Fostamatinib

Generic Name: fostamatinib

Over-the-Counter (OTC)

Brand Names:

Tavalisse

11 DESCRIPTION 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-(3,4,5-trimethoxyanilino) pyrimidin-4-yl]amino]-2,2-dimethyl-3-oxo-pyrido[3,2-b][1,4]oxazin-4-yl)methyl phosphate hexahydrate.

Overview

11 DESCRIPTION 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-(3,4,5-trimethoxyanilino) pyrimidin-4-yl]amino]-2,2-dimethyl-3-oxo-pyrido[3,2-b][1,4]oxazin-4-yl)methyl phosphate hexahydrate.

Uses

1 INDICATIONS AND USAGE 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. TAVALISSE is a kinase inhibitor 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

2 DOSAGE AND ADMINISTRATION Initiate TAVALISSE at 100 mg orally twice daily with or without food. After 4 weeks, increase to 150 mg twice daily, if needed, to achieve platelet counts of at least 50 × 10 9 /L as necessary to reduce the risk of bleeding. ( 2.1 ) Manage adverse reactions using dose reduction, interruption of treatment, or discontinuation. ( 2.3 ) Discontinue TAVALISSE after 12 weeks of treatment if the platelet count does not increase to a level sufficient to avoid clinically important bleeding. ( 2.5 ) 2.1 Recommended Dosage 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 × 10 9 /L, increase TAVALISSE dose to 150 mg twice daily.

Side Effects

6 ADVERSE REACTIONS The following clinically important adverse reactions, that can become serious are described elsewhere in the labeling: Hypertension [ see Warnings and Precautions (5.1) ] Hepatotoxicity [ see Warnings and Precautions (5.2) ] Diarrhea [ see Warnings and Precautions (5.3) ] Neutropenia [ see Warnings and Precautions (5.4) ] The most common adverse reactions (≥5% and more than placebo) are diarrhea, hypertension, nausea, respiratory infection, dizziness, ALT/AST increased, rash, abdominal pain, fatigue, chest pain and neutropenia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Rigel Pharmaceuticals, Inc. at 1-800-983-1329 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Interactions

7 DRUG INTERACTIONS Strong CYP3A4 Inhibitors: Concomitant use with a strong CYP3A4 inhibitor increases exposure to R406 (the major active metabolite).( 7 ) Strong CYP3A4 Inducers: Concomitant use is not recommended. ( 7 ) 7.1 Effect of Other Drugs on TAVALISSE Strong CYP3A4 Inhibitors Concomitant use with strong CYP3A4 inhibitors increases exposure to R406 (the major active metabolite), which may increase the risk of adverse reactions. Monitor for toxicities of TAVALISSE that may require dose reduction (see Table 1 ) when given concurrently with a strong CYP3A4 inhibitor [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3) ] . Strong CYP3A4 Inducers Concomitant use with a strong CYP3A4 inducer reduces exposure to R406.

Warnings

5 WARNINGS AND PRECAUTIONS Hypertension: Monitor blood pressure every 2 weeks until stable, then monthly. Manage hypertension using standard antihypertensive treatment and, if needed, interrupt, reduce or discontinue TAVALISSE. ( 5.1 ) Hepatotoxicity: Monitor LFTs monthly. If LFT levels are elevated, interrupt, reduce or discontinue TAVALISSE. ( 5.2 ) Diarrhea: Manage diarrhea with supportive measures. If diarrhea becomes severe, interrupt, reduce or discontinue TAVALISSE. ( 5.3 ) Neutropenia: Monitor ANC monthly, and for infection. If neutrophil count decreases below 1.0 × 10 9 /L, interrupt, reduce or discontinue TAVALISSE. ( 5.4 ) Embryo-Fetal Toxicity: TAVALISSE can cause fetal harm. Advise patients of potential risk to a fetus and to use effective contraception. 4 CONTRAINDICATIONS None. None. ( 4 )

Pregnancy

8.1 Pregnancy Risk Summary Based on findings from animal studies and the mechanism of action, TAVALISSE can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) ]. There are no available data in pregnant women to inform the drug-associated risk.

Storage

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.

Frequently Asked Questions

What is Fostamatinib used for?

1 INDICATIONS AND USAGE 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. TAVALISSE is a kinase inhibitor indicated for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment.

What are the side effects of Fostamatinib?

6 ADVERSE REACTIONS The following clinically important adverse reactions, that can become serious are described elsewhere in the labeling: Hypertension [ see Warnings and Precautions (5.1) ] Hepatotoxicity [ see Warnings and Precautions (5.2) ] Diarrhea [ see Warnings and Precautions (5.3) ] Neutropenia [ see Warnings and Precautions (5.4) ] The most common adverse reactions (≥5% and more than placebo) are diarrhea, hypertension, nausea, respiratory infection, dizziness, ALT/AST increased, rash, abdominal pain, fatigue, chest pain and neutropenia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Rigel Pharmaceuticals, Inc. at 1-800-983-1329 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Can I take Fostamatinib during pregnancy?

8.1 Pregnancy Risk Summary Based on findings from animal studies and the mechanism of action, TAVALISSE can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) ]. There are no available data in pregnant women to inform the drug-associated risk.

What are the important warnings for Fostamatinib?

5 WARNINGS AND PRECAUTIONS Hypertension: Monitor blood pressure every 2 weeks until stable, then monthly. Manage hypertension using standard antihypertensive treatment and, if needed, interrupt, reduce or discontinue TAVALISSE. ( 5.1 ) Hepatotoxicity: Monitor LFTs monthly. If LFT levels are elevated, interrupt, reduce or discontinue TAVALISSE. ( 5.2 ) Diarrhea: Manage diarrhea with supportive measures. If diarrhea becomes severe, interrupt, reduce or discontinue TAVALISSE. ( 5.3 ) Neutropenia: Monitor ANC monthly, and for infection. If neutrophil count decreases below 1.0 × 10 9 /L, interrupt, reduce or discontinue TAVALISSE. ( 5.4 ) Embryo-Fetal Toxicity: TAVALISSE can cause fetal harm. Advise patients of potential risk to a fetus and to use effective contraception. 4 CONTRAINDICATIONS None. None. ( 4 )

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.