Part 1 Results from PIONEER Trial in Indolent Systemic Mastocytosis Announced

Blueprint Medicines, a precision therapy company focused on genomically defined cancers, rare diseases and cancer immunotherapy, today announced updated results from the Phase 2 PIONEER trial of avapritinib in patients with indolent systemic mastocytosis (SM) showing significant clinical improvements versus placebo.

In Part 1 of the PIONEER trial, patients treated with avapritinib showed a statistically significant mean decline of approximately 30 percent in total symptom score (TSS) at 16 weeks, as measured by the Indolent SM Symptom Assessment Form (ISM-SAF), and reductions in symptom scores have deepened over time. In addition, patients treated with avapritinib achieved consistent improvements across objective measures of mast cell burden and patient-reported quality of life. Avapritinib was well-tolerated with no patients discontinuing treatment due to adverse events (AEs). Based on the full Part 1 data, 25 mg once daily (QD) has been selected as the recommended Part 2 dose (RP2D).

Results from this data presentation will be available on an American Academy of Allergy, Asthma & Immunology (AAAAI) virtual forum, which was established following the cancellation of the 2020 AAAAI Annual Meeting.

Read the full press release here

Source: Blueprint Medicines Corporation