New monoclonal antibody effective for plaque psoriasis

CNTO 1275, an anti-IL12p40, maintains efficacy in clearing plaque psoriasis for up to 24 weeks after 1 dose, according to results of a phase 2 study presented by researchers at the 64th Annual Meeting of the American Academy of Dermatology in San Francisco. The subcutaneously injected agent targets both interleukin 12 and 23, two key cytokines in type 1 immune responses, said study author Gerald G. Krueger, MD, of the department of dermatology, University of Utah Health Sciences Center, in Salt Lake City, Utah.

The 52-week, double-blind, placebo-controlled study randomized 320 plaque psoriasis patients to receive a single 50-mg or a single 100-mg injection of CNTO 1275, 4 weekly CNTO 1275 injections of 50 or 100 mg, or placebo. There were 64 patients in each group. Patients who did not achieve ≥75% improvement rated by physician's global assessment received an additional 50-mg or 100-mg dose at 16 weeks. Patients in the placebo group received 100 mg of CNTO 1275 at week 20.

After 12 weeks, a Psoriasis Area and Severity Index (PASI) response of ≥75 (indicating a 75% clearing or better) was seen in 52% of patients treated with the single 50-mg dose, 59% of those receiving a single 100-mg dose, 67% of those receiving 4 weekly 50- mg injections, and in 81% of patients receiving 4 weekly 100 mg injections. A 90% psoriasis clearing was seen in 23%, 30%, 44%, and 52% of patients in the respective dosing groups. Researchers noted that only 2% of patients in the placebo group achieved a PASI 75 response, and 2% achieved a PASI 90 response (P<.001).

A total of 87 patients, fewer than half, did not achieve a PASI 75 response and were retreated at Week 16. Dr Krueger said that with average follow-ups ranging from 17.9 to 20.1 weeks for the different dosing groups, the majority of patients achieving a PASI 50 response or better after treatment maintained their response through Week 24. After Week 24, response began to decline.

The researchers said there were no serious adverse events and that overall, 79% of patients in the CNTO 1275 group experienced >1 adverse event compared with 68.7% of patients in the placebo group.

A multicenter, phase 3 trial, which is enrolling 750 patients, is under way, and an additional long-term study of CNTO 1275 is planned, Dr Krueger said.