Remdesivir coronavirus treatment will eventually need a 'sustainable model' to keep it accessible, Gilead CEO says
Gilead Sciences is working to make experimental antiviral drug remdesivir accessible and affordable to coronavirus patients, but the company will eventually need to transition to a more "sustainable model," CEO Daniel O'Day said Friday.

"We understand our responsibility both to patients and also to shareholders and we'll be balancing that," he said during an interview with CNBC's "Squawk Box."

Gilead has said it is prepared to donate 1.5 million doses of its drug to patients hospitalized with Covid-19. However, O'Day said the research and manufacturing of the drug require investment.

Gilead spent $50 million on the research and development of remdesivir during the first quarter, it disclosed in its earnings report Thursday. The company said it will spend as much as $1 billion for the year.

"There is no playbook for this situation that we're in today," he said. "This is the time for us all as an industry, especially Gilead, to do the right thing."

Gilead shares, which have a market value of just under $100 billion, were trading down more than 5% Friday. The stock is up 20% so far this year.

On Wednesday, Gilead released preliminary results from its clinical trial of remdesivir, showing at least 50% of the Covid-19 patients treated with a five-day dosage of the drug improved. The clinical trial involved 397 patients with severe cases of Covid-19. The severe study is "single-arm," meaning it did not evaluate the drug against a control group of patients who didn't receive the drug.

The National Institute of Allergy and Infectious Diseases also released results from its own study Wednesday. It showed Covid-19 patients who took remdesivir usually recovered after 11 days, four days faster than those who didn't take the drug.

Remdesivir, touted by President Donald Trump, has not been formally approved to treat the virus, and U.S. health officials caution new data on the drug has yet to be peer-reviewed. Still the new results boosted hopes for a treatment for the coronavirus, which has infected more than 3.1 million people worldwide, according to data complied by Johns Hopkins University.

The company expects to produce more than 140,000 rounds of its 10-day treatment regimen by the end of May and anticipates it can make 1 million rounds by the end of this year. Gilead said it will be able to produce "several million" rounds of its antiviral drug next year.

O'Day said Friday that the company is scaling up its supply chain after learning from other serious outbreaks such as influenza.

"It's extremely important you have a robust supply chain with a lot of duplication in it," he said.