Daniel O’Day, Chairman and CEO of Gilead Sciences, issued an open letter on April 10, 2020 to provide an update on the clinical developments of the company’s antiviral drug, remdesivir, an investigational medicine for the treatment of the novel coronavirus (COVID-19)

The New England Journal of Medicine recently published an analysis on the effects of remdesivir being evaluated in a small group of patients with severe symptoms of COVID-19. The study is composed of patients who received treatment through the company’s compassionate-use program for remdesivir and are critically ill patients who are unable to take part in a clinical trial. “The results, which cover 53 of the first patients to have been treated in the program, show that the majority demonstrated clinical improvement after taking remdesivir,” O’Day said in the April 10, 2020 letter. “We recognize the limitations of these compassionate-use data from a purely investigational perspective while knowing they are of the greatest significance for the patients whose symptoms improved. These early data from 53 patients have not been generated in a clinical trial and cover only a small portion of the critically ill patients who have been treated with remdesivir.” 

The company has multiple clinical trials underway to examine how remdesivir works in various contexts. These studies cover a range of patient populations across different demographics and with varying types of symptoms: moderate, severe where patients need oxygen support, and critical where medical ventilation is required. These patients all receive remdesivir through intravenous infusions in a hospital setting. “In studying remdesivir, the question is not just whether it is safe and effective against COVID-19, but in which patients it shows activity, how long should they receive treatment, and at what stage of their disease would treatment be most beneficial. Many answers are needed, which is why we need multiple types of studies involving many types of patients,” he said.

Seven clinical trials have been initiated to determine whether remdesivir is a safe and effective treatment for COVID-19. The order in which the trials were initiated mirrors the path of the pandemic. China initiated the first two studies in early February (February 2020) for patients with severe and moderate symptoms of the disease. Since then, an additional five trials have been initiated globally.

Two Phase II studies are being run by Gilead in areas with a high prevalence of COVID-19 in the US, Asia, and Europe. One of these is for patients with severe disease and the other studies are with remdesivir in patients with more moderate symptoms. One of the questions in these studies is whether treatment duration can be shortened from 10 days to 5 days. The severe arm fully enrolled the number of patients it was originally designed for, and it has now expanded to study more patients, including those on mechanical ventilation.

The US National Institute of Allergy and Infectious Disease (NIAID) began a global trial on February 21, 2020. This trial randomly assigns patients to treatment with either remdesivir or with a placebo to enable a controlled comparison of outcomes. The trial is enrolling approximately 800 patients with a broad spectrum of symptoms. The World Health Organization is also conducting a global trial, and a trial recently began in Europe.

O’Day said that the company expects to have preliminary data from the study of remdesivir in severe patients at the end of April (April 2020). The publication of data from the China remdesivir trials rests with Chinese investigators, but the company says it has been informed that the study in patients with severe symptoms was stopped due to stalled enrollment. In May (May 2020), the company expects the initial data from the placebo-controlled NIAID trial as well as data from the Gilead study of patients with moderate symptoms of COVID-19.

Source: Gilead Sciences