BAFF inhibition does not significantly impair immunization responses in patients with rheumatoid arthritis

Table 1 Week 28 (4 weeks post-vaccination) tetanus and pneumococcal antibody immunization responses following 24 weeks of tabalumab treatment

	120/Q4W	90/Q2W	Placebo	P value versus placebo
	120/Q4W	90/Q2W	Placebo	120/Q4W	90/Q2W
Tetanus IgG antibody response	n = 21^a	n = 30^a	n = 17^a
Number of patients with ≥4-fold titer increase where baseline titers ≥0.1 IU/ml^b (%)	17 (81.0)	13 (43.3)	10 (58.8)	0.167	0.371
Number of patients with ≥2-fold titer increase where baseline titers ≥0.1 IU/ml^b (%)	19 (90.5)	19 (63.3)	10 (58.8)	0.051	0.766
GMT pre-vaccination baseline (95 % CI)	0.301 (0.182, 0.498)	0.491 (0.280, 0.861)	0.341 (0.163, 0.711)
GMT 4 weeks post-vaccination (95 % CI)	3.495 (1.469, 8.315)	2.216 (1.151, 4.267)	1.963 (0.674, 5.713)	0.263^c	0.423^c
Total pneumococcal IgG antibody response	n = 21^a	n = 31^a	n = 17^a
Number of patients with ≥2-fold titer increase where baseline titers ≥4 mg/L^b (%)	15 (71.4)	23 (74.2)	13 (76.5)	>0.999	>0.999
GMT pre-vaccination baseline (95 % CI)	61.78 (46.30, 82.42)	63.77 (50.06, 81.23)	52.53 (36.33, 75.95)
GMT post-vaccination (95 % CI)	235.62 (150.97, 367.72)	220.81 (147.19, 331.26)	213.04 (121.83, 372.52)	0.835^c	0.563^c

CI confidence interval, GMT geometric mean titer, Ig immunoglobulin, 120/Q4W 120 mg tabalumab every 4 weeks, 90/Q2W 90 mg tabalumab every 2 weeks
^aThe n values represent the number of patients immunized with vaccine and a baseline and a 28 week antibody titer
^bOr a titer of ≥0.2 IU/ml for patients with baseline titers <0.1 IU/ml (tetanus) or ≥6 mg/L for patients with baseline titers <4 mg/L (pneumococcus)
^c P value based on change from baseline log transformed data; rather than providing log transformed titers, we present geometric mean titers as this is the standard way to report these data

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