I believe ToInfinity was looking for a single entity that is effective against a broader range of gram negatives, including both CRE and P. aeruginosa. CC-1807 is very good for Klebsiella, E. coli and CRE but not P. aeruginosa. They have 6 distinct series effective against P. aeruginosa but these entities apparently aren't effective against CRE. It'd be great (as TIFB has suggested) if one compound could get both CRE, P. aeruginosa, K. pneumonia and E. coli. With the leads in the current library, it may be doable.