PIONEER Study: Avapritinib in Patients with Indolent Systemic Mastocytosis

Clinical Trial Title

PIONEER Study to Evaluate Efficacy and Safety of Avapritinib Versus Placebo in Patients With Indolent Systemic Mastocytosis

National Clinical Trial Number:


Contact Information

Rush Cancer Center Clinical Trials Office

Clinical Trial Protocol Description:

Indolent systemic mastocytosis (ISM) is a usually benign, chronic, form of systemic mastocytosis characterized by an abnormal accumulation of neoplastic mast cells mainly in the bone marrow (BM) but also in other organs or tissues such as the skin. ISM represents 90% of all cases of systemic mastocytosis. 

Avapritinib is a type of tyrosine kinase inhibitor approved by the FDA and used in adults whose cancer has certain mutations (changes) in a gene called PDGFRA. It is also being studied in the treatment of other types of cancer. Avapritinib blocks certain proteins made by the mutated PDGFRA gene, which may help keep cancer cells from growing.

This study is a 3-part, randomized, double-blind study. “Randomized” means that each participating subject has a random chance (like the flip of a coin) of being assigned to receive one of the treatments being tested during the study, and “double-blind” means that neither the participating subject nor the study doctor will know which one the participant is taking. Part 1 is closed to accrual. Subjects participating at RUMC will be in Parts 2 and 3.

The expected duration of a subject’s participation in Part 2 of this study is approximately 9.5 months. The Screening Period may last up to 14 weeks (3.5 months) for the study doctor to determine whether it is safe for a potential subject to participate in the study. After the Screening Period, Part 2’s treatment period will last 24 weeks (6 months). After treatment in Part 2, subjects will transition into participation in Part 3 of the study unless the participating subject chooses to leave the study or can no longer participate. The minimum duration of participation in Part 3 is 8 weeks. The maximum length of participation (for all of Parts 2 and 3) is 5 years total. Time in the study is individual to a subject’s circumstances and choices.

In Part 2, participating subjects will either be assigned to 25 milligrams of avapritinib (which was found to be the most safe and effective dose strength of avapritinib) or to placebo (a sugar pill with no active ingredients). Neither the participating subject nor the study doctor will know if they are receiving avapritinib or placebo while they are in Part 2. If the participating subject remains in the study into Part 3, their treatment may be changed, as everyone in Part 3 will receive 25 milligrams of avapritinib.

Clinical Trial Eligibility Criteria:

In order to participate you must meet the following criteria:

  • Are at least 18 years of age and have a confirmed diagnosis of systemic mastocytosis with moderate to severe symptoms.
  • Have had at least 2 other treatments for your disease but failed to achieve adequate symptom control.
  • Are able to swallow pills.

You will be excluded from the study if any of the following criteria apply to you:

  • Have been diagnosed with any of the following: smoldering systemic mastocytosis,; systemic mastocytosis with an associated hematologic neoplasm of non-MC lineage; aggressive systemic mastocytosis; mast cell leukemia; or mast cell sarcoma.
  • Have been diagnosed with another myeloproliferative disorder (such as myelodysplastic syndrome, myeloproliferative neoplasm).
  • Have had any prior treatment with avapritinib.
  • Take anticoagulant drugs such as warfarin, or similar agents.

This is a partial list of eligibility requirements. To inquire about your eligibility, please call the contact number provided. If you wish to inquire via email, please include the title of the study in your message.

Study Details

Clinical Trial Investigator

Celalettin Ustun, MD

Contact Information

Rush Cancer Center Clinical Trials Office


Rush University Medical Center

1620 W Harrison St
Chicago, IL 60612

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