4

According to the Infectious Disease Society of America (IDSA), one of the possible treatment options for COVID-19 patients is il-6 inhibitors (tocilizumab, sarilumab). What is the rationale behind this?

Source:

https://www.idsociety.org/practice-guideline/covid-19-guideline-treatment-and-management

2

Hemophagocytic lymphohistiocytosis (HLH) syndrome is a life-threatening condition commonly triggered by viral illness. It is caused by over-activated macrophages and low NK cell/cytotoxic T-cell activity, leading to increased cytokine release (cytokine storm) and organ failure. A non-exhaustive list of clinical features of this syndrome includes:

  • fever
  • splenomegaly
  • cytopenia
  • hypertriglyceridemia/hypofibrinogenemia
  • increased ferritin
  • macrophage phagocytosis of red blood cells in bone marrow, spleen, lymph node, or liver

COVID-19 infection seems to trigger a similar cytokine storm as HLH, as according to a Lancet paper[1]

A cytokine profile resembling sHLH is associated with COVID-19 disease severity, characterised by increased interleukin (IL)-2, IL-7, granulocyte-colony stimulating factor, interferon-γ inducible protein 10, monocyte chemoattractant protein 1, macrophage inflammatory protein 1-α, and tumour necrosis factor-α.

Cytokine storm is classically treated with IL-6 receptor inhibitors such as tocilizumab.

A preliminary study from China[2] has also shown that in a sample size 21 severe or critical COVID-19 patients treated with tocilizumab, 75% of patients needed oxygen therapy and there were no mortalities after 2 weeks of the study. Due to a low sample size and lack of control group, this is just an initial finding, but has prompted larger clinical trials on the efficacy of il-6 inhibitors for COVID-19.

Currently, two major U.S. clinical trials are being done on il-6 receptor inhibitors:

  1. Sanofi and Regeneron Pharmaceuticals is evaluating sarilumab[3]
  2. Genentech (of Roche Group) is evaluating tocilizumab in the COVACTA trial[4]

Source:

  1. COVID-19: consider cytokine storm syndromes and immunosuppression
  2. Effective Treatment of Severe COVID-19 Patients with Tocilizumab
  3. http://www.news.sanofi.us/2020-03-16-Sanofi-and-Regeneron-begin-global-Kevzara-R-sarilumab-clinical-trial-program-in-patients-with-severe-COVID-19
  4. https://www.genengnews.com/virology/coronavirus/genentech-launches-phase-iii-trial-of-actemra-as-coronavirus-treatment/
| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.