lower mortality (HR: 0.57306 (CI: 0.354−0.927, p = 0.023)). Conclusions: Tocilizumab is effective as a treatment in the most severely ill patients, in whom the level of lung involvement by the inflammatory process can exceed 50% with coexisting biochemical indices of cytokine storm (Il-6 > 100 pg/mL).

Differential Co-Expression Network Analysis Reveals Key Hub-High Traffic Genes as Potential Therapeutic Targets for COVID-19 Pandemic

Background

The recent emergence of COVID-19, rapid worldwide spread, and incomplete knowledge of molecular mechanisms underlying SARS-CoV-2 infection have limited development of therapeutic strategies. Our objective was to systematically investigate molecular regulatory mechanisms of COVID-19, using a combination of high throughput RNA-sequencing-based transcriptomics and systems biology approaches.

Methods

RNA-Seq data from peripheral blood mononuclear cells (PBMCs) of healthy persons, mild and severe 17 COVID-19 patients were analyzed to generate a gene expression matrix. Weighted gene co-expression network analysis (WGCNA) was used to identify co-expression modules in healthy samples as a reference set. For differential co-expression network analysis, module preservation and module-trait relationships approaches were used to identify key modules. Then, protein-protein interaction (PPI) networks, based on co-expressed hub genes, were constructed to identify hub genes/TFs with the highest information transfer (hub-high traffic genes) within candidate modules.

Results

Based on differential co-expression network analysis, connectivity patterns and network density, 72% (15 of 21) of modules identified in healthy samples were altered by SARS-CoV-2 infection. Therefore, SARS-CoV-2 caused systemic perturbations in host biological gene networks. In functional enrichment analysis, among 15 non-preserved modules and two significant highly-correlated modules (identified by MTRs), 9 modules were directly related to the host immune response and COVID-19 immunopathogenesis. Intriguingly, systemic investigation of SARS-CoV-2 infection identified signaling pathways and key genes/proteins associated with COVID-19's main hallmarks, e.g., cytokine storm, respiratory distress syndrome (ARDS), acute lung injury (ALI), lymphopenia, coagulation disorders, thrombosis, and pregnancy complications, as well as comorbidities associated with COVID-19, e.g., asthma, diabetic complications, cardiovascular diseases (CVDs), liver disorders and acute kidney injury (AKI). Topological analysis with betweenness centrality (BC) identified 290 hub-high traffic genes, central in both co-expression and PPI networks. We also identified several transcriptional regulatory factors, including NFKB1, HIF1A, AHR, and TP53, with important immunoregulatory roles in SARS-CoV-2 infection. Moreover, several hub-high traffic genes, including IL6, IL1B, IL10, TNF, SOCS1, SOCS3, ICAM1, PTEN, RHOA, GDI2, SUMO1, CASP1, IRAK3, HSPA5, ADRB2, PRF1, GZMB, OASL, CCL5, HSP90AA1, HSPD1, IFNG, MAPK1, RAB5A, and TNFRSF1A had the highest rates of information transfer in 9 candidate modules and central roles in COVID-19 immunopathogenesis.

Conclusion

This study provides comprehensive information on molecular mechanisms of SARS-CoV-2-host interactions and identifies several hub-high traffic genes as promising therapeutic targets for the COVID-19 pandemic.

Oral antiviral treatments for COVID-19: opportunities and challenges

The use of antiviral COVID-19 medications can successfully inhibit SARS-CoV-2 replication and prevent disease progression to a more severe form. However, the timing of antiviral treatment plays a crucial role in this regard. Oral antiviral drugs provide an opportunity to manage SARS-CoV-2 infection without a need for hospital admission, easing the general burden that COVID-19 can have on the healthcare system. This review paper (i) presents the potential pharmaceutical antiviral targets, including various host-based targets and viral-based targets, (ii) characterizes the first-generation anti-SARS-CoV-2 oral drugs (nirmatrelvir/ritonavir and molnupiravir), (iii) summarizes the clinical progress of other oral antivirals for use in COVID-19, (iv) discusses ethical issues in such clinical trials and (v) presents challenges associated with the use of oral antivirals in clinical practice. Oral COVID-19 antivirals represent a part of the strategy to adapt to long-term co-existence with SARS-CoV-2 in a manner that prevents healthcare from being overwhelmed. It is pivotal to ensure equal and fair global access to the currently available oral antivirals and those authorized in the future.

Demographic and Clinical Overview of Hospitalized COVID-19 Patients during the First 17 Months of the Pandemic in Poland

Long-term analyses of demographical and clinical characteristics of COVID-19 patients can provide a better overview of the clinical course of the disease. They can also help understand whether changes in infection symptomatology, disease severity, and outcome occur over time. We aimed to analyze the demographics, early symptoms of infection, laboratory parameters, and clinical manifestation of COVID-19 patients hospitalized during the first 17 months of the pandemic in Poland (March 2020-June 2021). The patients' demographical and clinical data (n = 5199) were extracted from the national SARSTer database encompassing 30 medical centers in Poland and statistically assessed. Patients aged 50-64 were most commonly hospitalized due to COVID-19 regardless of the pandemic period. There was no shift in the age of admitted patients and patients who died throughout the studied period. Men had higher C-reactive protein and interleukin-6 levels and required oxygenation and mechanical ventilation more often. No gender difference in fatality rate was seen, although the age of males who died was significantly lower. A share of patients with baseline SpO₂ < 91%, presenting respiratory, systemic and gastrointestinal symptoms was higher in the later phase of a pandemic than in the first three months. Cough, dyspnea and fever were more often presented in men, while women had a higher frequency of anosmia, diarrhea, nausea and vomiting. This study shows some shifts in SARS-CoV-2 pathogenicity between March 2020 and July 2021 in the Polish cohort of hospitalized patients and documents various gender-differences in this regard. The results represent a reference point for further analyses conducted under the dominance of different SARS-CoV-2 variants.

Prognostic parameters of in-hospital mortality in COVID-19 patients-An Italian experience

Background During COVID-19 outbreak, Italy was the first country in Europe to be heavily affected with an intensive care unit mortality of 26%. In order to reduce this percentage, physicians should establish clear and objective criteria to stratify COVID-19 patients at high risk of in-hospital death. Thus, the aim has been to test a large spectrum of variables ranging from clinical evaluation to laboratory biomarkers to identify which parameter would best predict all-cause in-hospital mortality in COVID-19 patients. Design observational study. Results Multivariate Cox regression analysis showed that each 5 years of increase in age corresponded to a hazard ratio (HR) of 1.28 (95% CI 1.00-1.65, P = .050); each increment of 803 ng/L of N-terminal pro-B-type natriuretic peptide (NT-proBNP) corresponded to a HR of 1.24 (95% CI 1.11-1.39, P < .001); each increment of 58 ng/L of interleukin (IL)-6 corresponded to a HR of 1.23 (95% CI 1.09-1.40, P < .001), and each increment of 250 U/L of lactate dehydrogenase (LDH) corresponded to a HR of 1.23 (95% CI 1.10-1.37, P < .001). According to the calculated cut-points for age (≥70 years), NT-proBNP (≥803 ng/L), IL-6 (≥58 ng/L) and LDH (≥371 U/L) when 2 out of these 4 were overcome, the HR was 2.96 (95% CI 1.97-4.45, P < .001). Conclusion In COVID-19 patients, besides age, the evaluation of three biochemical parameters, available in few hours after hospital admission can predict in-hospital mortality regardless of other comorbidities.

Alterations in platelets during SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) is a pandemic syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. SARS-CoV-2 infection induces a process of inflammation and thrombosis supported by an altered platelet activation state. This platelet activation is peculiar being characterized by the formation of platelet-leukocytes rather than platelet–platelet aggregates and by an increased procoagulant potential supported by elevated levels of TF positive platelets and microvesicles.

Therapeutic strategies targeting, beyond systemic inflammation (i.e. with tocilizumab, an anti interleukin-6 receptor), this state of platelet activation might therefore be beneficial. Among the antithrombotic drugs proposed as candidates to treat patients with SARS-CoV-2 infection, antiplatelet drugs, such as aspirin are showing promising results.

Effectiveness of Tocilizumab with and without Dexamethasone in Patients with Severe COVID-19: A Retrospective Study

Purpose

The pathogenesis of coronavirus disease 2019 (COVID-19) is complicated, and in addition to antiviral therapy and combating coagulopathy, treatment should also include inhibition of the proinflammatory cytokines overproduction. The purpose of this study is to compare the effectiveness of tocilizumab (TCZ) and dexamethasone (DEX) administered alone or in combination in patients with severe COVID-19.

Patients and Methods

Patients were selected from the SARSTer database, containing 3330 individuals with COVID-19 treated between 1 March 2020 and 10 March 2021. The current study included adult patients with baseline oxygen saturation (SpO₂) ≤90%, requiring regular or non-invasive high-flow oxygen supplementation.

Results

Among included 460 patients, 59 were treated with TCZ, 125 with TCZ and DEX, 169 with DEX, and 107 did not receive TCZ nor DEX. The groups were balanced regarding demographics, coexisting diseases, baseline SpO₂, and comedications with remdesivir or low-molecular-weight heparin. The death rate of 6.8% was significantly lower in patients receiving TCZ alone than each arm (19.6%–23.1%), particularly in patients with interleukin-6 concentration exceeding 100pg/mL (5% vs 22.9%–51.7%, respectively). Analysis of clinical improvement demonstrated doubled, significantly higher rate after 21 and 28 days in patients treated with TCZ alone (60% and 75%, respectively) compared to DEX (27.6% and 37.9%, respectively). The need for mechanical ventilation was similar in all arms.

Conclusion

In patients with severe course of COVID-19, particularly those developing cytokine storm, administration of TCZ provides a significantly better effect than DEX regarding survival, clinical improvement, and hospital discharge rate. The combination of TCZ and DEX does not improve therapy effectiveness in patients with severe COVID-19 compared to the administration of TCZ alone.

Clinical Characteristics of Hospitalized COVID-19 Patients Who Received at Least One Dose of COVID-19 Vaccine

The clinical trials of the COVID-19 vaccines that are authorized in the European Union have revealed high efficacy in preventing symptomatic infections. However, during vaccination campaigns, some vaccine recipients, including those partially and fully vaccinated, will experience severe COVID-19, requiring hospitalization. This may particularly concern patients with a diminished immune response to the vaccine, as well as non-responders. This work has retrospectively analyzed the 92 cases of patients who were hospitalized between 27 December 2020 and 31 May 2021 in four Polish healthcare units due to COVID-19, and who have previously received the COVID-19 vaccine (54.3% ≤ 14 days after the first dose, 26.1% > 14 days after the first dose, 7.6% ≤ 14 days after the second dose, and 12% > 14 days after the second dose). These patients represented a minute fraction (1.2%) of all the COVID-19 patients who were hospitalized during the same period in the same healthcare institutions. No significant differences in white blood count, absolute lymphocyte count nadir, C-reactive protein, interleukin-6, procalcitonin, oxygen saturation, lung involvement, and fever frequency were found between the recipients of the first and second vaccine dose. A total of 15 deaths were noted (1.1% of all fatal COVID-19 cases in the considered period and healthcare units), including six in patients who received the second dose (five > 14 days after the second dose)-three of these subjects were using immunosuppressive medicines, and two were confirmed to be vaccine non-responders. The study reassures that severe COVID-19 and deaths are not common in vaccinated individuals, highlights that the clinical course in such patients may not reveal any distinctive features, and advocates for close monitoring of those at a higher risk of vaccine failure.