Imatinib

Tyrosine kinase inhibitor (KIT, PDGFR, BCR-ABL) · also known as Gleevec, STI-571

KIT and PDGFR tyrosine kinase inhibitor with a treating-author MCAS report and a mutation-limited US mastocytosis indication.

How it relates to mast cells: MCAS patients
Types of studies cited: Case report , Cohort study
Approved in the US for: aggressive systemic mastocytosis without KIT D816V or with unknown KIT status
Clinical practice: Documented specialist use one case and a practice-record cohort, reported by the treating clinician · Treating-author report

What this relationship means: Studied in people diagnosed with mast cell activation syndrome. Current evidence consists of case reports, uncontrolled series, or retrospective review rather than randomised comparisons — so it establishes that people have taken it, not that it worked.

Mechanism of action

Imatinib inhibits several tyrosine kinases, including KIT and platelet-derived growth factor receptors. The mutation boundary is crucial: its current US label includes aggressive systemic mastocytosis only when KIT D816V is absent or KIT status is unknown, and states that D816V-positive disease is not sensitive to imatinib.

A 2024 report describes one person diagnosed with MCAS using consensus-2 criteria, and summarises a medical-record cohort from the treating clinician’s own practice. The paper identifies which of its authors treated those patients, which is why this entry carries the documented-specialist-use tag rather than inferring the role from authorship — co-authoring a report is not the same as having treated the patients in it.

Human exposure in a reported MCAS population makes this more than a laboratory hypothesis. It remains uncontrolled evidence, and the individual case combined medication changes with recognition and avoidance of a major occupational trigger. The specialist-use tag records who documented the practice; it does not upgrade the study design or imply an endorsement.

Sources

Gleevec (imatinib) current US prescribing information Drug label · link checked 21 Aug 2026
Imatinib and Trigger Avoidance for Mast Cell Activation Syndrome Presenting With Attacks of Abdominal Pain, Nausea, Vomiting, and Diarrhea Peer-reviewed study 2024 PMID 38883580 · link checked 21 Aug 2026
Phase II study of imatinib mesylate as therapy for patients with systemic mastocytosis Peer-reviewed study 2009 PMID 19193436 · link checked 21 Aug 2026
Phase II, open-label study evaluating the activity of imatinib in treating life-threatening malignancies known to be associated with imatinib-sensitive tyrosine kinases Peer-reviewed study 2008 PMID 18451237 · link checked 21 Aug 2026

What this evidence cannot establish

The MCAS evidence is an individual case plus a medical-record cohort described inside that report, without randomisation or a comparator. The case course included imatinib, other mast-cell-directed care, and later avoidance of an occupational trigger, so it cannot attribute the course to imatinib alone. The article uses consensus-2 diagnostic criteria, which are not interchangeable with every MCAS consensus definition. The US mastocytosis indication is mutation-limited: the label states that KIT D816V disease is not sensitive to imatinib. Serious toxicity and interaction boundaries make this very different from routine mediator blockade.

What this page does not say

No dosing, and no claim that this works. The entry describes a published mechanism, the cited study types, and what those studies cannot establish — nothing further. Why the site is built this way.

Recently verified. Verified 21 Aug 2026