Table 1.
Randomized controlled trials of romiplostim and eltrombopag in adults with ITP.
| Drug | Study Design [Reference] | Number of Subjects | Percentage of Subjects with Splenectomy (n) | Treatment Arms (n) | Duration of Study | Primary Endpoint | |
|---|---|---|---|---|---|---|---|
| Romiplostim | Phase II [1] | 21 | 67 (14) | Placebo (4) Romiplostim 1 μg/kg (8) Romiplostim 3 μg/kg (8) Romiplostim 6 μg/kg (1) |
6 weeks | Safety and tolerability | |
| Phase III [2] | 62 | 0 | Placebo (21) Romiplostim 1 μg/kg (41)a |
24 weeks | Platelet count ≥50 × 109/L during 6 of the last 8 weeks of treatment | ||
| Phase III [2] | 63 | 100 (63) | Placebo (21) Romiplostim 1 μg/kg (42)a |
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| Phase IIIb [3] | 234 | 0 | Standard of care (77) Romiplostim 3 μg/kg (157)b |
1 year | Incidence of splenectomy and of treatment failurec | ||
| Eltrombopag | Phase II [4] | 23 | 70 (16) | Placebo (8) Eltrombopag 12.5 mg (15)d |
6 weeks | Platelet count between 50 × 109/L and 400 × 109/L at week 7 | |
| Phase II [5] | 117 | 47 (55) | Placebo (29) Eltrombopag 30 mg (30) Eltrombopag 50 mg (30) Eltrombopag 75 mg (28) |
6 weeks | Platelet count ≥50 × 109/L at week 6 | ||
| Phase III [6] | 114 | 39 (45) | Placebo (38) Eltrombopag 50 mg (76)e |
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| Phase III [7] | 197 | 35 (69) | Placebo (62) Eltrombopag 50 mg (135)e |
6 months | Platelet count between 50 × 109/L and 400 × 109/L at any point during treatment | ||
a
Romiplostim could be increased to a maximum of 15 μg/kg based on platelet count.
b
Romiplostim could be adjusted to a maximum of 10 μg/kg based on platelet count.
c
Treatment failure defined as platelet count ≤20 × 109/L for 4 consecutive weeks at the highest allowable dose or major bleeding event or change in therapy due to intolerable side effects or bleeding symptoms.
d
Eltrombopag could be increased to a maximum of 25 mg based on platelet count.
e
Eltrombopag could be adjusted to a maximum of 75 mg based on platelet count.