demonstrated in
clinical trials1

57% overall response rate
(95% CI: 42%, 70%)*
Proven efficacy and demonstrated duration of response1
38.3-month median duration of response (DOR) demonstrated in clinical trials (95% CI: 19, NE) DRIVEN PRIMARILY BY SM-AHN PATIENTS
Watch Video Expert Series About AYVAKIT

Watch Dr Mesa review information about efficacy and safety.

Watch Now
EXPLORER and PATHFINDER were 2 multicenter, single-arm, open-label clinical trials evaluating the efficacy and safety of AYVAKIT® (avapritinib) for patients with Advanced SM.1

Efficacy was based on overall response rate (ORR) per modified IWG-MRT-ECNM criteria across all evaluable patients dosed up to 200 mg daily (N=53). In the subgroup of patients with MCL, the efficacy was based on complete remission (CR).

Watch Dr Mesa review information about efficacy and safety.

Watch Now

53 patients were evaluable for a response, with a median follow-up of 11.6 months (95% CI: 9.9 to 16.3 months)1

Patients enrolled in EXPLORER received a starting dose of AYVAKIT ranging from 30 mg to 400 mg orally once daily. In PATHFINDER, patients were enrolled at the recommended starting dose of 200 mg orally once daily1†

*ORR per modified IWG-MRT-ECNM is defined as patients who achieved a CR, CRh, or PR.

The recommended dosage for patients with Advanced SM is 200 mg orally once daily per the US Prescribing Information.

Response-evaluable patients: Confirmed diagnosis of Advanced SM per WHO criteria and deemed evaluable by modified IWG-MRT-ECNM criteria at baseline who received at least 1 dose of AYVAKIT, had at least 2 post-baseline bone marrow assessments, and were on study for at least 24 weeks, or had an end-of-study visit.

Median age67 years (37-85)
Gender58% male, 42% female
ECOG PS0-1: 68%
2-3: 32%
Ongoing corticosteroid use40%
Presence of KIT D816V mutation94% (as measured by ddPCR)
Prior antineoplastic therapy66%
Prior midostaurin47%
Advanced SM subtypesASM: 3.8% (n=2)
SM-AHN: 75.5% (n=40)
MCL: 20.7% (n=11)
Baseline platelet count 50 x 109/L91%

Proven efficacy
across all subtypes
and regardless of prior antineoplastic therapy1,6


57% overall response rate (95% CI: 42%, 70%)a

All subtypes: ASM, MCL, SM-AHN (N=53)

72% ORR was achieved with the addition of patients who had clinical improvementb

Median DOR of 38.3 months (95% CI: 38, NE)

  • Median time to response (n=30)6: 2.1 months
  • Median time to CR and CRh (n=15)6:
    9.2 months

CR+CRh: 28%
PR: 28%
Clinical improvement: 15%

aMedian duration of follow-up was 11.6 months (95% CI: 9.9 to 16.3 months).

bClinical improvement is defined as having a response duration of 12 weeks and fulfillment of 1 or more of the nonhematologic and/or hematologic response criteria.7

100% overall response rate

Aggressive systemic mastocytosis (ASM) (n=2)

  • 1/2 patients achieved CR/CRh
ORR was defined as patients who achieved a CR, CRh, or PR
45% overall response rate (95% CI: 17%, 77%)

Mast cell leukemia (MCL)

ORR was defined as patients who achieved a CR, CRh, or PR
58% overall response rate (95% CI: 41%, 73%)

Systemic mastocytosis with an associated hematological neoplasm (SM-AHN) (n=40)

ORR was defined as patients who achieved a CR, CRh, or PR

CI=confidence interval; CR=complete remission; CRh=complete remission with partial hematologic recovery; ddPCR=droplet digital polymerase chain reaction; DOR=duration of response; ECNM=European Competence Network on Mastocytosis; ECOG PS=Eastern Cooperative Oncology Group Performance Status; IWG-MRT=International Working Group-Myeloproliferative Neoplasms Research and Treatment; NE=not estimable; PR=partial remission; WHO=World Health Organization.

Learn about the safety of AYVAKIT evaluated in the EXPLORER and PATHFINDER clinical trials.


There are no contraindications for AYVAKIT.

Serious intracranial hemorrhage (ICH) may occur with AYVAKIT treatment; fatal events occurred in <1% of patients. Overall, ICH (eg, subdural hematoma, ICH, and cerebral hemorrhage) occurred in 2.9% of 749 patients who received AYVAKIT. In AdvSM patients who received AYVAKIT at 200 mg daily, ICH occurred in 2 of 75 patients (2.7%) who had platelet counts 50 x 109/L prior to initiation of therapy and in 3 of 80 patients (3.8%) regardless of platelet counts. Monitor patients closely for risk of ICH including those with thrombocytopenia, vascular aneurysm or a history of ICH or cerebrovascular accident within the prior year. Permanently discontinue AYVAKIT if ICH of any grade occurs. A platelet count must be performed prior to initiating therapy. AYVAKIT is not recommended in AdvSM patients with platelet counts <50 x 109/L. Following treatment initiation, platelet counts must be performed every 2 weeks for the first 8 weeks. After 8 weeks of treatment, monitor platelet counts every 2 weeks or as clinically indicated based on platelet counts. Manage platelet counts of <50 x 109/L by treatment interruption or dose reduction.

Cognitive adverse reactions can occur in patients receiving AYVAKIT. Cognitive adverse reactions occurred in 39% of 749 patients and in 28% of 148 SM patients (3% were Grade >3). Memory impairment occurred in 16% of patients; all events were Grade 1 or 2. Cognitive disorder occurred in 10% of patients; <1% of these events were Grade 3. Confusional state occurred in 6% of patients; <1% of these events were Grade 3. Other events occurred in < 2% of patients. Depending on the severity, withhold AYVAKIT and then resume at same dose or at a reduced dose upon improvement, or permanently discontinue.

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.

The most common adverse reactions (20%) at all doses were edema, diarrhea, nausea and fatigue/asthenia.

Avoid coadministration of AYVAKIT with strong and moderate CYP3A inhibitors. If coadministration with a moderate CYP3A inhibitor cannot be avoided, reduce dose of AYVAKIT. Avoid coadministration of AYVAKIT with strong and moderate CYP3A 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.


AYVAKIT is indicated for the treatment of adult patients with Advanced SM (AdvSM) including patients with aggressive systemic mastocytosis (ASM), systemic mastocytosis with an associated hematological neoplasm (SM-AHN), and mast cell leukemia (MCL).

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


  1. AYVAKIT [prescribing information]. Cambridge, MA: Blueprint Medicines Corporation; June 2021.
  2. Gilreath JA, et al. Clin Pharmacol. 2019;11:77-92.
  3. Garcia-Montero AC, et al. Blood. 2006;108(7):2366-2372.
  4. Verstovsek S. Eur J Haematol. 2013;90(2):89-98.