Mean steady-state FIX levels and prophylaxis status by participant
| Participant . | Pre-AMT-060 gene transfer . | Post-AMT-060 gene transfer . | ||||||
|---|---|---|---|---|---|---|---|---|
| FIX activity at diagnosis, IU/dL . | Hemophilia B phenotype . | FIX prophylaxis . | Presumed CRM status* (activity/antigen ratio) . | Mean steady-state FIX, IU/dL activity (95% CI) . | FIX prophylaxis . | Hemophilia B phenotype . | Lessening of severity . | |
| 1 | <1 | Severe | Yes | +(0.1) | 6.2 (5.8-6.6) | No | Mild | Yes |
| 2 | <1 | Severe | Yes | +(0.4) | 4.7 (4.5-5.0) | No | Moderate | Yes |
| 3 | <1 | Severe | Yes | –(NC)† | 1.3 (–0.7 to 3.2) | Yes | Moderate | Yes |
| 4 | 1.5 | Moderate | Yes | –(1.4) | 6.8 (6.3-7.3) | No | Mild | Yes |
| 5 | <1 | Severe | Yes | –(1.2) | 3.0 (2.6-3.4) | No | Moderate | Yes |
| 6 | <1 | Severe | Yes | –(1.1) | 12.7 (11.9-13.5) | No | Mild | Yes |
| 7 | <1 | Severe | Yes | +/−(0.7) | 6.4 (6.0-6.7) | No | Mild | Yes |
| 8 | <1 | Severe | No‡ | –(1.6) | 6.8 (5.8-7.7) | No | Mild | Yes |
| 9 | <1 | Severe | Yes | +(0.0) | 3.1 (2.8-3.3) | No | Moderate | Yes |
| 10 | <1 | Severe | Yes | –(1.4) | 5.8 (5.4-6.2) | No | Mild | Yes |
| Participant . | Pre-AMT-060 gene transfer . | Post-AMT-060 gene transfer . | ||||||
|---|---|---|---|---|---|---|---|---|
| FIX activity at diagnosis, IU/dL . | Hemophilia B phenotype . | FIX prophylaxis . | Presumed CRM status* (activity/antigen ratio) . | Mean steady-state FIX, IU/dL activity (95% CI) . | FIX prophylaxis . | Hemophilia B phenotype . | Lessening of severity . | |
| 1 | <1 | Severe | Yes | +(0.1) | 6.2 (5.8-6.6) | No | Mild | Yes |
| 2 | <1 | Severe | Yes | +(0.4) | 4.7 (4.5-5.0) | No | Moderate | Yes |
| 3 | <1 | Severe | Yes | –(NC)† | 1.3 (–0.7 to 3.2) | Yes | Moderate | Yes |
| 4 | 1.5 | Moderate | Yes | –(1.4) | 6.8 (6.3-7.3) | No | Mild | Yes |
| 5 | <1 | Severe | Yes | –(1.2) | 3.0 (2.6-3.4) | No | Moderate | Yes |
| 6 | <1 | Severe | Yes | –(1.1) | 12.7 (11.9-13.5) | No | Mild | Yes |
| 7 | <1 | Severe | Yes | +/−(0.7) | 6.4 (6.0-6.7) | No | Mild | Yes |
| 8 | <1 | Severe | No‡ | –(1.6) | 6.8 (5.8-7.7) | No | Mild | Yes |
| 9 | <1 | Severe | Yes | +(0.0) | 3.1 (2.8-3.3) | No | Moderate | Yes |
| 10 | <1 | Severe | Yes | –(1.4) | 5.8 (5.4-6.2) | No | Mild | Yes |
Only values at least 10 d after the preceding FIX administration are included.
CRM, cross-reactive material.
Baseline measurements for CRM were not collected.
The majority of individuals showed post-AMT-060 activity/antigen ratios of ∼1:1. Ratios lower than 1:1 are suggestive of CRM positivity.
Used on-demand FIX replacement before study entry.