How to take Romiplostim

For adult patients with immune thrombocytopenia (ITP), the initial dose of romiplostim is 1 mcg/kg. Actual body weight at the start of treatment should always be used when calculating initial dosage. Future dose adjustments for adults are based solely on changes in platelet count. Adjust the weekly dose of romiplostim in 1 mcg/kg increments until the patient's platelet count reaches ≥50 × 109/L to reduce the risk of bleeding, and do not exceed the maximum weekly dose of 10 mcg/kg. In clinical studies, most adult patients who responded to romigrastim achieved and maintained platelet counts ≥50 × 109/L at a median dose of 2-3 mcg/kg.

If the platelet count<50×109/L, increase the dose by 1mcg/kg; if the platelet count is >200×109/L and ≤400×109/L for 2 consecutive weeks, then reduce the dose by 1mcg/kg; if the platelet count is >400×109/L, do not administer the drug. Continue to evaluate platelet counts weekly. After the platelet count drops to <200 × 109/L, romiplostim is continued at a reduced dose of 1 mcg/kg.

For pediatric patients with immune thrombocytopenia (ITP), the initial dose of romiplostim is 1 mcg/kg. Actual body weight at the start of treatment should always be used when calculating initial dosage. For pediatric patients, future dose adjustments are based on changes in platelet count and body weight. It is recommended that body weight be reassessed every 12 weeks and dosage adjustments similar to those for adult patients. In a pediatric placebo-controlled clinical study, patients received a median of 5.5 mcg/kg of romigrastim at the most frequent dose at weeks 17-24.

Based on the need to reduce bleeding risk, use the lowest dose of romiplostim to achieve and maintain platelet counts≥50×109/L, injected subcutaneously weekly, and adjust the dose based on platelet count response. If platelet counts have not increased to a level sufficient to avoid clinically important bleeding after 4 weeks of treatment with romiplostim at a maximum weekly dose of 10 mcg/kg, discontinue romiplostim. Collect complete blood counts(CBCs), including platelet counts, weekly during the dose-titration phase of romigrastimtreatment and then monthly after a stable romigrastim dose has been established. After discontinuing romiplostim, obtain a complete blood count, including platelet count, weekly for at least2 weeks.

Applicable to adult and pediatric patients(including term newborns)The recommended dose of romiplostim is 10mcg/kg, once subcutaneous injection. Administer this dose as soon as possible after suspected or confirmed exposure to radiation levels greater than 2 Gray (Gy). Romigrastim should be used regardless of the availability of a complete blood count (CBC).

RomiplostimThe original drug has been approved by the State Food and Drug Administration for marketing. Due to its short time on the market, it is not included in the scope of medical insurance. It may be difficult to purchase it domestically. The price of the original version in Hong Kong may be RMB 10,000 per pill (the price may fluctuate due to exchange rates). The price of the European version of romiplostim the original drug may be 11,000 RMB per pill, the German version may be 9,850 RMB per pill, and the Hong Kong version may be 8,900 RMB per pill (the price may fluctuate due to the exchange rate). The ingredients of the drugs are basically the same. For specific prices and drug details, please consult Yaode’s medical consultant.