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DJ Enthusiasm Fades for Covid-19 Antibody Treatments in South Korea

· 02/05/2021 07:02
By Dasl Yoon

SEOUL--Late last year, South Korea's prime minister called a homegrown antibody treatment that was nearing completion "a ray of light," while the chairman of the pharmaceutical firm that was developing it boasted the medication could make the country free of Covid-19 by the spring.

But on Friday, even as South Korea's drug regulators granted fast-track approval to Celltrion Inc.'s monoclonal antibody treatment, hopes that it could be an immediate game-changer have diminished.

The introduction of the new treatment was met with skepticism as previously approved antibody drugs have had limited impacts on aiding recoveries from Covid-19 before vaccines become readily available.

"We are hoping the treatment will lighten the burden of hospitalizing patients with serious symptoms," said Kim Gang-lip, the country's top drug-approval official. "It's difficult to say how much [the treatment] will help in containing a surge."

Celltrion's drug, dubbed Regkirona, is intended for use with patients who have been diagnosed with Covid-19 and relies on lab-engineered versions of antibodies that simulate the body's natural immune response to viruses. The class of therapies attracted attention after former President Donald Trump said a monoclonal antibodies drug helped him achieve a speedy recovery.

But use of such treatment has been underwhelming globally due to a lack of clinical data that has caused infectious-disease experts to be skeptical.

Celltrion's initial clinical results won it conditional approval but fell short of initial optimism. In stage-two clinical trials, the Celltrion drug shortened recovery time by about three days but it is expected to make a minimal dent on intensive-care unit hospital beds when cases rise. More than 80% of South Korea's Covid-19 patients exhibit mild symptoms and won't be given Celltrion's drug unless they fall into the high-risk category under the drug ministry's guidelines.

"Covid-19 antibody drugs began ambitiously but the impact is not as clinically meaningful as we expected," said Lee Hyuk-min, an infectious disease expert advising the South Korean government.

A Celltrion spokesman said its antibody drug can help patients avoid developing more serious symptoms, while reducing hospitalization periods. "We are working to provide data on variants of the virus as soon as it is available," the spokesman said.

South Korea has procured enough vaccines to cover more than its population of 52 million, with a rollout that is expected to begin later this month. But officials initially held off on mass purchases, citing the use of antibody treatments as a tool that would lower fatalities by reducing the number of patients with severe symptoms.

Coupled with the country's track-and-trace success, the antibody treatments could keep hospitalizations low, buying the country extra time to assess whether the newly developed Covid-19 vaccines carry unknown side effects or prove effective. South Korean President Moon Jae-in has promised to fund Celltrion's clinical trials and support the treatment's exports.

Mr. Trump received an antibody cocktail developed by Regeneron Pharmaceuticals Inc. It gained emergency approval from the U.S. Food and Drug Administration, along with Eli Lilly & Co.'s antibody drug, to treat patients who aren't hospitalized but are at high risk of developing severe disease symptoms.

Initially those companies expected demand to exceed supply with positive initial results, but many of the treatments now sit idle in American hospitals as infectious-disease specialists wait for more clinical trial data before using them on a regular basis. Regeneron last month said its antibody drug reduced coronavirus infections by half for people at high risk, according to an interim analysis of a continuing study.

"There is a limited window for such medicines to be effective and even under the best of circumstances, monoclonal antibodies are only going to be useful for a subset of patients," said Keiji Fukuda, a former World Health Organization official who worked extensively on the H1N1 and other recent major outbreaks. "In contrast, vaccines are useful for virtually everyone because they help people develop immunity."

Celltrion's Regkirona drug will initially be administered to just a sliver of South Korea's Covid-19 patients. In recent weeks, new infections have numbered between 300 to 600 a day.

The Celltrion treatment would only be used on adults with moderate symptoms or people with mild symptoms who fall into high-risk categories, said Mr. Kim, at the Friday briefing. To use the Celltrion drug more widely, the phase-three clinical data will need to show an ability to work against new coronavirus variants, he added.

Celltrion has already produced 100,000 doses to supply to hospitals. The treatment is directed against the surface of the virus and is designed to block it from penetrating human cells. There are 10 other South Korean Covid-19 treatments in clinical trials.

One of the challenges that South Korean pharmaceutical companies have faced in developing Covid-19 treatment drugs was the lack of trial participants and plasma donations, local health officials said.

Write to Dasl Yoon at dasl.yoon@wsj.com

(END) Dow Jones Newswires

February 05, 2021 07:02 ET (12:02 GMT)

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