WHO pauses hydroxychloroquine trials citing safety concerns

The pause by WHO, although temporarily, is significant and reflects the growing concerns around safety of HCQ use, particularly post the results of a large observational study of 96,032 patients, published in the medical journal The Lancet, highlighting hydroxychloroquine posed significant cardiac risks.

The Lancet observational study followed 14,888 hospitalised COVID-19 patients and found that those being treated with the anti-malarial drugs hydroxychloroquine and chloroquine showed no benefit of the drug, and were at a higher risk of death and irregular heart rhythms.

Tedros said the review will look at data collected so far in the solidarity trial and in particular robust randomised available data, to adequately evaluate the potential benefits and harms from this drug.

Even as the medical community remains divided and more evidence are reported on limited benefits of the anti-malaria drugs hydroxychloroquine and chloroquine in treatment of COVID-19, countries like US, India, Brazil have still continued widespread use. US President Donald Trump had even said he was taking hydroxychloroquine as a prophylaxis (preventive therapy).

On the same day as The Lancet study was published, India’s premier medical research body ICMR expanded the use of HCQ as a preventive therapy against COVID-19. It added healthcare workers in non-COVID wards, frontline workers in containment and surveillance programs and police personnel as those who could be given HCQ as prophylaxis. However, it added G6PD deficiency, retinopathy and heart ailments as contraindications and advised one ECG during the 8 weeks period of prophylaxis.

Health experts have questioned India’s decision to expand HCQ as prophylactic even as the data emerging from latest research studies are indicating that HCQs may have little benefit against COVID-19. Apart from The Lancet study, another smaller study published in the New England Journal reported no significant effect on the outcome of intubation or death with HCQ treatment.

Two peer-reviewed observational studies in France and US and a small, randomiszed clinical trial by Chinese research have also reported no benefit of HCQ.

The largest randomised trial on HCQ which is ongoing is the ‘Recovery Trial’ in United Kingdom that is studying the overall effects of HCQ on the risk of death from COVID-19. The study is still recruiting patients and the UK’s drug regulator MHRA has said it is acceptable to allow continued randomisation into the hydroxychloroquine arm of the trial.

While all these trials are to study the efficacy of HCQ in treatment of COVID-19, there are no large-scale trials to establish the drug’s effectiveness as a preventive therapy. Many experts feel countries like US, India, Brazil ignored scientific evidence and took premature and hasty political decisions allowing widespread use of the drug for COVID-19, ignoring scientific evidence.

India’s ICMR in its advisory quoted three small observational studies from three central government hospitals in New Delhi showing those COVID-19 healthcare workers who were on HCQ prophylaxis were less likely to develop SARS-CoV-2 infection, compared to those who were not on it. The benefit was less pronounced in healthcare workers caring for a general patient population. Another observational prospective study of 334 healthcare workers at AIIMS, out of which 248 took HCQ prophylaxis in New Delhi also showed that those taking HCQ prophylaxis had lower incidence of SARS-CoV-2 infection than those not taking it.

There are reportedly over 150 studies currently ongoing across the world on hydroxychloroquine and its use in COVID-19 treatment. However, there has been a growing call from the medical research fraternity for better designed clinical trials to establish the effectiveness of the drug as preventive therapy.

Dr Soumya Swaminathan, Chief Scientist at WHO said in a tweet, “We firmly believe that RCTs are the best way to ascertain whether a drug or intervention is safe & efficacious for treatment or prevention of COVID.”

For WHO’s multi-country solidarity trial, nearly 3,500 patients from 17 countries have already been enrolled for the trials and over 400 hospitals in 35 countries are actively recruiting patients. WHO says other arms of the solidarity trial are continuing.

Hydroxychloroquine, the age-old anti-malaria drug, is also used widely for treatment of auto-immune diseases like rheumatoid arthritis and lupus. WHO has maintained that “these drugs are accepted as generally safe for use in patients with autoimmune diseases or malaria.”