Table 2.
IF and annualised FC for patients with available data pre- and post-switch to rFIXFc during B-SURE.
| Statistic | Switch from prior FIX prophylaxis to rFIXFc prophylaxis (n = 57) a | Switch from prior FIX on demand to rFIXFc prophylaxis (n = 15) b | ||||
|---|---|---|---|---|---|---|
| Pre-switch | Post-switch | Change c | Pre-switch | Post-switch | Change c | |
| Weekly IF (injections/week) | ||||||
| Mean (SD) | 1.66 (0.61) | 0.93 (0.26) | −0.73–(0.54) | 0.70 (1.21) | 0.66 (0.28) | −0.04 (1.20) |
| Median | 1.82 | 0.98 | −0.85 | 0.43 | 0.58 | 0.06 |
| IQR | 1.08–2.00 | 0.79–1.05 | −1.02−0.34 | 0.19–0.58 | 0.46–0.84 | −0.12–0.50 |
| Range | 0.34–3.46 | 0.39–1.99 | −2.44–0.14 | 0.00–4.97 | 0.32–1.30 | −4.13–1.11 |
| Annualised IF (injections/year) | ||||||
| Mean (SD) | 86.55 (31.60) | 48.31 (13.33) | −38.20 (28.24) | 36.39 (63.28) | 34.26 (14.38) | −2.13 (62.73) |
| Median | 94.84 | 51.22 | −44.10 | 22.20 | 30.27 | 3.29 |
| IQR | 56.19–104.40 | 41.06–54.93 | −53.00−17.50 | 9.98−30.44 | 24.07−43.80 | −6.37−26.28 |
| Range | 17.60–180.60 | 20.41–103.90 | −127.00−7.31 | 0.00−259.50 | 16.60−67.87 | −216.00−57.89 |
| Weekly FC (IU/kg/week) | ||||||
| Mean (SD) | 75.34 (40.87) | 56.03 (19.86) | −19.31 (32.50) | 31.18 (59.29) | 38.50 (18.13) | 7.32 (58.89) |
| Median | 66.13 | 51.67 | −8.36 | 15.50 | 34.39 | 16.67 |
| IQR | 49.26–86.66 | 45.56–64.09 | −35.12–5.54 | 8.13–22.04 | 23.20–47.63 | −0.27–39.47 |
| Range | 14.50–252.30 | 22.00–161.20 | −133.10–25.80 | 0.00–242.60 | 20.10–90.90 | −189.70–76.10 |
| Annualised FC (IU/kg/year) | ||||||
| Mean (SD) | 3,931 (2,132) | 2,924 (1,036) | −1,008 (1,696) | 1,627 (3,094) | 2,009 (945.92) | 381.8 (3,073) |
| Median | 3,451 | 2,696 | −436.40 | 809.00 | 1,789 | 869.60 |
| IQR | 2,570–4,522 | 2,377–3,344 | −1,833–289.20 | 424.20–1,150 | 1,211–2,485 | −14.20–2,060 |
| Range | 754.00–13,162 | 1,150–8,410 | −6,946–1,344 | 0.00–12,657 | 1,049–4,743 | −9,898–3,973 |
Pre-switch refers to the period prior to rFIXFc initiation; post-switch refers to the period since rFIXFc initiation.
a
57/65 patients with available data both pre- and post-switch to rFIXFc prophylaxis were included.
b
15/18 patients with available data both pre- and post-switch to rFIXFc prophylaxis were included.
c
Data were calculated from the date of rFIXFc initiation, including retrospective data.
FC, factor consumption; FIX, factor IX; IF, injection frequency; IQR, interquartile range; IU, international unit; rFIXFc, recombinant factor IX Fc fusion protein.