All clinical studies with first-generation candidate, CVnCoV, have completed the scheduled safety follow-up times for all trial participants as per the respective trial protocols. These include a Phase 1 study in Germany (initiated in June 2020), a Phase 2a study in Peru and Panama (initiated in September 2020), the Phase 2b/3 (HERALD) study in Europe and Latin America (initiated in December 2020), a Phase 3 study in healthcare workers in Germany (initiated in December 2020), and a Phase 3 study in participants with comorbidities in Belgium (initiated in April 2021).
The Phase 2b/3 (HERALD) study and Phase 3 study in healthcare workers in Germany are under final data analysis. Primary data of the Phase 2b/3 (HERALD) trial was published in The Lancet Infectious Diseases on November 23, 2021.
Data of an interim analysis of the Phase 1 trial in Germany was published in Wiener klinische Wochenschrift on August 10, 2021. Safety and immunogenicity data of the Phase 2a clinical trial in Peru and Panama was uploaded to the SSRN preprint server on December 10, 2021 and published in Vaccine: X on July 1, 2022. Neutralizing antibody data against the ancestral strain and the beta variant after a third dose of CVnCoV in the same trial were posted on the MedRxiv preprint server on February 24, 2022 and published in Vaccines on March 25, 2022.
Previously announced studies to be initiated with CVnCoV, including a Phase 2 clinical trial, focusing on immunogenicity in older adults above the age of 65 years old compared to younger adults and a flu-co-administration study, planned to be initiated together with Bayer AG to assess compatibility with established seasonal vaccines in an older population, were cancelled.
To assess the benefit of booster vaccinations, CVnCoV was also included in the Cov-Boost trial sponsored by the University of Southampton, UK, which is evaluating several COVID-19 vaccines and vaccine candidates as booster vaccines. Each participant in the Cov-Boost trial received one booster vaccine 84 or 70 days respectively after they completed their primary vaccination with two doses of either Comirnaty or Vaxzervia. The Cov-Boost trial started in June 2021 across 18 sites in the United Kingdom and dosed overall 2,878 participants with a third dose vaccine. Initial results from the Cov-Boost trial were published in The Lancet on December 2, 2021.
Our pivotal Phase 2b/3 trial for CVnCoV, which included approximately 40,000 participants, reported interim analysis outcomes following a first interim analysis on May 28, 2021, based on 59 adjudicated COVID-19 cases and a second interim analysis on June 16, 2021, based on 134 adjudicated COVID-19 cases in the unprecedented context of at least 13 variants circulating within the assessed study population subset. In the highly dynamic variant environment, the HERALD trial met the prespecified success criteria for efficacy against symptomatic COVID-19 of any severity and for efficacy against moderate-to-severe COVID-19, as defined in the protocol. The primary efficacy analysis included 12,851 participants in the CVnCoV group and 12,211 in the placebo group. The mean observation period, starting 15 days after administration of the second dose, was 48.2 days. Vaccine efficacy against COVID-19 of any severity was 48.2% in the overall primary efficacy analysis set of SARS-CoV-2-naive participants, and 52.5% in those aged 18–60 years. Vaccine efficacy against moderate-to-severe COVID-19 was 70.7% overall and 77.2% in participants aged 18–60 years. There were too few participants aged 61 years or older who developed COVID-19 to allow a meaningful estimate of efficacy in this age group.
HERALD was conducted in an unprecedented evolving landscape that reflects the changing reality of the global COVID-19 pandemic, with an increasing number of SARS-CoV-2 variants adding additional challenges to the assessment of COVID-19 vaccine candidates. Sequence data were available for 184 of 207 adjudicated cases in people aged 18–60 years. About 50% of cases of COVID-19 in our trial were caused by variants of concern, 35% were caused by variants of interest, as classified by WHO in September 2021, and about 3% were caused by wild-type, with the remaining 11% caused by other variants. Although we were only able to evaluate vaccine efficacy against these variants in participants aged 18–60 years, the results indicate that the vaccine had similar efficacies against Alpha, Gamma, and Lambda variants. Many newly emerged strains that have shown increased transmissibility, and differences in neutralizing antibody activity against these strains might alter vaccine efficacy.
The first non-COVID-19 vaccine candidate within the broader infectious disease program applying our second-generation backbone we are developing in collaboration with GSK is the influenza candidate, CVSQIV, a differentiated multivalent vaccine candidate featuring multiple non-chemically modified mRNA constructs to induce immune responses against relevant targets of four different influenza strains. On February 10, 2022, we announced the start of a Phase 1 dose-escalation study in Panama evaluating the safety, reactogenicity and immunogenicity of CVSQIV in the dose range of 3µg to 28µg. In line with the mRNA development strategy to also test chemically modified mRNA and similar to the setup of the COVID-19 vaccine program, CureVac and GSK announced the start of a Phase 1 dose-escalation study with a chemically modified influenza vaccine candidate, Flu SV mRNA, on August 18, 2022. The candidate is a monovalent candidate. The Phase 1 dose-escalation study will be conducted in Canada, Spain, and Belgium to evaluate the safety, reactogenicity and immunogenicity of FLU SV mRNA.
Beyond the GSK COVID-19 and general infectious disease collaboration, our next advanced prophylactic vaccine program, CV7202, is being developed for prophylactic vaccination against rabies. CV7202 is an mRNA based on our first-generation backbone that encodes the rabies virus glycoprotein, RABV-G, formulated with Lipid Nanoparticles. Safety, reactogenicity, and immunogenicity of CV7202 was investigated in a Phase 1 clinical trial that has completed the scheduled follow-up time for all trial participants as per trial protocol. In January 2021, we published data from our Phase 1 trial of CV7202 in rabies. CV7202 induced