In short
Quizartinib is a targeted cancer medicine that blocks the FLT3 protein, which drives the growth of some acute myeloid leukaemia (AML) cells. It is approved in the United States for adults with newly diagnosed AML that carries the FLT3-ITD genetic mutation. In the European trial registry, quizartinib is being studied in a Phase 3 trial involving 365 participants with AML or chronic lymphocytic leukaemia (CLL).
Key points
- Quizartinib is a targeted therapy that blocks the FLT3 protein in cancer cells.
- It is approved by the FDA for adults with newly diagnosed AML that has the FLT3-ITD mutation.
- A Phase 3 trial in the EU registry is studying quizartinib in 365 participants.
- The trial includes people with acute myeloid leukaemia (AML) and chronic lymphocytic leukaemia (CLL).
- In the QuANTUM-First trial, median overall survival was 31.9 months with quizartinib compared to 15.1 months with placebo.
What is quizartinib?
Quizartinib is a targeted cancer medicine known as a FLT3 inhibitor. It is a chemically synthesised, small-molecule substance that belongs to the therapeutic area of blood and lymphatic diseases. The medicine is also known by its trade name Vanflyta and its chemical name quizartinib dihydrochloride. In the United States, quizartinib is approved by the Food and Drug Administration (FDA) for adults with newly diagnosed acute myeloid leukaemia (AML) that carries the FLT3-ITD genetic mutation. It is manufactured by Daiichi Sankyo.
How does quizartinib work?
The FLT3 protein is a tyrosine kinase receptor found on blood-forming stem cells. In its normal form, FLT3 helps cells survive, grow and differentiate. When the FLT3 gene has a mutation called internal tandem duplication (ITD), the protein is constantly switched on, which drives the uncontrolled growth of leukaemia cells. Quizartinib blocks this mutated FLT3 protein, which helps slow or stop the growth of cancer cells. About a quarter of people with AML carry the FLT3-ITD mutation.
Which conditions is quizartinib used or studied for?
- Acute myeloid leukaemia (AML) — a fast-growing cancer of the blood and bone marrow. Quizartinib is approved in the US for newly diagnosed AML with the FLT3-ITD mutation and has been studied in AML that came back after treatment.
- Chronic lymphocytic leukaemia (CLL) — a slower-growing blood cancer affecting white blood cells. A Phase 3 trial in the EU registry includes people with CLL.
- Small lymphocytic lymphoma (SLL) — a related condition that is also included in the same Phase 3 trial.
How is quizartinib given?
Quizartinib is taken by mouth as a tablet. In the EU trial registry, the oral dose listed is 35.4 mg. The medicine is available in the UK as film-coated tablets in strengths of 17.7 mg and 26.5 mg under the brand name Vanflyta. In the QuANTUM-First trial, quizartinib was given together with standard chemotherapy and then continued alone as maintenance treatment.
What do the clinical trials show?
One Phase 3 trial in the EU Clinical Trials Information System (CTIS) is studying quizartinib. The trial, identified as 2024-512503-39-00, is authorised and plans to enrol 365 participants. It has two separate arms: Arm A includes people with newly diagnosed AML or myelodysplastic syndrome, while Arm B includes people with CLL or SLL. In Arm A, the trial measures how often people achieve measurable residual disease (MRD)-negative complete remission after one to two cycles of standard induction chemotherapy. In Arm B, it measures how often people achieve undetectable MRD after seven or nine cycles of treatment. The trial also compares overall survival between people who receive a stem cell transplant and those who do not.
A separate Phase 3 trial called QuANTUM-R studied quizartinib in people with AML that had got worse during treatment or come back after treatment. This trial was open between 2014 and 2017, and results were published in 2019 and 2021. The QuANTUM-First trial, which supported the FDA approval, involved over 500 people with newly diagnosed AML and the FLT3-ITD mutation. People who received quizartinib with standard chemotherapy had a median overall survival of 31.9 months, compared with 15.1 months for those who received placebo. This represented a 22.4% reduction in the risk of death.
What side effects are known?
Quizartinib carries a boxed warning from the FDA for QT prolongation, torsades de pointes and cardiac arrest — serious heart rhythm problems. Because of these risks, the medicine is only available in the US through a special programme called the Vanflyta REMS. The most common side effects reported in the QuANTUM-First trial were not fully listed in the available source, but the heart rhythm risks are the main safety concern highlighted by regulators.