Amgen (NASDAQ: AMGN) announced patients with ankylosing spondylitis who received treatment with Enbrel (R) (etanercept) experienced sustained improvement in signs and symptoms, spinal mobility and physical function over 148 to 160 weeks of therapy, according to data from an ongoing open-label, multinational, phase 4 extension study presented at the American College of Rheumatology scientific meeting. These results are consistent with an ENBREL phase 3 clinical trial at 24 weeks.
“These data demonstrate that ENBREL can provide substantial long-term improvement in AS symptoms such as total back pain and spinal mobility,” said Joachim Sieper, M.D., professor of rheumatology, Charite University in Berlin, Germany. “Because AS is a chronic inflammatory disease that requires ongoing management, it is important to offer patients a treatment option that is effective, has an established safety profile, and can be used over the long-term.”
Data presented at ACR showed that 59 patients who received open-label ENBREL treatment for up to 160 weeks experienced sustained clinical improvements. Overall, 78 percent of patients (n=46) continuing treatment with ENBREL achieved a 20 percent improvement in the Assessment on Ankylosing Spondylitis Response Criteria (ASAS 20) after 160 weeks of treatment. ASAS is a composite measure of improvement in AS symptoms that include total back pain, patient assessment of disease activity, inflammation and physical function. Thirty-one percent of patients (n= 18) achieved partial remission at week 160. Partial remission, as defined by ASAS, is a low disease activity level (score < 20 units out of 100 in each of the four ASAS criteria).Additional ENBREL data presented at ACR from this phase 4 extension study show that improvement in spinal mobility was also sustained through 148 to 160 weeks of treatment with ENBREL.Patients with ankylosing spondylitis have reported that their condition has negatively impacted their ability to perform daily activities including exercising, rising from a seated position and climbing stairs without aid. Overall, patients treated with ENBREL achieved a 46 percent improvement in physical function, as measured by the Bath Ankylosing Spondylitis Functional Index (BASFI), and these results were sustained through 160 weeks. The BASFI is a 10-question, patient self-assessment instrument consisting of 8 specific questions regarding physical function in AS and 2 questions reflecting the patient’s ability to cope with everyday life. Each question is answered on a 10 cm horizontal visual analog scale, the mean of which gives the BASFI score (0-10).ENBREL was generally well tolerated over 148 to 160 weeks of therapy.This study was designed to assess the safety and long-term efficacy of ENBREL in patients with AS, using clinical measures to assess disease activity, physical function, improvement in AS symptoms, and ongoing surveillance to assess the incidence of adverse events. The study is a 96-week open-label, multinational, phase 4 extension study in 59 patients with AS who completed each of two earlier trials, a 12-week randomized, double-blind, placebo-controlled study and a 96-week open-label study. The data presented at ACR is from the first 52-weeks of an ongoing 96-week extension study (total ENBREL treatment 148 ? 160 weeks).Enbrel received FDA approval to treat the signs and symptoms of active AS in 2003 following a randomized, double-blind, placebo-controlled phase 3 study in 277 patients with active ankylosing spondylitis. Treatment with ENBREL (n=138) resulted in significant clinical improvements through 24 weeks, compared to placebo (n=139). At 12 weeks, the ASAS 20 response was achieved by 60 percent of patients receiving ENBREL, compared to 27 percent of patients receiving placebo (p