German COVID-19 Vaccine Candidate Confronts Numerous Variants of Concern

Germany-based CureVac N.V. announced results of the second interim analysis of its HERALD pivotal Phase 2b/3 study in approximatively 40,000 subjects of the first-generation COVID-19 vaccine candidate, CVnCoV.

In the unprecedented context of at least 13 SARS-CoV-2 coronavirus variants circulating within the study population subset assessed at this interim analysis, CVnCoV demonstrated an interim vaccine efficacy of 47% against COVID-19 disease of any severity and did not meet prespecified statistical success criteria.

The interim results suggest vaccine efficacy in younger participants but did not allow to conclude on efficacy in those above 60.

The HERALD's initial analyses included 134 COVID-19 cases and suggested age and strain-dependent efficacy.

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 (21%) and B.1.621 (7%).

The Data Safety Monitoring Board confirmed a favorable safety profile for CVnCoV. The study is continuing to the final analysis, and the totality of the data will be assessed for the most appropriate regulatory pathway.

“While we were hoping for a stronger interim outcome, we recognize that demonstrating high efficacy in this unprecedented broad diversity of variants is challenging. As we are continuing toward the final analysis with a minimum of 80 additional cases, the overall vaccine efficacy may change,” stated Dr. Franz-Werner Haas, CEO of CureVac, in a press release.

“In addition, the variant-rich environment underlines the importance of developing next-generation vaccines as new virus variants continue to emerge.”

The HERALD study, conducted by Curevac in conjunction with Bayer, enrolled approximately 40,000 participants in ten countries in Latin America and Europe. To identify strains causing COVID-19 infections within the trial, sequencing of virus variants has so far been performed on 424 COVID-19 cases, of which 124 fulfilled adjudication criteria and were included in the present efficacy analysis.

Available data were communicated with the European Medicines Agency, which began its rolling review in February 2021. CureVac remains committed to COVID-19 vaccine development, said the company.

CureVac is a global biopharmaceutical company located in Tubingen, Germany, in the field of messenger RNA (mRNA) technology, with more than 20 years of expertise in developing and optimizing the versatile biological molecule for medical purposes. The principle of CureVac’s proprietary technology is the use of non-chemically modified mRNA as a data carrier to instruct the human body to produce its own proteins capable of fighting a broad range of diseases.