AstraZeneca's Evushield, a monoclonal antibody treatment for COVID-19, was granted an emergency use approval (EUA) in the US on Thursday by the country’s Food and Drug Administration (FDA) for use on immunocompromised individuals. The biopharmaceutical major said that it was also in talks with Indian authorities to provide evidence of the treatment to get the necessary emergency approvals in India as well.
"In India, the company intends to submit its application after emergency use authorisation by USFDA with a hope that addition of this monoclonal antibody cocktail will provide adequate ammunition in fight against COVID-19 disease especially for high risk vulnerable and immunocompromised patients," AstraZeneca said.
"We welcome this news and the opportunity it provides to support the unmet needs of high risk and immune-compromised patients and we have already initiated engagements with the relevant health authorities in India to provide them with the latest evidence," AstraZeneca India Pharma Ltd Managing Director Gagandeep Singh Bedi added in a statement.
What is Evushield?
Evushield is the name given by AstraZeneca to its monoclonal antibody cocktail that is going to be used as a treatment to prevent COVID-19 infections. The antibodies tixagevimab and cilgavimab are combined to provide immunity against COVID-19 for up to 6 months.
Tixagevimab and cilgavimab work against the SARS-CoV-2 virus by attaching onto the spike protein, the part of the virus which is used to infect human cells. This action prevents the virus from infecting the host. In the PROVENT study, it was found that one 300-mg dose reduced the risk of symptomatic COVID-19 by 83 percent over six months.
Unlike vaccines, which generate antibodies in the human body through exposure to a part of the virus, monoclonal antibodies are antibodies that are introduced directly to the body. Monoclonal antibodies are created in transgenic mice that have been genetically modified to have the same immune system as humans. The antibodies are taken from the mice and isolated through complex scientific procedures so that they can be ‘cloned’ and mass-produced for treatment. After being processed, these antibodies can then be introduced to the human immune system where they take over the same functions as exposure generated antibodies.
Who can use Evushield?
While the FDA has granted a EUA to AstraZeneca, the Evushield treatment can only be used for immunocompromised individuals currently. The FDA stated that the treatment can be used for patients that have "moderate to severely compromised immune systems due to a medical condition or due to taking immunosuppressive medications or treatments" or have "a history of severe adverse reactions to a COVID-19 vaccine".
Such children who are above the age of 12 and weigh at least 40 kilograms and adults will be eligible to receive the treatment.
Who are immunocompromised individuals and why are only they eligible?
Immunocompromised individuals are people whose immune system is not working at full capacity. This may be due to underlying health conditions like leukaemia, HIV AIDS, genetic disorders; or because they are on immunosuppressive therapy for health conditions like organ transplants, autoimmune disorders or rheumatoid diseases.
Immunocompromised individuals do not respond well to COVID-19 vaccines due to the mechanism of how vaccines work. Since vaccines elicit the generation of antibodies in an individual, the entire process is built upon a properly functioning human immune response. In a healthy immune system, the body recognises the exposure to the vaccines and builds the necessary cells to fight off future infections. Since immunocompromised individuals, as the name suggests, have a compromised immune system that don't elicit the same immune response to vaccines. According to the latest scientific findings, even when fully vaccinated, immunocompromised individuals have very little antibodies against COVID-19.
Since monoclonal antibody treatments don’t necessarily rely on the body’s immune system to such a great degree, they are able to provide protection against infection and symptoms in such individuals.
Vaccines still remain the primary method of preventing infections in healthy individuals who are eligible to receive them. "Vaccines have proven to be the best defense available against COVID-19," said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research.
First Published: IST