OBJECTIVES: The MORPHO trial evaluating the FLT3 inhibitor gilteritinib as post-transplant maintenance for patients with acute myeloid leukemia (AML) with a FLT3 internal tandem duplication mutation (FLT3+) demonstrated clinical benefit for 50% of patients with detectable minimal residual disease (MRD). Despite positive findings, there are clinical challenges with MRD testing and FLT3 inhibitors. FLT3+ mutations are age-associated with a prevalence of around 10% in pediatric patients and over 30% in patients over 55 years of age. This study explored providers’ perceptions and prescribing behavior related to MRD testing and FLT3 inhibitor utilization for patients with AML.

METHODS: US hematologists and oncologists attending an in-person forum in October 2023 provided a panel where they answered questions on clinical practice and healthcare trends. Not all participants answered every question. Data were analyzed using descriptive statistics.

RESULTS: Up to 57 respondents responded to AML questions and 64% reported they test for FLT3+ mutations at initial diagnosis and relapse. The two most frequently cited barriers to MRD testing were a lack of guidelines (48%) and availability of testing (29%). Twenty five percent of respondents reported no barriers to MRD testing. Twenty-four percent of respondents use gilteritinib as a maintenance treatment following transplantation in patients with AML. After reviewing findings from MORPHO, 75% of respondents reported that they will prescribe gilteritinib to patients with FLT3+ (only among MRD-positive cases among 52% of respondents and for most of their patients regardless of MRD status among 13%). Respondents perceived older (61%) and transplant-ineligible (61%) patients as populations with greatest unmet need in AML.

CONCLUSIONS: The lack of guidelines and availability of MRD testing may contribute to reduced gilteritinib usage in patients with FLT3+ and may further contribute to an unmet need in an older patient population that express higher levels of FLT3+.