Romiplostim is supplied in a 5 mL single use glass vial as a sterile, white, preservative-free, lyophilized powder.

The time from first dose of study drug to the last dose of 26-week test treatment period. A bleeding event is defined as any bleeding event reported during the test treatment period. Bleeding events that continue for more than 7 days are counted as separate events every eighth day. Multiple events that arose from one organ system on one day are collapsed into one single event. Exposure adjusted event rate per 100 patient-years = events / patient-year * 100).

The time from first dose of study drug to the last dose of 26-week test treatment period. A unit of platelets is defined as a single pack of pooled platelet-rich plasma comprised of 6 to 8 individual platelet concentrate packs (200 to 400 mL), a single pack of pooled buffy-coat concentrate, or 1 apheresis (single donor) concentrate. Exposure adjusted event rate per 100 patient-years = events / patient-years * 100.

Platelet Hematologic Improvemen defined by the international working group (IWG) as: an absolute increase in platelet count of ≥ 30 x 10^9/L for a patient starting with a platelet count of ≥ 20 x 10^9/L or an increase in platelet count from < 20 x 10^9/L to ≥ 20 x 10^9/L and by at least 100% in a patient that started with a platelet count < 20 x 10^9/L. To account for any possible contribution from platelet transfusions, platelet counts within 3 days following administration of platelet transfusion is not counted towards the platelet hematologic improvement endpoint. If no platelet measurements are available on the weekly scheduled dose day, then that week is not counted towards the platelet hematologic improvement endpoint.

Duration for participants who did not report HI-P during the period is 0. A platelet hematologic improvement (HI-P) is defined by an MDS International Working criteria as patients with a baseline platelet count of ≥ 20 x 10^9/L achieving an absolute increase of ≥ 30 x 10^9/L or increasing the platelet count to above 20 x 10^9/L and by at least 100% in patients with a baseline of < 20 x 10^9/L for at least 8 consecutive weeks. To account for any possible contribution from platelet transfusions, platelet counts within 3 days following administration of platelet transfusion is not counted towards the platelet hematologic improvement endpoint. If no platelet measurements are available on the weekly scheduled dose day, then that week is not counted towards the platelet hematologic improvement endpoint. The durations of HI-P are cumulative if more than one incidence occurred. Exposure adjusted event rate per 100 patient-weeks = total number of weeks / patient-weeks * 100.

Overall survival was calculated using Kaplan-Meier methods. For patients who discontinued early, additional information from the long term follow-up are added (closest available follow-up information up to 58 weeks).

Overall survival was calculated using Kaplan-Meier methods.

The number of bleeding events was obtained from the thrombocytopenia symptoms (Th-symptoms) survey. Patients reported spontaneous bleeding to have occurred 0, 1 or 2, 3 or 4, 5 or 6, or 7 or more times in the past week. The lower threshold of bleeding counts is used for conservative purposes (i.e., the "3" is used for the response option of "3 or 4 times"). Exposure adjusted event rate per 100 patient-years = number of events / patient-year * 100.

Total of all reporting groups

RA: Refractory Anemia RAEB-1: Refractory Anemia with Excess Blasts-1 RAEB-2: Refractory Anemia with Excess Blasts-2 RARS: Refractory Anemia with Ringed Sideroblasts RCMD: Refractory cytopenia with multilineage dysplasia RCMD-RS: Refractory cytopenia with multilineage dysplasia and ringed sideroblasts MDS-U: Myelodysplastic syndrome - unclassified MDS associated with isolated del(5q).

Had received MDS therapy prior to enter the study

The IPSS uses three "prognostic indicators" to develop a "score" which may be useful in understanding how the MDS may progress:

• the proportion of blast cells in the marrow;
• the type of chromosomal changes, if any, in the marrow cells;
• the presence of one or more low blood cell counts (cytopenias). Scores are sorted into one of four risk categories: 0 = low risk; 0.5-1.0 = intermediate-1; 1.5-2.0 = intermediate-2; >2.5 = high risk.

Weekly subcutaneous dosing based on platelet count for 26 weeks during the Test Treatment Period and for 24 weeks during the Extended Treatment Period, separated by a 4-week interim washout period. Starting dose is at 750 μg, up to a maximum dose of 1000 μg, or reduced to a minimum of 250 μg.

A discrete platelet transfusion is any number of platelet transfusion administered within a 3-day period. Transfusions administered more than 3 days apart are counted as separate events. Transfusion given in the absence of any bleeding, when platelet count is >10x10^9/L, is not counted as a platelet transfusion event. Events with start date between the first dose date and the last dose date of the test treatment period +7 days are included. Exposure adjusted event rate per 100 patient-years = (events / patient-years * 100). Patient Year = total patient years of exposure to investigational product during 26 weeks test treatment period.

Full analysis set includes all randomized patients.

The time from first dose of study drug to the last dose of 26-week test treatment period. A bleeding event is defined as any bleeding event reported during the test treatment period. Bleeding events that continue for more than 7 days are counted as separate events every eighth day. Multiple events that arose from one organ system on one day are collapsed into one single event. Exposure adjusted event rate per 100 patient-years = events / patient-year * 100).

Full analysis set includes all randomized patients.

The time from first dose of study drug to the last dose of 26-week test treatment period. A unit of platelets is defined as a single pack of pooled platelet-rich plasma comprised of 6 to 8 individual platelet concentrate packs (200 to 400 mL), a single pack of pooled buffy-coat concentrate, or 1 apheresis (single donor) concentrate. Exposure adjusted event rate per 100 patient-years = events / patient-years * 100.

Full analysis set includes all randomized subjects

Platelet Hematologic Improvemen defined by the international working group (IWG) as: an absolute increase in platelet count of ≥ 30 x 10^9/L for a patient starting with a platelet count of ≥ 20 x 10^9/L or an increase in platelet count from < 20 x 10^9/L to ≥ 20 x 10^9/L and by at least 100% in a patient that started with a platelet count < 20 x 10^9/L. To account for any possible contribution from platelet transfusions, platelet counts within 3 days following administration of platelet transfusion is not counted towards the platelet hematologic improvement endpoint. If no platelet measurements are available on the weekly scheduled dose day, then that week is not counted towards the platelet hematologic improvement endpoint.

Full analysis set includes all randomized patients.

Duration for participants who did not report HI-P during the period is 0. A platelet hematologic improvement (HI-P) is defined by an MDS International Working criteria as patients with a baseline platelet count of ≥ 20 x 10^9/L achieving an absolute increase of ≥ 30 x 10^9/L or increasing the platelet count to above 20 x 10^9/L and by at least 100% in patients with a baseline of < 20 x 10^9/L for at least 8 consecutive weeks. To account for any possible contribution from platelet transfusions, platelet counts within 3 days following administration of platelet transfusion is not counted towards the platelet hematologic improvement endpoint. If no platelet measurements are available on the weekly scheduled dose day, then that week is not counted towards the platelet hematologic improvement endpoint. The durations of HI-P are cumulative if more than one incidence occurred. Exposure adjusted event rate per 100 patient-weeks = total number of weeks / patient-weeks * 100.

Full analysis set includes all randomized patients.

Full analysis set includes all randomized patients.

Overall survival was calculated using Kaplan-Meier methods. For patients who discontinued early, additional information from the long term follow-up are added (closest available follow-up information up to 58 weeks).

Full analysis set includes all randomized patients.

Overall survival was calculated using Kaplan-Meier methods.

Full analysis set includes all randomized patients.

The number of bleeding events was obtained from the thrombocytopenia symptoms (Th-symptoms) survey. Patients reported spontaneous bleeding to have occurred 0, 1 or 2, 3 or 4, 5 or 6, or 7 or more times in the past week. The lower threshold of bleeding counts is used for conservative purposes (i.e., the "3" is used for the response option of "3 or 4 times"). Exposure adjusted event rate per 100 patient-years = number of events / patient-year * 100.

The Patient Reported Outcomes (PRO) analysis set consists of patients in the full analysis set who also completed the baseline and at least one post-baseline assessment for any PRO measure.

Weekly subcutaneous dosing based on platelet count for 26 weeks during the Test Treatment Period and for 24 weeks during the Extended Treatment Period, separated by a 4-week interim washout period. Starting dose is at 750 μg, up to a maximum dose of 1000 μg, or reduced to a minimum of 250 μg.