US restarts shipments of two mAbs that don't work against Omicron as Merck pills see wider distribution
For anyone who’s been following how the US government has been allocating and shipping supplies of its Covid-19 treatments over the past year, the news has shifted so many times that it can be difficult to keep track of what’s still being shipped and where.
More change is coming this week too, as HHS has now decided to re-start shipments of both Eli Lilly (bamlanivimab plus etesevimab) and Regeneron (casirivimab plus imdevimab) monoclonal antibody products after a short pause because neither product works against the new variant Omicron. Lilly’s combo also was halted last June due to the presence of other variants.
“If the Delta VOC [variant of concern] still represents a significant proportion of infections in a region and other options are not available or are contraindicated, eligible patients can be offered bamlanivimab plus etesevimab or casirivimab plus imdevimab, with the understanding that these treatments would be ineffective if the patients are infected with the Omicron VOC,” HHS’ ASPR said in a statement.
The announcement comes as the US has restarted shipments of GlaxoSmithKline and Vir’s mAb sotrovimab, which does work against Omicron, and as shipments began of AstraZeneca’s prophylactic antibody Evusheld, as well as the Merck and Pfizer pills to treat Covid, all of which are in short supply as Omicron cases rise nationwide.
While the restart for the Lilly and Regeneron monoclonal antibodies could potentially create issues if certain administering sites cannot identify if someone who’s tested positive for Covid-19 has either the Omicron or Delta strain, some doctors think the move by HHS still makes sense.
“I think it’s the right move, since there is still Delta around and some facilities may have ability to determine which infections are Delta still,” Walid Gellad, professor of medicine at the University of Pittsburgh, told Endpoints News. “Yes, the risk is some with Omicron will get older versions, while risk, on the other hand, is patients with Delta not getting a mAb because of severe shortages of sotrovimab. It’s not an ideal situation in any way, but better in my view to have it available for prescribers who are knowledgeable to have it as an option.”
Only regions with greater than 80% Omicron prevalence will not receive the Lilly and Regeneron mAbs, HHS said. But sites with more than 80% Omicron prevalence may continue to receive product upon request.
“It really is a provider’s decision which treatment to use. While of course we want the effective treatments to be matched with the appropriate variants, I think our bigger concern is if patients infected with Delta who could benefit from mAbs are not receiving any treatment at all due to a false assumption that they have Omicron,” a Regeneron spokesperson told Endpoints.
But others noted the time constraints and difficulty in guessing, now that the CDC says that more than 90% of cases nationwide are due to Omicron.
“As far as I am aware, the vast majority of sites are not equipped to distinguish the variants in the short time frame necessary to give mAbs. Administration in most cases is likely to be a matter of playing the odds about which variant is the most likely cause of the infection,” Jeff Henderson, associate professor in the infectious disease department of Washington University School of Medicine in St. Louis, told Endpoints.
He also noted that convalescent plasma from donors who have recovered from infection and have been immunized “may be effective with both Omicron and non-Omicron variants but is in extremely limited supply unless collections resume.” The FDA recently changed its EUA for convalescent plasma to allow for outpatient use in immunosuppressed patients.
Meanwhile, in a call last week with state health officials, ASPR officials said the jurisdictions are likely to see more of the Merck pill than the Pfizer pill until at least March. So far, the US has shipped out more than 300,000 courses of the Merck pill, and about 65,000 of the Pfizer pill, which ASPR said takes longer to manufacture.
In total, the US will have access to 3 million courses of the Merck pill, and 20 million of the Pfizer pill. But Pfizer said in a statement on Tuesday that 10 million of those courses will be available by June, and the remaining 10 million to follow by the end of September.
Currently, the pills are being distributed based on population data, but ASPR said the two oral antivirals will be distributed based on disease burden in the coming weeks. Also new: A website that says which pharmacies have the Merck and Pfizer pills.
“As you can imagine we rely heavily on good reporting of use, to see where there’s uptake of product and match that against surveillance data on disease burden,” BARDA’s Derek Eisnor said on the call.
Article updated with new information on Omicron from CDC, and comment from Dr. Henderson.