Newly Diagnosed Mutant-IDH2 AML: Enasidenib Plus Azacitidine Under Study
Posted: Monday, November 1, 2021
Patients with newly diagnosed mutant-IDH2 acute myeloid leukemia (AML) who are not eligible for intensive chemotherapy may benefit from combination therapy using azacitidine plus the IDH2 inhibitor enasidenib, according to a phase Ib/II trial conducted by Hartmut Döhner, MD, of the University Hospital of Ulm, Germany, and colleagues. In fact, enasidenib plus azacitidine appeared to double the likelihood of achieving overall response versus azacitidine alone. The initial findings of this open-label, multicenter, international trial were published in The Lancet Oncology.
“Combination therapy with enasidenib plus azacitidine was safe, generally well tolerated, and efficacious in adult patients with newly diagnosed, mutant-IDH2 AML who were ineligible for intensive chemotherapy. The overall response rate with enasidenib and azacitidine in combination was greater than historical response rates for either agent when used as monotherapy,” stated the study investigators.
Patients with newly diagnosed mutant-IDH2 AML with an Eastern Cooperative Oncology Group performance status of 0 to 2 were enrolled (n = 107). The phase Ib dose-finding portion of the study indicated that no dose-limiting toxicities occurred with 100 mg of enasidenib (n = 6). In phase II, patients were randomly assigned to receive either enasidenib plus azacitidine (n = 68) or azacitidine alone (n = 33).
A total of 74% of patients in the enasidenib-plus-azacitidine group achieved an overall response, compared with 36% of patients in the azacytidine-monotherapy group, at the median follow-up of 14.9 and 13.7 months, respectively (95% confidence interval [CI] = 2.0–11.9 months, P < .000). Common treatment-related grade 3 or 4 adverse events such as neutropenia, anemia, and febrile neutropenia appeared to be similar across the study groups. Thrombocytopenia was observed in 37% of patients given the combination therapy versus 19% of those given monotherapy. Serious treatment-related adverse events such as febrile neutropenia, differentiation syndrome, and pneumonia did not appear to differ across the study groups, and no treatment-related deaths were reported.
Disclosure: For full disclosures of the study authors, visit thelancet.com.