The war between Lexcorp and Cadmus is at the centre of Adventures of Superman 513 (June 1994), as Kesel, Kitson and McCarthy find the cure for the clone plague.
Dubbillex and the Guardian are the only clones not affected, it seems because they were grown far more slowly than the others. Things at Cadmus have gone haywire after the death of the director, Westfield, at the hands of Dabney Donovan. But the source of the plague is found – fallout from the destruction of Engine City. With that known, it is possible to create a cure, and the Guardian’s blood provides the key. Superboy, with his accelerated healing factor, is the first clone saved. Luthor demands the Guardian be turned over, so his life can be saved, but Cadmus refuses.
Cadmus gets destroyed in an explosion at the end of the story, and Superman insists that no one survived. But he is so casual about announcing that, that it is fairly obvious that the explosion is being used as a cover. Pretend Cadmus was destroyed, in order that it may survive.
The story continues in the next issue of Action.