SAN ANTONIO – Adalimumab proved safe and effective when used for up to 2 years for the treatment of psoriatic arthritis in a phase III open-label extension study, according to results reported at the annual meeting of the American Academy of Dermatology.
In 395 patients who completed 2 years of treatment with adalimumab (Humira) for the 120-week multinational trial, treatment showed rapid efficacy for psoriatic arthritis (PsA), and the effect was sustained through the duration of the study, said Dr. Philip Mease of the Swedish Medical Center in Seattle.
Among the measures used in the study to assess disease signs and symptoms were the American College of Rheumatology's ACR 20, ACR 50, and ACR 70 response rates, and the Psoriatic Arthritis Response Criteria (PsARC). The percentages of PsARC responders at weeks 48 and 104 were 77% and 81%, respectively, Dr. Mease reported.
Psoriasis disease activity was measured in those with at least a 3% body surface area involvement using the Psoriasis Activity Severity Index (PASI) 50, 75, and 90 and the Physician's Global Assessment of Psoriasis.
The percentage of patients achieving PASI 50, 75, and 90 scores at weeks 48 and 104 were 84%, 69%, and 55%; and 83%, 70%, and 53%, respectively, Dr. Mease said during a poster discussion at the conference. The percentages of patients with a Physician's Global Assessment of clear or almost clear at those time points were 38% and 30%, and 40% and 31%, respectively.
Patients in the study, which was funded by Abbott Laboratories, were participants in either the 24-week Adalimumab Effectiveness in Psoriatic Arthritis Trial or a similar 12-week trial of the drug. Both trials were placebo-controlled trials comparing placebo with 40 mg of adalimumab every other week, and both showed that adalimumab provided statistically and clinically significant improvement, compared with placebo.
Quality of life was also evaluated using a variety of measures. Among them was the Health Assessment Questionnaire, which measures disability. The mean change at both weeks 48 and 104 was −0.4, which surpassed the “minimum clinically important difference level” of −0.3, Dr. Mease noted.
As for safety, a total of 10.6 serious adverse events per 100 patient-years occurred during the course of the study. There were 2.4 serious infectious adverse events per 100 patient-years, 0.5 malignancies other than nonmelanoma skin cancer per 100 patient-years, 0.78 nonmelanoma skin cancers per 100 patient-years, and two deaths–neither of which was thought to be due to adalimumab treatment, Dr. Mease said. “Overall, the take-home message was that safety issues were similar to those in rheumatoid arthritis trials.” The current findings demonstrate that adalimumab is safe, efficacious, and well tolerated for both skin and joint manifestations through 2 years in patients with psoriatic arthritis, Dr. Mease said.
The agent safely controlled skin and joint symptoms in some patients through 2 years of use. DR. MEASE