The National Institutes of Health announced the start of two clinical trials for a potential coronavirus treatment called monoclonal antibodies.
Two treatments — remdesivir and dexamethasone — have been shown to help severely ill COVID-19 patients, but this would be the first potential drug to help patients early in the disease.
"What we're dealing with now is trying to determine what works in early disease," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a press briefing Tuesday.
Monoclonal antibodies are made in a lab to mimic the body's natural antibodies. Antibodies act by recognizing specific pathogens — in this case, SARS-CoV-2, the virus that causes COVID-19 — and harnessing the immune system to fight them off.
The NIH trials will use a monoclonal antibody developed by Eli Lilly, called LY-CoV555. This antibody was isolated from a COVID-19 patient in Washington state in the early months of the pandemic, Fauci said. It works by binding to the virus's infamous spike protein, interfering with its ability to infect cells.
Gigi Gronvall, a senior scholar at the Johns Hopkins Center for Health Security, said that there are good reasons to be optimistic about monoclonal antibodies. Early data from Regeneron, another drugmaker working on monoclonal antibodies, found that the drug was effective in both treating and preventing infection in animals. Those findings were published Monday on the preprint server bioRxiv.
If monoclonal antibodies are shown to work as a treatment in the clinical trials, that would give a lot of promise for their use as a preventive medicine, as well — one that would likely be available before a vaccine, Gronvall, who is not involved with either drug trial, said.
The clinical trials are part of the NIH's Accelerating COVID-19 Therapeutic Intervention and Vaccines program, or ACTIV.
One trial, ACTIV-2, focuses on patients early in the course of the disease, who have not been hospitalized but have tested positive within seven days and have had symptoms for no more than 10 days. A total of 220 patients will be enrolled in the phase 2 stage of this trial; half of whom will receive the experimental treatment and half of whom will receive the placebo.
The goal of the trial is to determine whether the treatment reduces the duration of a patient's symptoms through 28 days, as well as if the treatment increases the proportion of patients who test negative for the virus at various points during the trial period.
If things go well, the trial will transition to phase 3, enrolling an additional 1,780 patients for a total of 2,000, Fauci said. These patients — some of whom are at high-risk for severe illness, including older individuals — will be monitored to see if the monoclonal antibody treatment reduces the risk of hospitalization and death.
The treatment is given intravenously and takes about an hour to deliver, the NIH said in a statement.
Though the trial is enrolling nonhospitalized patients, it's possible that these individuals may need hospitalization later on; the trial will determine whether the treatment reduces these odds.
The second trial, ACTIV-3, will include sicker patients: those who are hospitalized with COVID-19, but do not have end-stage organ failure. Notably, these patients are not sick enough to receive dexamethasone, Fauci said, although they will be given remdesivir. Three hundred patients will initially receive treatment or placebo in the phase 2 trial, and in phase 3, another 700 will be included for a total of 1,000 patients. The goal of the ACTIV-3 trial is to determine whether patients continue to recover for 14 days at home after they are released from the hospital.
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Fauci said that results from the trials should be available sometime in October, and if the treatments are shown to be successful, the drug would be available to Americans "pretty quickly thereafter."
Dr. Dan Skovronsky, chief scientific officer at Eli Lilly, said that the company is currently working on manufacturing large quantities of the drug, and will have more than 100,000 doses available by the end of the year.
However, he noted, "production capacity for monoclonal antibodies in general is limited in the world," and the 100,000 doses is "still not enough."
On Monday, Eli Lilly announced another phase 3 clinical trial with the same monoclonal antibody candidate. That trial, which will include participants who live and work in nursing homes, aims to determine whether the drug works prophylactically, to prevent coronavirus infection.
CORRECTION (Aug. 5, 2020, 3:27 p.m. ET): A previous version of this article misstated what drugs patients enrolled in the ACTIV-3 trial will be given. They will be given remdesivir, but not dexamethasone.