Study 1

non-splenectomised patients
 Study 2

splenectomised patients
 Combined

studies 1 & 2
 
  romiplostim

(n = 41)
 Placebo
(n = 21)
 romiplostim

(n = 42)
 Placebo

(n = 21)
 romiplostim

(n = 83)
 Placebo
(n = 42)
No. (%) patients with durable platelet responsea
 25 (61%)
 1 (5%)
 16 (38%)
 0 (0%)
 41 (50%)
 1 (2%)
(95% CI)
 (45%, 76%)
 (0%, 24%)
 (24%, 54%)
 (0%, 16%)
 (38%, 61%)
 (0%, 13%)
p-value
 < 0.0001
 0.0013
 < 0.0001
No. (%) patients with overall platelet responseb
 36 (88%)
 3 (14%)
 33 (79%)
 0 (0%)
 69 (83%)
 3 (7%)
(95% CI)
 (74%, 96%)
 (3%, 36%)
 (63%, 90%)
 (0%, 16%)
 (73%, 91%)
 (2%, 20%)
p-value
 < 0.0001
 < 0.0001
 < 0.0001
Mean no. weeks with platelet responsec
 15
 1
 12
 0
 14
 1
(SD)
 3.5
 7.5
 7.9
 0.5
 7.8
 2.5
p-value
 < 0.0001
 < 0.0001
 < 0.0001
No. (%) patients requiring rescue therapiesd
 8(20%)
 13 (62%)
 11 (26%)
 12 (57%)
 19 (23%)
 25 (60%)
(95% CI)
 (9%, 35%)
 (38%, 82%)
 (14%, 42%)
 (34%, 78%)
 (14%, 33%)
 (43%, 74%)
p-value
 0.001
 0.0175
 < 0.0001
No. (%) patients with durable platelet response with stable dosee
 21 (51%)
 0 (0%)
 13 (31%)
 0 (0%)
 34 (41%)
 0 (0%)
(95% CI)
 (35%, 67%)
 (0%, 16%)
 (18%, 47%)
 (0%, 16%)
 (30%, 52%)
 (0%, 8%)
 
p-value
 0.0001
 0.0046
 < 0.0001
a Durable platelet response was defined as weekly platelet count  50 x 109/l for 6 or more times for study weeks 18-25 in the absence of rescue therapies any time during the treatment period.

b Overall platelet response is defined as achieving durable or transient platelet responses. Transient platelet response was defined as weekly platelet count  50 x 109/l for 4 or more times during study weeks 2-25 but without durable platelet response. Patient may not have a weekly response within 8 weeks after receiving any rescue medicinal products.

c Number of weeks with platelet response is defined as number of weeks with platelet counts  50 x 109/l during study weeks 2-25. Patient may not have a weekly response within 8 weeks after receiving any rescue medicinal products.

d Rescue therapies defined as any therapy administered to raise platelet counts. Patients requiring rescue medicinal products were not considered for durable platelet response. Rescue therapies allowed in the study were IVIG, platelet transfusions, anti-D immunoglobulin, and corticosteroids.

e Stable dose defined as dose maintained within ± 1 µg/kg during the last 8 weeks of treatment.

Reduction in permitted concurrent ITP medical therapies

In both placebo-controlled, double-blind studies, patients already receiving