CureVac reported on June 30 that its COVID-19 vaccine was 48 percent effective in the final analysis of its pivotal mass trial, only marginally better than the 47 percent shown after an initial read-out two weeks ago.
The German biotech firm stated that efficacy, measured by preventing symptomatic disease, was slightly better, at 53 percent, when excluding trial participants over 60 years old, the age group most affected by COVID-19.
CureVac stated on June 16 that its COVID-19 vaccine, known as CVnCoV, proved 47 percent effective in an initial trial read-out and that new variants had created a headwind, denting investor confidence in its ability to take on rival shots.
The announcement wiped billions of euros from its market value.
The June 30 update sent U.S.-listed shares of the company 10.2 percent lower, to $66, after the bell.
Late-stage trials of BioNTech/Pfizer and Moderna vaccines, which like CureVac’s are based on mRNA technology, had efficacy rates of well above 90 percent across all age groups, but took place when the original version of COVID-19 was dominant.
Data on their products, however, have so far suggested only somewhat weaker protection against new variants.
The CureVac study, which involved about 40,000 adult volunteers in Europe and Latin America, showed that efficacy was 77 percent in the age group below 60 when considering only moderate to severe symptoms and excluding mild cases.
CureVac said it had sent the data to the European Medicines Agency (EMA) as part of an ongoing dialogue with the EU drug regulator.
CureVac previously said that the regulatory hurdle was 50 percent efficacy in principle, but that various other considerations would come into play.
“In this final analysis, CVnCoV demonstrates a strong public health value in fully protecting study participants in the age group of 18 to 60 against hospitalization and death and 77 percent against moderate and severe disease—an efficacy profile, which we believe will be an important contribution to help manage the COVID-19 pandemic and the dynamic variant spread,” CureVac Chief Executive Officer Franz-Werner Haas said in a statement.
CureVac had registered 228 infections overall for the final analysis, after 134 cases for the interim analysis.
Public health representatives across the globe are pushing for a fast deployment of available vaccines to counter more contagious mutations of COVID-19, such as the Delta variant that first emerged in India.
The EMA has said it wouldn’t impose a 50 percent efficacy threshold for vaccines and that full trial data was necessary for it to make a sound assessment on the benefits and risks of a vaccine.
Under CureVac’s only major supply deal for the product tested in the trial, the European Union has secured up to 405 million doses of the vaccine in November, of which 180 million are optional.
In a bet on CureVac’s technology, Britain placed a conditional 50 million dose order in February on yet-to-be-developed vaccines that build on the product tested in the trial.
CureVac had lined up a network of manufacturing partners, including Celonic Group of Switzerland, Novartis, Bayer, Fareva, Wacker, and Rentschler Biopharma SE.
