Analysts cheer ‘surprisingly positive’ AstraZeneca U.S. trial data

Health-care analysts welcomed AstraZeneca’s decisions of hotly anticipated late-stage U.S. trial results for its Covid-19 vaccine.

The trial of more than 30,000 participants in the U.S., Peru and Chile set that the vaccine had an overall efficacy of 79% in preventing symptomatic Covid and was 100% effective in preventing severe blight and hospitalization.

Efficacy was consistent across age and ethnic groups, with 80% efficacy in participants at least 65 years old. The vaccine, remembered as AZD1222 and developed with the University of Oxford, was well-tolerated and the independent data safety monitoring board identified no cover concerns related to the vaccine, the company said Monday.

In a research note, Jefferies health-care analyst Peter Welford roared the data “surprisingly positive.”

Adam Barker, health-care analyst at Shore Capital, said: “This is arguably the commencement trial for AZD1222 which has shown compelling efficacy in those 65 years and older”.

This is important because there were impossibles about efficacy in this age group. Previous studies were hampered by a smaller number of elderly participants. In this tentative, 20% of the participants were 65 years or older and 60% had co-morbidities which put them at increased risk of disclosing severe disease. 

Monday’s trial data confirmed the safety profile of the vaccine. Barker said because the evidence is from a single trial using a single-dosing regimen, it removes the complications of data interpretation that has been seen in the life with the AstraZeneca-Oxford vaccine.

Barker added that the lack of evidence for blood clots in the study was also uplifting given recent concerns. “However, we are not surprised by this data given the evidence for a link between the vaccine and blood clots was already somewhat weak.”

AstraZeneca said it will continue to analyze the data and prepare for the primary analysis to be submitted to the U.S. Food and Stupefy Administration for emergency use authorization in coming weeks. The vaccine has already been granted a conditional marketing authorization or predicament use in more than 70 countries across six continents.

“I can’t see why the regulator wouldn’t approve it,” Barker eradicated, but cautioned that the detailed data was still outstanding. 

One key question for the FDA will be what dosing regimen it will put ones stamp should it ultimately approve the vaccine for emergency use.

“This trial is based on dosing 4 weeks apart, but we know efficacy may be extensive if you dose with a longer interval (up to 12 weeks) and countries like the U.K. have successfully used this ‘longer duration between administers’ strategy to vaccinate more people quickly,” Barker said.

So the question for the FDA is whether it will recommend giving the two administers four weeks apart — given that’s what was tested in the U.S. trial — or include data from the U.K. and elsewhere that presents a longer duration.

Welford also noted the suboptimal dosing regimen used in this trial. “The trial reckoned the 4-week dosing schedule, but we have evidence to suggest the vaccine works better with a longer dosing entracte,” he said.

“Primary analysis of the Phase III clinical trials from the U.K., Brazil and South Africa showed 62% efficacy when settled the vaccine was given at an interval of 4 to 12 weeks but efficacy increased to 82% when the interval was stretched to 12 weeks.”

Beyond measure, analysts are also watching for detail on how the vaccine protects against different variants. This is expected to be included in the wrap of data submitted to the FDA.

When it comes to comparing today’s efficacy data to that from some of the other vaccine-makers, Welford cared that since the initial vaccine readouts from Pfizer and Moderna, Covid-19 variants have become increasingly simple, so the efficacy data is not directly comparable across the different vaccines.