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RomiPLOStim

Medically reviewed by Drugs.com. Last updated on Feb 21, 2019.

Pronunciation

(roe mi PLOE stim)

Index Terms

  • AMG 531

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution Reconstituted, Subcutaneous [preservative free]:

Nplate: 250 mcg (1 ea); 500 mcg (1 ea)

Brand Names: U.S.

  • Nplate

Pharmacologic Category

  • Colony Stimulating Factor
  • Hematopoietic Agent
  • Thrombopoietic Agent

Pharmacology

Romiplostim is a thrombopoietin (TPO) peptide mimetic that increases platelet counts in ITP by binding to and activating the human TPO receptor.

Absorption

SubQ: Slow (Wang 2004)

Onset of Action

Platelet count increase: SubQ: 4 to 9 days (Wang 2004); Peak platelet count increase: Days 12 to 16 (Wang 2004)

Time to Peak

SubQ: Median: 14 hours (range: 7 to 50 hours)

Duration of Action

Platelet counts return to baseline by day 28 (Wang 2004)

Half-Life Elimination

Median: 3.5 days (range: 1 to 34 days)

Use: Labeled Indications

Chronic immune thrombocytopenia: Treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had insufficient response to corticosteroids, immune globulin, or splenectomy; treatment of thrombocytopenia in pediatric patients ≥1 year of age with ITP for ≥6 months who have had insufficient response to corticosteroids, immune globulin, or splenectomy

Limitations of use: Romiplostim should be used only when the degree of thrombocytopenia and clinical condition increase the risk for bleeding; romiplostim should not be used in attempt to normalize platelet counts; romiplostim is not indicated for the treatment of thrombocytopenia due to myelodysplastic syndrome or any cause of thrombocytopenia other than chronic ITP.

Contraindications

There are no contraindications listed in the manufacturer's US labeling.

Canadian labeling: Hypersensitivity to romiplostim or any component of the formulation; known history of sensitivity or allergy to any E. coli-derived product.

Dosing: Adult

Note: Use the lowest dose sufficient to maintain platelet count ≥50,000/mm3 as necessary to reduce the risk of bleeding. Do not use to normalize platelet counts.

Chronic immune thrombocytopenia (ITP): SubQ: Initial: 1 mcg/kg once weekly (based on actual body weight); adjust dose by 1 mcg/kg/week increments to achieve platelet count ≥50,000/mm3 and to reduce the risk of bleeding; Maximum dose: 10 mcg/kg/week (median dose needed to achieve response in clinical trials: 2 mcg/kg)

Dosage adjustment recommendations:

Adjust dose based on platelet count response:

Platelet count <50,000/mm3: Increase weekly dose by 1 mcg/kg.

Platelet count >200,000/mm3 to ≤400,000/mm3 for 2 consecutive weeks: Reduce weekly dose by 1 mcg/kg.

Platelet count >400,000/mm3: Withhold dose; assess platelet count weekly; when platelet count <200,000/mm3, resume with the weekly dose reduced by 1 mcg/kg.

Discontinue if platelet count does not increase to a level sufficient to avoid clinically important bleeding after 4 weeks at the maximum recommended dose of 10 mcg/kg/week.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Use the lowest dose sufficient to maintain platelet count ≥50,000/mm3 as necessary to reduce the risk of bleeding. Do not use to normalize platelet counts. Reassess body weight every 12 weeks.

Chronic immune thrombocytopenia (ITP): Note: Calculate dose using actual body weight. Children and Adolescents: SubQ: Initial: 1 mcg/kg/dose once weekly; adjust dose by 1 mcg/kg/week increments to achieve platelet count ≥50,000/mm3 and to reduce the risk of bleeding; maximum dose: 10 mcg/kg/week

Dosage adjustment recommendations:

Adjust dose based on platelet count response:

Platelet count <50,000/mm3: Increase weekly dose by 1 mcg/kg.

Platelet count >200,000/mm3 to ≤400,000/mm3 for 2 consecutive weeks: Reduce weekly dose by 1 mcg/kg.

Platelet count >400,000/mm3: Withhold dose; assess platelet count weekly; when platelet count <200,000/mm3, resume with the weekly dose reduced by 1 mcg/kg.

Discontinue if platelet count does not increase to a level sufficient to avoid clinically important bleeding after 4 weeks at the maximum recommended dose of 10 mcg/kg/week.

Reconstitution

Reconstitute with only preservative free SWFI (add 0.72 mL to 250 mcg vial or 1.2 mL to 500 mcg vial) to a concentration of 500 mcg/mL (due to overfill). Do not use bacteriostatic water for injection. Gently invert vial and swirl; do not shake. Usually dissolves within 2 minutes. If calculated dose is <23 mcg, additional dilution (after initial reconstitution with SWFI) with 0.9% sodium chloride (NS) is required (add 2.25 mL NS to 250 mcg vial or 3.75 mL NS to 500 mcg vial); final concentration will be 125 mcg/mL (due to overfill). Do not pool unused portions from vials; do not administer more than one dose from a vial.

Administration

SubQ: Administer subcutaneously only. Administration volume may be small; use appropriate syringe (with graduations to 0.01 mL) for administration. Verify calculations, final concentration, and volume drawn up for administration. Do not pool unused portions from vials; do not administer more than one dose from a vial.

Dietary Considerations

Some products may contain sucrose.

Storage

Store intact vials at 2°C to 8°C (36°F to 46°F); do not freeze. Protect from light. Store in original carton until use. If needed, unopened vials may be stored in the original carton at room temperature up to a maximum of 25°C (77°F) for a single period of up to 30 days. The new expiration date must be written in the space provided on the carton. Once stored at room temperature, do not place back in the refrigerator. Discard if not used within 30 days. Reconstituted solution (with SWFI) that has not been further diluted may be stored in the original vial at room temperature of 25°C (77°F) or refrigerated at 2°C to 8°C (36°F to 46°F) for up to 24 hours following reconstitution. Reconstituted solution (with SWFI) may be stored in a syringe at room temperature of 25°C (77°F) for a maximum of 4 hours following reconstitution. Protect reconstituted solution from light; do not shake. Solution diluted for infusion with 0.9% sodium chloride (NS) may be stored in a syringe at room temperature of 25°C (77°F) or in the original vial refrigerated at 2°C to 8°C (36°F to 46°F) for no longer than 4 hours prior to administration; protect from light; do not shake. Discard any unused portion.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

>10%:

Central nervous system: Headache (35%), dizziness (17%), insomnia (16%)

Gastrointestinal: Abdominal pain (11%)

Neuromuscular & skeletal: Arthralgia (26%), myalgia (14%), limb pain (13%)

1% to 10%:

Central nervous system: Paresthesia (6%)

Gastrointestinal: Dyspepsia (7%)

Hematologic & oncologic: Thrombocytopenia (7%; rebound)

Immunologic: Antibody formation (≤4%; no correlation between antibody development and drug safety or efficacy has been established)

Neuromuscular & skeletal: Shoulder pain (8%)

Frequency not defined:

Hematologic & oncologic: Myelofibrosis (bone marrow reticulin formation/deposition)

<1%, postmarketing, and/or case reports: Angioedema, erythromelalgia, hypersensitivity reaction, myelofibrosis (marrow fibrosis with collagen), thromboembolism, thrombosis

Warnings/Precautions

Concerns related to adverse effects:

• Bone marrow reticulin: May increase the risk for bone marrow reticulin fiber formation; this formation may improve upon discontinuation of therapy.

• Concomitant ITP medications: May be used in combination with other therapies for ITP, including corticosteroids, danazol, azathioprine, immune globulin, or Rho(D) immune globulin. Reduce dose of or discontinue ITP medications when platelet count ≥50,000/mm3.

• Error prevention: To prevent overdose or underdose, use caution when calculating dose and appropriate volume for administration (volume may be very small; administer with syringe that allows for 0.01 mL graduations).

• Hyporesponsiveness: Lack of response or failure to maintain platelet response should trigger investigation in to causative factors, including neutralizing antibodies to romiplostim.

• Malignancy: Progression from existing myelodysplastic syndrome (MDS) to acute myeloid leukemia (AML) has been observed in clinical trials studying romiplostim for severe thrombocytopenia associated with MDS (not an approved indication); a higher percentage of patients receiving romiplostim experienced transformation to AML (compared to placebo). An increase in the percentage of circulating myeloblasts in peripheral blood counts was also noted (both in patients who progressed to AML and in those who did not); blast cells decreased to baseline after discontinuation in some patients.

• Thromboembolism: Thromboembolism or thrombotic complications may occur with increased platelet counts. Follow dosage adjustment recommendations to minimize the risk for thrombotic or thromboembolic complications. Portal vein thrombosis has been observed in patients with chronic liver disease receiving romiplostim.

Monitoring Parameters

CBC with differential and platelets at baseline, weekly during dosage adjustment phase of treatment, then monthly, and weekly for at least 2 weeks following discontinuation or completion of treatment

Evaluate for neutralizing antibodies in patients with inadequate response (blood samples may be submitted to the manufacturer for assay [1-800-772-6436]).

Pregnancy Considerations

Based on the mechanism of action and findings from animal reproduction studies, romiplostim may cause fetal harm if administered to a pregnant female.

Women exposed to romiplostim during pregnancy are encouraged to enroll in the pregnancy surveillance program (1-800-772-6436). In Canada, women who become pregnant during treatment are encouraged to enroll in Amgen's Pregnancy Surveillance Program (1-866-512-6436).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience dizziness, headache, joint pain, common cold symptoms (children), pharyngitis (children), mouth pain or irritation (children), diarrhea (children), cough (children), eye irritation (children), heartburn, shoulder pain, muscle pain, muscle weakness, or insomnia. Have patient report immediately to prescriber signs of severe cerebrovascular disease (change in strength on one side is greater than the other, difficulty speaking or thinking, change in balance, or vision changes), signs of blood clots (numbness or weakness on one side of the body; pain, redness, tenderness, warmth, or swelling in the arms or legs; change in color of an arm or leg; angina; shortness of breath; tachycardia; or coughing up blood), burning or numbness feeling, bruising, bleeding, swelling of arms or legs, ear pain, or severe abdominal pain (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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