FDA Grants Priority Review to Quizartinib for Newly Diagnosed FLT3-ITD+ AML

Based on findings from the QuANTUM-First trial (NCT02668653), the FDA has granted priority review to quizartinib (Japanese trade name: Vanflyta) in combination with standard cytarabine and anthracycline induction followed by consolidation cytarabine and continuation of quizartinib monotherapy after consolidation in patients with newly diagnosed FLT3-ITD­–positive acute myeloid leukemia (AML), according to a press release from Daiichi Sankyo.

The decision was based on data presented at the 2022 European Hematology Association (EHA) Congress. In the QuANTUM-First trial, the quizartinib regimen demonstrated a statistically significant and clinically meaningful benefit to overall survival (OS) among patients with newly diagnosed FLT3-ITD–positive AML compared with chemotherapy alone. The prescription drug use fee act date has been set for April 24, 2023.

“There is a need for new targeted therapy options for patients with [AML] and the results of the QuANTUM-First trial showed that quizartinib in combination with standard chemotherapy has potential to change the current standard of care for newly diagnosed patients with the historically difficult-to-treat FLT3-ITD subtype,” Ken Takeshita, MD, global head and R&D at Daiichi Sankyo, said in the press release. “The FDA’s prioritization of this application reflects the importance of the data, and we will continue to work with the FDA and other global regulatory authorities to support the review of quizartinib for the treatment of patients with newly diagnosed FLT3-ITD–positive [AML].”

In the study, patients received induction for up to 2 cycles with cytarabine and daunorubicin/idarubicin followed by quizartinib or placebo. Consolidation cytarabine was given for up to 4 cycles followed by quizartinib or placebo and/or hematopoietic stem cell transplant; continuation lasted up to 36 cycles with quizartinib or placebo.

The primary end point of the QuANTUM-First study was OS. Secondary end points included event-free survival, complete remission rate, and safety.

Patients with FLT3-ITD–positive newly diagnosed AML between the ages of 18 to 75 years old were eligible to enroll on the study. Additionally, patients were required to have an ECOG performance status of 0 to 2, reception of standard “7+3” induction chemotherapy, adequate renal function and hepatic function, and serum electrolytes within normal limits. Patients were excluded from enrolling if they had a secondary AML diagnosis following prior chemotherapy for other neoplasms and prior treatment for AML with the exception of several treatments such as treatment for leukapheresis, hyperleukocytosis with hydroxyurea, and cranial radiotherapy for central nervous system metastases. Prior treatment with quizartinib or similar FLT3-ITD inhibitors and previous treatment with any experimental regimens or devices 30 days prior to drug randomization were also not allowed.

Investigators on the QuANTUM-First trial reported no new safety signals and that the agent yielded a generally manageable safety profile. Incidence of grade 3 or higher QT prolongation was infrequent, and ventricular arrythmia events were uncommon. Risk of QT prolongation was manageable with the use of ECG monitoring, dose modifications of quizartinib, and the elimination of additional risk factors in the study.

Reference

Quizartinib granted priority review in the U.S for patients with newly diagnosed FLT3-ITD positive acute myeloid leukemia. News release. Daiichi Sankyo. October 24, 2022. Accessed October 24, 2022. https://bit.ly/3N2RPQs