Midostaurin

Multikinase inhibitor (KIT, FLT3, PDGFR, PKC) · also known as Rydapt, PKC412

Multikinase inhibitor active against wild-type and D816V-mutant KIT; approved for defined advanced systemic mastocytosis diagnoses, not MCAS.

How it relates to mast cells: Mast cell disease
Types of studies cited: Cohort study
Approved in the US for: advanced systemic mastocytosis, including ASM, SM-AHN, and mast cell leukemia

What this relationship means: Studied in patients with a different mast cell disease, usually systemic mastocytosis. Those disorders have diagnostic criteria and disease biology that differ from MCAS, so a result there does not establish an MCAS outcome.

Mechanism of action

Midostaurin is a small-molecule inhibitor of several kinases. The current US label identifies activity against wild-type and D816V-mutant KIT as well as FLT3, PDGFR, and members of the protein kinase C family. This is therefore not a mast-cell-selective mechanism.

Its mast-cell indication is narrowly defined: aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic neoplasm, and mast cell leukemia. The supporting published study was open-label and single-arm in advanced systemic mastocytosis.

That indication belongs on an MCAS reference as adjacent biology and a boundary, not as a suggested next step. The disease population, kinase target, and safety profile differ materially from the downstream mediator blockers used in routine symptom management.

Sources

Rydapt (midostaurin) current US prescribing information Drug label · link checked 21 Aug 2026
Efficacy and Safety of Midostaurin in Advanced Systemic Mastocytosis Peer-reviewed study 2016 PMID 27355533 · link checked 21 Aug 2026

What this evidence cannot establish

The pivotal study was an open-label, single-arm study in advanced systemic mastocytosis, without a randomised comparator. That is a clonal mast cell disease with a distinct diagnostic and biological context, not MCAS. Midostaurin inhibits several kinases rather than mast-cell KIT alone, and the current label includes serious pulmonary, reproductive, interaction, and monitoring boundaries. Neither the approval nor the cohort can be generalized to MCAS populations.

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