FDA testing coronavirus treatments, including chloroquine, plasma from recovered COVID-19 patients

Darrell Etherington

U.S. Food and Drug Administration Commissioner Stephen Hahn addressed the ongoing work of the agency in terms of its work on potential treatments and vaccines for the COVID-19 coronavirus currently spreading globally. Despite a claim early in Thursday's White House briefing on the pandemic by President Donald Trump that one proposed treatment, anti-malarial chloroquine, had already been approved by the FDA for COVID-19 treatment, Hahn said that in fact the agency is currently looking at widespread clinical trials of the drug, but it is not yet approved for that use.

"In the short term, we're looking at drugs that are already approved for other indications," Dr. Hahn said. "Many Americans have read studies and heard media reports about this drug chloroquine, which is an anti-malarial drug. It's already approved, as the president said, for the treatment of malaria [Trump had not said this, but had instead said it was now approved for COVID-19] as well as an arthritis condition. That's a drug that the president has directed us to take a closer look at, as to whether an expanded use approach to that could be done to actually see if that benefits patients. And again, we want to do that in the setting of a clinical trial, a large pragmatic clinical trial to actually gather that information and answer the question that needs to be answered."

Another potential treatment which has shown signs of possible positive effect, remdesivir, was also cited by Trump as being very "near" approval for use by the FDA. Hahn clarified that in fact, while remdesivir is currently undergoing clinical trials, it's following the normal FDA process for approval for clinical medical therapeutic use in the U.S. He declined to comment on ongoing commercial arrangements with remdesivir maker Gilead when asked when we might expect the drug to be available commercially.

Hahn also highlighted another experimental treatment possibility that the FDA is investigating: Using plasma derived from blood taken from coronavirus patients who have recovered, and injecting that into other patients in an attempt to potentially jump start their own immune response.

"There's a cross-agency effort about something called convalescent plasma," he said. "This is a pretty exciting area. And again, this is something that we have given assistance to other countries with as this crisis has developed, so FDA has been working for some time on this. If you've been exposed to coronavirus and you're better, you don't have the virus in your blood. We could collect the blood now, this is a possible treatment. This is not a proven treatment, I just want to emphasize that, [but we would] collect the blood, concentrate that and have the ability, once it's pathogen-free, that is virus-free, be able to give that to other patients and the immunoglobulins, the immune response could potentially provide a benefit to patients."

All of the treatments currently approved for use by the FDA to treat other ailments are available to medical professionals in case of "compassionate use," Hahn said. This provision allows a practitioner to use these medications on COVID-19 patients, even though they aren't technically cleared specifically to do so, in extreme cases. The benefit of this compassionate use model is that doctors who take advantage of that are then required to share all patient info regarding administration and response to the drug, which helps inform ongoing trials and regulatory efforts.

Numerous clinical studies have been conducted globally regarding the performance of chloroquine and remdesivir since the beginning of the pandemic. Most recently a French study that included use of a chloroquine variant called hydroxychloroquine found that it performed particularly well in tandem with an antibiotic known as azithromycin. Still, Hahn said that even if a drug is already approved for other use, it's crucial for the safe deployment of any therapeutic treatment that researchers determine the right dose to protect a patient's health.