Salvage Therapy Outcomes in a Historical Cohort of Patients With Relapsed or Refractory Acute Myeloid Leukemia

Background: The prognosis of patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) is poor, with no universal standard salvage therapy currently available for most patients. Novel therapies with efficacy in patient subsets often have limited activity in alternative subsets, resulting in a majority of patients not gaining benefit from these therapies. This study systematically evaluated patient outcomes in a large cohort of R/R AML patients from a single institution across all salvage therapy lines, up to and including the third line.

Patients and methods: Outcomes of R/R AML patients treated at a single institution (MD Anderson Cancer Center, Houston, TX) between 2002 and 2016 were entered into a central database. Eligible patients received one or more lines of salvage therapy after first occurrence of R/R AML. Patients who received second- or third-line salvage treatment were also included in the first salvage analysis. Eligible patients were ≥ 18 years old at time of initial AML diagnosis, with no central nervous system involvement.

Results: A total of 818 eligible patients received one or more lines of salvage therapy, 809 received second-line salvage therapy, and 397 received third-line salvage therapy. Complete remission rates decreased from 14% after first salvage therapy to 9% after second salvage therapy and 3% after third salvage therapy. Median overall survival was 6.30, 4.07, and 2.98 months after first, second, and third salvage therapies, respectively.

Conclusion: These data indicate that the best chance of obtaining long-term remission in AML is with a successful first induction. Strategies that improve initial response and decrease the likelihood of relapse should be pursued.