By Mrinalika Roy
(Reuters) -Regeneron Pharmaceuticals Inc's COVID-19 antibody drug could be less effective against Omicron, it said on Tuesday, adding to fears about the efficacy of existing treatments after Moderna (NASDAQ:MRNA)'s top boss raised similar concerns about the company's vaccine.
Global markets tumbled after comments from Moderna's chief executive officer rekindled worries that the variant may weigh on a nascent global economic recovery.
Based on its study of Omicron's individual mutations, "there may be reduced neutralization activity of both vaccine-induced and monoclonal antibody conveyed immunity", Regeneron (NASDAQ:REGN) said, adding that the analysis included its COVID-19 antibody cocktail, REGEN-COV.
The company said it was doing further study to quantify the potential impact using the variant's genetic sequence.
One of the antibodies used in the treatment will likely take a hit, the other less so, CEO Len Schleifer said in a CNBC interview.
"Just like vaccines will have to adapt, we're probably going to have to constantly adapt our monoclonals."
Eli Lilly (NYSE:LLY) and Co, which makes a similar monoclonal antibody treatment, is also working to understand neutralization activity of its therapies on Omicron, the company told Reuters in an e-mailed statement.
Regeneron shares fell about 3% in morning trading, while those of Lilly shed 2.5%.
Rival Vir Biotechnology (NASDAQ:VIR) Inc said based on the Omicron sequence its antibody therapy, sotrovimab, will likely maintain potency against the variant.
The company is "working to confirm this in the lab as a matter of urgency", it added.
Gilead (NASDAQ:GILD) Inc said it believed its intravenous therapy, Remdesivir, currently the only antiviral approved for treating COVID-19, will continue to be effective against currently identified variants, including Omicron
The U.S. Food & Drug Administration said on Tuesday it was evaluating the effectiveness of authorized COVID-19 vaccines against Omicron and was expecting to have more information in the next few weeks.[nL4N2SL3Y8]