Miami — Etanercept therapy in children and adolescents with moderate to severe plaque psoriasis remained safe, well tolerated, and efficacious in the first 96 weeks of a 5-year open-label extension study, Dr. Richard Langley reported at the annual meeting of the American Academy of Dermatology.
The multicenter study, designed to evaluate long-term safety and efficacy of the immunosuppressant drug in the pediatric population, followed an initial 48-week randomized controlled trial reported in 2008 (N. Engl. J. Med. 2008;358:241-51). Read our story here.
Of 211 patients aged 4-17 years included in the initial trial, 182 (86%) completed that trial or achieved Psoriasis Area Severity Index (PASI) of 50 or better on or after week 12 with no adverse events, and thus were eligible and agreed to participate in the extension study. Of these, most (80%) reported at least one adverse event by week 96 of the extension study, but only three reported a total of five serious adverse events, none of which were infectious or deemed attributable to etanercept, Dr. Langley, director of research in the division of clinical dermatology and cutaneous science at Dalhousie University, Halifax, N.S., said during a poster discussion session.
The most common adverse events were upper respiratory tract infections in 25% of patients, nasopharyngitis in 17%, streptococcal pharyngitis in 13%, headache in 12%, and sinusitis in 11%. Serious adverse events were anxiety in one patient, intestinal obstruction in one patient, and abdominal pain, dehydration, and elective abortion all in one patient, Dr. Langley said, stressing that no opportunistic infections or malignancies occurred, which is particularly important to consider when evaluating the safety of an immunosuppressive agent.
Only two patients in the extension phase withdrew due to adverse events, and neither of these (Crohn’s disease in one, and sinusitis in one) were considered to be due to etanercept. Other patients did withdraw, however, most often due to consent withdrawal (19 patients) and loss to follow-up (14 patients); 140 patients completed 96 weeks of the extension study, and most (89%) of these achieved PASI of 50 or better (relative to baseline in the initial 48-week trial), including 30% who achieved PASI of 90 or better.
The mean PASI improvement was about 70%, and static Physician Global Assessment scores of 0 or 1 (clear or almost clear) were achieved in 47% of patients.
Treatment in both the initial and extension phases of the trial involved once-weekly subcutaneous injection of 0.8 mg/kg of etanercept, with a maximum dose of 50 mg/kg. Patients were also allowed to use standard topical treatments.
The conclusion at this stage of the trial is that etanercept is acceptably safe in this population at 96 weeks, Dr. Langley said, adding that this is the longest extension in a randomized controlled trial of patients receiving etanercept. No new adverse events or serious adverse events were seen, compared with the initial research.
“We believe this supports the continued study [of etanercept] and we will continue to follow these patients up to 5 years for infections and major adverse events,” he said.
Dr. Langley disclosed that he was an adviser and investigator for Amgen, and he has received grants and honoraria from Amgen. This trial was funded by Immunex Corp., a wholly-owned subsidiary of Amgen. Amgen and Wyeth Pharmaceuticals Inc. (now a part of Pfizer) together market Enbrel (etanercept).