Tocilizumab for the treatment of non‐critical COVID‐19 pneumonia: an overview of the rationale and clinical evidence to date

ABSTRACT

Introduction: Tocilizumab is one of the main repurposed therapies investigated for COVID-19 pneumonia since the start of the pandemic, but there has been conflicting evidence for its use.

Areas covered: This review covers the physiology of interleukin-6 and its role in the pathophysiology of COVID-19. We discuss the use of tocilizumab in other diseases and the rationale for its use in COVID-19. We summarize the design, contrasting results, and implications of the clinical trials of tocilizumab in COVID-19 to date and discuss the current guidance for its use.

Expert opinion: The evidence to date suggests benefit with the use of tocilizumab in some but not all patients with COVID-19. Benefit seems to be greatest when given early after clinical deterioration with the presence of systemic inflammation. However, questions remain around the optimal timing, patient selection, and concomitant treatments.

KEYWORDS:

• Tocilizumab
• COVID-19
• interleukin-6
• cytokine release syndrome
• immunomodulatory therapy

Article highlights

• Tocilizumab is a monoclonal antibody which inhibits signalling of the pleiotropic cytokine IL-6, repurposed for use in COVID-19.

• Observational trials have suggested benefit in the use of tocilizumab in COVID-19.

• Several randomized controlled trials have been performed but these differ in patient population, primary outcome, drug timing, and concomitant treatments.

• Results of the randomized controlled trials have been mixed, but in total suggest potential benefit when used early in severe disease.

• Further research is needed to establish the optimal patient, dose, and timing of tocilizumab in COVID-19.

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.

Additional information

Funding

This paper was not funded.