OBJECTIVE:

To investigate the efficacy and safety of ABT-874, an interleukin 12/23 monoclonal antibody, in psoriasis.

DESIGN:

Phase 2, 12-week, multicenter, randomized, double-blind, placebo-controlled trial.

SETTING:

Outpatient dermatology clinics. Patients One hundred eighty patients with clinically stable moderate to severe chronic plaque psoriasis. Interventions Patients were randomized in groups of 30 to receive 1 of 6 treatments with ABT-874 provided as a subcutaneous injection: one 200-mg dose at week 0; 100 mg every other week for 12 weeks; 200 mg weekly for 4 weeks; 200 mg every other week for 12 weeks; 200 mg weekly for 12 weeks; or placebo. Main Outcome Measure At least a 75% reduction in the Psoriasis Area and Severity Index.

RESULTS:

The percentage of patients achieving a 75% reduction in the Psoriasis Area and Severity Index at week 12 was statistically significantly greater in all of the ABT-874 treatment groups than in the placebo group (200 mg once, 63% [19 of 30]; 100 mg every other week for 12 weeks, 93% [28 of 30]; 200 mg weekly for 4 weeks, 90% [27 of 30]; 200 mg every other week for 12 weeks, 93% [28 of 30]; 200 mg weekly for 12 weeks, 90% [27 of 30]; placebo, 3% [1 of 30]; P < .001). Treatment with ABT-874 was well tolerated. The most common adverse event was injection-site reaction, and the most common infectious adverse events were nasopharyngitis and upper respiratory tract infection. There were no serious infectious adverse events.

CONCLUSIONS:

ABT-874, an interleukin 12/23 monoclonal antibody, was highly effective and well tolerated in the treatment of psoriasis. Longer-term studies are required to confirm these findings.