Table 2.

Immunogenicity summary

	End of period II (Withdrawal phase)		End of period III (Reintroduction phase)*
	Period II SC abatacept (n=40)	Period II SC placebo (n=80)	Period II SC abatacept†(n=40)	Period II SC placebo‡(n=79)
Anti-abatacept, n/N (%)	0/37 (0)	1/71 (1.4)	0/38 (0)	0/73 (0)
95% CI	–	0.0 to 4.1	–	–
Anti-CTLA4-T, n/N (%)	0/38 (0)	6/73 (8.2)	1/38 (2.6)	2/73 (2.7)
95% CI	–	1.9 to 14.5	0.0 to 7.7	0.0 to 6.5
Total, n/N (%)	0/38 (0)	7/73 (9.6)	1/38 (2.6)	2/73 (2.7)
95% CI	–	2.8 to 16.3	0.0 to 7.7	0.0 to 6.5
Estimate of difference, % (95% CI)	9.59 (0.83 to 18.34)		0.11 (–8.21 to 8.43)
p Value	0.119		–

^*All patients received SC abatacept during period III, with results shown by period II treatment group.

^†Patients received intravenous placebo loading at the start of period III.

^‡Patients received intravenous abatacept or intravenous placebo (1:1 ratio) loading at the start of period III.

SC, subcutaneous.