The Washington University School of Medicine in St. Louis reported on Monday that a cocktail of two types of antibodies used as a therapy for Covid-19 was found to be working well against a wide range of variants of the coronavirus when tested in mice and hamster.
Covid-19 cases are often treated early in the process by antibodies. In October last year, an antibody cocktail by Regeneron Pharmaceuticals was used for treating the former United States president Donald trump after he tested positive for Covid-19.
Three of the four variant of the coronavirus detected so far and those that have been designated “variants of concern” by the World Health Organization were included in this latest study. The variants included Alpha, which was first identified in the United Kingdom, Beta, which was first found in South Africa and the Gamma variant that was first identified found in Brazil. The study also included an emerging variant from India which has been identified to be similar to the Delta variant which has caused concerns among experts.
Arguing that the single antibody therapy for Covid-19 from Eli Lilly resulted in an increase in circulation of variants resistant to the therapy when used alone, the emergency use authorization of the therapy was revoked in April this year by the United States Food and Drug Administration.
Some of the combination therapies of antibodies were found in other studies to retain potency against those emerging variants of the coronavirus which were identified to by resistant to single antibody therapies.
Potency against variants were often found to be increased by the combinations of two antibodies in the latest study even though one of the two antibodies used in the combination was found to lose some or all of its ability of neutralizing the variant in lab studies.
All the available single and combination antibody therapies that have been authorized for emergency use by the FDA were used by this latest study which was conducted in mice and hamsters, against the emerging US and international variants of the novel coronavirus.
Combination therapies authorised by the FDA for emergency use and made by Regeneron, Eli Lilly and a single antibody therapy, sotrovimab, by Vir Biotechnology Inc and GlaxoSmithKline Plc werte all evaluated in the study by the researchers.
The antibodies currently in clinical trials by AbbVie Inc, Vir and AstraZeneca were also assessed and evaluated in the study.
“Resistance arose with some of the monotherapies, but never with combination therapy,” study co-author Jacco Boon wrote.
(Adapted from ScienceDaily.com)