Coronaviruses are a diverse group of viruses infecting many different animals, and they can cause mild to severe respiratory infections. In 2002 and 2012, respectively, two highly pathogenic coronaviruses with zoonotic origin, SARS-CoV and MERS-CoV, emerged in humans and caused fatal respiratory illness. By the way, CoVs have enveloped viruses with a positive-sense, single-stranded RNA. CoVs have four main structural proteins: spike(S), membrane (M), envelope (E), and nucleocapsid (N) proteins. An S protein mediates the CoV entry into host cells by attaching to a cellular receptor. Thus, the virus can fuse with the host cell membranes
SARS-CoV-2, a novel coronavirus that emerged in 2019, causes an outbreak of viral pneumonia COVID-19. Being highly transmissible, this novel coronavirus disease has spread fast all over the world. SARS-CoV-2 shares 79% genome sequence identity with SARS-CoV and 50% with MERS-CoV. Furthermore, SARS-CoV-2 uses the same receptor as SARS-CoV, angiotensin-converting enzyme 2 (ACE2). Besides human ACE2 (hACE2), SARS-CoV-2 also recognizes ACE2 from pigs, ferrets, rhesus monkeys, civets, cats, pangolins, rabbits, and dogs. Meanwhile, recent studies reported specific monoclonal antibodies neutralizing SARS-CoV-2 infection in vitro and in vivo.
Amubarvimab (BRII-196) is a human IgG1 mAb that binds to non-competing epitopes on the RBD of the spike protein.
Amubarvimab can effectively neutralize SARS-CoV-2 variants. Therefore, Amubarvimab completely blocks viral entry and neutralizes live SARS-CoV-2 infection in cell culture assays. Romlusevimab has an additive effect when combined with Amubarvimab. What’s more, in a mouse model of SARS-CoV-2 infection, a single intraperitoneal injection of Amubarvimab/Romlusevimab protected animals from Omicron infection. Besides, the pharmacokinetics of Amubarvimab/Romlusevimab were consistent with those for Amubarvimab and Romlusevimab as monotherapies, suggesting no interactions between the two monoclonal antibodies.
All in all, Amubarvimab is an IgG1 mAb that binds to RBD and against SARS-CoV-2.