Serono S.A. reported positive Phase II results for onercept (r-hTBP-1) in both psoriasis and psoriatic arthritis. Onercept is a recombinant, unmodified, fully human soluble type I TNF receptor (p55), which acts as an anti TNF agent.

In a multi-center double-blind placebo-controlled study for psoriasis, patients treated with onercept at a dose of 150mg, subcutaneously, three times a week for a period of 12 weeks, showed a significant improvement in their Psoriasis Area and Severity Index (PASI) score. PASI is the globally accepted measure of treatment efficacy in this indication.

After 12 weeks of therapy, 54% (23/43) of patients receiving onercept 150mg demonstrated 75 percent or greater PASI score improvement (PASI 75) versus 12% (5/43) of patients on placebo (p<0.001). In addition, 74% (32/43) achieved 50 percent or greater PASI score improvement (PASI 50), versus 26% (11/43) in the placebo group (p<0.001). In the study, patients treated with onercept showed significant improvement in PASI after two weeks of treatment compared with placebo (p<0.05). Side effects for onercept-treated patients were similar to those observed in the placebo group. Injection site reactions were more frequent in the onercept group.

Over the 12-week treatment period patients treated with onercept 150mg experienced a significant improvement in quality of life, based on the standard measurements of Short Form 36 (SF-36) and Dermatology Life Quality Index (DLQI).

In an earlier multi-center double-blind placebo-controlled study of onercept in psoriatic arthritis, doses of 50mg and 100mg were given subcutaneously three times a week for a period of 12 weeks. The improvement in the psoriatic arthritis response criteria (PsARC) was more favorable at the 100mg dose. After 12 weeks of treatment at 100mg, 86% (36/42) of patients on onercept met the PsARC primary endpoint compared with 45% (19/42) on placebo (p<0.001). The secondary endpoint of ACR20 was achieved by 67% (28/42) of onercept patients compared to 31% (13/42) on placebo (p=0.001). Side effects for onercept-treated patients were similar to those observed in the placebo group. Injection site reactions were more frequent in the onercept groups.