BIRMINGHAM, ENGLAND (FRONTLINE MEDICAL NEWS) – A proportion of patients with ankylosing spondylitis (AS) were able to remain on a reduced-dose regimen of a tumor necrosis factor inhibitor (TNFi) for almost 4 years, according to data from a small study presented at the British Society for Rheumatology annual conference.

In an extension of the ANSWERS (Ankylosing Spondylitis with Etanercept Regimens) trial , 4 of 12 patients receiving a once-weekly 25-mg dose of etanercept (Enbrel) had a sustained response as did 14 of 21 patients who remained on the usual once-weekly dose of 50 mg.

“Although a minority of patients maintained response to the lower dose of etanercept over the longer term, the costs savings are substantial,” said Lauren Steel and coauthors from the Norfolk and Norwich Hospitals NHS Foundation Trust in a poster presentation. Almost 18,000 pounds sterling ($23,000) could be saved per each patient who is able to stay on the lower dose for 50 months.

Further, patients who did not maintain a response on the lower dose were usually able to regain their responses when the higher dose therapy was reinstituted. On average, disease control was reestablished in three out of four patients within 14 months of reverting to standard therapy.

ANSWERS was an open-label, multicenter, randomized, pilot study that sought to determine if tapering the dose of etanercept from the recommended 50 mg to 25 mg was feasible in 47 patients with AS ( J Rheumatol. 2015;42:1177–85 ). The premise was that dose tapering in patients who achieved a response would perhaps reduce the risk for side effects in the long term, as well as provide considerable cost savings.

About half of the patients studied achieved a response to full-dose etanercept and were able to reduce their dose. At 6 months, a clinical response was maintained by 52% of the patients taking 25 mg and 92% of the patients taking 50 mg (P = .003).

The current prospective extension of the study looked at the longer-term outcomes of the patients who successfully maintained a response to the lower dose of etanercept.

Maintenance of response was defined as no change in the primary outcome of a reduction of 50% or more or a fall of at least 2 units in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and at least a 2-unit reduction in spinal pain measured using a 10-point scale.

In all, 12 patients, 9 of them male, with a mean age of 52 years entered the extension study. The comparator group consisted of 21 patients who had continued taking the 50-mg dose, 20 of them male, with a mean age of 60 years.

Of the 12 patients in the 25-mg group, 1 discontinued treatment because of side effects and did not restart any further biologic treatment; 7 patients experienced a disease flare after a median of 16 months and were retreated with the 50-mg dose. Five of the seven patients who reverted to the higher dose of etanercept regained a good response; the other two patients were switched to adalimumab (Humira) because of a loss of efficacy.

Pfizer funded the original study. One author disclosed he had received research funding and acted as an adviser to Pfizer and other pharmaceutical companies.