December 10, 2021: FDA Approves Anti - SARS - CoV - 2 Monoclonal Antibodies For The Vaccine Insensitive Immune Suppressed Population

Immunocompromised Americans who are not adequately protected by their Covid-19 vaccination series will now have an additional option for long-term protection in the form of an antibody cocktail drug developed by AstraZeneca.

Antibody drugs have been a standard treatment for Covid-19 infections for over a year, but the AstraZeneca drug is the first intended for long-term prevention against COVID-19 infection, rather than short-term treatment. This development demonstrates the potential for monoclonal antibodies to be used in tandem with vaccines for the strongest possible long-term protection against this ever-evolving virus.

The FDA has issued an emergency use authorization for AstraZeneca’s drug which will be sold as Evusheld. The drug is a cocktail of tixagevimab co-packaged with cilgavimab and administered together and is authorized for the pre-exposure prophylaxis of Covid-19 in adults and children 12 and older whose immune systems haven't responded adequately to COVID-19 vaccines or have a history of severe allergic reactions to the shots. The drug is given via an intramuscular injection.

Specific groups who could benefit from the antibody drug include cancer patients, organ transplant recipients, elderly populations, and people taking immune-suppressing drugs for conditions like rheumatoid arthritis. A study published earlier this year found that out of 3 million insured Americans, 2.8% were taking immunosuppressant drugs.

The US has a contract with AstraZeneca to purchase up to 700,000 doses of the treatment which will be allocated proportionally to states and distributed at no cost within the next few weeks. Yet the decision by AstraZeneca to price the drug commercially while negotiating contracts with governments around the world during the pandemic will broadly constrain the effectiveness of the drug and create issues of equity.

Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to fight off harmful pathogens such as viruses. Tixagevimab and cilgavimab are long-acting monoclonal antibodies that are specifically directed against the spike protein of SARS-CoV-2, designed to block the virus’ attachment and entry into human cells. Tixagevimab and cilgavimab bind to different, nonoverlapping sites on the spike protein of the virus.

AstraZeneca tested the Evusheld drug in approximately 5150 adults who were older than 59, had a prespecified chronic medical condition or were at increased risk of Covid infection in a randomized, double-blind, placebo-controlled trial. In the primary analysis, those who received the drug saw a 77% reduced risk of developing Covid-19 compared to those who received a placebo. In further analyses, the reduction in risk of developing Covid-19 was maintained for drug recipients through six months.

MonoclonalAntibodies:TheOnceandFutureCureforCovid-19

Evusheld has not presently been authorized for the treatment of post-exposure prevention of Covid-19. But it is important to ask why and continue to collect data on how monoclonal antibodies can be used prophylactically in high-risk congregate settings such as nursing homes, prisons, and military ships. We also need greater research into how antibodies can match the variant in circulation. Although widespread vaccination against Covid-19 remains the top priority, the emergence of the Omicron variant highlights that additional lines of defense are needed.

This articleoriginallyappeared on Forbes, and can be read online here:FDAApprovesAnti-SARS-CoV-2MonoclonalAntibodiesFor TheVaccine Insensitive ImmuneSuppressedPopulation