Can plasma treatment become alternative when remdesivir fails?

Shincheonji Church of Jesus members who have recovered from COVID-19 wait in line to donate blood plasma at Kyungpook National University Hospital in Daegu, 300 kilometers south of Seoul, July 13, to support the development of a vaccine or drug to treat the virus. Yonhap

By Bahk Eun-ji

The most promising drug shown to treat COVID-19 patients so far is remdesivir, an antiviral medication made by Gilead Science, but it requires more rigorous clinical trials at least here in Korea, according to the health authorities.

The Korea Centers for Disease Control and Prevention (KCDC) said it has administered remdesivir to 42 COVID-19 patients from July 2 to 10. On July 13, it reported results from the group given the drug in different hospitals; nine showed an improvement, 15 showed no change, and three showed a worsened condition.

Because the result has yet to be compared with a control group, KCDC Deputy Director Kwon Joon-wook said the quarantine authorities would seek experts' opinions as well as conduct further analysis in order to ascertain its efficacy.

Plasma transfusions is one of two therapies that many researchers have proposed to treat the novel coronavirus with remdesivir. In a recent guideline of National Health Commission in China, Zhang Dingyu, director of Jinyintan Hospital in Wuhan, said a new treatment using the plasma of the patients recovered from the virus was effective in other patients battling it. He said the plasma contained a large number of immune antibodies.

Plasma extracted from blood of recovered patients is used to make products that are the most effective treatment for COVID-19 when there is no drug or vaccine. These products can significantly lower the fatality rate of patients with severe symptoms, Zhang was quoted as saying by The Global Times.

“Blood from recovered patients contains a high concentration of antibodies. Trials on patients in a severe condition using plasma from recovered patients have been carried out in Jinyintan Hospital, a facility designated for COVID-19 treatment, and we have seen good results so far,” he said.

In the absence of a vaccine experts said the plasma appears to be the most reliable alternative.

Kwon said a clinical trial for plasma therapy is likely to start here in September, while the government already started a joint study on the treatment in March.

The number of plasma samples needed for the clinical trial is at least 130. As of July 14, health authorities received the plasma from 182 out of 390 recovered patients who expressed their intention to donate their blood plasma for the government's research. The number is expected to increase as more than 4,000 followers of Shincheonji Church of Jesus, the country's minor religious sect, who have recovered from COVID-19 have said they will donate their blood plasma to support the development of a treatment.

Shincheonji was at the center of the early stage of the virus outbreak in Korea from February to March. Some 4,000 followers, most of whom were from its branch in the southeastern city of Daegu, were infected with the virus.

Experts said the massive donation of blood plasma by the religious group could accelerate the development of blood plasma treatment in the country. In particular, the treatment success in cases previously identified in Korea has raised expectations for the development.

In April, a group of doctors at the Severance Hospital in Seoul, which administered plasma therapy on two elderly patients, uploaded their method of treatment to the website of the Journal of Korean Medical Science.

The two patients were a 67-year-old woman with a medical history of hypertension who tested positive on March 6, and a previously healthy 71-year-old man who was confirmed to have contracted the virus on Feb. 22, according to the article. Both patients recovered after being treated with plasma from coronavirus survivors.

Limitation to therapy

Blood plasma is the perfect medicine in theory, but in fact, there are many limitations and no country has yet succeeded in developing a vaccine. The theory goes that giving the plasma containing the antibody to people currently infected with COVID-19 helps them recover. This approach has been used in the past to treat severe acute respiratory syndrome (SARS) and Ebola, but results were mixed.

“It's an old technique,” Scott Koepsell, medical director in the division of transfusion and transplantation support services at the University of Nebraska Medical Center who has collected plasma from Ebola survivors was quoted as saying by The Verge. He says that while plasma transfusions have been used for over a century, it's still a treatment of last resort.

“It's a really well-meaning approach, but it has a lot of variability and limitations,” he said.

For example, every person who survives an infection will have a slightly different mix of immune substances in their plasma. Each sick person treated with plasma, then, is getting a slightly different treatment. That can make it really difficult for researchers to tell whether plasma therapy is generally effective (or ineffective) or whether it depends on if a patient gets a really good (or bad) batch of plasma.

Choi Joon-yong, an infectious medicine professor at Severance Hospital, who conducted an earlier study on the plasma treatment, said, “The treatment has its own side-effects and there is not enough scientific evidence as there have been no large-scale clinical trials yet.”

“But it will be an alternative treatment for severe patients who are not seeing effects with anti-virus treatment if it can be combined with other drugs including steroids,” he said.

GC Pharma, a Korean biopharmaceutical company, is in charge of developing the domestic plasma treatment. The company is currently preparing for clinical trials of the plasma with the aim of commercializing it in the second half of the year.