After matching Comirnaty, Providence plans phase 3 booster study for COVID-19 vaccine candidate

Almost two years after phase 3 results on the leading COVID-19 vaccines started rolling in, Providence Therapeutics has posted midphase data on its mRNA candidate and outlined plans to move into a pivotal booster study.

Canada-based Providence created the COVID-19 vaccine, which is based on the ancestral virus found in Wuhan, in April 2020 and began a phase 1 clinical trial early the next year. A phase 2 trial got underway at the start of 2022 to compare the safety, tolerability and immunogenicity of PTX-COVID19-B to Pfizer and BioNTech’s Comirnaty, leading to Wednesday’s data drop.

The study of 565 subjects found PTX-COVID19-B is noninferior to Comirnaty in terms of the geometric mean titer ratio of neutralizing antibodies two weeks after the second of two intramuscular injections. Providence also reported that the two vaccines had similar safety and tolerability profiles. 

Based on the data, Providence plans to move into a phase 3 clinical trial that will assess PTX-COVID19-B as a booster. Everest Medicines, which licensed PTX-COVID19-B in China and Southeast Asia, has already filed to run phase 3 trials that will compare the vaccine to Comirnaty and AstraZeneca’s Vaxzevria in the booster setting.

While Providence is still working to validate its vaccine against the original SARS-CoV-2 virus, Moderna and the Pfizer-BioNTech collaboration have already moved onto shots designed to protect against certain subvariants of omicron. Data on other vaccines suggest the viruses now circulating may partly evade the protection provided by PTX-COVID19-B, but Providence sees value in advancing the candidate.

The biotech lists a second vaccine candidate, PTX-COVID19-LT, designed in light of COVID-19 variants in its pipeline. Providence envisages its vaccine against the ancestral COVID-19 strain paving the way for PTX-COVID19-LT, the status of which will be determined “in the near future.”