A month af­ter re­veal­ing that its mon­o­clon­al an­ti­body com­bi­na­tion was 77% ef­fec­tive at pre­vent­ing symp­to­matic Covid-19 com­pared to place­bo, As­traZeneca says it’s head­ed to the FDA.

“We’ve cer­tain­ly shared the da­ta with reg­u­la­tors, and we an­tic­i­pate sub­mit­ting the emer­gency use au­tho­riza­tion very short­ly,” Mark Ess­er, VP and head of mi­cro­bial sci­ences and bio­phar­ma­ceu­ti­cals R&D, said dur­ing a press con­fer­ence on Wednes­day af­ter­noon.

Just eight of 3,460 vol­un­teers giv­en AZD7442 in the Phase III PROVENT tri­al came down with symp­to­matic Covid-19 over a six-month pe­ri­od, Ess­er said, com­pared to 17 of 1,737 peo­ple in the place­bo group.

The study en­rolled par­tic­i­pants across the US, UK, Spain, France and Bel­gium, many of whom had co­mor­bidi­ties or oth­er con­di­tions that would cause a re­duced im­mune re­sponse to vac­ci­na­tion. That in­clud­ed peo­ple on im­muno­sup­pres­sive drugs, or with dis­eases like di­a­betes, smok­ing-re­lat­ed lung dis­ease, kid­ney dis­ease, and chron­ic liv­er dis­ease, among oth­ers.

Over­all, the ther­a­py post­ed a 77% ef­fi­ca­cy rate — a sig­nif­i­cant­ly high­er rate than the 63% ef­fi­ca­cy re­port­ed to the WHO for the com­pa­ny’s own Covid-19 vac­cine. At an in­ter­im read­out in March, As­traZeneca had re­port­ed that its vac­cine was 70% ef­fec­tive at pre­vent­ing symp­to­matic Covid-19, which was slight­ly high­er than the 62% fig­ure post­ed in the UK.

There were no se­vere cas­es or deaths in the AZD7442 treat­ment arm, and three se­vere cas­es and two deaths in the place­bo arm, the phar­ma said. Though it’s un­clear how the FDA may view the tri­al’s rel­a­tive­ly small sam­ple size.

De­spite the pos­i­tive ef­fi­ca­cy re­sults, Ess­er stressed that AZD7442 is in­tend­ed for use on top of vac­ci­na­tion, not in lieu of it.

Mark Ess­er

“First and fore­most, we want peo­ple to get vac­ci­nat­ed. We know the vac­cines work in most peo­ple,” he said. “Now, if there is some­one who’s had an al­ler­gic re­ac­tion to one of the vac­cines, or for some rea­son can­not get vac­ci­nat­ed, I think 7442 could be a so­lu­tion for that.”

AZD7442 was dis­cov­ered by the Van­der­bilt Uni­ver­si­ty Med­ical Cen­ter, and li­censed to As­traZeneca last June. It’s a com­bi­na­tion of the an­ti­bod­ies tix­agevimab and cil­gav­imab, de­rived from B cells do­nat­ed by a hus­band and wife team who had re­cov­ered from Covid-19. The ben­e­fit of a mon­o­clon­al an­ti­body is that it pro­vides “al­most im­me­di­ate” pro­tec­tion, where­as cur­rent vac­cines ap­proved in the US take a cou­ple weeks to kick in.

The down­side is that the du­ra­tion of pro­tec­tion is much short­er. As­traZeneca says it has tech­nol­o­gy that can ex­tend the an­ti­body’s half life from an av­er­age of around 20 days to 90 days.

“What this means is that a sin­gle in­tra­mus­cu­lar shot could eas­i­ly af­ford six months, and we’re hope­ful up to 12 months of pro­tec­tion,” Ess­er said on the call.

In ad­di­tion to PROVENT, AZD7442 is al­so in the on­go­ing TACK­LE COVID-19 pro­gram, which looks at the an­ti­bod­ies’ abil­i­ty to treat and pre­vent Covid across more than 9,000 par­tic­i­pants in the out­pa­tient set­ting. And while vol­un­teers got the can­di­date in­ject­ed in­to the mus­cle in PROVENT, it’s al­so be­ing as­sessed as an IV drug.

Back in June, AZD7442 missed the mark in a study as­sess­ing its abil­i­ty to pre­vent symp­toms in adults who had a con­firmed ex­po­sure to Covid-19. As­traZeneca says the an­ti­body com­bo per­formed bet­ter in a pre-planned analy­sis of PCR-neg­a­tive vol­un­teers.

Ess­er says he’s “quite con­fi­dent” AZD7442 will work against the Delta vari­ant, as well as oth­er emerg­ing vari­ants, adding that there were few Delta cas­es re­port­ed in the treat­ment arm, and many in the place­bo arm. He said the com­pa­ny is se­quenc­ing the virus­es, and will have more da­ta to share soon.

Hugh Mont­gomery, a pro­fes­sor of med­i­cine and di­rec­tor of the Cen­tre for Hu­man Health and Per­for­mance at Uni­ver­si­ty Col­lege in Lon­don, point­ed to the ben­e­fit of hav­ing two long-act­ing an­ti­bod­ies.

“If one was look­ing at the risk of vi­ral es­cape down the line, the chances of get­ting two mu­ta­tions to pre­vent these an­ti­bod­ies bind­ing would be very, very un­like­ly,” Mont­gomery said.

The news comes a month af­ter fed­er­al of­fi­cials reau­tho­rized Eli Lil­ly’s an­ti­body com­bo, which had been tak­en off the mar­ket due to a “sus­tained in­crease” of coro­n­avirus vari­ants in the US. That com­bo — bam­lanivimab and ete­se­vimab — is now au­tho­rized in states where the fre­quen­cy of re­sis­tant vari­ants like the Delta-plus or Gam­ma is 5% or low­er.

Researchers may be nearing an answer for the mysterious and life-threatening blood clots that appeared on very rare occasions in people who received the J&J or AstraZeneca Covid-19 vaccine.

The new work builds on an early hypothesis researchers in Norway put forward last spring, when the cases first cropped up. They proposed the events were similar to blood clots that can occur in a small subset of patients who receive heparin, one of the most commonly used blood thinners.

Outside of Covid-19, 2021 has been the year of the accelerated approval.

Beginning last spring, FDA openly challenged six “dangling” accelerated approvals (hadn’t confirmed their clinical benefit yet), three of which were later pulled by the companies.

Then in June, FDA pulled out the accelerated approval pathway, seemingly out of nowhere, to sign off on Biogen’s controversial Alzheimer’s drug Aduhelm. It hadn’t even been mentioned at the drug’s adcomm.