Tocilizumab for the treatment of COVID-19

ABSTRACT

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.

KEYWORDS:

• COVID-19
• interleukin-6
• monoclonal antibodies
• therapy
• SARS-CoV-2
• tocilizumab

Article highlights

• Tocilizumab is a recombinant humanized monoclonal antibody binding soluble and membrane-bound IL-6 receptors, preventing IL-6-mediated inflammation signaling.

• Observational studies and randomized clinical trials have proven the efficacy and safety of tocilizumab in the treatment of COVID-19.

• Tocilizumab was included in the most important expert guidelines and received approvals from the European Medicines Agency and the U.S. Food and Drug Administration for the treatment of COVID-19.

• The criteria for optimizing tocilizumab therapy in SARS-CoV-2 infections are still undetermined, although it seems reasonable that they should be based on measurements of interleukin-6 concentration.

• Knowledge of COVID-19 immunotherapy with tocilizumab may be useful in managing future possible viral outbreaks.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contribution statement

All authors substantially contributed to the conception and design of the review article and interpreting the relevant literature, and been involved in writing the review article or revised it for intellectual content.

Additional information

Funding

This paper was not funded.