Duration of remission after halving of the etanercept dose in patients with ankylosing spondylitis: a randomized, prospective, long-term, follow-up study

Figures & data

Table 1 Demographic and clinical characteristics of 78 patients with ankylosing spondylitis at baseline and at the end of follow-up in December 2009

Patients	Baseline	End of follow-up	P
Total (n)	78	66
Female (n, %)	21 (28%)	16 (24%)
Male (n, %)	57 (72%)	50 (76%)
Median age at study entry (years)	38
Mean disease duration (years)	12
ESR (mm/hour)	30.1 ± 16.3	12.3 ± 4.2	<0.001
CRP (mg/dL)	1.9 ± 1.1	0.34 ± 0.23	<0.001
Patients with elevated ESR (n, %)	36 (46.1%)	3 (4.5%)
Patients with elevated CRP (n, %)	40 (51.2%)	5 (7.6%)
B27+ (n, %)	72 (92.3%)
Peripheral arthritis (n, %)	15 (19.2%)	1 (1.5%)
Enthesitis/dactylitis (n, %)	28 (35.8%)	7 (10.6%)
Iridocyclitis at onset or complicating the clinical course (n, %)	13 (16.6%)
BASDAI	6.9 ± 1.9	3.0 ± 1.6	<0.001
BASFI	5.5 ± 1.7	2.8 ± 1.3	<0.001
BASMI	4.8 ± 1.1	3.1 ± 1.5	<0.001
Modified Schober test (cm)	4.9 ± 1.56	3.1 ± 1.87	<0.001
Fingertip to floor distance (cm)	15.3 ± 6.6	7.6 ± 2.1	<0.001
Chest expansion (cm)	3.3 ± 0.28	3.96 ± 0.14	<0.001
Overall drug discontinuation and reason (n, %)		12 (15.3%)
No response		9 (11.5%)
Adverse events*		3 (4.0%)
ASAS 20 (n, %)		66 (100%)
ASAS 50 (n, %)		48 (72.7)
ASAS 70 (n, %)		43 (55.1)
Remission (patients, n, %)		43 (55.1%)
Time to remission (months)		9 ± 4.9
Follow-up duration (months)	25 ± 11

Notes: Data are expressed as the mean ± SD except where otherwise indicated.

* As reported in text.

Abbreviations: ASAS, Assessments in Ankylosing Spondylitis; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; SD, standard deviation; ESR, erythrocyte sedimentation rate (Westergren); CRP, C-reactive protein.

Table 2 Baseline and end of follow-up results in 22 patients with ankylosing spondylitis receiving etanercept 50 mg every other week and 21 patients receiving 50 mg weekly

Clinical parameter	Baseline		End of follow-up		P
	Group 1 Etanercept 50 mg eow	Group 2 Etanercept 50 mg weekly	Group 1 Etanercept 50 mg eow	Group 2 Etanercept 50 mg weekly
Patient (n)	22	21
Male (n, %)	18 (81.8%)	16 (76.1%)
Female (n, %)	4 (18.1%)	5 (23.8%)
Age (years, median)	37	38
Disease duration (years, median)	13	12
ESR (mm/hour)	11.8 ± 3.2	10.6 ± 2.4	10.2 ± 2.4	11.1 ± 1.8	NS
CRP (mg/dL)	0.28 ± 0.21	0.32 ± 0.12	0.38 ± 0.13	0.26 ± 0.24	NS
BASDAI	2.4 ± 0.3	2.3 ± 0.4	2.5 ± 0.7	2.3 ± 0.87	NS
BASFI	2.6 ± 1.4	2.5 ± 1.3	2.5 ± 1.1	2.4 ± 0.9	NS
BASMI	3.0 ± 1.2	3.1 ± 0.8	3.1 ± 1.1	3.1 ± 1.2	NS
Modified Schober test (cm)	2.9 ± 1.65	3.0 ± 1.23	2.7 ± 1.96	2.5 ± 1.57	NS
Fingertip to floor distance (cm)	6.5 ± 3.2	6.1 ± 2.5	5.9 ± 2.8	5.8 ± 2.1	NS
Chest expansion (cm)	4.1 ± 0.22	4.0 ± 0.67	4.2 ± 0.34	4.2 ± 0.65	NS
Remission			19 (86.3%)	19 (90.4%)	NS
Relapse (n, %)			3 (13.6%)	2 (9.5%)	NS
Time to relapse (months)			8 ± 3.2	10 ± 1.1	NS
Follow-up (months)			22 ± 1.1	21 ± 1.6	NS

Abbreviations: BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BASMI, Bath Ankylosing Spondylitis Metrology Index; eow, every other week; ESR, erythrocyte sedimentation rate (Westergren); CRP, C-reactive protein.