This section briefly summarizes the preliminary results of our highly potent broad-spectrum therapeutic antibodies for COVID-19. The above figure outlines the development processing of our therapeutic antibodies for COVID-19. We first expressed the ECD domain of spike protein in trimer form as antigen and performed the bio-panning process to identify possible binders.
We got 79 unique clones from our synthetic libraries and used a series of functional assays to select suitable candidates. These assays include the ELISA, Epitope mapping, Cell surface spike binding, ACE competition assay, and affinity measurement by Biacore system. We identified 24 hits and six hits are validated by the true virus neutralization assay performed by Dr. Sui-Yuan Chang from the Department of Laboratory Medicine, National Taiwan University Hospital. We finally select two antibodies named ATBM-36M and ATBM-14M as therapeutic antibody candidate.
After our affinity maturation and pseudovirus neutralization assay based on different variants including alpha, beta and epsilon, we got the optimized neutralizing antibodies showing the increase of inhibition capacity by 100 times than the original antibodies.
Further validations, including mutant escape assay in the VSV infection system and animal challenge, are in progress. We expect that these two therapeutic antibody candidates could be used for combination therapy.