Regeneron’s stock spiked more than 4% after-hours on the news. The drug Trump is taking is a cocktail of antibodies, an approach that other companies such as Eli Lilly have been testing to fight COVID with existing products for other conditions that can be treated with these biological protectors.

Here’s what the President is taking, according to White House physician Sean Conley via a press release: “Following PCR-confirmation of the President’s diagnosis, as a precautionary measure he received a single 8 gram dose of Regeneron’s polyclonal antibody cocktail. He completed the infusion without incident. In addition to the polyclonal antibodies, the President has been taking zinc, vitamin D, famotidine, melatonin, and a daily aspirin.”

What he’s not taking, or at least has not said he’s taking, is any of the products or questionable therapies he’s has played up to the public, often to the outright condemnation of public health officials such as his own former Food and Drug Administration (FDA) chief Scott Gottlieb. Specifically, hydroxycloroquine: the supposed anti-malarial miracle cure for coronavirus that Trump has touted on numerous occasions despite a lack of compelling scientific evidence that it can lessen COVID’s impact.

Regeneron released data just two days ago showing that its antibody cocktail can reduce the so-called viral load of coronavirus, specifically among those who may be symptomatic but not seriously ill. That may explain why Trump and his physicians chose to go down this particular therapeutic route.

Other COVID treatments which have shown promise against the pathogen include Gilead’s remdesivir and common steroids such as dexamethasone.