National Institute of Health

This new curative demonstrated a substantial reduction in viral load and an alleviation of clinical symptoms

Two years into the COVID-19 pandemic, the need for effective therapeutics remains as urgent as ever. Medical researchers from South Korea recently identified a human monoclonal antibody named CT-P59, isolated from the blood cells of a recovering COVID-19 patient, can potently neutralize coronavirus strains such as variants of concern (VoCs) such as alpha, beta, gamma, and delta, thereby, becoming an efficient therapeutic antibody for COVID-19. This treatment, approved by the European Commission and marketed as Regkirona (regdanvimab as for international non-proprietary name (INN)), has saved numerous lives in South Korea.

As the pandemic fear still grips the world, researchers develop a new and effective therapeutic for COVID-19.

Image courtesy: Photo by Viki Mohamad on Unsplash

It is now over two years since the world has been plunged into unchartered territories with the COVID-19 pandemic. With new variants on the horizon, governments and medical authorities are constantly on the lookout for new resources to help tackle the SARS-CoV-2 virus. 2021 saw great success in the development and roll out of vaccines, with almost half the population having received at least partial vaccination as the year closed. But what of people who are infected?

Research into treatment options for COVID-19 has also been steadily progressing. A team of researchers, led by Dr Cheolmin Kim of a global biopharmaceutical company , CELLTRION, has now developed a novel monoclonal antibody (mAb), CT-P59, to act as a therapeutic or preventative intervention for COVID-19. Their findings were published in Nature Communications.

To understand the effectiveness of CT-P59, one must first understand the structure of the virus itself. Transmembrane fusion proteins called spike proteins present on SARS-CoV-2 allows the virus to penetrate host cells and cause infection by mediation of both receptor binding and fusion of the viral and host membranes. A short immunogenic fragment called the receptor-binding domain (RBD) situated on the spike helps the virus bind to the receptor, angiotensin converting enzyme 2, present in human cells.

The researchers created an antibody library constructed from peripheral blood mononuclear cells of a recovering patient. Screening this library for human mAbs targeting the RBD of the viral spike protein with neutralization efficacy against SARS-CoV-2 virus pointed them towards CT-P59.

They then conducted virus challenge studies on animal models, which revealed that CT-P59 binds to the RBD of the spike protein before the virus itself can. This slows down the overall viral binding and eliminates the infection symptoms. They also found that CT-P59 significantly inhibited the viral replication of viruses clinically isolated. It also decreased the amount of virus in the lungs and improved clinical symptoms. This success has led the team to brand this novel mAb treatment option as ‘Regkirona’.

This treatment has subsequently been approved by the Ministry of Food and Drug Safety in South Korea and the European Commission. Dr Kim says, “Regdanvimab is one of the first antibody therapeutics against COVID-19 which has obtained approval in Europe. Through this approval, CELLTRION proves its own capabilities to contribute to global healthcare by developing a new antibody-drug beyond antibody biosimilar.”

From the research stage to the implementation, regdanvimab has been a lesson in cooperation. This endeavor brought together the company, governments, and regulators, making rapid development and approval possible. “If the development goes well, and further cooperation is assured,” suggests Dr Kim, “regdanvimab can be employed immediately to fight the pandemic, allowing great strides towards protecting public health.”

Employing regdanvimab can lead to the reduction of morbidity to severe diseases caused by SARS-CoV-2 infection, which will suppress the burden on the medical system and prevent the paralysis of the national system. In practice, regdanvimab has already been administered to more than 30,000 patients in South Korea and is fulfilling its role by saving numerous lives.

This study was supported by a Korea National Institute of Health fund (2020-ER5311-00,2020-ER5323-00, 2019-NI-077-01, 2019-NG-044-01).

Reference

About National Institute of Health in Korea 

The Korea National Institute of Health (KNIH), one of the major operating components of the Ministry of Health and Welfare, leads the nation’s medical research. Over the past seven decades, the KNIH has made unwavering efforts to enhance the public’s health and innovate biomedical research. The KNIH seeks to eradicate diseases and make people healthier. The KNIH establishes a scientific basis and evidence underlying health policy as well as provides national research infrastructures. We also promote public health research. To this end, we make efforts to enrich a health research environment by granting funds to research projects and keeping our resources, data, and facilities more open and accessible to researchers.

Website: http://www.nih.go.kr/eng/

About Dr. Cheolmin Kim

Cheolmin Kim leads the antibody discovery team at CELLTRION, a leading biopharmaceutical company in South Korea. He is in charge of discovering antibodies that can be a new pipeline of the company. He has been working to develop several therapeutic antibodies against infectious diseases such as rabies, Middle East Respiratory Syndrome (MERS), COVID-19. His team is also developing anti-cancer therapeutic antibodies for new pipelines and trying to establish and optimize antibody screening platform for better performance. He received a PhD in pharmaceutical biotechnology from Korea University in 2010.