The effect of tocilizumab on cytokine release syndrome in COVID-19 patients

An overview of the development of pharmacotherapeutics targeting SARS-CoV-2

Coronavirus disease 2019 (COVID-19) was declared a global pandemic in March 2020, which precipitated urgent public health responses. The causative agent, SARS-CoV-2, spreads primarily via respiratory droplets, necessitating precautions to mitigate transmission risks. Biopharmaceutical industries and academic institutions worldwide swiftly redirected their research endeavors towards developing therapeutic interventions, focusing on monoclonal antibodies, antiviral agents, and immunomodulatory therapies. The evolving body of evidence surrounding these treatments has prompted successive updates and revisions from the FDA, delineating the evolving landscape of COVID-19 therapeutics. This review comprehensively examines each treatment modality within the context of their developmental trajectories and regulatory approvals throughout the pandemic. Furthermore, it elucidates their mechanisms of action and presents clinical data underpinning their utility in combating the COVID-19 crisis.

To go or not to go? Biological logic gating engineered T cells

Genetically engineered T cells have been successfully used in the treatment of hematological malignancies, greatly increasing both progression-free and overall survival in patients. However, the outcomes of patients treated with Chimeric Antigen Receptor (CAR) T cells targeting solid tumors have been disappointing. There is an unmet clinical need for therapies which are specifically designed to overcome the challenges associated with solid tumors such as tumor heterogeneity and antigen escape. Genetic engineering employing the use of biological logic gating in T cells is an emerging and cutting-edge field that may address these issues. The advantages of logic gating include localized secretion of anti-tumor proteins into the tumor microenvironment, multi antigen targeting of tumors and a potential increase in safety when targeting tumor antigens which may not be exclusively tumor specific. In this review, we introduce the concept of biological logic gating and how this technology addresses some of the challenges of current CAR T treatment. We outline the types of logic gating circuits and finally discuss the application of this new technology to engineered T cells, in the treatment of cancer.

An updated overview of recent advances, challenges, and clinical considerations of IL-6 signaling blockade in severe coronavirus disease 2019 (COVID-19)

Since 2019, COVID-19 has become the most important health dilemma around the world. The dysregulated immune response which results in ARDS and cytokine storm has an outstanding role in the progression of pulmonary damage in COVID-19. IL-6, through induction of pro-inflammatory chemokines and cytokines, is the pioneer of the hyperinflammatory condition and cytokine storm in severe COVID-19. Therefore, IL-6 pathway blockade is considered an emerging approach with high efficacy to reduce lung damage in COVID-19. This article aims to review the pleiotropic roles of the IL-6 pathway in lung damage and ARDS in severe COVID-19, and the rationale for IL-6 signaling blockade at different levels, including IL-6 soluble and membrane receptor pathways, IL-6 downstream signaling (such as JAK-STAT) inhibition, and non-specific anti-inflammatory therapeutic approaches. Recent clinical data of each method, with specific concentration on tocilizumab, along with other new drugs, such as sarilumab and siltuximab, have been discussed. Challenges of IL-6 signaling inhibition, such as the risk of superinfection and hepatic injury, and possible solutions have also been explained. Moreover, to achieve the highest efficacy, ongoing clinical trials and special clinical considerations of using different IL-6 inhibitors have been discussed in detail. Special considerations, including the appropriate timing and dosage, monotherapy or combination therapy, and proper side effect managment must be noticed regarding the clinical administration of these drugs. Future studies are still necessary to improve the productivity and unknown aspects of IL-6 signaling blockade for personalized treatment of severe COVID-19.

Beneficial and harmful outcomes of tocilizumab in severe COVID-19: A systematic review and meta-analysis

Introduction

The results of studies of tocilizumab (TCZ) in COVID‐19 are contradictory. Our study aims to update medical evidence from controlled observational studies and randomized clinical trials (RCTs) on the use of TCZ in hospitalized patients with COVID‐19.

Methods

We searched the following databases from January 1, 2020 to April 13, 2021 (date of the last search): MEDLINE database through the PubMed search engine and Scopus, using the terms (“COVID‐19" [Supplementary Concept]) AND "tocilizumab" [Supplementary Concept]).

Results

Sixty four studies were included in the present study: 54 were controlled observational studies (50 retrospective and 4 prospective) and 10 were RCTs. The overall results provided data from 20,616 hospitalized patients with COVID‐19: 7668 patients received TCZ in addition to standard of care (SOC) (including 1915 patients admitted to intensive care units (ICU) with reported mortality) and 12,948 patients only receiving SOC (including 4410 patients admitted to the ICU with reported mortality). After applying the random‐effects model, the hospital‐wide (including ICU) pooled mortality odds ratio (OR) of patients with COVID‐19 treated with TCZ was 0.73 (95% confidence interval (CI) = 0.56–0.93). The pooled hospital‐wide mortality OR was 1.25 (95% CI = 0.74–2.18) in patients admitted at conventional wards versus 0.66 (95% CI = 0.59–0.76) in patients admitted to the ICU. The pooled OR of hospital‐wide mortality (including ICU) of COVID‐19 patients treated with TCZ plus corticosteroids (CS) was 0.67 (95% CI = 0.54–0.84). The pooled in‐hospital mortality OR was 0.71 (95% CI = 0.35–1.42) when TCZ was early administered (≤10 days from symptom onset) versus 0.83 (95% CI 0.48–1.45) for late administration (>10 days from symptom onset). The meta‐analysis did not find significantly higher risk for secondary infections in COVID‐19 patients treated with TCZ.

Conclusions

TCZ prevented mortality in patients hospitalized for COVID‐19. This benefit was seen to a greater extent in patients receiving concomitant CS and when TCZ administration occurred within the first 10 days after symptom onset.

Cyclosporin A: A Repurposable Drug in the Treatment of COVID-19?

Coronavirus disease 2019 (COVID-19) is now at the forefront of major health challenge faced globally, creating an urgent need for safe and efficient therapeutic strategies. Given the high attrition rates, high costs, and quite slow development of drug discovery, repurposing of known FDA-approved molecules is increasingly becoming an attractive issue in order to quickly find molecules capable of preventing and/or curing COVID-19 patients. Cyclosporin A (CsA), a common anti-rejection drug widely used in transplantation, has recently been shown to exhibit substantial anti-SARS-CoV-2 antiviral activity and anti-COVID-19 effect. Here, we review the molecular mechanisms of action of CsA in order to highlight why this molecule seems to be an interesting candidate for the therapeutic management of COVID-19 patients. We conclude that CsA could have at least three major targets in COVID-19 patients: (i) an anti-inflammatory effect reducing the production of proinflammatory cytokines, (ii) an antiviral effect preventing the formation of the viral RNA synthesis complex, and (iii) an effect on tissue damage and thrombosis by acting against the deleterious action of angiotensin II. Several preliminary CsA clinical trials performed on COVID-19 patients report lower incidence of death and suggest that this strategy should be investigated further in order to assess in which context the benefit/risk ratio of repurposing CsA as first-line therapy in COVID-19 is the most favorable.

A meta-analysis of granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody treatment for COVID-19 patients

OBJECTIVE

This meta-analysis aims to assess the efficacy and safety of granulocyte-macrophage colony-stimulating factor (GM-CSF) antibodies on COVID-19.

METHODS

Relevant literatures about GM-CSF antibody treatment in COVID-19 patients were searched from the PubMed, Cochrane Library, Embase, Google scholar, and Baiduscholar databases from the COVID-19 outbreak in December 2019 until 1 January 2021. The primary outcomes included the death, intensive care unit (ICU) admission risk, ventilation requirement, and secondary infection.

RESULTS

A total of 12 eligible literature involving 8979 COVID-19 patients were recruited, and they were divided into experimental group (n = 2673) and control group (n = 6306). Using a random-effect model, it is found that the GM-CSF antibody treatment was associated with a 23% decline of the risk of death [odd's ratio (OR): 0.34, 95% confidence interval (CI): 0.21-0.56, p < 0.0001] and a 20% enhancement of ventilation (OR: 1.47, 95% CI: 1.19, 1.80, p = 0.0002). GM-CSF antibody treatment did not have a significant correlation to secondary infection and increased risk of ICU admission in COVID-19 patients, which may be attributed to the older age and the length of stay.

CONCLUSIONS

Severe COVID-19 patients can benefit from GM-CSF antibodies.

Efficacy and safety of Tocilizumab in severe and critical COVID-19: A Systematic Review and Meta-Analysis

OBJECTIVES

Currently published papers and clinical guidelines regarding the effects of tocilizumab in severe and critical COVID-19 are contradictory. The aim of this meta-analysis was to combine the results of clinical studies of different designs to investigate the efficacy and safety of tocilizumab in severely-to-critically ill COVID-19 patients.

METHODS

A systematic search was performed in PubMed, Embase, CENTRAL, ClinicalTrials.gov, Scopus, and preprint servers up to 26 December 2020. Since a substantial heterogeneity was expected, a random-effects model was applied to calculate the pooled effect size (ES) and 95% confidence interval (CI) for each study outcome.

RESULTS

Forty-five comparative studies involving 13,189 patients and 28 single-arm studies involving 1,770 patients were analyzed. The risk of mortality (RR of 0.76 [95%CI 0.65 to 0.89], P < 0.01) and intubation (RR of 0.48 [95%CI 0.24 to 0.97], P = 0.04) were lower in tocilizumab patients compared with controls. We did not find any significant difference in secondary infections, length of hospital stay, hospital discharge before day 14, and ICU admission between groups.

CONCLUSION

Tocilizumab can improve clinical outcomes and reduce mortality rates in severe to critical COVID-19 patients. Large-scale randomized controlled trials are still required to improve the statistical power of meta-analysis.

Interleukin-6 receptor blockade in patients with COVID-19: placing clinical trials into context

The pleiotropic cytokine interleukin-6 (IL-6) has been implicated in the pathogenesis of COVID-19, but uncertainty remains about the potential benefits and harms of targeting IL-6 signalling in patients with the disease. The efficacy and safety of tocilizumab and sarilumab, which block the binding of IL-6 to its receptor, have been tested in adults with COVID-19-related acute respiratory illness in randomised trials, with important differences in trial design, characteristics of included patients, use of co-interventions, and outcome measurement scales. In this Series paper, we review the clinical and methodological heterogeneity of studies of IL-6 receptor antagonists, and consider how this heterogeneity might have influenced reported treatment effects. Timing from clinical presentation to treatment, severity of illness, and concomitant use of corticosteroids are among the factors that might have contributed to apparently inconsistent results. With an understanding of the sources of variability in these trials, available evidence could be applied to guide clinical decision making and to inform the enrichment of future studies.