FDA Approves Avapritinib for the Treatment of Adult Patients with Indolent Systemic Mastocytosis

Blueprint Medicines is pleased to announce that AYVAKIT® (avapritinib) is now approved by the US Food and Drug Administration (FDA) for the treatment of adult patients with indolent systemic mastocytosis (ISM). ISM is a rare mast cell disease that can lead to the proliferation and activation of abnormal mast cells which can affect multiple organ systems.1,2 ISM is driven by the KIT D816V mutation in about 95% of cases. It can be characterized by a range of symptoms, including skin, gastrointestinal, neurocognitive, and systemic symptoms (including anaphylaxis).2,6-8.

AYVAKIT is a tyrosine kinase inhibitor designed for the potent and selective inhibition of KIT D816V—the only FDA-approved treatment to selectively target the underlying driver of disease in ~95% of patients with ISM.3-5,9.

INDICATION

AYVAKIT® (avapritinib) is indicated for the treatment of adult patients with indolent systemic mastocytosis (ISM).

Limitations of Use: AYVAKIT is not recommended for patients with platelet counts of <50 x 109/L.

IMPORTANT SAFETY INFORMATION

There are no contraindications for AYVAKIT.

Intracranial Hemorrhage (ICH)—Serious ICH may occur with AYVAKIT treatment; fatal events occurred in <1% of patients. No events of ICH occurred in the 246 patients with ISM who received any dose of AYVAKIT in the PIONEER study. Monitor patients closely for risk factors of ICH which may include history of vascular aneurysm, ICH or cerebrovascular accident within the prior year, concomitant use of anticoagulant drugs, or thrombocytopenia. Symptoms of ICH may include headache, nausea, vomiting, vision changes, or altered mental status.

Advise patients to seek immediate medical attention for signs or symptoms of ICH. Permanently discontinue AYVAKIT if ICH of any grade occurs.

Cognitive Effects—Cognitive adverse reactions can occur in patients receiving AYVAKIT and occurred in 7.8% of patients with ISM who received AYVAKIT + best supportive care (BSC) versus 7.0% of patients who received placebo + BSC; <1% were Grade 3. Depending on the severity, withhold AYVAKIT and then resume at the same dose, or permanently discontinue AYVAKIT.

Photosensitivity—AYVAKIT may cause photosensitivity reactions. In all patients treated with AYVAKIT in clinical trials (n=1049), photosensitivity reactions occurred in 2.5% of patients. Advise patients to limit direct ultraviolet exposure during treatment with AYVAKIT and for one week after discontinuation of treatment.

Embryo-Fetal Toxicity—AYVAKIT can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females and males of reproductive potential to use an effective method of contraception during treatment with AYVAKIT and for 6 weeks after the final dose of AYVAKIT. Advise women not to breastfeed during treatment with AYVAKIT and for 2 weeks after the final dose.

Adverse Reactions—The most common adverse reactions (≥10%) in patients with ISM were eye edema, dizziness, peripheral edema, and flushing.

Drug Interactions—Avoid coadministration of AYVAKIT with strong or moderate CYP3A inhibitors or inducers. To report suspected adverse reactions, contact Blueprint Medicines Corporation at 1-888-258-7768 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Please click here to see the full Prescribing Information for AYVAKIT.

Posted 5/24/2023