Pfizer COVID-19 vaccine candidate over 90 percent effective, Phase III study shows

Pfizer Inc and BioNTech’s COVID-19 vaccine candidate was shown to be over 90 percent effective in preventing infection from SARS-CoV-2 in participants without prior evidence of novel coronavirus infection in the first interim efficacy analysis. 

The companies that announced their mRNA-based vaccine candidate, BNT162b2, against SARS-CoV-2 has demonstrated evidence of efficacy against COVID-19 in a Phase III clinical study. After discussion with the US Food and Drug Administration (FDA), the companies recently elected to drop the 32-case interim analysis and conduct the first interim analysis at a minimum of 62 cases. Upon the conclusion of those discussions, the evaluable case count reached 94 and an external, independent Data Monitoring Committee (DMC) performed its first analysis on all cases.

The case split between vaccinated individuals and those who received the placebo indicates a vaccine efficacy rate above 90 percent, at seven days after the second dose. The companies say this means that protection is achieved 28 days after the initiation of the vaccination, which consists of a two-dose schedule. As the study continues, the companies say the final vaccine efficacy percentage may vary.

The Phase III clinical trial of BNT162b2 began on 27 July and has enrolled 43,538 participants to date, 38,955 of whom have received a second dose of the vaccine candidate as of 8 November 2020. The study continue and will also evaluate the potential for the vaccine candidate to provide protection against COVID-19 in those who have had prior exposure to SARS-CoV-2, as well as vaccine prevention against severe COVID-19 disease.

The DMC has not reported any serious safety concerns and recommends that the study continues to collect additional safety and efficacy data as planned. The data will be discussed with regulatory authorities worldwide.

“Today is a great day for science and humanity. The first set of results from our Phase III COVID-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent COVID-19,” said Dr Albert Bourla, Pfizer Chairman and Chief Executive Officer (CEO). “With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis. We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks.”

“The first interim analysis of our global Phase III study provides evidence that a vaccine may effectively prevent COVID-19. This is a victory for innovation, science and a global collaborative effort,” said Professor Ugur Sahin, BioNTech Co-founder and CEO. “We will continue to collect further data as the trial continues to enrol for a final analysis planned when a total of 164 confirmed COVID-19 cases have accrued. I would like to thank everyone who has contributed to make this important achievement possible.”

In addition to the primary efficacy endpoints evaluating confirmed COVID-19 cases accruing from seven days after the second dose, the final analysis now will include, with the approval of the FDA, new secondary endpoints evaluating efficacy based on cases accruing 14 days after the second dose as well. 

Submission for Emergency Use Authorization (EUA) to the FDA is planned soon after the required safety milestone is achieved, which is currently expected to occur in the third week of November. 

Along with the efficacy data generated from the clinical trial, Pfizer and BioNTech are working to prepare the necessary safety and manufacturing data to submit to the FDA to demonstrate the safety and quality of the vaccine product produced. The companies plan to submit data from the full Phase III trial for scientific peer-review publication.