AstraZeneca on Thursday cemented its lead in bringing a preventative COVID-19 shot to market, saying its antibody cocktail offered 83% protection over six months, providing another possible weapon in the fight against the pandemic.
The therapy, called AZD7442 or Evusheld, had previously been shown to confer 77% protection against symptomatic illness after three months, in an earlier readout of the late-stage PROVENT trial in August.
The data give hope of additional protection for people who do not respond well to vaccines, such as cancer patients.
The Anglo-Swedish company also said a separate study in patients with mild-to-moderate COVID-19 showed a higher dose of AZD7442 cut the risk of symptoms worsening by 88% when given within three days of the first symptoms.
The antibody treatment, enhanced to remain intact in the body for months, is given in one go, as two sequential shots in the arm.
The latest results from the longer-term follow-ups potentially position AstraZeneca, like rival Pfizer as a future supplier of both COVID-19 vaccines and treatments, with AstraZeneca having said the therapy's "real advantage" was as a preventative shot.
The full results will be submitted for publication in a peer-reviewed medical journal.
Pfizer has presented promising efficacy data on its oral COVID-19 treatment candidate, which can be more easily distributed than injections, and is also a leading vaccine supplier with partner BioNTech.
"These new data add to the growing body of evidence supporting AZD7442's potential ... We are progressing regulatory filings around the world and look forward to providing an important new option against SARS-CoV-2 as quickly as possible," AstraZeneca Executive Vice President Mene Pangalos said in a statement, referring to the coronavirus that causes COVID-19.
The group last month sought approval for the medicine from U.S. and European authorities. Monoclonal antibodies from Regeneron, Lilly and GSK-Vir have been approved by U.S. regulators for treating unhospitalised COVID-19 patients.
Earlier this month, Regeneron said a single dose of its antibody cocktail reduced the risk of contracting COVID-19 by 81.6% in a late-stage trial.
LONG-TERM
"This is an important addition to the therapeutic armamentarium for COVID" if the published study confirms the data released on Thursday, said Penny Ward, visiting professor in pharmaceutical medicine at King's College London.
While the injection may be seen as a potential alternative to vaccines, antibody drugs cost significantly more, which may limit their use to particularly high-risk groups.
Antibody cocktails typically cost above $1,000 per dose, while COVID-19 shots have on average sold for between $3 and $30 per dose.
Astra's Executive Vice President for vaccines and immune therapies, Iskra Reic, said on a call with media that unlike its vaccine, the drug would be priced commercially as it negotiates supply contracts with governments around the globe.
Chief executive Pascal Soriot said the treatment was more complicated to produce than a vaccine but that there would be enough production capacity around the world to meet demand.
Monoclonal antibody drugs deliver lab-made versions of the body's natural antibodies to fight off infection, while vaccines spur the body to make its own antibodies and build its own immunity.
AstraZeneca has said the shot is primarily meant to help immunocompromised and at-risk individuals but at some point a wider group could benefit, such as military personnel on tours of duty or cruise ship passengers.
It would be administered in addition to vaccines, the company has said.
It added that about 2% of the global population was considered to inadequately respond to a COVID-19 vaccine.
For AstraZeneca's PROVENT trial, close to 5,200 participants without an infection were randomly split into two groups, with one volunteer receiving an ineffective placebo without knowing for every two receiving Evusheld.
Participants were at risk of suffering severe COVID-19 if infected or were immunocompromised, meaning they were in cancer care, or receiving drugs due to an autoimmune disease or an organ transplant.
The trial volunteers were not vaccinated, even though high-risk groups have been prioritized in global vaccination campaigns. Anyone opting to get vaccinated during the trial was excluded from the analysis.
Trial volunteers will be followed up for 15 months to provide evidence of longer-lasting protection.