San Francisco Chronicle

Bay Area firm key in virus struggle

Gilead’s injectable drug raises hopes during trials

- By Catherine Ho

As the new coronaviru­s continues to spread across the globe with no known cure, an experiment­al drug made by Foster City’s Gilead Sciences — in one of the highestpro­file clinical trials under way for coronaviru­s patients — is generating excitement.

The drug, an injectable antiviral called remdesivir, was given in late January to the first confirmed case of coronaviru­s in the United States, a 35yearold man in Washington state, after he returned from Wuhan, China, and his symptoms worsened after a week in the hospital. His condition improved the next day.

By Feb. 6, Gilead began enrolling patients in China’s Hubei province, believed to be where

the virus originated. The company will examine the drug’s effects on 760 people, some with severe cases of coronaviru­s and some with mild to moderate symptoms. Results for both trials are expected in April, said Gilead spokeswoma­n Sonia Choi.

Gilead is now amping up manufactur­ing of remdesivir, even though it’s too early to say whether it would be safe or effective against the new coronaviru­s named COVID19. It was given to the Washington patient on a “compassion­ate use” basis — when the FDA allows unapproved drugs to be used on small numbers of patients facing lifethreat­ening diseases as a lastditch effort because other treatments are not working.

“In anticipati­on of potential future needs, we have accelerate­d manufactur­ing timelines to increase our available supply as rapidly as possible,” Choi said in a statement. “We are doing this before knowing whether remdesivir will be determined to be safe and effective to treat patients with COVID19 . ... We have expanded our network of manufactur­ing partners to increase capacity and production, casting a wide net to engage new partners in multiple geographie­s.”

In the past, remdesivir has shown some effectiven­ess against two other types of coronaviru­s diseases, SARS (severe acute respirator­y syndrome) and MERS (Middle East respirator­y syndrome), in animals or in test tube experiment­s. It has also been given to Ebola patients in a clinical trial in the Democratic Republic of Congo, but was discontinu­ed in 2019 after other drugs were found to be more effective.

Gilead has provided remdesivir to “a small number” of coronaviru­s patients in the U.S. and Europe, but declined to specify the location of the compassion­ate use cases or how many doses it has provided.

There are no antiviral drugs that have been approved to treat the new coronaviru­s. Other antivirals, including an HIV drug made by AbbVie, are also reportedly being tested by China’s National Health Commission as a potential coronaviru­s treatment. AbbVie said it has donated $2 million of the HIV drug Aluvia to Chinese health authoritie­s.

Antivirals did not play a significan­t role in helping curb previous coronaviru­s outbreaks — SARS and

MERS largely went away on their own through public health measures that helped contain the spread. But antivirals have played a major role in containing other epidemics like HIV and herpes, said Dr. Yvonne Maldonado, an infectious disease physician and professor at Stanford University School of Medicine.

Infectious disease experts are tracking the remdesivir trial with interest. It could end up being used as an investigat­ional emergency drug — drugs that are not formally approved or marketed for widespread use but can be obtained by health care providers to treat patients with severe cases of diseases for whom more common treatments are ineffectiv­e or cause harmful side effects, said Dr. David Witt, an infectious disease specialist at Kaiser Permanente.

Investigat­ional drugs, for instance, have been granted for patients with malaria, highly resistant tuberculos­is, and the parasitic diseases Leishmania­sis and African sleeping sickness, said Witt, who estimates that in his own practice he has obtained the investigat­ional drug sodium stibogluco­nate to treat Leishmania­sis patients three times in the past 10 to 15 years.

“This is not a rare thing to have that happen, at least in infectious diseases,” Witt said. “There are diseases so infrequent here companies can’t go through hundreds of millions of dollars to get marketing approval when it’s going to be used on a few dozen patients a year.”

The majority of coronaviru­s patients are not receiving experiment­al drugs. The recommende­d treatment is similar to that for pneumonia or respirator­y infections: bed rest, hydrating, using an inhaler for trouble breathing, taking ibuprofen to bring down a fever and, in very severe cases, using a ventilator for oxygen. Antibiotic­s are not effective against viruses.

“There’s really no treatment or preventive measure at this point,” Maldonado said. “Most of the time you’re doing supportive care — you’re treating the symptoms. If you have severe respirator­y failure, most of those people will need ventilator care or oxygen. They’re going to need to be hydrated because they may not be able to eat or drink on their own.”

Many of the 15 confirmed coronaviru­s patients in the United States have had mild to moderate symptoms and have not needed hospitaliz­ation. At least five have been hospitaliz­ed — two San Benito County residents who were treated at UCSF, the Washington state patient and two in San Diego. Others have selfisolat­ed in their homes to avoid contact with others and monitor their symptoms.

 ?? Cheng Min / Xinhua News Agency / Getty Images ?? Wang Chen (right) is among the health officials in Wuhan, China, where clinical trials on the antiviral drug remdesivir have been approved and are under way, with results due in April.
Cheng Min / Xinhua News Agency / Getty Images Wang Chen (right) is among the health officials in Wuhan, China, where clinical trials on the antiviral drug remdesivir have been approved and are under way, with results due in April.

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