German-based mRNA company CureVac has announced the start of a phase 1 study of its modified COVID-19 mRNA vaccine candidate – CV0501 – administered as a booster dose to previous vaccination.
Developed in collaboration with GSK, CV0501 is based on CureVac’s ‘second-generation mRNA backbone’ specifically designed to protect against the Omicron variant.
Set to be conducted at clinical sites in the UK, the US, Australia and the Philippines, the dose-escalation study will enrol up to 180 healthy, COVID-19-vaccinated adults to evaluate the safety, reactogenicity and immunogenicity of a single booster dose of CV0501 in the dose range of 12μg to 50μg.
Additional dose levels below 12μg and above 50μg may be evaluated as safety is confirmed, the company said.
CureVac interim chief development officer, Dr Ulrike Gnad-Vogt, said: “Licensed COVID-19 vaccines that encode for the original virus variant, continue to protect against severe disease and hospitalisation, but they are increasingly challenged by immune evasion of new variants such as Omicron.
“As we extend the clinical studies of our second-generation backbone into modified mRNA, targeting the Omicron variant will further explore the full potential of our improved second-generation design as a booster vaccination for a relevant variant.”
The CV0501 study follows the start of a phase 1 study evaluating an unmodified second-generation COVID-19 vaccine candidate – CV2CoV – encoding for the original virus variant in March 2022. The dose-escalation study is being conducted at clinical sites in the US in the dose range of 2 to 20µg.
CureVac explained in a statement how the comprehensive approach to evaluate both an unmodified and modified, second-generation vaccine candidate against COVID-19 is ‘expected to identify the best-performing candidate for later-stage clinical development’. Data from both studies is expected to be reported together, in line with this approach.
The infectious disease collaboration between CureVac and GSK was first announced in July 2020, focusing on the development of new products based on CureVac’s mRNA technology for different targets in the field of infectious diseases.
The collaboration was extended in February 2021 to also include jointly developed vaccine candidates for COVID-19, with the companies broadening their development strategy to test modified mRNA technologies in addition to unmodified mRNA earlier this year.
Image used with permission. Copyright held by CureVac AG