GSK Covid-19 treatment gets emergency approval, vaccine trial progresses

GlaxoSmithKline announced on Wednesday that ‘sotrovimab’ has received emergency use approval in the United States for the treatment of Covid-19, while it also started a global phase 3 study of its Covid-19 vaccine candidate with Sanofi.

The FTSE 100 drugmaker said the US Food and Drug Administration (FDA) granted an emergency use authorisation for sotrovimab, previously known as VIR-7831, which is an investigational single-dose monoclonal antibody.

It said the authorisation allowed for the treatment of mild-to-moderate Covid-19 in adults and paediatric patients 12 years and older weighing at least 40 kilograms, with positive results of direct SARS-CoV-2 viral testing, and who were at high risk for progression to severe disease, including hospitalisation or death.

Sotrovimab was given the approval to facilitate the availability and use of the investigational monoclonal antibody for the treatment of Covid-19 in the US, while the pandemic remained a public health emergency.

The FDA fact sheet for healthcare providers regarding the emergency use of sotrovimab reflected the recently-updated definition of high risk for Covid-19 to include additional medical conditions and factors associated with increased risk for progression to severe disease.

GSK said the authorisation for sotrovimab also included post-authorisation commitments, as specified in the letter of authorisation received from the FDA.

Sotrovimab was being studied in ongoing clinical trials, with an analysis of safety and efficacy data at day 29 for the full population from the ‘COMET-ICE’ trial expected as early as the first half of 2021.

GSK and its partner Vir Biotechnology said they were planning to submit a biologics licence application to the FDA in the second half of 2021.

“The fast pace of Covid-19 vaccinations in the US is encouraging, yet despite these aggressive efforts, there is still a need to help prevent infected patients from developing complications,” said Dr Hal Barron, GlaxoSmithKline’s chief scientific officer and president of research and development.

“In just over a year since starting our collaboration and in less than 10 months since beginning clinical trials, we are delighted that, as of today, the benefits of this unique monoclonal antibody will now be available to patients in need.”

GlaxoSmithKline also announced that it had started enrolment in a phase 3 clinical study to assess the safety, efficacy and immunogenicity of its adjuvanted recombinant-protein Covid-19 vaccine candidate, alongside its partner Sanofi.

The global randomised, double-blind, placebo-controlled study would include more than 35,000 volunteers aged 18 and older from a number of countries, including sites in the US, Asia, Africa and Latin America.

It said the primary endpoint of the study was the prevention of symptomatic Covid-19 in ‘SARS-CoV-2 naïve’ adults, with secondary endpoints being the prevention of severe Covid-19 disease and the prevention of asymptomatic infection.

In a two-stage approach, the study would initially investigate the efficacy of a vaccine formulation targeting the original D.614, or ‘Wuhan variant’ virus, while a second stage would evaluate a second formulation targeting the B.1.351, or ‘South African variant’ virus.

Recent scientific evidence showed that antibodies created against the B.1.351 variant could provide broad cross-protection against other more transmissible variants.

The design of the study, conducted across a broad diversity of geographies, would also allow evaluation of the efficacy of the candidate against a variety of circulating variants.

Following encouraging interim results from the recent phase 2 study, the companies would also begin clinical studies in the coming weeks to assess the ability of the adjuvanted recombinant-protein Covid-19 vaccine candidate to generate a strong booster response regardless of the initial vaccine platform received.

“We believe further solutions for Covid-19 are very much needed to help reach people around the world, especially as the pandemic evolves and variants continue to emerge,” said GlaxoSmithKline president of vaccines, Roger Connor.

“Adjusting our technology and study designs reflects this need and will further build the potential of this adjuvanted protein-based vaccine.

“We are grateful to the volunteers who will take part in the trials and hope the results will add to the encouraging data we've seen so far so we can make the vaccine available as quickly as possible.”

The phase 3 study followed interim phase 2 results, which showed that the vaccine candidate achieved “high rates” of neutralising antibody responses in all adult age groups, with seroconversion rates of between 95% and 100%.

After a single injection, high neutralising antibody levels were also generated in participants with evidence of prior SARS-CoV-2 infection, suggesting strong potential for development as a booster vaccine.

Pending positive phase 3 outcomes and regulatory reviews, the vaccine could be approved in the fourth quarter of 2021.

Manufacturing would begin in the coming weeks, GSK said, to enable rapid access to the vaccine should it be approved.

At 0908 BST, shares in GlaxoSmithKline were down 0.7% at 1,343.79.