The U.S. Food and Drug Administration (FDA) approved Daiichi Sankyo’s Vanflyta® (quizartinib) tablets on July 20, 2023. It is indicated for the initial treatment of adults who have acute myeloid leukemia (AML) that tests positive for internal tandem duplication mutations in FMS-like tyrosine kinase 3 (FLT3-ITD). To be used in combination with cytarabine and anthracycline for induction, and with cytarabine for consolidation; it also can be taken by itself for maintenance. Recommended dosing for induction is 35.4mg (two 17.7mg tablets) daily for 14 days beginning on the eighth day of up to two 28-day cycles. For consolidation, daily 35.4mg doses start on day six and last for the next 14 consecutive days for as many as four 28-day cycles. For most patients, the maintenance dose is 26.5mg on the first 14 days of the first cycle, increased to 53mg (two 26.5mg tablets) on day 15, and then continued at 53mg once a day for as long as three years. A risk evaluation and mitigation strategy (REMS), a patient Medication Guide, and a boxed warning are required because Vanflyta may cause abnormalities in heart function. Its launch is planned in the next few weeks at a wholesale acquisition cost (WAC) of $546 per tablet of either strength. Look here for prescribing information.
At a Glance
- Brand (Generic) Name: Vanflyta (quizartinib)
- Manufacturer: Daiichi Sankyo
- Date Approved: 17.7mg and 26.5mg oral tablets
- Indication: for the treatment of adult patients newly diagnosed to have AML that is FLT3-ITD-positive as detected by an FDA-approved diagnostic test
- Dosage Forms Available: 17.7mg and 26.5mg oral tablets
- Launch Date: Within the coming weeks
- Estimated Annual Cost: WAC for maintenance therapy is approximately $399,000 per year.
- AML is diagnosed by about 20,000 U.S. patients per year – mostly older adults. Around one-third of cases have FLT3-ITD mutations, which typically raise the chances of relapses and shorten five-year survival rates to only around 20%.
- Vanflyta blocks the effects of type II FLT3, a protein that helps cancer cells grow.
- In a clinical trial that included 539 patients who all received standard induction and consolidation treatment, the complete remission (CR) rate was 55% for patients taking Vanflyta as well as for those taking chemo alone. CR lasted an average of 38.6 months for the group taking Vanflyta, however; compared to 12.4 months for the participants taking chemo alone. In the study, adding Vanflyta to chemo reduced the risk of death by 22%.
- Vanflyta has a REMS, a patient Medication Guide, and a boxed warning because some patients experienced QT prolongation, torsades de pointes, or cardiac arrest while using it. Patients should have electrocardiograms (ECGs) before beginning Vanflyta treatment, and then once a week during induction, consolidation, and the first month of maintenance. They also should be checked frequently for low blood levels of potassium and magnesium.
- Other relatively common adverse effects can include diarrhea, headache, insomnia, low blood cell counts, nausea, sepsis, and other infections.
- Two other FLT3 inhibitors are FDA approved for treating AML. Rydapt® (midostaurin – Novartis) is used for first-line treatment and Xospata ® (gilteritinib – Astellas Pharma) for treating relapsed or recurrent cases.
- A Breakthrough Therapy, Vanflyta also received the FDA’s Priority Review and Fast-Track processing.