FDA Approves Fostamatinib for ITP After Insufficient Response to Previous Treatment

Share this content:
FDA approval of fostamatinib was based on results from FIT-1 and FIT-2 trials.
FDA approval of fostamatinib was based on results from FIT-1 and FIT-2 trials.

Fostamatinib disodium hexahydrate (Tavalisse), a kinase inhibitor, was granted FDA approval for the treatment of thrombocytopenia in adult patients with chronic immune thrombocytopenia (ITP) who have had insufficient response to a previous treatment.

Recommended dose is 100 mg orally twice daily. If a platelet count of at least 50×109/L is not achieved in 1 month after therapy initiation, the dose should be increased to 150 mg orally twice daily.

The application was granted a standard review and orphan product designation. The approval was based on results from FIT-1 [ClinicalTrials.gov Identifier: NCT02076399] and FIT-2 [ClinicalTrials.gov Identifier: NCT02076412] trials, two identical, double-blind, placebo-controlled trials that enrolled a total of 150 patients with persistent or chronic ITP. The patients had had insufficient response to previous treatment with corticosteroids, immunoglobulins, splenectomy, and/or a thrombopoietin receptor agonist. In the trials, patients were randomized 2:1 to receive fostamatinib 100 mg orally twice daily or placebo for 24 weeks. Dose escalation to 150 mg orally twice daily was allowed after 1 month.

Stable platelet response of at least 50×109/L on at least 4 visits between weeks 14 and 24 was used to determine efficacy. In FIT-1, stable response was achieved in 9 patients (18%) in the fostamatinib group vs 0 patients (0%) in the placebo group (P=.03). In FIT-2, stable platelet response was achieved in 8 patients (16%) in the fostamatinib group vs 1 patient (4%) in the placebo group (P=.26).

In the FIT-3 extension study (ClinicalTrials.gov Identifier: NCT 02077192), a stable response was observed in 10 patients (23%) newly exposed to fostamatinib. Durable platelet responses were seen in all the studies.

The most common adverse reactions — reported by at least 5% of patients in the treatment groups — were abdominal pain, chest pain, diarrhea, dizziness, fatigue, hypertension, increased ALT/AST, rash, respiratory infection, nausea, and neutropenia. In the ITP double-blind studies, Serious adverse drug reactions reported in the ITP double-blind studies were diarrhea, febrile neutropenia, hypertensive crisis, and pneumonia; each reaction occurred in 1% of patients receiving fostamatinib.

Reference

FDA approves fostamatinib tablets for ITP [news release]. Silver Spring, MD: US Food and Drug Administration; April 17, 2018. https://www.fda.gov/drugs/informationondrugs/approveddrugs/ucm604956.htm. Accessed April 18, 2018.

You must be a registered member of ONA to post a comment.

Sign Up for Free e-newsletters



Regimen and Drug Listings

GET FULL LISTINGS OF TREATMENT Regimens and Drug INFORMATION

Bone Cancer Regimens Drugs
Brain Cancer Regimens Drugs
Breast Cancer Regimens Drugs
Endocrine Cancer Regimens Drugs
Gastrointestinal Cancer Regimens Drugs
Genitourinary Cancer Regimens Drugs
Gynecologic Cancer Regimens Drugs
Head and Neck Cancer Regimens Drugs
Hematologic Cancer Regimens Drugs
Lung Cancer Regimens Drugs
Other Cancers Regimens
Rare Cancers Regimens
Skin Cancer Regimens Drugs