Johnson & Johnson’s Centocor reported positive results from a phase III trial of CNTO1275 (ustekinumab) for the treatment of psoriasis. CNTO1275 is a monoclonal antibody (mAb) against the p40 subunit of interleukin 12 (IL-12) and IL-23. This randomized, double-blind, placebo-controlled study, dubbed PHOENIX 2, enrolled 1,230 subjects with chronic psoriasis.

The subjects received CNTO1275 administered subcutaneously or placebo. In the CNTO1275 arm, the subjects received 45 mg or 90 mg doses at weeks 0 and 4 followed by the same dose every twelve weeks. Those in the placebo arm crossed over to receive either 45 mg or 90 mg doses of CNTO1275 at weeks 12 and 16 and every subsequent twelve weeks.

The primary endpoint was the proportion of subjects who achieved a Psoriasis Area and Severity Index (PASI) score of 75 at Week 12.

By Week 12, 67% of the subjects treated with 45 mg of CNTO1275 and 76% of those treated with 90 mg of CNTO1275 achieved PASI75 compared with 4% of those treated with placebo (p < 0.001). In addition, 42% of the subjects in the 45 mg arm and 51% in the 90mg arm achieved a PASI 90, or almost complete clearance of psoriasis, compared with 1% in the placebo arm (p < 0.001).

Comparable results were seen in the placebo group twelve weeks after crossover to CNTO1275. Following an additional dose at Week 16, responses were maintained through Week 28.

Treatment was well tolerated, with adverse events comparable between the CNTO1275 and placebo groups.

Psoriasis is an immune-mediated, genetic disease affecting the skin and the joints. According to the National Institutes of Health (NIH), an estimated 125 million people worldwide have psoriasis.