Leading experts in spondylitis from around the world recently met to obtain an international consensus about the use of anti-tumor necrosis factor-alpha (TNF-a) blockers for treating people with ankylosing spondylitis (AS). The recommendations were developed upon review of published reports in combination with expert opinion, and a consensus meeting of the Assessments in AS (ASAS) Working Group.

Comprised of more than 25 international clinical researchers and the Spondylitis Association of America (SAA), the ASAS Working Group recently submitted a draft “Guidance Document for AS” to the Food and Drug Administration (FDA) on issues relating to drugs, TNF-a therapy, and devices for the treatment of AS.

This statement (summarized below) may be used in guidance in clinical decision making and as the basis for the development of guidelines.

To begin TNF-a therapy
a. a diagnosis of definitive AS
b. presence of active disease for at least four weeks as defined by both a sustained Bath AS Disease Activity Index (BASDAI) of at least four items and expert opinion
c. presence of difficult to disease defined by failure of at least two non-steroidal anti-inflammatory drugs (NSAIDs) during a single three month period, failure of intra-articular steroids if prescribed, and failure of sulphasalazine in patients with peripheral arthritis
d. application and implementation of the usual precautions and contraindications for biological therapy

Monitor TNF-a therapy
a. Both the BASDAI and the ASAS core set for clinical practice should be followed regularly

Discontinue TNF-a therapy in nonresponders
Consideration should be made after 6-12 weeks of treatment. The ASAS group defines “responsive” as improvement of at least 50% or 2 units (on a 0-10 scale) of the BASDAI and expert opinion that treatment should be continued.

Evaluation of the healthcare consequences of this consensus is subject to further research by the ASAS group.

-- International ASAS consensus statement for the use of anti-tumor necrosis factor agents in patients with ankylosing spondylitis. Annals of the Rheumatic Diseases 2003; 62: 817-824.