What is the difference between Quizartinib and Giritinib?

Quizartinib) and Gilitinib (Gilteritinib) are both targeted drugs used to treat acute myeloid leukemia (AML) carrying FLT3 mutations, but they have certain differences in their mechanisms of action, indications, efficacy and drug resistance. They are all tyrosine kinase inhibitors (TKI), but their target selectivity is different, so they have their own characteristics in clinical application.

From the perspective of its mechanism of action, quizartinib is highly selective against FLT3-ITD mutations and has weak activity against FLT3-TKD mutations. Giritinib inhibits both FLT3-ITD and FLT3-TKD mutations, and its target is broader. In addition, giritinib can also inhibit other kinase pathways such as AXL, which may be helpful in delaying drug resistance. Therefore, giritinib is relatively more adaptable in dealing with the diversity of FLT3 mutations.

In terms of efficacy, studies have shown that giritinib has a better response rate in patients with relapsed or refractory FLT3mutated AML, and the overall survival (OS) is better than traditional chemotherapy. Quizartinib has shown a good response rate in newly treated elderly or frail AML patients, especially when combined with low-dose chemotherapy. Both have good application prospects in specific groups of people, but they cannot simply replace each other.

In general, although both quizartinib and giritinib target FLT3 mutationsAML, gilitinib has a more comprehensive target and is applicable to the population. It is wider and suitable for relapsed/refractory patients; while quizartinib is more preferred as a combination treatment option for patients with specific mutations (FLT3-ITD) and treatment-naïve patients. The specific choice of drug should be determined by the hematologist after evaluation based on the patient's mutation type, disease status, and previous treatment options.

Reference materials:https://go.drugbank.com/drugs/DB12874