Long-term safety evaluated in an open-label extension study with patients from prior Nplate® clinical trials11
Study design11
  • 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 patients11,*

Treatment Duration

1 to 277 weeks (mean: 110 weeks). Patients entered study at different times during the defined 277-week study period

Nplate® or placebo/standard of care (SOC) patients from prior Nplate® trials
Prior Nplate® patients:
continued on their same dose*
Prior placebo/SOC patients:
started on Nplate® 1 mcg/kg/wk*

Learn about dosing for once-weekly Nplate®. See more >

Study enrollment and completion
Treatment period
# of patients
> 24 weeks
271 patients (93%)
> 48 weeks
242 patients (83%)
> 96 weeks
117 patients (40%)
> 144 weeks
93 patients (32%)
> 192 weeks
53 patients (18%)
> 240 weeks
23 patients (8%)

291 patients received at least one dose of Nplate® during the rolling enrollment period11

  • 93% (271/291) were treated longer than 24 weeks.11
  • During the 277-week study period, treatment duration varied due to study entry at different times and discontinuation (mean treatment was 110 weeks).11
  • 8% (23/291) of patients were treated longer than 240 weeks.11

200 patients completed the study11

  • “Completers” were defined as those who were followed through the last study visit, regardless of whether they were still on treatment.11
  • The most common reason for discontinuing the trial was withdrawn consent (25 patients).11
    • 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).11

Study results: AEs did not increase in frequency with longer Nplate® drug exposure11

Long-term safety profile in open-label extension study11

AEs with Nplate®
% of patients (n)
Serious treatment-related AEs
8% (24/291)
Thrombotic events
6.5% (19/291)
Bone marrow reticulin increase
1.4% (4/291)
Neutralizing antibodies
< 1% (2/291)
Deaths
5% (16/291)

25 thrombotic events were reported in 19 patients; 6 events were considered possibly treatment related.11

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.11

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.11

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%).

Review the article for the Nplate® long-term safety study. Learn more > (Please be advised that you are leaving an Amgen website and will be directed to a third party site. Amgen is not responsible for the content on the site you are about to enter.)

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.11 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.22

Important Safety Information

Risk of Progression of Myelodysplastic Syndromes to Acute Myelogenous Leukemia

  • In Nplate® (romiplostim) clinical trials of patients with myelodysplastic syndromes (MDS) and severe thrombocytopenia, progression from MDS to acute myelogenous leukemia (AML) has been observed.
  • Nplate® is not indicated for the treatment of thrombocytopenia due to MDS or any cause of thrombocytopenia other than chronic ITP.

Thrombotic/Thromboembolic Complications

  • Thrombotic/thromboembolic complications may result from increases in platelet counts with Nplate® use. Portal vein thrombosis has been reported in patients with chronic liver disease receiving Nplate®.
  • To minimize the risk for thrombotic/thromboembolic complications, do not use Nplate® in an attempt to normalize platelet counts. Follow the dose adjustment guidelines to achieve and maintain a platelet count of ≥ 50 x 109/L.

Loss of Response to Nplate®

  • Hyporesponsiveness or failure to maintain a platelet response with Nplate® should prompt a search for causative factors, including neutralizing antibodies to Nplate®.
  • To detect antibody formation, submit blood samples to Amgen (1‑800‑772‑64361‑800‑772‑6436). Amgen will assay these samples for antibodies to Nplate® and thrombopoietin (TPO).
  • Discontinue Nplate® if the platelet count does not increase to a level sufficient to avoid clinically important bleeding after 4 weeks at the highest weekly dose of 10 mcg/kg.

Laboratory Monitoring

  • Obtain CBCs, including platelet counts, weekly during the dose adjustment phase of Nplate® therapy and then monthly following establishment of a stable Nplate® dose.
  • Obtain CBCs, including platelet counts, weekly for at least two weeks following discontinuation of Nplate®.

Adverse Reactions

  • In the placebo-controlled trials, headache was the most commonly reported adverse drug reaction, occurring in 35% of patients receiving Nplate® and 32% of patients receiving placebo. Headaches were usually of mild or moderate severity.
  • Most common adverse reactions (≥ 5% higher patient incidence in Nplate® versus placebo) were Arthralgia (26%, 20%), Dizziness (17%, 0%), Insomnia (16%, 7%), Myalgia (14%, 2%), Pain in Extremity (13%, 5%), Abdominal Pain (11%, 0%), Shoulder Pain (8%, 0%), Dyspepsia (7%, 0%), and Paresthesia (6%, 0%).
  • Nplate® administration may increase the risk for development or progression of reticulin fiber formation within the bone marrow. This formation may improve upon discontinuation of Nplate®. In a clinical trial, one patient with ITP and hemolytic anemia developed marrow fibrosis with collagen during Nplate® therapy.


Women who become pregnant during Nplate® treatment are encouraged to enroll in Amgen's Pregnancy Surveillance Program. Patients or their physicians should call 1‑800‑77‑AMGEN1‑800‑77‑AMGEN (1‑800‑772‑64361‑800‑772‑6436) to enroll.

Indication

Nplate® is a thrombopoietin receptor agonist indicated for the treatment of thrombocytopenia in patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.

Nplate® is not indicated for the treatment of thrombocytopenia due to myelodysplastic syndrome (MDS) or any cause of thrombocytopenia other than chronic ITP. Nplate® should be used only in patients with ITP whose degree of thrombocytopenia and clinical condition increase the risk for bleeding. Nplate® should not be used in an attempt to normalize platelet counts.

Please see full Prescribing Information and Medication Guide.

See More Close

Important Safety Information

Risk of Progression of Myelodysplastic Syndromes to Acute Myelogenous Leukemia

  • In Nplate® (romiplostim) clinical trials of patients with myelodysplastic syndromes (MDS) and severe thrombocytopenia, progression from MDS to acute myelogenous leukemia (AML) has been observed.
  • Nplate® is not indicated for the treatment of thrombocytopenia due to MDS or any cause of thrombocytopenia other than chronic ITP.

Thrombotic/Thromboembolic Complications

  • Thrombotic/thromboembolic complications may result from increases in platelet counts with Nplate® use. Portal vein thrombosis has been reported in patients with chronic liver disease receiving Nplate®.
  • To minimize the risk for thrombotic/thromboembolic complications, do not use Nplate® in an attempt to normalize platelet counts. Follow the dose adjustment guidelines to achieve and maintain a platelet count of ≥ 50 x 109/L.

Loss of Response to Nplate®

  • Hyporesponsiveness or failure to maintain a platelet response with Nplate® should prompt a search for causative factors, including neutralizing antibodies to Nplate®.
  • To detect antibody formation, submit blood samples to Amgen (1‑800‑772‑64361‑800‑772‑6436). Amgen will assay these samples for antibodies to Nplate® and thrombopoietin (TPO).
  • Discontinue Nplate® if the platelet count does not increase to a level sufficient to avoid clinically important bleeding after 4 weeks at the highest weekly dose of 10 mcg/kg.

Laboratory Monitoring

  • Obtain CBCs, including platelet counts, weekly during the dose adjustment phase of Nplate® therapy and then monthly following establishment of a stable Nplate® dose.
  • Obtain CBCs, including platelet counts, weekly for at least two weeks following discontinuation of Nplate®.

Adverse Reactions

  • In the placebo-controlled trials, headache was the most commonly reported adverse drug reaction, occurring in 35% of patients receiving Nplate® and 32% of patients receiving placebo. Headaches were usually of mild or moderate severity.
  • Most common adverse reactions (≥ 5% higher patient incidence in Nplate® versus placebo) were Arthralgia (26%, 20%), Dizziness (17%, 0%), Insomnia (16%, 7%), Myalgia (14%, 2%), Pain in Extremity (13%, 5%), Abdominal Pain (11%, 0%), Shoulder Pain (8%, 0%), Dyspepsia (7%, 0%), and Paresthesia (6%, 0%).
  • Nplate® administration may increase the risk for development or progression of reticulin fiber formation within the bone marrow. This formation may improve upon discontinuation of Nplate®. In a clinical trial, one patient with ITP and hemolytic anemia developed marrow fibrosis with collagen during Nplate® therapy.

Women who become pregnant during Nplate® treatment are encouraged to enroll in Amgen's Pregnancy Surveillance Program. Patients or their physicians should call 1‑800‑77‑AMGEN1‑800‑77‑AMGEN (1‑800‑772‑64361‑800‑772‑6436) to enroll.

Indication

Nplate® is a thrombopoietin receptor agonist indicated for the treatment of thrombocytopenia in patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.

Nplate® is not indicated for the treatment of thrombocytopenia due to myelodysplastic syndrome (MDS) or any cause of thrombocytopenia other than chronic ITP. Nplate® should be used only in patients with ITP whose degree of thrombocytopenia and clinical condition increase the risk for bleeding. Nplate® should not be used in an attempt to normalize platelet counts.

Please see full Prescribing Information and Medication Guide.

References: 1. Kuter DJ, Bussel JB, Newland A, et al. Long-term treatment with romiplostim in patients with chronic immune thrombocytopenia: safety and efficacy. Br J Haematol. 2013;161:411-423. 2. Nplate® (romiplostim) prescribing information, Amgen.

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