近日,Rigel制药宣布，美国FDA已批准TAVALISSE™(fostamatinib disodium hexahydrate)用于对之前治疗缓解不佳的成年慢性免疫性血小板减少症（ITP）患者血小板减少的治疗。TAVALISSE是一种口服的脾脏酪氨酸激酶(SYK)抑制剂，通过阻止血小板的破坏来应对疾病的潜在自身免疫原因，为成年慢性ITP患者提供了一个重要的新的治疗方案。
药品名称:fostamatinib disodium hexahydrate
持证商地址：1180 Veterans B1vd.South San Francisco,CA 94080 USA
TAVALISSE(fostamatinib disodium hexahydrate) Tablets, for Oral Use
Fostamatinib is a tyrosine kinase inhibitor. TAVALISSE is formulated with the disodium hexahydrate salt of fostamatinib, a phosphate prodrug that converts to its pharmacologically active metabolite, R406, in vivo.
The chemical name for fostamatinib disodium hexahydrate is disodium (6-[[5-fluoro-2-(3,4,5trimethoxyanilino) pyrimidin-4-yl]amino]-2,2-dimethyl-3-oxo-pyrido[3,2-b][1,4]oxazin-4-yl)methyl phosphate hexahydrate. The molecular formula is C23H24FN6Na2O9P·6H2O, and the molecular weight is 732.52. The structural formula is:
Fostamatinib disodium is a white to off-white powder that is practically insoluble in pH 1.2 aqueous buffer, slightly soluble in water, and soluble in methanol.
Each TAVALISSE oral tablet contains 100 mg or 150 mg fostamatinib, equivalent to 126.2 mg or 189.3 mg fostamatinib disodium hexahydrate, respectively.
The inactive ingredients in the tablet core are mannitol, sodium bicarbonate, sodium starch glycolate, povidone, and magnesium stearate. The inactive ingredients in the film coating are polyvinyl alcohol, titanium dioxide, polyethylene glycol 3350, talc, iron oxide yellow, and iron oxide red.
TAVALISSE is indicated for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment.
DOSAGE AND ADMINISTRATION
Initiate TAVALISSE at a dose of 100 mg taken orally twice daily. After a month, if platelet count has not increased to at least 50 x 109/L, increase TAVALISSE dose to 150 mg twice daily.
Use the lowest dose of TAVALISSE to achieve and maintain a platelet count at least 50 x 109/L as necessary to reduce the risk of bleeding.
TAVALISSE may be taken with or without food. In the case of a missed dose of TAVALISSE, instruct patients to take their next dose at its regularly scheduled time.
After obtaining baseline assessments:
•Monitor CBCs, including platelet counts, monthly until a stable platelet count (at least 50 x 109/L) is achieved. Thereafter, continue to monitor CBCs, including neutrophils, regularly.
•Monitor liver function tests (LFTs) (e.g., ALT, AST, and bilirubin) monthly.
•Monitor blood pressure every 2 weeks until establishment of a stable dose, then monthly thereafter.
Dose Modification For Adverse Reactions
TAVALISSE dose modification is recommended based on individual safety and tolerability. Management of some adverse reactions may require dose -interruption, reduction, or discontinuation.
A dose reduction schedule is provided in Table 1, based on daily dose. For example, if a patient is on the maximum dose at the time of an adverse reaction, the first dose reduction would be from 300 mg/day to 200 mg/day.
Dose Modification For Drug Interactions
Concomitant use with a strong CYP3A4 inhibitor increases exposure to R406 (the major active metabolite). Monitor for toxicities of TAVALISSE that may require TAVALISSE dose modifications (see Table 1) when given concurrently with a strong CYP3A4 inhibitor [see DRUG INTERACTIONS].
Discontinue TAVALISSE after 12 weeks of treatment if the platelet count does not increase to a level sufficient to avoid clinically important bleeding [see Clinical Studies].
Storage And Handling
TAVALISSE 100 mg tablets are round, biconvex, orange, film-coated tablets debossed with “100” on one side and “R” on the reverse side.
TAVALISSE 150 mg tablets are oval, biconvex, orange, film-coated tablets debossed with “150” on one side and “R” on the reverse side.
100 mg tablets: Available in bottle of 60 with 2 desiccant canisters NDC 71332-001-01
150 mg tablets: Available in bottle of 60 with 2 desiccant canisters NDC 71332-002-01
Store at room temperature, 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. Do not remove desiccants.
Dosage Forms And Strengths
TAVALISSE is available as:
•100 mg tablet: orange, film-coated, round, biconvex tablets debossed with “100” on one side and “R” on the reverse side.
•150 mg tablet: orange, film-coated, oval, biconvex tablets debossed with “150” on one side and “R” on the reverse side.