Royal Pharmaceutical Society

Tocilizumab and sarilumab - new treatments for COVID-19

by Professor Luigi Martini, RPS Chief Scientist 

You may have heard in the news recently that two therapeutic agents are being used to help combat COVID-19.  These agents are the monoclonal antibodies, tocilizumab and sarilumab, originally developed for the treatment Rheumatoid Arthritis.  Preliminary findings (data has not been peer reviewed) are from the Government-sponsored REMAP-CAP* trial which compares therapeutic treatments for community acquired pneumonia.

You may be wondering why treatments for pneumonia are being investigated for COVID-19?  Well, although the infection is viral in origin in certain individuals (e.g. the elderly), some people experience a severe inflammatory reaction or ‘cytokine’ storm throughout their body but particularly within their lungs.  This over-reaction can lead to fluid build-up within the lungs and cause those infected to experience difficulty in breathing, or acute respiratory distress. Severe cases require the use of a ventilator and stays in intensive care units with significant risk of mortality.

One of the most important factors that drives the inflammation process is a protein called Interleukin 6 (often called IL-6). Both tocilizumab and sarilumab block IL-6, therefore, reducing inflammation and so improving the outcomes for those patients suffering from acute respiratory distress.

We need to bear in mind that the data is preliminary and these are used in the treatment of symptoms, not a cure. Nevertheless, the data show these medicines reduce the relative risk of death by 24% for critically ill patients and their time spent in intensive care by up to 10 days.