Regeneron’s COVID-19 drug boosts survival in hospitalised patients lacking antibodies

Regeneron’s Roche-partnered antibody treatment REGEN-COV can improve survival in hospitalised COVID-19 patients who lack an immune response to the SARS-CoV-2 virus, according to new study data.

In the UK-based RECOVERY trial, 9,785 hospitalised COVID-19 patients were randomly allocated to receive usual care plus REGEN-COV (casirivimab and imdevimab) or usual care alone.

Around one-third of participants did not have a natural antibody response to SARS-CoV-2 (seronegative) at baseline, while half had developed natural antibodies (seropositive) and one-sixth had unknown antibody status.

The 28-day mortality rate for patients who received usual care alone was twice as high among those who were seronegative versus those who were seropositive at the beginning of the study.

Among patients who were seronegative at baseline, REGEN-COV significantly reduced 28-day mortality by one-fifth compared to usual care alone – 24% of patients in the REGEN-COV group died versus 30% in the usual care group.

The researchers noted that there was a clear difference in the effect of the treatment in seronegative patients compared to seropositive patients.

In the overall patient population – including seropositive, seronegative and unknown statuses – there wasn’t a significant effect on 28-day mortality resulting from REGEN-COV treatment.

However, for seronegative patients treated with Regeneron’s antibody combination, the duration of their hospital stays was reduced by four days compared to the usual care alone group.

In addition, the number of patients discharged alive by day 28 was greater in the REGEN-COV group.

The risk of progressing to invasive mechanical ventilation or death was lower among seronegative patients allocated to the antibody treatment compared to the usual care group.

"We are incredibly grateful to the RECOVERY team, participating investigators and patients for conducting this in-depth analysis, and hope that the results mean that even more patients may soon be able to benefit from this life-saving medicine,” said George Yancopoulos, president and chief scientific officer of Regeneron.

“We intend to rapidly discuss these results with regulatory authorities, including in the US where we will ask for our EUA to be expanded to include appropriate hospitalised patients,” he added.

Earlier this year, Regeneron and Roche announced that REGEN-COV can reduce the risk of symptomatic infections by 81% among household contacts of individuals who have been infected with COVID-19.

REGEN-COV is currently available in the US under an emergency use authorisation (EUA) issued by the Food and Drug Administration (FDA) for the treatment of high-risk mild-to-moderate COVID-19 in adults and also in paediatric patients at least 12 years of age who weigh at least 40kg.