- The U.S. government has paused distribution of Vir Biotechnology and GlaxoSmithKline's COVID-19 antibody drug sotrovimab in eight Northeastern states, as well as Puerto Rico and the Virgin Islands, due to the spread of a virus variant the medicine is unlikely to neutralize.
- The variant, known as BA.2, is a substrain of omicron, which spurred a surge of cases in the U.S. over the winter. While sotrovimab is potent against omicron, new lab tests indicate it's likely weaker against BA.2, which accounted for more than half of the infections as of March 19 in the states and territories covered by the government's order.
- Vir and GSK believe that a higher dose of sotrovimab may be more effective and are preparing to share supportive data with regulators in the U.S. and elsewhere. In the meantime, however, the Food and Drug Administration has amended its authorization of the drug and advised healthcare providers to rely on other options, like Pfizer's Paxlovid or Eli Lilly's newest COVID-19 antibody, bebtelovimab.
Vir and GSK's drug was initially an afterthought when it was first authorized last May. Similar treatments from Eli Lilly and Regeneron were already available and keeping COVID-19 patients out of the hospital. Both drugmakers generated billions of dollars in revenue, and Regeneron's treatment, in particular, appeared to remain effective against variants like alpha and delta.
But omicron and its more extensive list of mutations changed that. The variant rendered Regeneron and Lilly's drugs ineffective, leaving Vir's medicine the only useful antibody treatment available in the U.S. Antiviral pills like Pfizer's Paxlovid and Merck's molnupiravir were then in short supply. That situation led to a "pivotal moment" for Vir, CEO George Scangos said in January, as the biotech cut deals with the U.S. and other countries and accelerated plans to make 2 million doses of the drug in 2022.
Vir's moment may be short-lived, however. The omicron wave has subsided, and the variant's dominance has since been challenged by a substrain known as BA.2 that U.S. government officials are concerned may drive an uptick in infections. In February, the FDA cleared a new antibody from Lilly, bebtelovimab, that has appeared effective in laboratory testing against all known variants of concern, including BA.2. The U.S. quickly bought 600,000 doses and grabbed an option to acquire another half million.
Supplies of Paxlovid and molnupiravir, meanwhile, have grown. The federal government distributed 175,000 doses of Paxlovid and nearly 100,000 of molnupiravir this past week versus about 33,000 sotrovimab doses and 28,000 of bebtelovimab. Roughly 5,000 of the allocated sotrovimab doses went to the states and territories where its use is no longer recommended.
The numbers could dwindle for Vir and GSK if BA.2 spreads further and Congress doesn't authorize new emergency funding for COVID-19 treatments. On a press call last week, White House COVID-19 response coordinator Jeff Zients said the government had to cut allocations of antibody drugs to each state by 35% and expects to exhaust its current supply in May.
"Unless we get the funding requested of Congress, we will not be able to continue to make these purchases," said National Institute of Allergy and Infectious Diseases director Anthony Fauci, of the government's ability to buy more COVID-19 antibodies.
Vir shares fell by about 13% on Friday following the FDA's announcement and have lost more than half their value since December.