Table 1.

Baseline characteristics of participants

Characteristic	Cohort 1 (2.0 × 1011 vg/kg)		Cohort 2 (1.0 × 1012 vg/kg)				Cohort 3 (3.0 × 1012 vg/kg)
Participant no.	1	2	3	4	5	8	6	7
Age at informed consent, y	25	29	25	21	24	69	31	20
F9 mutation HGVS*	p.Ser365Argfs*2	p.Arg-4Gln; p.Arg43Gln	p.Gln121*; p.Gln167*	p.Tyr325*; p.Tyr371*	P.Arg180Trp	p.Ile214HisfsX8	p.Lys440Glu	p.I316T
Baseline FIX activity at screening,† IU/mL	0.005	0.008	0.02	<0.005	0.009	0.011	0.018	0.021
Baseline CRM status	Negative	Positive	Negative	Negative	Positive	Negative	Positive	Negative
Prior prophylactic FIX replacement therapy (past 12 mo)	No	Yes	Yes	No	No	Yes	Yes	Yes
Annualized bleeding rate	12	12	7.2	12	24	0	3	0
Average no. of FIX infusions per year	24	60	48	12	36	72	48	96
HIV status	Negative	Negative	Negative	Negative	Negative	Negative	Negative	Negative
HCV antibody status	Negative	Positive	Negative	Negative	Negative	Positive	Negative	Negative
Anti-AAV8 NAb titer	<1:5	<1:5	<1:5	<1:5	<1:5	<1:5	<1:5	<1:5
Anti-AAV2 NAb titer	<1:5	<1:5	1:10	1:5	<1:5	<1:5	<1:5	<1:5

^*According to Human Genome Variation Society nomenclature.

^†Retesting of FIX activity at screening was performed to ensure appropriate washout from exogenous FIX, specified in the study protocol as at least 5 days after a dose of exogenous short half-life recombinant FIX or 15 days if the participant was using extended half-life FIX.