The drug works by inhibiting a substance the virus uses to make copies of itself. Certain kidney and liver tests are required before starting patients on it to ensure it's safe for them and to monitor for any possible side effects. And the label warns against using it with the malaria drug hydroxychloroquine, because that can curb its effectiveness.
CDC director Dr. Robert Redfield told state governors last week to prepare for the vaccine.
“We now have enough knowledge and a growing set of tools to help fight COVID-19,” Gilead's chief medical officer, Dr. Merdad Parsey, said in a statement.
The drug is either approved or has temporary authorization in about 50 countries, he noted.
Its price has been controversial, given that no studies have found it improves survival. Last week, a large study led by the World Health Organization found the drug did not help hospitalized COVID-19 patients, but that study did not include a placebo group and was less rigorous than previous ones that found a benefit. The FDA's approval statement noted that, besides the NIH-led one, two other studies found the drug beneficial.
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Gilead charges $2,340 for a typical treatment course for people covered by government health programs in the United States and other developed countries, and $3,120 for patients with private insurance. The amount that patients pay out of pocket depends on insurance, income and other factors.
So far, only steroids such as dexamethasone have been shown to cut the risk of dying of COVID-19. The FDA also has given emergency authorization to using the blood of survivors, and two companies are currently seeking similar authorization for experimental antibody drugs.