For a fair number of ankylosing spondylitis (AS) patients with low disease activity, apparently it's possible to reduce the dose of anti-tumor necrosis factor-alpha (anti-TNF-α) agents without compromising effectiveness, judging from a small observational cohort study reported at the 2013 annual meeting of the European League Against Rheumatism (EULAR) in Madrid.
Researchers observed a small group of patients in the Groningen Leeuwarden AS (GLAS) cohort in the Netherlands after their anti-TNF-α drug doses were lowered by a mean of 37%. A sizable number (18 of 49, or 37%) are able to maintain a stable, reduced disease activity level at the lower dose after two years.
The patients (mostly men, with a mean age of 46 and symptom duration of 20 years) had achieved a mean Bath AS disease activity index (BASDAI) of 1.8 (down from 6.2) and were stable at that level for six months after starting a conventional dose of anti-TNF-α treatment, mostly etanercept(Drug information on etanercept).
Between November 2005 and January 2011, doses were lowered for 49 AS patients taking etanercept (n=35), infliximab (n=8), or adalimumab(Drug information on adalimumab) (n=6). Data on dose, reasons for change, and disease activity were collected at six, 12, 18, and 24 months.
Among the 25 patients who did not continue on the lower dose, 23 returned to a conventional dose regimen and two stopped TNF-α blocking therapy altogether. One patient halted therapy after an adverse event and the other stopped due to antibody formation that had rendered the drug ineffective.
For the 18 patients who remained on the reduced dose for fully two years, disease activity levels remained low (BASDAI <4) in 86%.