What the label lists and what reports show
Quizartinib side effects
Quizartinib's FDA label: “The most common (>20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, potassium decreased, albumin decreased, phosphorus decreased, alkaline phosphatase increased, magnesium decreased, febrile neutropenia, diarrhea …” FAERS holds 634 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is nausea (43 reports).
- No generic listed
- Boxed warning
Check it at the source: the quizartinib FDA label on DailyMed (effective April 16, 2026, Daiichi Sankyo Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of VANFLYTA?VANFLYTA may cause serious side effects, including: See " What is the most important information I should know about VANFLYTA? " The most common side effects of VANFLYTA include: low white blood cell counts changes in levels of electrolytes in the blood changes in liver function tests low white blood cell counts with fever diarrhea mouth sores nausea stomach (abdominal) pain serious infection throughout the body and organs (sepsis) headache vomiting upper respiratory tract infections low platelet counts decreased appetite fungal infections nosebleed herpesvirus infections trouble sleeping abnormal electrocardiogram (QT prolongation) upset stomach low red blood cell counts (anemia) eye irritation Your healthcare provider will do blood tests and ECGs before you start and during treatment with VANFLYTA. […]
Source: FDA drug label, Daiichi Sankyo Inc., effective April 16, 2026 (SPL set 29cdbcfe-497d-4e78-bb7b-2d4acafe8e86), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common (>20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, potassium decreased, albumin decreased, phosphorus decreased, alkaline phosphatase increased, magnesium decreased, febrile neutropenia, diarrhea, mucositis, nausea, calcium decreased, abdominal pain, sepsis, neutropenia, headache, creatine phosphokinase increased, vomiting, and upper respiratory tract infection.
Table 5: Adverse Reactions (≥10%) in Patients with Newly Diagnosed FLT3-ITD positive AML Who Received VANFLYTA (with a Difference Between Arms of ≥2% Compared to Placebo) in the Clinical Trial
| Reaction | All Grades % | Grade 3 or 4 % | All Grades % | Grade 3 or 4 % |
|---|---|---|---|---|
| Febrile neutropenia Including fatalities. | 44 | 43 | 42 | 41 |
| Neutropenia Includes other related terms. | 29 | 26 | 14 | 12 |
| Thrombocytopenia | 18 | 13 | 13 | 12 |
| Anemia | 11 | 6 | 7 | 5 |
| Diarrhea Diarrhea includes colitis, diarrhea, enteritis, enterocolitis, gastroenteritis,… | 42 | 8 | 39 | 8 |
| Mucositis Mucositis includes anal inflammation, anal ulcer, anorectal discomfort,… | 38 | 5 | 33 | 4.1 |
| Nausea | 34 | 1.5 | 31 | 1.9 |
| Abdominal pain | 30 | 2.3 | 22 | 1.1 |
| Vomiting | 25 | 0 | 20 | 1.5 |
| Dyspepsia | 11 | 0.4 | 9 | 0.7 |
| Sepsis Sepsis includes acinetobacter infection, bacteremia, bacterial sepsis,… | 30 | 19 | 26 | 20 |
| Upper respiratory tract infection | 21 | 2.6 | 12 | 3 |
| Fungal infection Fungal infection includes aspergillosis oral, aspergillus infection,… | 16 | 6 | 10 | 3 |
| Herpesvirus infection Herpesvirus infection includes disseminated varicella zoster virus… | 14 | 2.6 | 8 | 1.9 |
| Headache | 28 | 0 | 20 | 0.7 |
| Hypertransaminasemia Hypertransaminasemia includes alanine aminotransferase increased,… | 19 | 7 | 14 | 6 |
| Decreased appetite | 17 | 4.9 | 13 | 1.9 |
| Epistaxis | 15 | 1.1 | 11 | 0.4 |
| Insomnia | 14 | 0 | 11 | 0 |
| Electrocardiogram QT prolonged | 14 | 3 | 4.1 | 1.1 |
| Eye irritation Eye irritation includes dry eye, eye inflammation, eye irritation, eye… | 11 | 0 | 7 | 0 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: QT Prolongation, Torsades de Pointes, and Cardiac Arrest [see Warnings and Precautions (5.1) ] The most common (>20%) adverse reactions, including laboratory abnormalities, are lymphocytes decreased, potassium decreased, albumin decreased, phosphorus decreased, alkaline phosphatase increased, magnesium decreased, febrile neutropenia, diarrhea, mucositis, nausea, calcium decreased, abdominal pain, sepsis, neutropenia, headache, creatine phosphokinase increased, vomiting, and upper respiratory tract infection. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Daiichi Sankyo, Inc. at 1-877-437-7763 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. …
Source: FDA drug label, Daiichi Sankyo Inc., effective April 16, 2026 (SPL set 29cdbcfe-497d-4e78-bb7b-2d4acafe8e86), via openFDA; the full label on DailyMed
What do FAERS reports show?
634 reports list quizartinib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 100 are coded as a death and 217 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 19 reactions below, 8 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Quizartinib: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions