The SOLIDARITY trial is an international trial led by the World Health Organisation (WHO), exploring possible drugs that can be repurposed to treat severely affected COVID-19 patients. Repurposed drugs are already in use in treating other ailments but can also be effective against COVID-19. The SOLIDARITY trial is the largest global, randomized clinical trial conducted in over 30 countries.
This trial has already been conducted since the beginning of the pandemic in different phases. This time, the SOLIDARITY trial plans to evaluate three drug candidates for their repurposing in treating hospitalized COVID-19 patients.
The drug candidates are imatinib, a cancer drug; infliximab, an antibody; and artesunate, an anti-malarial drug.
According to reports, the three candidates have already been sent to Finland, the first country to have all the approvals cleared. John Arne Rottingen, chairing the study’s executive group and belonging to the Norwegian Institute of Public Health, commented: “I expect that the first patients will probably be recruited there any day.”
Other countries are expected to join the trial soon, with over 40 nations currently in the clearance of regulatory and ethical approval stages.
The first SOLIDARITY trial began in March 2020, and over a dozen countries are believed to have participated in it to evaluate drug efficacy in treating COVID-19 patients.
In October 2020, the trial produced an interim report on four treatments, none of which showed significant benefits. The trial involved 11,000 patients in 400 hospitals in over 30 countries. The four drugs in the first trial were Remdesivir, an anti-viral drug; Lopinavir/ritonavir combination, which are HIV drugs; Hydroxychloroquine, the anti-malarial drug; and Interferon Beta.
The SOLIDARITY trial is not the only one to assess drug efficacy in COVID-19. There have been other trials, too. For example, the Recovery trial conducted by the United Kingdom could find out two drug candidates that are effective in treating serious COVID patients.
Dexamethasone, a steroid, and a cheap and readily available drug, was found to be effective in reducing deaths by up to one-third among the participants recruited in the trial. The result came out in June 2020, and dexamethasone has been in use since then.
Again in February this year, the Recovery trial declared another drug to be effective: the tocilizumab. Tocilizumab is a monoclonal antibody (a designed antibody) and blocks an inflammatory cytokine molecule called the interleukin-6. Cytokines are protein molecules involved in the immune system (the defense mechanism of the body). Cytokines can cause inflammation in different organs, and sometimes these can cause a hyper-reactive immune system which may prove dangerous for the body. The cytokine storm (over secretion of cytokines) can cause severe disease in COVID-19 patients.
Tocilizumab was found to reduce mortality in patients. Both Dexamethasone and Tocilizumab are immune suppressants, which can dampen the overreacting immune system in severely ill patients.
The drugs considered in the current SOLIDARITY trial also target the immune system rather than the coronavirus itself.
Imatinib is an oral drug used to treat Leukemia and other types of cancer. Imatinib has been chosen based on a previously conducted trial consisting of 400 hospitalized COVID-19 patients in the Netherlands. The trial results were published in Lancet in June 2021 and showed that patients spent less time on ventilator support, and mortality also decreased. Imatinib can protect the alveoli of the lungs, the place where oxygen transfers from the lungs into the blood.
Infliximab is an antibody and is administered as a single infusion. This drug is widely used to treat a variety of inflammatory conditions, such as rheumatoid arthritis and inflammatory bowel disease. The basic functioning of this drug is to block tumor necrosis factor (TNF) alpha. TNF alpha is a key protein molecule involved in signaling in the immune system. There have been some observational data suggesting that the drug may effectively protect severely affected COVID-19 patients.
Artesunate is used against malaria parasites. This drug has also shown some anti-viral activities in some laboratory studies. However, the main reason behind the recruitment of this drug under the SOLIDARITY trial is because artesunate can reduce inflammation.
After the first SOLIDARITY trial results came out in October last year, the trial took a long time to revive. The results of the largest trial with new drugs will be awaited eagerly by the medical community.