Enabling the immune escaped etesevimab fully-armed against SARS-CoV-2 Omicron subvariants including KP.2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving since 2019. Some monoclonal antibodies (mAbs) have been developed and widely used, such as etesevimab (CB6) developed by Eli-Lilly/Junshi. However, the mAb escaped from the variant of concern (VOC) ever since the emergence of Beta VOC, with a complete loss of efficacy against the Omicron subvariants. Here, we developed a broad-spectrum and affinity-mature antibody design (BAADesign) procedure to design CB6, enabling it to bind to the receptor-binding domains (RBDs) of multiple important Omicron subvariants, including the recent variant KP.2. Structural analysis confirmed the desired CB6-RBD interactions. Additionally, identical mutations in the complementarity determining regions (CDR)1 and CDR2 of the CB6 mutants also restored neutralizing potency for some RBD-1 group antibodies. Overall, the enhanced CB6 neutralizing capacity makes it a promising candidate against SARS-CoV-2 infection, and the BAADesign method has implications for the design of other antibodies.