Gilternib 40 mg tablets for FLT3-mutated acute myeloid leukemia treatment

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Gilternib 40 mg

Gilteritinib 40mg tablets – Everest Pharmaceuticals Ltd.

Approved for adults with relapsed or refractory FLT3-mutated acute myeloid leukemia (AML) — confirmed FLT3-ITD or FLT3-TKD mutation, as detected by an FDA-approved test.

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  • Clinical outcomes at a glance

9.3 mo

Median overall survival vs 5.6 mo with chemotherapy (ADMIRAL trial)

2.8 mo

Median event-free survival, relapsed/refractory AML

34%

Composite complete remission rate (CR/CRh)

~25%

Of responders able to proceed to stem cell transplant
  • Am I a candidate? — Take Decesion

1

Confirm FLT3 mutation status
Requires bone marrow or blood testing (PCR or NGS) showing FLT3-ITD or FLT3-TKD mutation using an FDA-approved companion diagnostic.

2

Confirm relapsed or refractory status
To confirm a relapsed or refractory (R/R) status, your healthcare team evaluates your specific disease response and history using established clinical guidelines (e.g., from the National Cancer Institute or the Leukaemia Foundation).

3

Review contraindications with your hematologist
QTc prolongation history, pancreatitis history, posterior reversible encephalopathy syndrome (PRES) risk factors — discuss fully before prescribing.

4

Discuss your goals of care
Weigh survival benefit and potential as a bridge to stem cell transplant against close monitoring requirements (ECG, liver function, pancreatic enzymes).
Important safety information: Gilteritinib carries a boxed warning for differentiation syndrome, which can be fatal if untreated. It can also cause QTc prolongation, posterior reversible encephalopathy syndrome (PRES), and pancreatitis. Do not take without confirmed FLT3 mutation testing and close hematologist monitoring.
  • common side effects to know
  • Liver enzyme elevation (~40%)
  • Fatigue / weakness (~38%)
  • Edema (~33%)
  • Diarrhea / nausea (~30%)
  • Differentiation syndrome (~3%)
  • QTc prolongation / PRES (rare)
  • Trust & expertise
  • FDA Approved 2018
  • EMA Approved 2019
  • NCCN AML Guidelines
  • ADMIRAL Phase III RCT

MD

Medical Oncologist Review

Board-certified oncologist · 12+ years in thoracic malignancies

Gilteritinib gave us a real option for FLT3-mutated relapsed AML, a population with historically poor outcomes. The survival benefit over salvage chemotherapy is meaningful, but differentiation syndrome and QTc monitoring require vigilance from day one.”

Content reviewed against FDA prescribing information, NCCN Guidelines v2.2024, and published Phase III trial data. Last updated June 2026.

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Questions to ask my healthcare provider

What questions should I ask my hematologist about starting gilteritinib?

Here are key questions to bring to your hematologist, organized by stage of conversation:

Before confirming gilteritinib as your treatment

  • Has my FLT3 mutation been confirmed with an FDA-approved test — and is it FLT3-ITD, FLT3-TKD, or both?
  • Am I being considered for gilteritinib because of relapse, or because my prior treatment didn’t achieve remission?
  • Is the goal of this treatment to bridge me to a stem cell transplant, or is it intended as ongoing therapy?

About the boxed warning and serious risks

  • What is differentiation syndrome, and what symptoms should make me call you immediately rather than wait?
  • Will I need a baseline ECG before starting, and how often will my heart rhythm (QTc) be monitored afterward?
  • Do I have any history of pancreatitis, and how will that be monitored on this medication?
  • What does posterior reversible encephalopathy syndrome (PRES) look like, and how urgent is it if it occurs?

About what to expect on treatment

  • What does the monitoring schedule look like in the first month — how often will I need blood draws and liver function tests?
  • How will we know if the treatment is working, and when would we expect to see a response?
  • What symptoms of liver enzyme elevation, fatigue, or fluid retention (edema) should I watch for at home?
  • Are there foods, medications, or supplements I need to avoid — particularly anything affecting heart rhythm or liver metabolism?

About my specific situation

  • Given my current blood counts and overall health, am I a strong candidate for transplant if I respond well?
  • If I’m of childbearing potential, what precautions are needed during and after treatment?
  • How does this interact with any other medications I’m currently taking, including those for other conditions?

About the longer road

  • If gilteritinib stops working or I don’t respond, what would the next steps look like?
  • Is there a clinical trial that might be relevant for me, either now or later?
  • Are there financial assistance programs through Astellas if cost becomes a barrier?

A practical tip: Given the boxed warning and intensive monitoring schedule, it’s especially worth asking for a written summary of warning signs and who to call (and when) if something feels off between appointments.

Compare gilteritinib vs other FLT3 inhibitors like midostaurin and quizartinib

Here’s how the three FLT3 inhibitors compare. Unlike the osimertinib generations, these three drugs aren’t really “newer vs older” in a simple line — they’re approved for different points in the AML treatment journey and have different mutation specificities.

Where each drug fits in treatment

Midostaurin (Rydapt)Quizartinib (Vanflyta)Gilteritinib (Xospata)
Approved settingNewly diagnosed FLT3+ AML, combined with induction/consolidation chemo, then maintenanceNewly diagnosed FLT3-ITD AML, combined with chemo, then maintenance monotherapyRelapsed/refractory FLT3-mutated AML, monotherapy
Pivotal trialRATIFY (2017)QuANTUM-First (2023)ADMIRAL (2019)
FLT3 subtypes coveredITD and TKDITD onlyITD and TKD (including D835)

So the practical decision tree often looks like: midostaurin or quizartinib at diagnosis (alongside chemo) → gilteritinib if the disease relapses or doesn’t respond.

Selectivity and mechanism

Midostaurin is a multi-kinase inhibitor — it hits FLT3 along with several other kinases, which contributes to its broader side-effect profile but was the first drug to demonstrate a survival benefit when added to standard chemotherapy.

Quizartinib is a type II inhibitor, meaning it binds the inactive form of FLT3 — highly potent against FLT3-ITD specifically, but it doesn’t reliably cover TKD mutations (like D835), which is why it’s restricted to FLT3-ITD-positive patients only.

Gilteritinib is a type I inhibitor, binding the active form of FLT3 — this gives it activity against both ITD and TKD mutations, including resistance mutations that can emerge after treatment with the other two drugs.

Efficacy snapshot

  • Midostaurin + chemo improved median overall survival to roughly 74.7 months vs 25.6 months with chemo alone in newly diagnosed patients (RATIFY).
  • Quizartinib + chemo showed a median overall survival not yet reached vs roughly 15.1 months with chemo alone at the time of analysis (QuANTUM-First), in FLT3-ITD-positive newly diagnosed patients.
  • Gilteritinib, in the relapsed/refractory setting, improved median overall survival to 9.3 months vs 5.6 months with salvage chemotherapy (ADMIRAL) — a different population, so direct comparison across all three isn’t apples-to-apples.

Side effect and monitoring differences

MidostaurinQuizartinibGilteritinib
Boxed warningNoneQTc prolongation / cardiac arrestDifferentiation syndrome
GI toxicityCommon (nausea, vomiting)ModerateModerate
QTc monitoring neededLess intensiveVery intensive — REMS program requiredYes, required
MyelosuppressionPresentMore pronouncedPresent
Used alongside chemoYesYesNo (monotherapy)

Quizartinib’s QTc risk is significant enough that it’s only available in the US through a restricted REMS (Risk Evaluation and Mitigation Strategy) program requiring cardiac monitoring infrastructure.

Bottom line

These three drugs aren’t usually competing for the same decision — they’re sequential tools depending on disease stage and FLT3 subtype. If you’re newly diagnosed with FLT3-ITD, midostaurin or quizartinib (combined with chemo) would typically be discussed first. If you’re relapsing after prior FLT3-targeted therapy or weren’t on one initially, gilteritinib’s broader mutation coverage (including TKD/D835 resistance mutations) becomes particularly relevant.

Your specific FLT3 subtype (ITD vs TKD vs both), your prior treatment history, and your institution’s monitoring capabilities (especially for quizartinib’s cardiac requirements) will all shape which option your hematology team recommends — definitely worth mapping against your own pathology report.

FLT3 testing is essential before starting any FLT3-targeted therapy, and unlike EGFR testing in lung cancer, it’s typically done at diagnosis as part of standard AML workup — not as a separate add-on step.

What’s being tested

FLT3 (FMS-like tyrosine kinase 3) is a gene that, when mutated, drives uncontrolled growth of leukemic blasts. There are two clinically distinct mutation types, and the distinction matters for both prognosis and drug selection:

FLT3-ITD (internal tandem duplication) is a duplication of part of the gene, and is the more common and generally higher-risk mutation. The proportion of mutated to normal alleles (the “allelic ratio”) also matters — a high ratio is associated with worse prognosis.

FLT3-TKD (tyrosine kinase domain) mutations, most commonly at position D835, are point mutations in a different region of the gene. Gilteritinib covers both ITD and TKD; quizartinib covers ITD only.

Sample source

Testing is done on bone marrow aspirate (preferred) or peripheral blood if marrow isn’t immediately available. Since AML is a blood/marrow cancer rather than a solid tumor, there’s no equivalent of a “tissue biopsy” the way there is in lung cancer — the leukemic cells are already circulating or in the marrow.

How the lab analyzes it

  • PCR-based fragment analysis is the traditional method for detecting ITD mutations and calculating the allelic ratio
  • Next-generation sequencing (NGS) panels are increasingly standard, since they detect FLT3-ITD, FLT3-TKD, and other relevant AML mutations (NPM1, CEBPA, IDH1/2, TP53) simultaneously — important because these co-mutations significantly affect risk stratification and treatment choice
  • The FDA-approved companion diagnostics for gilteritinib and quizartinib are specific PCR-based assays validated for treatment-decision use

Timeline

This is one of the most time-pressured tests in oncology. AML is acute — treatment often needs to start within days of diagnosis. Most labs aim to return FLT3 results within 48–72 hours, sometimes faster at specialized centers, precisely because the decision to add midostaurin or quizartinib to induction chemotherapy needs to be made quickly. In practice, induction chemo sometimes starts before FLT3 results return, with the targeted agent added once results are confirmed.

What the result means for treatment

ResultWhat it typically means
FLT3-ITD positive (newly diagnosed)Midostaurin or quizartinib added to induction/consolidation
FLT3-TKD positive (newly diagnosed)Midostaurin may be added (quizartinib does not cover TKD)
FLT3 negativeFLT3 inhibitors not indicated; other risk-stratification markers guide treatment
FLT3 mutation at relapse (newly emerged or persistent)Gilteritinib considered for relapsed/refractory disease

Re-testing at relapse

Similar to EGFR testing in lung cancer, FLT3 status is re-checked at relapse even if the original diagnosis was FLT3-negative — mutations can emerge during treatment that weren’t present initially, and this newly acquired FLT3 mutation could open the door to gilteritinib even if it wasn’t an option at diagnosis.

Medical disclaimer: This page is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Osimertinib is a prescription medication that must only be used under the supervision of a qualified oncologist. Clinical outcomes data is drawn from published Phase III trials; individual results vary. Always consult your healthcare provider and refer to the full prescribing information before making any treatment decisions. Emergency: call your local emergency services or poison control immediately if you experience serious adverse effects.

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