AstraZeneca publishes Covid-19 vaccine PhIII protocols in lockstep with Moderna and Pfizer. How are they different?
Following in the steps of Moderna and Pfizer, the other two American drugmakers currently in Phase III trials for their Covid-19 vaccines, AstraZeneca posted its own study protocols over the weekend. The move is the latest in a series of rare peeks behind the curtain, as such blueprints are typically shared once such trials are completed.
“Given the unprecedented global impact of the Coronavirus pandemic and the need for public information, AstraZeneca has published the detailed protocol and design of our AZD1222 clinical trial. As with most clinical development, protocols are not typically shared publicly due to the importance of maintaining confidentiality and integrity of trials. AstraZeneca continues to work with industry peers to ensure a consistent approach to sharing timely clinical trial information,” the company said in a statement.
AstraZeneca’s trial, unlike the ones from counterparts, only plans for one interim analysis that could allow the company to stop the trial early and petition for an emergency use authorization. That analysis is expected to occur at 75 infections. Moderna expects two analyses, at 53 and 106 events, while Pfizer penciled in four — at 32, 62, 92 and 120 cases.
The British pharma also indicated that it is aiming for a 50% efficacy rate for its candidate, the threshold that the FDA has set for in its coronavirus vaccine guidelines, whereas Moderna and Pfizer are both aiming for 60% effectiveness.
All three companies also have different criteria for symptoms in the primary endpoints of their trials, with each including those associated with mild infections. Eric Topol, one of the industry’s strongest advocates for vaccine transparency, summarized those differences in a tweet.
The all-important primary endpoint is different for the 3 trials. This show how infections are defined in the 3 protocols (with a positive PCR test for virus). pic.twitter.com/JOPbH0SrI8
— Eric Topol (@EricTopol) September 19, 2020
Vaccine makers have been under intense political pressure throughout the Covid-19 pandemic, but that has only ramped up as November’s presidential election draws nearer. President Donald Trump has repeatedly offered promises that a vaccine could be ready before the election, and HHS secretary Alex Azar effectively set the FDA staff on notice saying that his signature is required on all rule making.
Thus far, Pfizer CEO Albert Bourla has been the only executive to say his company could know whether or not its vaccine works in October. Moderna president Stephen Hoge, appearing on CBS Evening News last week, said the drugmaker could know if its own vaccine works by November.
Despite a green light to resume in the UK, AstraZeneca’s Phase III trial remains on hold in the US after a volunteer in the UK developed a condition thought to be transverse myelitis, a rare spinal inflammation disorder, after taking their second dose of the vaccine. The company has not confirmed the diagnosis, and a document posted by Oxford University last week suggested that the vaccine was not linked to the condition.
That instance was the second time AstraZeneca’s trial was placed on hold following a case of undiagnosed multiple sclerosis occurring in a separate trial participant.
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