Gilteritinib a potential treatment option for FLT3-mutated relapsed, refractory AML

Patients with relapsed or refractory (R/R) FLT3-mutated acute myeloid leukaemia (AML) and with prior exposure to tyrosine kinase inhibitors (TKIs) may benefit from gilteritinib treatment, which leads to better remission and survival outcomes than salvage chemotherapy (SC), a recent study has found.

Researchers drew from the CHRYSALIS (n=145) and ADMIRAL (n=247) trials, which enrolled adult patients with R/R FLT3-mutated AML. In the respective trials, 33 (22.8 percent) and 33 (13.4 percent) gilteritinib-treated patients had had prior lines of TKI treatment.

Gilteritinib appeared to be an effective treatment for this patient population. In the ADMIRAL trial, for instance, researchers noted a trend toward longer median overall survival in patients with prior TKI exposure who were treated with gilteritinib vs SC (8.7 vs 5.1 months; hazard ratio [HR], 0.602, 95 percent confidence interval [CI], 0.299–1.210). This effect was stronger and reached significance in those who had no previous TKI exposure (9.5 vs 6.1 months; HR, 0.631, 95 percent CI, 0.482–0.841).

In terms of treatment response, the researchers reported that more than 40 percent of gilteritinib-treated patients in both the CHRYSALIS (42 percent) and ADMIRAL (52 percent) trials, after previous TKI therapy, achieved composite complete remission. A similar effect was reported among those without prior TKI exposure (CHRYSALIS: 43 percent; ADMIRAL: 55 percent).

“As the use of FLT3 TKIs such as midostaurin becomes more prevalent in the frontline setting, physicians may still consider using gilteritinib as a subsequent FLT3-targeted therapy in the R/R AML setting. Further studies in a larger patient population will help validate these findings and determine the molecular profile(s) of patients for whom gilteritinib as a second FLT3 TKI therapy at relapse fails to improve outcomes relative to alternate regimens,” the researchers said.