With new strains of the coronavirus showing their elusiveness and pushing more antibody treatments toward irrelevance, is there danger of an over-reliance on COVID-19 oral antivirals, especially Pfizer’s Paxlovid?
Friday, the U.S. paused the distribution of GlaxoSmithKline and Vir Biotechnology’s antibody drug sotrovimab in the northeast, where the omicron subvariant BA.2 now accounts for more than half of new infections.
The states included in the directive are Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island and Vermont. In addition, Xevudy’s use will be halted in Puerto Rico and the Virgin Islands.
Lab testing shows that a 500-mg dose of sotrovimab is not “fully active” against the BA.2 variant, the FDA said.
In response, Vir said it's "preparing a package of data in support of a higher dose of sotrovimab for the omicron BA.2 variant and will be sharing these data with regulatory and health authorities around the world."
The move leaves doctors with one less tool with which to combat the virus. In January, after the emergence of omicron in the U.S., the FDA halted distribution of two antibody treatments—Regeneron’s REGEN-COV and Eli Lilly’s cocktail of bamlanivimab and etesevimab.
Then, a few weeks later, the FDA endorsed another Lilly antibody drug—bebtelovimab—which was found to be effective against omicron.
Pfizer’s Paxlovid, for its part, has been shown to be the most reliable treatment against mild-to-moderate COVID-19 infection, retaining its effectiveness across all variants. Since it was approved by the FDA in December, demand has been high for the drug which is taken in tablet form.
Earlier this month, in an agreement with the United Nations-back Medicines Patent Pool (MPP), Pfizer licensed the technology to produce a generic version of Paxlovid to 35 manufacturers around the world that will supply it to 95 low- and middle-income countries.
Merck and Ridgeback have made a similar pact with the MPP, licensing the tech for their oral antiviral molnupiravir to 27 manufacturers who will supply it to 105 needy countries.
Sales of sotrovimab came in at 958 million pounds sterling ($1.26 billion) last year, with 89% of the figure coming in the fourth quarter. Last month, GSK said it expected—based on contracts signed—that it would sell 1.4 billion pounds ($1.83 billion) worth of the treatment this year.