Does Telmisartan improve clinical outcomes in people with COVID-19? CLARITY Trial reports data on Indian Patients
New Delhi: Can angiotensin receptor blockers disrupting the renin-angiotensin-system, help in improving COVID-19 outcomes?
The answer seems to be 'no' as per the results of CLARITY trial recently published in the BMJ. The trial which was performed on patients at 17 sites in India and Australia, showed that the drug used to treat high blood pressure, was found to be ineffective in treating even mild COVID-19 cases.
CLARITY was a pragmatic, adaptive, multicentre, phase 3, randomised controlled trial promoted by previous data on Mice that suggested that modulation of the renin-angiotensin-system with ARBs might have protective effects in patients with SARS-CoV-2
As a result, a randomised controlled trial was performed involving 787 patients (778 from India and nine from Australia) with an average age of 49 years who were admitted to hospital from May 2020 to November 2021. It Included patients with predominantly mild disease, although the researchers aimed to recruit patients at risk of severe covid.
Half of the total participants received angiotensin receptor blockers or ARBs (drugs widely used to treat high blood pressure and heart disease) and the other half (controls) received a placebo for 28 days.
The primary endpoint was Covid-19 disease severity using a modified World Health Organization Clinical Progression Scale (WHO scale) at day 14. Secondary outcomes were WHO scale scores at day 28, mortality, intensive care unit admission, and respiratory failure. Analyses were evaluated on an ordinal scale in the intention-to-treat population.
A standard dose of the ARB drug, Telmisartan (starting dose 40 mg/d) was used only in India while the type and dose of ARB was at the discretion of the treating physicians in Australia.
These drugs were chosen because they work by regulating the same angiotensin protein that is used by coronavirus to enter the body, and in the laboratory, they have shown potential protectivity against severe effects of coronaviruses.
However, after 14 days of treatment, the researchers found no meaningful difference in illness severity between the two groups. The trial was stopped when a prespecified futility rule was met.
These findings should help to improve clinical practice. The lack of effect provides reassurance that it is safe to use these protective agents in people indicated, with or without covid-19.
The study has some important limitations.
The randomised controlled trial, the researchers were unable to source placebo in Australia, meaning participants and treating clinicians knew they were taking an active drug. Participants were also treated with a relatively low drug dose, so the effect of higher doses remains unknown.
Ref: BMJ 2022;379:e072175
