Promising Results for Crenolanib with Intensive Chemotherapy in Adults with FLT3-Mutated AML

A study recently published in the Journal of Clinical Oncology examined the safety and efficacy of crenolanib alongside intensive chemotherapy in adults newly diagnosed with FLT3-mutated acute myeloid leukemia (AML).

AML is a type of blood cancer that starts in the bone marrow and affects the production of blood cells. It is more common in older adults but can also affect younger adults and children. AML is characterized by a buildup of immature white blood cells that crowd out healthy blood cells.

Mutations in the FLT3 gene are common in AML, occurring in around 30% of cases, and tend to be associated with poorer outcomes.

There is no staging system for AML, and the treatment strategy depends on various factors such as subtype, spread of the cancer, patient age and other patient-specific factors. Treatment may include chemotherapy, stem cell transplant, and targeted therapies such as FLT3 inhibitors for certain mutated forms of AML. Despite recent advancements in treatment options, there is still a high risk of relapse in FLT3-mutated AML.

Now, a group of researchers including lead author Eunice Wang, M.D., chief of the leukemia service at Roswell Park Comprehensive Cancer Center in Buffalo, New York, have published a paper detailing promising results of a phase two trial of adults with newly diagnosed FLT3-mutated AML. The study, funded by Arog Pharmaceuticals, aimed to assess the utility of crenolanib along with intensive chemotherapy.

The trial involved 44 patients with FLT3-mutated AML ranging from 19 to 75 years of age. The patients received crenolanib in conjunction with induction chemotherapy, followed by consolidation therapy and potentially stem cell transplant. The results showed an overall complete remission rate of 86% (90% in younger adults and 80% in older patients).

The study reported favorable survival outcomes, with a median overall survival that had not been reached at a 45-month follow-up. Among adults ages 60 years and under, the estimated 3-year survival rate was 71.4% with a low rate of relapse at 15%. Participants 60 years and younger patients generally had a higher survival rate, with over 50% still alive after four years of follow-up. Older patients experienced more toxicities and dose reductions.

“We think that this data is highly promising, and that this regimen should be explored particularly for those younger [adult] patients,” Wang told MHE in an interview.

The combination of crenolanib and intensive chemotherapy demonstrated acceptable safety, with common adverse events including febrile neutropenia, diarrhea, and nausea.

Wang discussed some of the distinguishing qualities known so far about the new drug compared to existing FLT3 inhibitors, such as midostaurin (Rydapt). She highlighted that no evidence of cardiac issues or prolonged suppression of blood counts was seen with crenolanib. She also noted the new drug’s short half-life, which meant that side effects were generally short-lived, allowing patients to resume treatment relatively quickly. Wang also pointed out that this drug was safe to take on a continuous schedule, unlike other FLT3 inhibitors that have dosing limitations.

Overall, these findings suggest that crenolanib in combination with intensive chemotherapy may be a promising treatment option for adults with newly diagnosed FLT3-mutated AML. A randomized phase three trial is underway to compare crenolanib to other standard treatments, with an anticipated completion date later this year.