Covid-19 roundup: Regeneron nabs priority review for mAb; Preprint suggests mixing boosters is safe ahead of adcomms
Nearly a year after being granted an EUA, Regeneron and Roche’s Covid-19 antibody cocktail will now go before the FDA for a chance at full approval.
The big biotech announced Thursday it has submitted a BLA for the drug, shooting for an OK to treat Covid-19 in non-hospitalized patients and as prophylaxis in certain individuals. Regulators granted priority review, setting April 13, 2022 as the PDUFA date, and Regeneron said the agency is preparing an adcomm before then.
Regeneron’s cocktail, containing the compounds casirivimab and imdevimab, is already authorized to treat mild to moderate Covid-19 patients with high-risk comorbidities and in certain prophylaxis settings.
Researchers are centering their pitch around two Phase III studies looking at Covid-19 patients who haven’t been hospitalized and asymptomatic household contacts of Covid-positive individuals. Regeneron is expected to follow up later this year with another BLA for hospitalized Covid-19 patients.
Last month, Regeneron and Roche secured a new contract with the US government for the cocktail totaling nearly $3 billion after the Delta variant caused a new Covid-19 wave across the country. Uptake of the cocktail had been slow up before the surge, but skyrocketed over the summer with fresh cases.
Preprint suggests mixing and matching boosters is safe
A new preprint of an NIH study has emerged detailing some possible effects of mixing and matching Covid-19 shots, as the FDA prepares for back-to-back vaccine adcomms for Moderna and J&J boosters.
The preprint details a trial of about 450 individuals who were 12 weeks out from receiving both of their mRNA vaccine doses or the J&J shot, enrolling roughly 150 from each of the vaccine groups. Across the nine possible combinations of second shots, antibodies increased between fourfold and 76-fold and neutralizing antibody titers went up between fourfold and 56-fold.
Notably, the highest increases were detected when those who had initially received a J&J shot got a booster of either the Moderna or Pfizer-BioNTech vaccine. The mean increase in antibodies for these respective groups were 56-fold and 33-fold two weeks after the second dose, respectively.
Individuals who received two J&J shots only saw a mean antibody increase of about fourfold, meanwhile. Researchers saw no new vaccine-related adverse safety events outside what had been reported previously: injection site soreness, headaches and fatigue, among others.
But researchers stressed that the main finding is that boosters can potentially be used regardless of one’s primary vaccine regimen. There were several limitations to the study, chiefly that researchers did not track the number of Covid-19 infections.
The preprint further noted the study is not designed to directly compare responses between booster regimens, the study is too small to make any sweeping conclusions and the trial population is not representative of the US writ large. The different populations also were not randomized and the follow-up periods of two and four weeks were much shorter than the time sought for boosters by Pfizer and Moderna.
Pfizer’s booster received authorization in some populations six months after the initial two-dose regimen, while Moderna is seeking a similar timeframe. The Moderna shot used in this study is also double the dose of what the biotech is seeking for a booster EUA.
It remains to be seen how the preprint will shape the debates at the booster adcomms — Thursday for Moderna and Friday for J&J. In their review for Moderna boosters, regulators offered the same lukewarm take as given to the Pfizer-BioNTech pitch, noting the data to be less than gobsmackingly persuasive.
But the agency authorized Pfizer-BioNTech boosters nonetheless after a chaotic adcomm, saying older individuals and adults with underlying health conditions could receive a third shot. The agency also offered the option for workers in high-risk situations to get a booster.
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