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Adverse Reactiona,bAYVAKIT (25 mg once daily)
n=141, %
Placebo + BSC
n=71, %
Eye edemac137
Peripheral edemad126
Respiratory tract infectione81
Face edema71
Liver transaminase increasedd63
Blood alkaline phosphatase increased61

aAdverse reactions that occurred in 5% of AYVAKIT-treated patients and 2% more than placebo-treated patients.
bPer National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
cEye edema includes periorbital edema, eye edema, swelling of eyelid, orbital edema, eye swelling, eyelid edema and eyelid ptosis.
dTerm includes several similar terms.
eRespiratory tract infection includes pneumonia, upper respiratory tract infection, bronchitis and respiratory tract infection.
fHematoma includes contusion, hematoma and pelvic hematoma.
gHemorrhage includes epistaxis, gingival bleeding, hematochezia, rectal hemorrhage, retinal hemorrhage.

  • Serious adverse reactions occurred in 1 patient (0.7%) who received AYVAKIT due to pelvic hematoma1
  • Permanent discontinuation of AYVAKIT due to an adverse reaction occurred in 1 patient (0.7%) due to dyspnea and dizziness1
  • Dosage interruptions of AYVAKIT due to an adverse reaction occurred in 5% of patients1
  • Of all adverse reactions, 55% were Grade 1, 38% were Grade 2, and 7% were Grade 31
  • Among patients with edema adverse reactions, 95% were Grade 1 and 5% were Grade 2. Among patients with hemorrhage adverse reactions, 86% were Grade 1 and 14% were Grade 21
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Learn more about once-daily dosing with AYVAKIT
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AYVAKIT® (avapritinib) is indicated for the treatment of adult patients with indolent systemic mastocytosis (ISM).

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


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 contraception during treatment with AYVAKIT and for 6 weeks after the final dose. Advise women not to breastfeed during treatment with AYVAKIT and for 2 weeks following 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

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


  1. AYVAKIT [prescribing information]. Cambridge, MA: Blueprint Medicines Corporation; May 2023.
  2. Kristensen T et al. Am J Hematol. 2014;89(5):493-498.
  3. Garcia-Montero AC et al. Blood. 2006;108(7):2366-2372.
  4. Ungerstedt J et al. Cancers. 2022;14(16):3942.
  5. Pardanani A. Am J Hematol. 2023;98(7):1097-1116.
  6. Data on file. Blueprint Medicines Corporation, Cambridge, MA. 2023.
  7. Gülen T et al. J Intern Med. 2016;279(3):211-228.
  8. Theoharides TC et al. N Engl J Med. 2015;373(2):163-172.
  9. Gotlib J et al. NEJM Evidence. 2023;2(6). Published online May 23, 2023. doi:10.1056/EVIDoa2200339
  10. Padilla B et al. Orphanet J Rare Dis. 2021;16(1):434.