Tocilizumab has been shown to reduce mortality from Covid-19 in the largest clinical trial in hospitalized and severely ill patients. It could be the second life-saving drug besides the cortisone dexamethasone. But the cost is higher
(photo: Miguel Á. Padriñán via Pixabay) Tocilizumab, a monoclonal antibody used in rheumatoid arthritis, could be the second most effective drug in severe cases of Covid-19, in addition to dexamethasone - the first life-saving identified against the coronavirus. The result is shown by the largest clinical study, called Recovery, on treatments for Covid, conducted by the University of Oxford and other British universities, not peer reviewed yet but published in preprint on medRxiv. The trial may have identified the second drug - tocilizumab, in fact - which reduces mortality from Covid-19.
The tocilizumab monoclonal antibody
Tocilizumab has already been studied for some time against coronavirus and from the early stages of the pandemic it was counted among the potentially promising therapies. It is an anti-inflammatory drug, a monoclonal antibody that blocks a protein, the interleukin 6 receptor (Il-6). Interleukin 6 is another protein of the cytokine class, which plays an important role in the immune response that can promote inflammation in various diseases, including Covid-19. In severe cases and in the advanced stages of the disease, in fact, the excessive immune response is the cause of extensive and severe inflammation that can lead to death.
The study
From the end of April 2020 to the end of January 2021, the study involved over 4 thousand hospitalized patients with severe symptoms. 55% of them received respiratory support (41% non-invasive while the remaining 14% invasive, with intubation) and 45% did not need support. The participants were divided into two groups: the first, consisting of 2022 patients, received tocilizumab and the other (2094 patients) a standard treatment used in coronavirus; altogether 82% of them were also given dexamethasone.
A reduction in mortality
The results show that in the tocilizumab group 596 people (29%) died within 28 days, compared to 694 (33%) in the control group. A 4% reduction in mortality might seem very small when compared with the effect of dexamethasone - which would cut the death rate in severe cases by a third. But it's not irrelevant anyway. "It's not marginal," noted physician Ashish Jha, dean of Brown University's School of Public Health in an article in Science. It is likely the second drug to impact mortality, second only to dexamethasone, adds Athimalaipet Ramanan, a rheumatologist at the University of Bristol, not involved in the trial but on the drug evaluation committee in a clinical trial in India. In patients hospitalized because they had oxygen deficiency and systemic inflammation, tocilizumab improved survival and ultimate health status, the study reported. These results were observed regardless of the type of ventilation support needed at the time of hospitalization and treatment with systemic corticosteroids (such as dexamethasone).
Other antibodies
In addition to tocilizumab already exists another monoclonal antibody, sarilumab, used in rheumatology, which always acts against the interleukin 6 receptor. This antibody appears to have shown a similar effect in the Remap-Cap clinical trial, although data are very limited and the study must be still concluded. It will be important to have the results to understand if interleukin 6 antagonists are a viable alternative.
The cost problem
Various experts are enthusiastic about the first results on the drug, which it could provide one more weapon in the fight against Covid. However, the therapy is 100 times more expensive than dexamethasone, an element that opens up a debate on how to make it possible for everyone to access it. If rich countries can benefit, as Ashis Jha explains, poor ones probably won't. Hoping that the situation will change as soon as possible and that everyone can have the same treatment possibilities and in general the best therapy, a right for everyone.
