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Risk Monitoring
Monitoring Patient Safety With the Nplate® NEXUS Program
The Nplate® NEXUS Program is designed to promote informed risk-benefit decisions and includes a system of reminders, guides, and databases to monitor patient safety. For instance, the Medication Guide presents information on the risks of Nplate® in patient-friendly language. Every new patient will be educated on the content of the Medication Guide including the risk-benefit profile of Nplate®.

Healthcare providers submit baseline patient data as patients begin Nplate® therapy. The purpose of this data collection is to establish the long-term safety and safe use of Nplate® through periodic monitoring.The registry also includes available baseline patient data.

Twice a year, a NEXUS Specialist will contact the healthcare provider to verify his/her enrolled patient roster and collect safety information. The healthcare provider (or staff under his/her direction) will be asked to complete a safety questionnaire for each patient via fax or phone. This questionnaire asks whether the patient remains on Nplate® therapy and whether the patient has experienced side effects. The NEXUS Specialist will log any adverse events and discontinuation information into a registry database. Whenever a serious adverse event is reported, someone from the Nplate® NEXUS Program or Amgen Global Safety will follow up by contacting the reporting provider or representative to obtain additional information.

Please call the Nplate® NEXUS Program at 1-877-NPLATE1 (1-877-675-2831) to answer any questions or for additional materials. You may also click here for information and downloadable materials.
What Risks Are Monitored Through the Nplate®
NEXUS Program?
Bone Marrow Reticulin Formation and Risk for Bone Marrow Fibrosis
  • Nplate® administration increases the risk for development or progression of reticulin fiber deposition within the bone marrow.
  • In clinical studies, Nplate® was discontinued in four of the 271 patients because of bone marrow reticulin deposition. Six additional patients had reticulin observed upon bone marrow biopsy. All 10 patients with bone marrow reticulin deposition had received Nplate® doses ≥ 5 mcg/kg and six received doses ≥ 10 mcg/kg.
  • Progression to marrow fibrosis with cytopenias was not reported in the controlled clinical studies. In the extension study, one patient with ITP and hemolytic anemia developed marrow fibrosis with collagen during Nplate® therapy.
  • Clinical studies have not excluded a risk of bone marrow fibrosis with cytopenias.
  • Prior to initiation of Nplate®, examine the peripheral blood smear closely to establish a baseline level of cellular morphologic abnormalities. Following identification of a stable Nplate® dose, examine peripheral blood smears and CBCs monthly for new or worsening morphological abnormalities (eg, teardrop and nucleated red blood cells, immature white blood cells) or cytopenia(s).
  • If the patient develops new or worsening morphological abnormalities or cytopenia(s), discontinue treatment with Nplate® and consider a bone marrow biopsy, including staining for fibrosis.
Worsened Thrombocytopenia After Cessation of Nplate®
  • Discontinuation of Nplate® may result in thrombocytopenia of greater severity than was present prior to Nplate® therapy. This worsened thrombocytopenia may increase the patient’s risk of bleeding, particularly if Nplate® is discontinued while the patient is on anticoagulants or antiplatelet agents.
  • In clinical studies of patients with chronic ITP who had Nplate® discontinued, 4/57 patients developed thrombocytopenia of greater severity than was present prior to Nplate® therapy.
  • This worsened thrombocytopenia resolved within 14 days.
  • Following discontinuation of Nplate®, obtain weekly CBCs, including platelet counts, for at least 2 weeks and consider alternative treatments for worsening thrombocytopenia, according to current treatment guidelines.
Thrombotic/Thromboembolic Complications
  • Thrombotic/thromboembolic complications may result from excessive increases in platelet counts. Excessive doses of Nplate® or medication errors that result in excessive Nplate® doses may increase platelet counts to a level that produces thrombotic/ thromboembolic complications. In controlled clinical studies, the incidence of thrombotic/thromboembolic complications was similar between Nplate® and placebo.
  • 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 ≥ 50 x 109/L.
Hematological Malignancies and Progression of Malignancy in Patients with a Pre-existing Hematological Malignancy or Myelodysplastic Syndrome (MDS)
  • Nplate® stimulation of the thrombopoietin (TPO) receptor on the surface of hematopoietic cells may increase the risk for hematologic malignancies. In controlled clinical studies among patients with chronic ITP, the incidence of hematologic malignancy was low and similar between Nplate® and placebo.
  • In a separate single-arm clinical study of 44 patients with myelodysplastic syndrome (MDS), 11 patients were reported as having possible disease progression, among whom four patients had confirmation of acute myelogenous leukemia (AML) during follow-up.
  • Nplate® is not indicated for the treatment of thrombocytopenia due to MDS or any cause of thrombocytopenia other than chronic ITP.
Non-ITP Populations
  • Nplate® is not indicated for the treatment of thrombocytopenia due to MDS or any cause of thrombocytopenia other than chronic ITP.
Medication Error Due to Small Volumes Administered
  • Medication errors may occur because Nplate® is administered in small volumes, and small differences in dose can have large effects on platelet counts. Healthcare providers should pay special attention to accurate calculation of the dose of Nplate®, transcription of the medication order, and dosing instructions to minimize the risk of medication errors, overdose, and underdose.
  • Nplate® must be administered by the enrolled prescribers or healthcare providers under their direction.
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What Other Risks Are Associated With Nplate®?
Lack or 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® or bone
    marrow fibrosis.
  • To detect antibody formation, submit blood samples to Amgen at 1-800-772-6436.
    Amgen will assay these samples for antibodies to Nplate® and thrombopoietin.
  • 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
Common Adverse Drug Reactions
  • In the placebo-controlled studies, 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%).