Romiplate Dosage/Direction for Use

Treatment should remain under the supervision of a physician who is experienced in the treatment of haematological diseases.
Posology: Romiplate should be administered once weekly as a subcutaneous injection.
Initial dose: Chronic immune (idiopathic) thrombocytopenic purpura (ITP): The initial dose of romiplostim is 1 μg/kg based on actual body weight.
Aplastic anaemia: Usually administer an initial dose of 10 μg/kg subcutaneously as romiplostim (genetical recombination) for adults. After initiation of treatment, the dose may be adjusted based on the patient's condition, and administer once weekly. The maximum weekly dose is 20 μg/kg.
Dose calculation: The volume of romiplostim to administer is calculated based on body weight, dose required, and concentration of product. (See Table 5.)

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Dose adjustments: A subject's actual body weight at initiation of therapy should be used to calculate dose.
Chronic immune (idiopathic) thrombocytopenic purpura (ITP): The once weekly dose of romiplostim should be increased by increments of 1 μg/kg until the patient achieves a platelet count ≥50 x 10⁹/L. Platelet counts should be assessed weekly until a stable platelet count (≥50 x 10⁹/L for at least 4 weeks without dose adjustment) has been achieved. Platelet counts should be assessed monthly thereafter and appropriate dose adjustments made as per the dose adjustment table (Table 6) in order to maintain platelet counts within the recommended range. See Table 6 as follows for dose adjustment and monitoring. A maximum once weekly dose of 10 µg/kg should not be exceeded. (See Table 6.)

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Due to the interindividual variable platelet response, in some patients platelet count may abruptly fall below 50 x 10⁹/L after dose reduction or treatment discontinuation. In these cases, if clinically appropriate, higher cut-off levels of platelet count for dose reduction (200 x 10⁹/L) and treatment interruption (400 x 10⁹/L) may be considered according to medical judgement.
A loss of response or failure to maintain a platelet response with romiplostim within the recommended dosing range should prompt a search for causative factors (see Loss of response to romiplostim under Precautions).
Aplastic anaemia: Blood count should be measured weekly at the initial treatment phase and during the dose adjustment phase. Even if the dose has been maintained, it should be measured about once in 4 weeks.
Generally, the dose should be adjusted with increments of 5 μg/kg. Do not exceed a maximum once weekly dose of 20 μg/kg.
Dose increase should be considered in cases where platelet count has not risen (e.g. increase by ≥20 × 10⁹/L from baseline or increase to ≥10 × 10⁹/L and ≥100% increase from baseline with blood transfusion independence) though the same dose has been administered for 4 consecutive weeks.
Use romiplostim at the lowest dose required for treatment in accordance with the following table: (See Table 7.)

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Reduce the dose in case where 3 blood cell lineage improvement is observed (e.g. platelet count above 50 × 10⁹/L with blood transfusion independence, haemoglobin above 10 g/dL with blood transfusion independence, and neutrophil count above 1 × 10⁹/L) for at least 8 consecutive weeks. If the improvement in 3 blood lineages has been maintained with the reduced dose for 4 weeks, further reduce the dose and consider subsequent dose reduction every 4 weeks (in the case of 5 μg/kg or lower, consider suspension of treatment). If the condition has worsened in any of the 3 blood cell lineages, consider a dose increase (if the treatment has been suspended, it may be resumed at the previous dose).
Treatment discontinuation: Chronic immune (idiopathic) thrombocytopenic purpura (ITP): Treatment with romiplostim should be discontinued if the platelet count does not increase to a level sufficient to avoid clinically important bleeding after four weeks of romiplostim therapy at the highest weekly dose of 10 μg/kg.
Patients should be clinically evaluated periodically and continuation of treatment should be decided on an individual basis by the treating physician, and in non-splenectomised patients this should include evaluation relative to splenectomy. The reoccurrence of thrombocytopenia is likely upon discontinuation of treatment (see Precautions).
Aplastic anaemia: Appropriate measures such as discontinuing romiplostim should be taken in cases where none of the 3 blood lineages has improved even though the maximum weekly dose of 20 μg/kg has been administered for 8 consecutive weeks.
Elderly patients (≥65 years): No overall differences in safety or efficacy have been observed in patients <65 and ≥65 years of age (see Pharmacology: Pharmacodynamics under Actions). Although based on these data no adjustment of the dosing regimen is required for older patients, care is advised considering the small number of elderly patients included in the clinical trials so far.
Paediatric population: Romiplate is not recommended for use in children below age 18 due to insufficient data on safety or efficacy. No recommendation on a posology can be made in this population.
Patients with hepatic impairment: Romiplostim should not be used in patients with moderate to severe hepatic impairment (Child-Pugh score ≥7) unless the expected benefit outweighs the identified risk of portal venous thrombosis in patients with thrombocytopenia associated to hepatic insufficiency treated with thrombopoietin (TPO) agonists (see Precautions).
If the use of romiplostim is deemed necessary, platelet count should be closely monitored to minimise the risk of thromboembolic complications.
Patients with renal impairment: No formal clinical studies have been conducted in these patient populations. Romiplate should be used with caution in these populations.
Method of administration: For subcutaneous use.
After reconstitution of the powder, Romiplate solution for injection is administered subcutaneously. The injection volume may be very small. Caution should be used during preparation of Romiplate in calculating the dose and reconstitution with the correct volume of sterile water for injection. Special care should be taken to ensure that the appropriate volume of Romiplate is withdrawn from the vial for subcutaneous administration - a syringe with graduations of 0.01 mL should be used.
For instructions on reconstitution of Romiplate before administration, see Special precautions for disposal and other handling under Cautions for Usage.
Administration Precautions: Caution should be used during preparation of Romiplate in calculating the dose and reconstitution with the correct volume of sterile water for injection. Special care should be taken to ensure that the appropriate volume of Romiplate is withdrawn from the vial for subcutaneous administration (see Precautions and Overdosage).