- Open-label, single-arm, extension study in patients with adult chronic immune thrombocytopenia (ITP).
- 292 adult patients enrolled from previous Nplate® clinical trials, regardless of whether they had received Nplate® in those trials.
- Primary safety assessment: incidence of adverse events (AEs), including death, thrombosis, bleeding, abnormal laboratory values, and the incidence of neutralizing antibody formation.
Open-label, single-arm, extension study in adult chronic ITP patients1,*
1 to 277 weeks (mean: 110 weeks). Patients entered study at different times during the defined 277-week study period
continued on their same dose*
started on Nplate® 1 mcg/kg/wk*
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291 patients received at least one dose of Nplate® during the rolling enrollment period1
- 93% (271/291) were treated longer than 24 weeks. 1
- During the 277-week study period, treatment duration varied due to study entry at different times and discontinuation (mean treatment was 110 weeks). 1
- 8% (23/291) of patients were treated longer than 240 weeks. 1
200 patients completed the study1
- “Completers” were defined as those who were followed through the last study visit, regardless of whether they were still on treatment. 1
- The most common reason for discontinuing the trial was withdrawn consent (25 patients). 1
- Other reasons included death while on study (15 patients); adverse events, alternative therapy, and other reasons (11 patients each); administrative decision (7 patients); noncompliance, protocol-specified criteria, and lost to follow-up (3 patients each); and pregnancy and protocol deviation (1 patient each). 1
Long-term safety profile in open-label extension study1
25 thrombotic events were reported in 19 patients; 6 events were considered possibly treatment related.1
Bone marrow biopsies were performed at the discretion of the investigators. 40 bone marrow biopsies were performed in 38 patients. Some biopsies were also assessed for type 1 collagen and evidence of myeloproliferative disease, although none was observed. Of 11 patients with increased bone marrow reticulin, the investigator reported it as an AE in 4 patients.1
2 deaths were considered possibly treatment related, one due to myocardial infarction and one to unstable angina. Per the authors, there did not appear to be any relationship between the duration of romiplostim treatment or platelet count and the number or types of deaths during the study.1
The most common AEs included headache (38% of patients), nasopharyngitis (34%), fatigue (32%), contusion (31%), upper respiratory tract infection (26%), diarrhea (25%), and epistaxis (25%).
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Some information included in this article may not be consistent with the approved product labeling. For specific information regarding the approved use of Nplate®, see the full Prescribing Information.
*Given as a once-weekly subcutaneous injection. Patients who had been off Nplate® for > 24 weeks or who had not previously received Nplate® initiated therapy at 1 mcg/kg. Dose adjustments were allowed to maintain platelet counts ≥ 50 x 109/L.1 The recommended starting dose for Nplate® is 1 mcg/kg and the maximum weekly dose is 10 mcg/kg. Please see the Nplate® full Prescribing Information for complete dosing instructions, including guidelines for dose adjustments. 2