Key takeaways

  • Ayvakit (avapritinib) is a targeted therapy used to treat advanced systemic mastocytosis, indolent systemic mastocytosis, and certain gastrointestinal stromal tumors with a PDGFRA exon 18 mutation.
  • Clinical trials show high response rates and improved quality of life for people taking Ayvakit for these conditions. However, the drug can cause serious side effects like brain bleeds, cognitive changes, and sun sensitivity which require close monitoring.
  • Ayvakit costs roughly $42,000 for a 30-day supply, but most commercial insurance and Medicare plans cover it. The manufacturer offers a patient support program that can bring out-of-pocket costs down to $0 per month for eligible commercially insured patients.

Ayvakit (avapritinib) is a targeted therapy approved by the Food and Drug Administration (FDA) to treat advanced systemic mastocytosis, indolent systemic mastocytosis, and PDGFRA exon 18–mutant gastrointestinal stromal tumors. Clinical trials show high response rates and improved quality of life in those taking Ayvakit for these conditions, with careful monitoring for side effects required.

Ayvakit belongs to a group of targeted drugs called kinase inhibitors. It contains the active ingredient avapritinib. Unlike traditional chemotherapy which kills all fast-growing cells, Ayvakit specifically targets and blocks abnormal proteins that trigger cells to multiply. This medication is prescribed for two main conditions in adults:

  • Gastrointestinal stromal tumor (GIST): This is a rare type of cancer that begins in the stomach or digestive tract. Ayvakit is used when the tumor can’t be removed via surgery or is metastatic (has spread to other parts of the body), and contains a very specific genetic mutation called a PDGFRA exon 18 mutation, including the D842V mutation.
  • Systemic mastocytosis (SM): This is a rare disorder where the body produces too many mast cells (a type of immune cell), which build up and damage organs. Ayvakit is approved for:
    • advanced systemic mastocytosis (AdvSM), which are severe forms of the disease, including aggressive mastocytosis and mast cell leukemia
    • indolent systemic mastocytosis (ISM): chronic (ongoing), less aggressive form of the disease that causes severe but manageable symptoms throughout the body

Ayvakit comes as a tablet that you swallow. This drug is available in five strengths: 25 (milligrams) mg, 50 mg, 100 mg, 200 mg, and 300 mg.

The recommended starting dose of Ayvakit depends on the condition it’s being used to treat:

  • GIST: 300 mg once per day
  • Advanced SM: 200 mg once per day
  • Indolent SM: 25 mg once per day

Important rules for taking Ayvakit:

  • You must take this medication on an empty stomach at least 1 hour before or 2 hours after eating a meal.
  • If you miss a dose, you can take it as soon as you remember. However, if your next scheduled dose is less than 8 hours away, skip the missed dose and just take the next one at your regular time.
  • If you vomit after taking a dose, do not take an extra pill. Simply wait and take your next regularly scheduled dose the following day.

Side effects of Ayvakit vary depending on the condition it’s being used to treat. The most common side effects reported in the drug’s clinical studies include:

Experiencing side effects? After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you develop a side effect while taking this drug and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Ayvakit has several important safety warnings for conditions that require close monitoring by a doctor.

Brain bleeds

Ayvakit can cause serious, sometimes life-threatening intracranial hemorrhage (bleeding inside the skull). A healthcare professional will check your platelet levels before and during your treatment, and may have you stop taking Ayvakit if your platelets are very low.

Seek immediate emergency medical care if you experience severe dizziness, weakness on one side of your body, vision changes, confusion, or a sudden, severe headache.

Cognitive changes

Ayvakit can significantly impact your central nervous system which can cause confusion, forgetfulness, mood changes, extreme sleepiness, or hallucinations. You should not drive or operate machinery if you experience these side effects.

Sun sensitivity

Ayvakit can make your skin highly sensitive to UV light (a condition called photosensitivity). You must limit direct sunlight, avoid tanning beds, wear protective clothing, and use sunscreen during treatment with Ayvakit and for 1 week after stopping it.

Harm to unborn babies

Ayvakit can cause severe problems with fetal development (commonly known as birth defects) or pregnancy loss.

People who can become pregnant must take a pregnancy test before starting this medication and use highly effective birth control during Ayvakit treatment and for 6 weeks after their last dose.

You should not breastfeed while taking Ayvakit and for 2 weeks after your last dose.

Men with female partners who are able to become pregnant must also use effective birth control during treatment and for 6 weeks after their last dose.

Note: The use of binary terms such as “male” and “female” or “men” and “women” in this article reflects the language of the sources we’ve used. Unless otherwise noted, it’s unclear whether the research we reference included participants with expansive gender identities.

Ayvakit interacts strongly with other drugs processed by the liver — specifically an enzyme called CYP3A. Because of this, you should avoid strong to moderate CYP3A inhibitors and inducers.

CYP3A inhibitors

Certain antifungal medications (such as ketoconazole), antibiotics (such as clarithromycin), and grapefruit juice can slow how quickly your body breaks down Ayvakit. This can increase the amount of the drug in your body to dangerous levels, raising your risk of serious side effects. If you must take these other medications, your doctor will significantly lower your Ayvakit dose.

CYP3A inducers

Medications like rifampin (an antibiotic), St. John’s wort (an herbal supplement), and certain seizure drugs increase the speed at which your body processes Ayvakit. This means the drug is cleared from your system too quickly, making it ineffective in treating your condition.

Because Ayvakit is a highly specialized orphan drug (meaning it’s used to treat rare medical conditions), it’s extremely expensive. The wholesale list price is roughly $42,000 for a 30-day supply, regardless of the strength of the pill you’re prescribed. However, very few patients pay the actual list price.

Ayvakit is covered by the vast majority of commercial insurance and Medicare plans. And the drug manufacturer (Blueprint Medicines) provides a patient support program called YourBlueprint, which offers co-pay cards that can bring out-of-pocket costs down to $0 per month for eligible commercially insured patients, alongside separate patient assistance programs for those without sufficient coverage. For more information, check out the program website or call 888-258-7768 (888-BLUPRINT).

Note: Ayvakit is a limited-distribution drug, which means it’s only available through specialty pharmacies rather than standard retail store pharmacies.

If Ayvakit is not appropriate or well-tolerated, there are other treatments that may be possible options for your condition.

For GIST

Standard treatments include older target-therapy kinase inhibitors like imatinib (Gleevec), sunitinib (Sutent), regorafenib (Stivarga), or ripretinib (Qinlock).

Note: Ayvakit is unique because it’s the only drug that’s highly effective against the PDGFRA D842V mutation. The standard alternatives don’t usually work well for this specific mutation.

For systemic mastocytosis

Alternate treatments include another targeted drug called midostaurin (Rydapt), or symptom-management therapies like cromolyn sodium (Gastrocrom), high-dose antihistamines, and corticosteroids to control the severe allergic-like reactions caused by this condition.

Ayvakit (avapritinib) is a highly specialized, targeted kinase inhibitor approved to treat rare conditions, specifically advanced systemic mastocytosis, indolent systemic mastocytosis, and certain gastrointestinal stromal tumors (GIST) carrying a PDGFRA exon 18 mutation.

While clinical trials have shown the drug to be effective in treating these conditions, Ayvakit requires close medical supervision due to severe potential side effects such as brain bleeds and cognitive changes.

Although the drug has an extremely high list price of about $42,000 per month, insurance coverage and manufacturer copay programs can significantly lower out-of-pocket costs — often as low as $0 for those who are eligible.

Disclaimer: While Healthline strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.