Notably, all patients who relapsed after consolidation chemotherapy were able to receive allogeneic HCT, suggesting that transplantation may be safely delayed in some patients until their first relapse.
“The results of this randomized clinical trial indicate that the probability of survival after [allogeneic] HCT is not superior to that of conventional consolidation chemotherapy” among patients 60 years or younger with intermediate-risk AML, the authors concluded.
However, two experts highlighted several caveats to the study, which suggest the results may not translate to current clinical practice.
The study was published online in JAMA Oncology.
Approximately 50%-70% of patients with AML who receive intensive induction chemotherapy for AML and achieve a first complete remission are referred for post-remission therapy.
While consolidation chemotherapy with high-dose cytarabine has shown a benefit for those with a favorable risk profile, patients considered high-risk with adequate performance status may be candidates for allogeneic HCT.
However, determining the optimal post-remission treatment option for patients who fall into the intermediate-risk category can be more challenging.
To compare outcomes among intermediate-risk patients, researchers from Germany conducted a multicenter trial, enrolling 143 adults aged 60 or younger with intermediate-risk AML who had achieved first complete remission or complete remission with incomplete blood cell count recovery following conventional induction therapy.
The patients, who had a mean age of 48.2 years, were randomly assigned to consolidation treatment with allogeneic HCT (n = 76) or chemotherapy with high-dose cytarabine (n = 67), with the option for salvage HCT in the case of relapse. Overall, 12 patients in the HCT group received one consolidation course of high-dose cytarabine after achieving complete remission to bridge until allogeneic HCT, while all other patients in this group received allogeneic HCT directly after induction therapy.
Overall, disease-free survival at 2 years was significantly higher in the allogeneic HCT group (69%), compared with the consolidation therapy group (40%; P = .001). And the cumulative incidence of relapse at 2 years in the allogeneic HCT group was also lower, at 20%, compared with 58% in the consolidation therapy group (P < .001).
The overall survival data, however, painted a slightly more complex picture. In the intention-to-treat analysis, the probability of survival at 2 years was similar between the allogeneic HCT group (74%, or 56 of 76 patients), compared with consolidation chemotherapy (84%, or 56 of 67 patients; P = .22).
In addition, the rates of nonrelapse mortality at 2 years were higher in the allogeneic HCT group (9%) versus chemotherapy (2%; P = .005).
Although the rate of nonrelapse mortality was higher with allogeneic HCT, the relatively low rate with each treatment strategies was “an important and rewarding finding,” the authors noted. “This achievement is clearly due to the availability of less toxic but still effective conditioning therapies and modern antiviral and antifungal prophylaxis.”
In addition, among the 41 patients who relapsed after consolidation chemotherapy, all received allogeneic HCT, and the authors observed no significant differences between the groups in terms of health-related quality of life measures.