According to the researchers, including Regis G Rosa from Hospital Moinhos de Vento in Brazil, there was an increased number of deaths at 15 days in patients receiving an drug ' title=' arthritis drug '>arthritis drug -- tocilizumab -- that resulted in the trial being stopped early.

 

These results contradict earlier observational studies suggesting benefit from tocilizumab. However, observational effects are limited by a high risk that they may be due to other unknown (confounding) factors -- and some studies have not yet been peer reviewed or published in a medical journal, the researchers said in a paper published in The BMJ journal.

 

Tocilizumab blocks a specific part of the immune system (interleukin 6) that can go into overdrive in some patients with Covid-19.

 

According to the team, doctors think this might help lessen the body's inflammatory response to the virus and avert some of the more dire consequences of the disease, but its effects are not well defined.

 

To test this theory, researchers conducted a randomised controlled trial involving 129 Covid-19 patients with an average age of 57 years and compared tocilizumab plus standard care with standard care alone.

 

Patients were receiving supplemental oxygen or mechanical ventilation and had abnormal levels of at least two chemicals linked to inflammation in their blood.

 

The study participants were randomly divided into two groups -- 65 received tocilizumab plus standard care and 64 received standard care alone. All patients were monitored for 15 days.

 

By day 15, 18 (28 per cent) patients in the tocilizumab group and 13 (20 per cent) in the standard care group were receiving mechanical ventilation or had died.

 

Death at 15 days occurred in 11 (17 per cent) patients in the tocilizumab group compared with 2 (3 per cent) in the standard care group.