Avapritinib (Ayvakit®) plus best supportive care improved symptoms and quality of life (QoL) in patients with indolent systemic mastocytosis (SM), according to results from the registrational PIONEER trial.

The findings will be presented in a poster at the 2023 American Academy of Allergy, Asthma and Immunology (AAAAI) Annual Meeting being held February 24 to 27, 2023, in San Antonio, Texas.

“PIONEER is the largest randomized controlled trial ever conducted in indolent SM, and we look forward to reporting study results on the significant clinical impact of Ayvakit across measures of mast cell burden, symptoms, and quality of life,” Becker Hewes, MD, chief medical officer of Blueprint Medicines, said in a press release.

“Ayvakit was designed to target the primary underlying driver of SM, and the totality of data from PIONEER highlights the treatment’s potential to modify the disease and set a new standard of care, benefiting a broad range of patients with indolent SM.”

Read more about SM treatment

Patients treated with daily avapritinib (25 mg) plus best supportive care showed significantly greater improvement from baseline to 24 weeks in total symptom score (TSS) compared to patients receiving placebo plus best supportive care. Moreover, they were more likely to achieve 30% and 50% reductions in TSS-measured symptoms.

Additionally, the study found that avapritinib-treated patients experienced improvements from baseline to 24 weeks in all QoL and health status measures, including the total 12-Item Short-Form Health Survey (SF-12) and physical and mental health subscores, Mastocytosis Quality of Life (MC-QoL) questionnaire, European Quality of Life 5 Dimensions (EQ-5D) questionnaire, Patient Global Impression of Severity (PGIS) scale, and Patient Global Impression of Change (PGIC) scale.

PIONEER Trial Suggests Avapritinib Ameliorates Indolent SM Skin Symptoms

The randomized, double-blind, placebo-controlled study enrolled 212 patients (treatment arm, 141; placebo arm, 71) with moderate to severe indolent SM with inadequately controlled symptoms, despite best supportive care. The primary endpoint of the study was the mean change in TSS in patients treated with avapritinib vs placebo, based on the 14-day average of patient-reported severity of 11 indolent SM symptoms.


Akin C, Siebenhaar F, Gotlib J, et al. Avapritinib improved symptoms and quality of life in patients with indolent systemic mastocytosis in the PIONEER study. J Allergy Clin Immunol. 2023;151(2):AB50. doi:10.1016/j.jaci.2022.12.157

Blueprint Medicines to present positive data from PIONEER trial of Ayvakit® (avapritinib) in indolent systemic mastocytosis at 2023 AAAAI Annual Meeting. News release. Blueprint Medicines Corporation; February 3, 2023.