Is Fostamatinib on the market?

Fostamatinib (Fostamatinib) was approved for medical use in the United States in April 2018 for the treatment of adult patients with chronic immune thrombocytopenia (ITP), especially those who have had an inadequate response to previous treatments. The brand name is Tavliesse. The drug was subsequently approved for medical use in the EU in January 2020, marketed as Tavlesse.

The drug's approval was primarily based on two double-blind, placebo-controlled clinical trials, respectivelyFIT-1 (NCT02076399) and FIT-2 (NCT02076412), which included a total of 150 adult patients. These patients were all chronic ITP patients who had an inadequate response to previous treatments (including corticosteroids, immunoglobulins, splenectomy, and thrombopoietin receptor agonists). The evaluation of efficacy mainly relies on a stable platelet response, that is, a platelet count of more than 50*10^9/L on at least 4 out of 6 visits between weeks 14 and 24.

In theFIT-1 trial, 18% of patients (n=9) who received fotantinib demonstrated a stable platelet response compared with none of those who received placebo (0%, n=0, p=0.03). Results from the FIT-2 trial showed that 16% (n=8) and 4% (n=1) of patients had stable platelet responses, respectively, although this difference did not reach statistical significance (p=0.26). Stable responses were also observed in 23% (n=10) of patients newly exposed to fotantinib in the FIT-3 (NCT 02077192) extension study. These studies demonstrate that fotantinib can effectively provide durable platelet responses, providing new hope for patients who have failed to respond to other treatments.

Although fotantinib has shown certain efficacy in ITP patients, attention should be paid to its possible serious side effects. These side effects can be controlled with appropriate precautions and dosage adjustments.

Reference materials:https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-fostamatinib-tablets-itp