According to the Phase 3 data, a booster dose of Comirnaty elicited significant immune responses, with a favourable safety and tolerability profile
Submissions filed for booster dose of Comirnaty. (Credit: conorlinehan7 from Pixabay.)
Pfizer and BioNTech have initiated a regulatory submission to the US Food and Drug Administration (FDA) seeking approval for a third/booster dose of their Covid-19 vaccine, in people aged 16 years and above.
The current supplemental Biologics License Application (sBLA) follows the recent full FDA approval of Comirnaty to prevent Covid-19 in the same age group.
The sBLA includes data from a Phase 3 clinical trial in 306 participants aged 18 to 55 years, who received a booster dose of Comirnaty, 4.8 to 8 months after a two-dose primary regimen.
In the study, the booster dose elicited superior neutralising antibodies to the wild-type strain in participants without SARS-CoV-2 infection through one month.
The SARS-CoV-2 neutralising titres after booster dose were 3.3 times the titres after the second dose, which met the prespecified non-inferiority criterion of 1.5 times for superiority.
Among the study participants, 99.5% of them had a four-fold response after the third dose, compared to 98.0% after the second dose.
Also, the titres after booster dose met the pre-specified 10% non-inferiority margin for the difference in the four-fold seroresponse rates.
The third dose of Comirnaty demonstrated a reactogenicity profile that was typically mild to moderate, within seven days after immunisation.
Most common adverse events include injection site pain, fatigue, headache, muscle and joint pain, and chills, whose profile was consistent with other clinical data for Comirnaty.
Pfizer and BioNTech are planning to submit the data to the European Medicines Agency (EMA) and other regulatory authorities worldwide, in few weeks.
The third dose of Comirnaty is not currently authorised in the US but was authorised under Emergency Use Authorisation (EUA) for use in immunocompromised people, aged 12 years and above.
Comirnaty, previously known as Pfizer-BioNTech Covid-19 vaccine, was developed based on BioNTech’s proprietary mRNA technology.
BioNTech holds marketing authorisation for the vaccine in the US, the EU and the UK, along with regulatory authorisations in the US, together with Pfizer, Canada and other countries.