(Bloomberg) -- U.S. regulators may decide within a week or two whether to approve a shorter course of Gilead Sciences Inc.’s Covid-19 drug remdesivir that could be used for patients outside the hospital, Chief Executive Officer Daniel O’Day said in an interview.

A five-day course of the infused drug is already a mainstay for hospitalized Covid patients. Gilead has applied for U.S. clearance of a three-day course that could be used in the outpatient setting, after a big trial last year showed it could sharply reduce hospitalizations in at-risk patients.

Officials at the U.S. Food and Drug Administration “are working really collaboratively with us, quickly with us,” O’Day said in the interview. “Everything is moving really fast.”

The U.S. Food and Drug Administration declined to comment on its timeline for a decision. 

If approved, outpatient remdesivir, or Veklury, could provide another treatment option to manage the omicron surge. While doctors can legally prescribe the outpatient regimen now, as the drug is already on the market for hospitalized patients, many doctors are likely to wait for an official blessing from regulators before employing the treatment widely for outpatients.

An an infused drug, remdesivir is more complicated to administer than the Pfizer Inc. Covid pill Paxlovid. But Gilead has an abundance of supply on hand, O’Day said in the interview. By contrast, supplies of Pfizer’s drug are limited in the short term as the company ramps up supply.

Pill Option

“We are ready to go once we have the approval,” O’Day said in the interview. The drug works against all variants including omicron, and the company has a distribution system ready to ship the drug upon approval for the new use, O’Day said. 

Meanwhile, O’Day said that Gilead is working hard to develop a chemical cousin of remdesivir that could be given as a pill. That oral drug is about to begin human trials. If it works, it could be combined with other drugs to treat Covid, he said.

Gilead’s long experience with HIV has showed that drug combinations are one way to counter a continually mutating virus. If Covid keeps evolving, combination therapies may be needed in the long run.

“There is no doubt in my mind” that Covid will continue to mutate, O’Day said. “We want to be prepared for that.” 

Globally, remdesivir has been used by more than 10 million Covid patients to date, O’Day said in a conference presentation earlier on Monday. In the U.S. more than 3 out of 5 hospitalized patients are getting it, he said.

(Updates with FDA response in fourth paragraph)

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