- Top Pfizer executives are standing by the ambitious timeline that the drugmaking giant will have in October conclusive efficacy data for its coronavirus vaccine candidate.
- Albert Bourla, Pfizer’s CEO, and Kathrin Jansen, the company’s head of vaccine research, both said Tuesday they expect data by the end of October.
- The experimental vaccine, developed by Pfizer and the German biotech BioNTech, is in the final stage of clinical testing. More than 29,000 people have enrolled in the study, which was recently expanded to recruit 44,000 participants.
- Company executives also said regulators will require safety data from 6,000 trial participants — 3,000 receiving the experimental vaccine and 3,000 getting placebo — for emergency approval.
- For more stories like this, sign up here for Business Insider’s daily healthcare newsletter.
Pfizer’s top executives are standing by their expectation that the pharmaceutical giant will know conclusively by the end of October whether its coronavirus vaccine candidate works.
The $205 billion drugmaker is leading one of the few vaccine programs in the final stage of clinical trials. Pfizer started a phase-three study in July. While several vaccine candidates are now in phase-three trials, including Moderna and AstraZeneca, Pfizer has been alone in voicing confidence of getting efficacy data in October.
Company CEO Albert Bourla and head of vaccine research Kathrin Jansen both reiterated the October timeline Tuesday as part of a two-day investor presentation and on a press call.
Data by October requires perfection
A lot will have to go not just right, but perfectly, for Pfizer to achieve that speedy timeline. Overall, Pfizer is banking on an interim analysis of the study to show conclusive effectiveness. That means the group of study volunteers randomly receiving the experimental vaccine registered far less COVID-19 disease than a placebo group.
The FDA has said any coronavirus vaccine has to be at least 50% effective at preventing disease. An independent group of scientists who regularly monitor Pfizer’s study will need to examine the data and conclude there is a statistically meaningful difference between the group getting the real vaccine and the placebo.
Pfizer will have to show its vaccine is safe in data from thousands of trial participants for emergency authorization
Even if that data shows the vaccine works, Jansen said Tuesday the US Food and Drug Administration will require safety data from at least 6,000 people — 3,000 participants receiving Pfizer’s vaccine and 3,000 receiving a placebo. She did not specify how long the follow-up time must be for that safety data.
Safety is widely seen as the top priority for any vaccine, since the shots are given to otherwise healthy people. AstraZeneca’s trials were recently halted, as the company investigated a suspected serious adverse event reaction. While the UK-based study has since resumed, other global trials, including one in the US, remain on pause.
The FDA has not issued formal guidance on what it will take to issue an emergency approval for a vaccine — something the regulatory agency has never done before in its history with a previously unapproved vaccine. But top vaccine experts in the US government have said most side effects from vaccines are seen within a month and half of receiving the doses.
Some basic back-of-the-envelope math shows how extraordinarily tight Pfizer’s October timeline is shaping up to be. But it also shows it’s theoretically possible for Pfizer to land a Halloween surprise with enough data to support an emergency use authorization.
This chart shows how quickly Pfizer’s study has enrolled volunteers. The study reached 6,000 volunteers sometime around August 15. The vaccine is given as a two-dose regimen, with the shots a month apart.
So that initial group should have received the second dose by September 15. Then, the study watches for and tracks side effects. The top vaccine regulator at the FDA has commented that a month and half of follow-up captures most side effects with vaccines. Call that 45 days, and that puts the timeline out to October 30, just at the end of the month.
Top experts think vaccine data by October is unlikely
While Bourla and Jansen have expressed confidence in hitting this timeline, other top infectious-disease experts have not.
“To get a readout in October from these clinical trials, you really need to have absolute perfection,” Dr. Scott Gottlieb, the former head of the FDA and now a board member of Pfizer said on CNBC in September. “I think it’s far more likely that you’re not going to get a readout until at least November.”
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Moncef Slaoui, the co-leader of Operation Warp Speed, the Trump administration’s initiative dedicated to accelerating vaccine development, called the October timeline “extremely unlikely but not impossible.”
The FDA has scheduled an advisory committee for October 22 of independent vaccine experts. Dr. Paul Offit, one of the select members of that group, told Business Insider they would likely discuss the criteria needed for an emergency use authorization.
If Pfizer succeeds in reaching this timeline, it will be a historic accomplishment in the fight against COVID-19. But it will also only be the start of a complicated rollout process, with authorities still contemplating how to prioritize and allocate extremely limited quantities of a safe and effective vaccine.
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