TAVALISSE (fostamatinib disodium)

TAVALISSE is a prodrug that is converted in the gut to the major active metabolite, R406. Mean (± standard deviation [SD]) exposure estimates of R406 are 550 (± 270) ng/mL for C max and 7080 (± 2670) ng∙h/mL for AUC. R406 exposure is approximately dose proportional up to 200 mg twice daily (1.3 times the 150 mg dosage). R406 accumulates approximately 2- to 3-fold upon twice daily dosing at 100–160 mg (0.67 to 1.06 times the 150 mg dosage).

AbsorptionAfter oral administration of TAVALISSE, the a...

TAVALISSE was studied in two placebo-controlled efficacy and safety studies (referred to as FIT-1 [NCT02076399] and FIT-2 [NCT02076412]), and in an open-label extension study referred to as FIT-3 (NCT 02077192). Randomized, Placebo-Controlled Studies A total of 150 patients with persistent or chronic ITP, who had an insufficient response to previous treatment (which included corticosteroids, immunoglobulins, splenectomy, and/or a thrombopoietin receptor agonists) were enrolled in two identical, double-blind, placebo-controlled studies that were conducted in different countries. For each study,...

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, fat...

None. None. ( 4 )

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...

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 ...