Why COVID sufferers in the US can’t get ensitrelvir, the antiviral drug better than Paxlovid

Medicine

By Marc Lallanilla

For people suffering from a COVID-19 attack, the antiviral Paxlovid has been a godsend.

The drug became the go-to antiviral treatment during the pandemic after the Food and Drug Administration granted it emergency use authorization in December 2021.

Now there is a new antiviral drug superior to Paxlovid, but Americans can’t get it because it’s delayed in the long FDA approval process.

Ensitrelvir, marketed under the name Xocova in Japan, the only country where it is legally available, has several advantages over Paxlovid.

However, experts lament that the newest and most effective drug will likely not be available in the United States until the end of 2024.

The FDA appears to be slowing down the approval process for ensitrelvir, Dr. David Boulware, an infectious disease specialist and professor of medicine at the University of Minnesota, told the Atlantic.

And because the COVID-19 emergency was declared over in May of this year, ensitrelvir likely won’t have the same emergency use authorization as Paxlovid.

Nonetheless, the FDA has granted the new drug fast-track status, meaning its review process will be expedited once the drug’s manufacturer, Shionogi of Osaka, Japan, submits the required documentation.

Ensitrelvir vs. Paxlovid

Ensitrelvir has a number of advantages over Paxlovid and other antivirals.

People who take the drug test negative almost two days earlier than people who take a placebo. Symptoms such as fever, congestion, sore throat, cough and fatigue go away more quickly in some groups of people than with Paxlovid.

Rebound infections, in which symptoms disappear and then appear to return, common among Paxlovid users, have been rare among ensitrelvir users. In addiction, the taste of ensitrelvir is unremarkable, according to anecdotal reports, while patients on Paxlovid have described the aftertaste as a mouthful of dirty coins and rotten soy milk.

And ensitrelvir is easier to take because it only requires one dose per day, whereas Paxlovid users must take three tablets twice a day for five days.

However, the two drugs have never been compared in head-to-head trials, so medical experts are reserving their enthusiasm for ensitrelvir until more data is available.

Loss of smell and taste

Despite this, a new study found that ensitrelvir effectively diminishes one of the most bothersome and problematic effects of a COVID infection: loss of smell and taste.

After seven days, the percentage of study participants experiencing loss of smell or taste was 39% lower in a group taking ensitrelvir than in a placebo group.

Most people will eventually recover on their own, but we know that some people have long-term problems with smell and taste, said Dr. Yohei Doi, an infectious disease researcher at the University of Health. Fujita in Japan who worked on the ensitrelvir study. Nature.

When the omicron variants became dominant, loss of taste and smell began to become less and less common, Dr. Amesh Adalja, an infectious disease specialist at the Johns Hopkins Center for Health Security, told Nature.

But it still happens and is a distressing symptom, Adalja added. What we’re trying to do is not only minimize serious illness, hospitalizations and deaths, but also minimize the disruption that an infection has on people’s activities.

Drugmaker Shionogi continues to conduct clinical trials on the safety and effectiveness of ensitrelvir among different user groups.