The German biotech said the data showed the vaccine candidate "did not meet prespecified statistical success criteria” in its pivotal Phase 2b/3 trial called HERALD.
The interim results suggest CureVac’s vaccine, CVnCoV, is way off the mark in terms of the efficacy shown by other mRNA jabs against COVID-19.
The trial, though, will continue to final analysis, and the company said the overall final efficacy could change.
The study, which CureVac ran in conjunction with Bayer, was conducted in 10 countries and involved about 40,000 people. The findings indicated CVnCoV performed poorly in a “fast changing environment” of at least 29 COVID-19 variants, with the original virus strain “almost completely absent.”
“In total, 134 Covid-19 cases were assessed in this interim analysis. Out of these cases, 124 were sequenced to identify the variant causing the infection. The outcome confirms that only one single case was attributable to the original SARS-CoV-2 virus. More than half of the cases (57%) were caused by variants of concern.
“Most of the remaining cases were caused by other less characterized variants such as Lambda or C.37, first identified in Peru (21%) and B.1.621, first identified in Colombia (7%).“
The interim results also suggest efficacy of its shot in younger participants. The data did not allow the company to conclude on vaccine efficacy in those older than 60 years of age.
“While we were hoping for a stronger interim outcome, we recognize that demonstrating high efficacy in this unprecedented broad diversity of variants is challenging,” Franz-Werner Haas, CEO of CureVac, said.
“In addition, the variant-rich environment underlines the importance of developing next-generation vaccines as new virus variants continue to emerge,” he added.
CureVac has shared the initial results with the European Medicines Agency (EMA) and will analyze the final data for the most appropriate regulatory pathway.
In November 2020, the EU Commission secured 405 million doses of CureVac’s COVID-19 vaccine candidate. The deal includes access to an initial 225 million doses of CureVac's vaccine, with the EC eligible to purchase a further 180 million.
CureVac said it remains committed to COVID-19 vaccine development. Beyond CVnCoV, the company, in partnership with GSK, is developing second-generation COVID-19 vaccine candidates, which are based on new mRNA backbones and include potential variants in multivalent vaccine formats as well as combination vaccines for potential protection against multiple infectious diseases in one vaccine.