The US National Institutes of Health (NIH) said Thursday that it is launching a clinical trial evaluating the combination of hydroxychloroquine plus azithromycin to treat patients with mild-to-moderate COVID-19 in the US. Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases, noted that while "there is anecdotal evidence that hydroxychloroquine and azithromycin may benefit people with COVID-19, we need solid data from a large randomised, controlled clinical trial to determine whether this experimental treatment is safe and can improve clinical outcomes."
The Phase IIb trial, dubbed A5395, will enroll approximately 2000 adults with confirmed SARS-CoV-2 infection who are experiencing fever, cough and/or shortness of breath. Investigators anticipate that many of the study subjects will be at least 60 years of age or have a comorbidity associated with developing serious complications from COVID-19, such as cardiovascular disease or diabetes. They will be randomly assigned to receive short-term treatment with either hydroxychloroquine and azithromycin or matching placebos.
Participants, who will be given the oral medications to take at home, are asked to record their symptoms, adherence to treatment, and major events such as hospitalisations in a diary for 20 days. Additional follow-ups will be conducted by telephone three months and six months after treatment starts. The study's main objective is to assess whether hydroxychloroquine taken together with azithromycin can prevent hospitalisation and death due to COVID-19. It will also evaluate the safety and tolerability of the experimental treatment for SARS-CoV-2 infection. Initial results may be available later this year, according to the NIH.
The FDA recently issued an emergency-use authorisation for hydroxychloroquine and related drug chloroquine for treating hospitalised adults and adolescents with COVID-19, when a clinical trial is not available or feasible. However, the agency has since warned  about the need to closely monitor patients, as known side effects of the antimalarial drugs, such as potentially life-threatening heart rhythm problems, have been reported when prescribed to treat or prevent COVID-19. Meanwhile, a panel of medical experts convened by the NIH recently released treatment guidelines for COVID-19 in which they specifically come out against using hydroxychloroquine plus azithromycin to treat the novel coronavirus given the "potential for toxicities."
Novartis has also been approved to go ahead with a placebo-controlled Phase III trial  evaluating the efficacy of hydroxychloroquine, as well as hydroxychloroquine plus azithromycin, in hospitalised patients with COVID-19 disease. That study is expected to recruit some 440 patients in the US.