Data from a large-scale clinical study conducted by Columbia University Irving Medical Center in the US showed that Covid-19 patients treated with hydroxychloroquine did not experience better performance than those who did not receive the drug.

Hydroxychloroquine, which was touted by US President Donald Trump as a potential Covid-19 treatment, is currently being assessed in various clinical trials, including studies by Novartis and University of Pennsylvania.

In laboratory studies, the malaria drug demonstrated ability to potentially prevent the replication of SARS-CoV-2 virus in mammalian cells. Data obtained from small human clinical studies has been difficult to interpret, said Columbia University researchers.

The university’s trial involved approximately 1,400 patients with moderate to severe Covid-19 disease at one New York hospital. It is said to be the largest published study of the drug in Covid-19 patients to date, where prior studies enrolled not more than 100 patients.

Of 1,376 participants in the latest trial, 811 were given hydroxychloroquine and 565 patients did not receive the drug. The aim of the study is to evaluate the impact of hydroxychloroquine’s use on the development of respiratory failure leading to intubation or death.

Overall, 346 patients went on to develop respiratory failure, 180 were intubated and 166 died without intubation. The findings showed that patients on hydroxychloroquine had the same risk of intubation or death as those who were not treated with the drug.

Based on the results, the researchers concluded that hospitalised Covid-19 patients should not be routinely treated with hydroxychloroquine.

Columbia University Irving Medical Center NewYork-Presbyterian Pulmonary, Allergy and Critical Care Medicine division chief Neil Schluger said: “Given the observational design of the study, our results cannot completely exclude the possibility of either modest benefit or harm of hydroxychloroquine treatment, but the findings do not support its use outside of randomised clinical trials.”

Schluger added that a randomised, controlled trial could help determine if a drug has a benefit.