Advancing Treatment in Indolent Systemic Mastocytosis: Updates at EAACI 2025

A panelist discusses how indolent systemic mastocytosis presents with chronic, mast cell–mediated symptoms that significantly reduce quality of life, often persist despite treatment, and may lead to serious complications like anaphylaxis and osteoporosis.

A panelist discusses how indolent systemic mastocytosis is driven by a KIT D816V mutation that causes constant mast cell activation, leading to heterogeneous clinical presentations and highlighting the importance of targeted therapies like selective KIT inhibitors.

A panelist discusses how the current standard of care for indolent systemic mastocytosis involves stepwise symptom management with antihistamines and other antimediator therapies, though treatment challenges include limited efficacy, adverse effects, and the burden of polypharmacy.

A panelist discusses how long-term safety and efficacy data are essential for treating indolent systemic mastocytosis, given its chronic nature and the potential need for lifelong therapy, with recent findings supporting the sustained benefits of avapritinib.

A panelist discusses how the three part PIONEER study shows that avapritinib 25 mg (with optional escalation to 50 mg) sustains meaningful symptom and quality of life improvements with a favorable safety profile for up to five years, supporting its FDA approval for indolent systemic mastocytosis.

A panelist discusses how appropriate candidates for avapritinib include patients with moderate to severe indolent systemic mastocytosis who remain symptomatic despite standard therapies, while those with low platelet counts, pregnancy, bleeding risks, or certain comorbidities should be excluded through shared decision-making.

A panelist discusses how the durability and safety of avapritinib over several years support its long-term use in indolent systemic mastocytosis, potentially increasing confidence among community providers to prescribe it beyond specialized centers.

A panelist discusses how patients with indolent systemic mastocytosis who have high mast cell burdens, inadequate symptom control, and stable tolerance at 25 mg may be ideal candidates for avapritinib dose escalation to 50 mg.

A panelist discusses how avapritinib provides broad, multi-organ symptom relief in indolent systemic mastocytosis—improving skin, gastrointestinal, and neurocognitive symptoms—leading to significant quality-of-life gains, though its effects on osteoporosis and anaphylaxis remain under investigation.

A panelist discusses how they have growing confidence in pipeline therapies for indolent systemic mastocytosis based on their experience with the PIONEER trials, particularly noting improvements in patient symptoms and quality of life, while expressing hope for additional data on the drug's effects on bone health and anaphylactic events, and describing other investigational treatments including selective inhibitors and Bruton tyrosine kinase inhibitors currently in clinical trials.

A panelist discusses how they have growing confidence in pipeline therapies for indolent systemic mastocytosis based on their experience with the PIONEER trials, particularly noting improvements in patient symptoms and quality of life, while expressing hope for additional data on the drug's effects on bone health and anaphylactic events, and describing other investigational treatments including selective inhibitors and Bruton tyrosine kinase inhibitors currently in clinical trials.