NEW ORLEANS — Psoriatic arthritis patients receiving etanercept reported sustained clinical benefits for up to 2 years, according to data from an open-label extension study.
Patients treated with the drug reported inhibition of disease as well as significant improvements in physical functioning and quality of life, Philip J. Mease, M.D., reported at the annual meeting of the American Academy of Dermatology.
After an initial 24-week blinded phase of the study, 169 patients received 25 mg of etanercept (Enbrel) twice weekly for an additional 48 weeks during the open-label extension phase.
Patient-reported outcomes included the physical and mental components of the Short-Form (SF-36) Health Survey and the Health Assessment Questionnaire-Disability Index (HAQ-DI). During the placebo-controlled phase, etanercept-treated patients had a mean improvement of 9.3 points on the SF-36 physical component summary scale, whereas placebo patients improved only 0.7 on the scale.
In the open-label phase, patients originally randomized to etanercept maintained their improvements (mean 12.6 points), and patients switched to etanercept from placebo improved almost to the same level as those on continuous etanercept, said Dr. Mease, a rheumatologist at the Swedish Medical Center, the University of Washington, Seattle. Both groups had normal mental health at baseline and maintained it throughout the industry-sponsored trial.
In the placebo-controlled phase, the HAQ-DI improved from 1.1 to 0.5 in the etanercept group and from 1.1 to 1 in the placebo group. At 48 weeks, 40 (53%) of 75 patients originally randomized to etanercept had an HAQ-DI of zero, indicating no disability in performing activities of daily living. The mean HAQ-DI score at 48 weeks was 0.4 for patients continuously treated with etanercept and 0.6 for 70 patients switched from placebo to the drug.
Eleven patients originally randomized to placebo and 10 patients on continuous etanercept dropped out of the open-label phase.
A change of 0.3 in the HAQ score is considered a minimal clinically important difference. Thus a change of 0.6 in the etanercept group “clearly was highly clinically meaningful to the patients,” said Dr. Mease, who receives grant support and is a consultant and member of the speaker's bureau for Amgen, which manufactures Enbrel.