Efficacy of Ustekinumab Followed by Abatacept for the Treatment of Psoriasis Vulgaris

"Ustekinumab interferes with the actions of proteins, interleukin 12 (IL12) and interleukin 23 (IL23), which reduces inflammation (swelling) in the skin. Stelara™ is the trade name for ustekinumab and is approved by the U.S. Food and Drug Administration (FDA) to treat psoriasis.~Dose:~Participants who weigh \<= 100 kg at study entry will receive 45 mg of ustekinumab.~Participants who weigh \> 100 kg at study entry will receive 90 mg of ustekinumab."

"Abatacept (one form of the protein called CTLA4-Ig) interacts with the immune system, reducing the activity of T-cells and may prevent relapse. Orencia™ is the trade name for abatacept, and it is approved by the FDA to treat rheumatoid arthritis in adults.~Dose:~125 mg sub-cutaneous injection"

The abatacept treatment group will also receive subcutaneous placebo for ustekinumab (sterile normal saline) at week 16 and week 28, corresponding to the ustekinumab dosing regimen.

The ustekinumab treatment group will also receive weekly subcutaneous injections of placebo for abatacept from week 12 to week 39, corresponding to the abatacept dosing regimen.