By Paul R. La Monica, CNN Business

(CNN) -- President Trump received a high dose of an experimental antibody cocktail from Regeneron as part of his Covid-19 treatment. Now the drugmaker's stock is up sharply -- and questions are swirling about the president's ties to Regeneron's billionaire CEO.

Trump's team revealed Friday that the president received the drug, called REGN-COV2, which is being used to alleviate symptoms and reduce viral load. Shares of Regeneron surged 7% in midday trading Monday, bringing the stock's year-to-date gain to more than 60%.

Regeneron CEO Dr. Leonard Schleifer and President Trump are acquainted: The CEO has been a member at Trump's golf club in Westchester, New York, and his company also received $450 million in government funding in July as part of the president's Operation Warp Speed plan to quickly develop a vaccine and other treatments for Covid-19.

Meanwhile, Trump also recently owned shares of Regeneron -- as well as Gilead Sciences, maker of the antiviral drug remdesivir that the president is also taking. Both stocks were listed as assets on Trump's 2017 filing with the U.S. Office of Government Ethics, though neither were holdings on the president's most recent filing for 2020.

"Len and President Trump are acquaintances from both living in the Westchester area for many years but didn't have any regular contact until this year, when they've discussed matters around Covid on occasion," Regeneron told CNN Business in a statement.

According to Forbes, Schleifer is now worth $2.5 billion, up from $2.1 billion in the middle of March. Schleifer primarily donated to Democratic political candidates and PACs in the 2016 and 2018 elections, according to Federal Election Commission records.

Regeneron is one of many biotechs and Big Pharma firms that has skyrocketed on hopes that it may be able to quickly develop an effective coronavirus treatment. The company started human trials for its antibody cocktail in June and began a phase 3 trial just a month later.

It has not yet been approved by the Food and Drug Administration, however. The FDA can approve the administration of it through so-called "compassionate use" requests on an individual basis. Regeneron confirmed to CNN Business that it made such a request to the FDA to approve administering the drug to Trump.

Schleifer defended the decision to give Trump the cocktail last week, telling CNN's Wolf Blitzer that Trump "is in a higher-risk group for a variety of reasons" and that "we hope that we will give his immune system enough of a boost so that he can win this and make a complete recovery."

"We've got a lot of data, but we're still in the experimental phase. But when you're in the midst of a pandemic and you have people at risk, we think it makes sense to try these," Schleifer added.

Regeneron added in its statement to CNN Business that it is "in discussions with the FDA about potential for an Emergency Use Authorization for REGN-COV2" following the release of positive data about the drug last week.

The company had announced just a few days before President Trump's admission to Walter Reed that its cocktail "reduced viral load and the time to alleviate symptoms in non-hospitalized patients."

Regeneron said it is also in the process of studying the effect of the cocktail on hospitalized patients, as well as whether it can prevent infection in people who have been exposed to Covid-19.

Dr. George Yancopoulos, Regeneron's president and chief scientific officer, told CNN's Julia Chatterley in an interview Monday that the company is hoping it can get more doses of REGN-COV2 to patients within the next few months thanks to a partnership with Big Pharma giant Roche.

"We are on track to deliver 300,000 doses by the end of the year and...produce 300,000 doses a month while the demand may even still exceed that," Yancopoulos said. "If the drug is really working and having the effects that we all hope it would, it could be doing a lot of good for a lot of people."