Table 3.
Romiplostim usage and dosing during follow-up period, overall and stratified by duration of ITP at romiplostim initiation
| Overall (n = 340) |
ITP duration (months) | |||
|---|---|---|---|---|
| < 3 (n = 64) |
3–12 (n = 50) |
> 12 (n = 226) |
||
| Duration of exposure (weeks) | ||||
| Mean (SD) | 22 (5.9) | 20 (7.3) | 22 (6.0) | 22 (5.4) |
| Median (min, max) | 24 (1.0, 24) | 24 (2.0, 24) | 24 (1.0, 24) | 24 (1.0, 24) |
| Number of romiplostim administrations | ||||
| Mean (SD) | 18 (7.6) | 17 (7.8) | 18 (7.4) | 19 (7.5) |
| Median (min, max) | 22 (1.0, 46) | 21 (2.0, 25) | 23 (1.0, 24) | 22 (1.0, 46) |
| Cumulative dose (μg/kg) | ||||
| Mean (SD) | 64 (52) | 52 (35) | 71 (56) | 65 (55) |
| Median (min, max) | 52 (1.0, 440) | 44 (4.0, 140) | 59 (1.0, 210) | 53 (1.0, 440) |
| Average weekly dose (μg/kg)a | ||||
| Mean (SD) | 3.0 (2.2) | 2.8 (1.7) | 3.2 (2.2) | 3.0 (2.3) |
| Median (min, max) | 2.5 (0.04, 18) | 2.4 (0.3, 10) | 2.5 (0.2, 8.6) | 2.5 (0.04, 18) |
| Initial romiplostim dose, n (%) | ||||
| 1 µg/kg | 238 (70.0%) | 38 (59.4%) | 32 (64.0%) | 168 (74.3%) |
| 2 µg/kg | 42 (12.4%) | 9 (14.1%) | 10 (20.0%) | 23 (10.2%) |
| ≥ 3 µg/kg | 60 (17.6%) | 17 (26.6%) | 8 (16.0%) | 35 (15.5%) |
| Maximum dose (µg/kg) | ||||
| ≤ 3 | 160 (47.1%) | 34 (53.1%) | 17 (34.0%) | 109 (48.2%) |
| 4–9 | 145 (42.6%) | 26 (40.6%) | 25 (50.0%) | 94 (41.6%) |
| 10 | 35 (10.3%) | 4 (6.2%) | 8 (16.0%) | 23 (10.2%) |
| > 10 | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Romiplostim discontinuation at week 24, % | 15.8 (11.2–20.4) | 19.2 (8.8–29.7) | 12.5 (7.7–17.4) | |
SD standard deviation
aAverage weekly dose was calculated as cumulative dose/duration of exposure and some patients received more than one dose per week