Perhaps I'm being unduly harsh but do you see a lot of long-term upside for another RA monoclonal antibody that's just in mid-stage testing given the existing RA monoclonal antibodies on the market, the other ones in development, and the prospect of the oral RA pills and generic RA biologics to come?
If a drug could have TNF-alpha-like efficacy and significantly better safety/tolerability, it would have the potential to be a colossal blockbuster. This is presumably what ABT has in mind.
Just to echo Dew's comments a bit. In addition to side effects if you look at some of the risks (e.g. higher risk of Lymphoma) I would be a bit concerned taking (or having family take) Humira and I believe most if not all the other RA drugs too. So, I suspect there are a fair number of RA patients too who are reluctant to start especially if outbreaks/symptoms are not frequent and/or milder.