- Gilead will this week begin human study of an inhaled version of its COVID-19 drug remdesivir, potentially opening up an avenue to making the antiviral therapy more widely available to patients infected with the new coronavirus.
- Currently, remdesivir is given intravenously once daily, making early or outpatient treatment more challenging. But results from a government-run study, as well as scientists' understanding of how antiviral drugs work, suggest that patients who are treated with remdesivir earlier on benefit the most.
- Gilead will first test its inhaled formulation in healthy volunteers, to be recruited into a Phase 1 study. Studies of COVID-19 patients could begin by August, said Gilead CEO Daniel O'Day in an open letter dated June 22.
Infectious disease doctors now view COVID-19 as a two-stage disease, marked first by early signs of infection and rapid viral replication and then followed by widespread inflammation amid an overactive immune response.
It's in the second phase where the disease can be the most lethal, compromising breathing function and damaging organs like the heart and kidneys.
As an antiviral, remdesivir would in theory be most effective earlier on, when it can block SARS-CoV-2 from co-opting the body's cells to make copies of itself.
A study run by the National Institutes of Health, results from which led to an emergency authorization of remdesivir's use in the U.S., supports that line of thinking. Data published last month in the New England Journal of Medicine showed remdesivir benefits were greatest before patients got so sick they needed invasive breathing support.
Remdesivir also appeared to help patients who didn't need oxygen — typically the first line of defense as symptoms worsen — although the difference between them and patients on placebo was not statistically significant.
Overall benefit to the drug was modest, however, reducing the median time to recovery by four days. Remdesivir was associated with lower mortality but that, too, was judged not statistically clear.
Because remdesivir is given by an IV drip once daily, administering the drug to patients outside the hospital isn't as easily done, particularly when healthcare systems are strained taking care of those critically ill from COVID-19.
Due to the way the drug is made, an oral formulation doesn't appear easily within reach. An inhaled version, given via a nebulizer like some asthma drugs currently are, could still help, though.
Gilead is planning to test the inhaled version at earlier stages of the disease, and also will conduct trials of the current intravenous drug in certain outpatient settings like nursing homes and infusion centers.
Even if studies testing earlier treatment are successful, limited supplies of remdesivir could hinder efforts to make the drug more widely available, at least over the next few months. The hundreds of thousands of doses Gilead donated upon receiving emergency authorization from the Food and Drug Administration are due to run out by the end of this month.
Gilead is quickly making more but, even with a streamlined manufacturing process, remdesivir still takes six or more months to make. The company now expects to have more than 2 million treatment courses produced by year end — double what it initially estimated.
With donated supplies running out, however, Gilead could soon start charging for remdesivir — a decision that will likely be met with considerable scrutiny and, depending on the price, potential political and public backlash.
The question of price could become even more stark as recent results from a large U.K. study showed dexamethasone, a generic and inexpensive steroid, cut the risk of dying from COVID-19 by about a third in the most severely ill patients.
Pairing remdesivir early on with dexamethasone later could give physicians a way to treat both phases of the disease, but the drugs have not been studied together yet.