Patients unable to produce Covid antibodies supported by new drug

The Erasmus Medical Center has begun using the drug REGEN-Cov to treat patients with Covid-19 who have a reduced ability to produce antibodies themselves. This includes patients who are taking immunosuppressive medications which are prescribed after a person is the recipient of a transplant.

“You are buying time for patients to make their own antibodies”, said Bart Rijnders, an internist and infectious diseases specialist at the hospital. “In patients who will never produce their own antibodies, it helps the other immune systems in the body in their fight against the virus.”

The hospital referred to the drug as a breakthrough. It consists of two monoclonal antibodies that reduce the ability of the SARS-CoV-2 coronavirus to enter human cells. These monoclonal antibodies are called casirivimab and imdevimab.

Monoclonal antibodies were first discovered in the blood plasma of a patient who had recovered from Covid-19. These antibodies can be produced in the lab and given to patients who lack them.

About one in three patients who end up in hospital due to Covid-19 do not yet make antibodies against the virus themselves. “Some of them do not make antibodies against the Sars-CoV-2 virus after full vaccination. So, they will get really sick when they encounter the virus”, Rijnders said.

A British study showed that Covid-19 patients who did not yet have antibodies upon admission were able to be released four days earlier on average if they were treated with monoclonal antibodies. Researchers identified casirivimab and imdevimab as some of the most potent antibodies which is why they were isolated and included in the new drug.

Monoclonal antibodies have been approved by the European Medicines Agency (EMA) and have been included in the Dutch Covid-19 treatment guideline. The first patients have already been treated with the new drug.

In a few months, 80 percent of the Dutch population will be fully vaccinated, Rijnders hoped. The majority of Covid-19 patients will then either be unvaccinated or cannot produce antibodies. “Every new Covid-19 patient is now checked immediately upon admission for antibodies. If they do not produce any, we have a new weapon in our arsenal.”