For those who doubt the ability of auto immune drugs to cross...

For those who doubt the ability of auto immune drugs to cross over from one auto immune condition such as psoriasis to another such as arthritis , check this out . Other biologics are on their way:

Amgen's Enbrel is already on the market for treating psoriatic arthritis, rheumatoid arthritis and juvenile rheumatoid arthritis, and it is now being reviewed by the FDA for the treatment of psoriasis.
Centocor's Remicade is already on the market for rheumatoid arthritis and Crohn's disease; additional late-stage clinical studies in psoriasis and psoriatic arthritis are ongoing.

Solbecs Psoriasis trial is just the first auto immune disease they are tackling . The implications of a successful trial are enormous .