Management of a number of hematological malignancies like acute lymphoblastic leukemia has included a maintenance phase, and this has been going on for several decades. In AML, we haven’t been using maintenance strategies as a standard of care. However, there have been a number of attempts to design or develop maintenance strategies using a variety of agents. And I think over the years, because of the fact that many of these agents have toxicity and also because none of the strategies have been proven on a randomized trial, a maintenance therapy had not been used in acute myeloid leukemia...
Management of a number of hematological malignancies like acute lymphoblastic leukemia has included a maintenance phase, and this has been going on for several decades. In AML, we haven’t been using maintenance strategies as a standard of care. However, there have been a number of attempts to design or develop maintenance strategies using a variety of agents. And I think over the years, because of the fact that many of these agents have toxicity and also because none of the strategies have been proven on a randomized trial, a maintenance therapy had not been used in acute myeloid leukemia.
I think the agents decitabine and azacitidine over hypomethylating agents have been a very good candidate for such maintenance therapy for two reasons. One, that they are relatively non-toxic, and two, they do have significant activity in myeloid neoplasms. So there’ve been a number of attempts to use these agents in their usual administration format, which is either intravenous or subcutaneous, but the studies have not been able to accrue enough patients to definitively show the role of maintenance.
The QUAZAR AML-001 study, which used oral azacitidine or CC-486 as a maintenance strategy in patients above age 55 who had received traditional ara-C and anthracycline-based induction followed by one to three consolidations, did show a benefit for these patients who were deemed not candidates for allogeneic stem cell transplant.
So, this has now been established in the US and as an FDA approved strategy for maintenance therapy after initial induction and consolidation in patients who are not candidates for transplant. There are a few patients on that study who did receive transplant, but this did not affect their outcome adversely.
Of course, post-transplant strategies are also of interest nowadays. Probably the furthest along are the FLT3 inhibitors. Studies from Germany and China have shown the efficacy of sorafenib in post-transplant setting in FLT3-mutated AML in terms of increasing at least relapse-free survival and perhaps overall survival. And there are also potential future studies using the oral hypomethylating agent. AMADEUS study, which is looking at CC-486 in the post-transplant setting and is currently accruing patients. And I think maintenance therapy is here to stay. And we are going to use more different strategies now that we have a number of orally active and non-toxic agents that can potentially be used even in the post-transplant setting.