Roche’s casirivimab and imdevimab antibody reduced hospitalisation or death with COVID-19

March 23, 2021: Roche confirmed positive topline results from the largest trial to date assessing a COVID-19 treatment in infected non-hospitalised patients (n=4,567; REGN-COV 2067).

The phase III outcomes trial in high-risk non-hospitalised patients with COVID-19 met its primary endpoint, showing the investigational antibody cocktail of casirivimab and imdevimab significantly reduced the risk of hospitalisation or death by 70% (1,200 mg intravenously [IV]) and 71% (2,400 mg IV) compared to placebo.

Casirivimab and imdevimab also met all key secondary endpoints in the phase III REGN-COV 2067 trial, including the ability to reduce symptom duration from 14 to 10 days (median numbers).

In addition, a companion phase II trial (REGN-COV 20145) in low risk symptomatic or asymptomatic non-hospitalised patients with COVID-19 showed significant and comparable viral load reductions across doses ranging from 300 to 2,400 mg.

“Today’s results show the important medical benefit casirivimab and imdevimab may provide to people with COVID-19 by significantly reducing their risk of hospitalisation and death,” said Levi Garraway, M.D., Ph.D., Roche’s Chief Medical Officer and Head of Global Product Development.

“New infections continue to rise globally with over three million reported cases last week, so this investigational antibody cocktail may offer hope as a potential new therapy to high-risk patients – particularly in light of recent evidence showing that casirivimab and imdevimab together retain activity against key emerging variants.

Together with our partner Regeneron, we are grateful to the patients and investigators who have participated in ongoing clinical trials and look forward to discussing the growing body of evidence with health authorities and to bringing the treatment to as many people as possible.”

In addition to these trials in non-hospitalised patients, the investigational antibody cocktail of casirivimab and imdevimab is currently being studied in a phase II/III clinical trial for the treatment of COVID-19 in hospitalised patients, the phase III open label RECOVERY trial of hospitalised patients in the UK, and a phase III trial for the prevention of COVID-19 in household contacts of infected individuals. As of March 2021, approximately more than 25,000 people have participated in casirivimab and imdevimab clinical trials.

Detailed results from both trials (REGN-COV 2067 and REGN-COV 20145) will be shared with regulatory authorities and submitted for peer review as soon as possible.

Regeneron will share new data with the U.S. Food and Drug Administration (FDA) and Roche and Regeneron will continue to work with the European Medicines Agency (EMA) and other health authorities across the globe.

Earlier this year, the EMA’s Committee for Medicinal Products for Human Use issued a scientific opinion under Article 5(3) of Regulation 726/2004, supporting the use of casirivimab and imdevimab as a treatment option for patients with confirmed COVID-19.

In these exceptional times, Roche stands together with society, governments, healthcare providers and all those working to overcome the pandemic.

Key results from phase III REGN-COV 2067 trial in non-hospitalised patients

1.    Based on the mFAS population, which includes all randomised patients with a positive SARS-CoV-2 RT-qPCR test from NP swabs at randomisation and ≥1 risk factor for severe COVID-19.
2.    The formal hierarchical analysis first evaluated 2,400 mg dose versus concurrent placebo and then evaluated 1,200 mg dose versus concurrent placebo.
3.    Based on phase I/II analyses showing that the 8,000 mg and 2,400 mg doses were indistinguishable, the phase III protocol was amended to compare 2,400 mg and 1,200 mg versus placebo, and 8,000 mg data were converted to a descriptive analysis.

A safety assessment was conducted on all available patient data up to day 169, and identified no new safety signals. Serious adverse events (SAEs) were largely related to COVID-19 and occurred in 1.1% of patients in the 1,200 mg group, 1.3% in the 2,400 mg group and 4.0% in the placebo groups.

There was one death in the 1,200 mg group (n=827), one death in the 2,400 mg group (n=1,849) and five deaths in the placebo groups (n=1,843).

All patients in this analysis had at least one risk factor, including obesity (58%), age 50 years (51%) and cardiovascular disease, including hypertension (36%).

Approximately 35% of patients were Latino/Hispanic, 5% were Black/African American and the median age was 50 years (range: 18-96 years).

The phase III REGN-COV 2067 trial in non-hospitalised patients was previously amended to stop enrollment in the placebo group, following a recommendation from the Independent Data Monitoring Committee, which found clear efficacy for both doses.

About casirivimab and imdevimab
Casirivimab and imdevimab is a cocktail of two monoclonal antibodies (also known as REGN10933 and REGN10987, respectively) and was designed by Regeneron scientists to block infectivity of SARS-CoV-2, the virus that causes COVID-19.

They evaluated thousands of fully-human antibodies produced by the company’s proprietary VelocImmune® mice, which have been genetically modified to have a human immune system, as well as antibodies identified from humans who have recovered from COVID-19.

The two potent, virus-neutralising antibodies casirivimab and imdevimab are believed to bind non-competitively to the critical receptor binding domain of the virus’s spike protein, which is hypothesised to diminish the ability of mutant viruses to escape treatment and to protect against spike variants that may arise in the human population, as detailed in Science publications.”

https://www.roche.com/media/releases/med-cor-2021-03-23.htm