Immunomodulatory treatments

Immunomodulatory treatments

Corticosteroids: Interim guidance from WHO states that routine use of corticosteroids should not be used in routine treatment of COVID-19 (15). This is based on systematic reviews in the context of SARS and MERS which showed lack of effectiveness, and possible harm.

In a study of 138 hospitalised patients with COVID-19 in Wuhan, 72.2% of ICU patients and 35.3% of non-ICU patients received glucocorticoid therapy. The authors commented that while the dose of methylprednisolone varied depending on disease severity, no effective outcomes were observed.

Outside of clinical trials, corticosteroids should only be used if there is an evidence-based indication for them e.g. acute exacerbation of asthma.

Interleukin 6 (IL-6) antagonists: Tocilizumab is a humanised monoclonal antibody which binds to the IL-6 receptors resulting in reduced immune activation and inflammation. It is licensed in Australia for use in autoimmune conditions including rheumatoid arthritis and giant cell arteritis. In addition to complications of immunosuppression including serious infections, adverse effects can include hepatotoxicity and gastrointestinal complications.

The theory behind use of tocilizumab or other agents that target the IL-6 pathway in the context of COVID-19 is that part of the pathogenesis in some patients may be attributable to an acute inflammatory syndrome or ‘cytokine storm’, which is associated with elevated IL-6 levels. Guidelines have been issued in China regarding use of tocilizumab for severe or critical COVID-19 with elevated IL-6 levels, however clinical evidence of efficacy is not yet available, with two clinical trials currently underway.