What is maintenance therapy for AML? What drugs are currently being used for maintenance therapy?

What is maintenance therapy for AML? I think of maintenance therapy as the therapy that one gets after someone has completed their intensive chemotherapy for their acute myeloid leukemia. That is intensive induction and intensive consolidation. And maintenance is usually a low intensity treatment, and by low intensity I mean a treatment that is easy to take, doesn't cause significant side effects. And the purpose of maintenance therapy is to maintain the remission, that is to keep the patient from relapsing. Yeah, so maintenance therapy would be some treatment that's given after a patient is in remission. So we're familiar with that from other types of diseases. In AML, maintenance therapy has been tested for many years, but it's a newer part of the therapy. You know, there's other leukemias like ALL or pediatric ALL, specifically where maintenance has for a long time been a part of the regimen. And so we know for acute leukemias it can work. For AML though, I think the difficult part is finding the right regimen that works, And so far it's not as advanced as in other types of leukemias or even other cancer types. So maintenance therapy is anything that can improve your overall survival. And one could argue that transplantation used to be or can be considered a maintenance therapy, although a very, very aggressive therapy, because the goal of that treatment is not to cure the disease, but to keep it from coming back. Now of course, transplant is not something that can be offered to every single person and it is a very aggressive therapy. So the goal of modern maintenance therapy or people who cannot have aggressive therapies like allogeneic stem cell transplantation is to have a usually less intense therapy that can help improve their overall survival while minimizing side effects and improving quality of life. Maintenance therapy. We have one FDA approved drug for maintenance therapy in patients who have gotten intensive chemotherapy and then not had a transplant. Let's say you get your intensive induction chemotherapy and then you either get consolidation or you don't get consolidation for whatever reason. There's a maintenance therapy called CC486. The trade name is Onyureg, which is an oral hypomethylating agent that patients take daily continuously, actually it's 14 days on, 14 days off, that they take and the goal of that therapy is to maintain the remission. There are other therapies that we think about using after an allogeneic stem cell transplant. So there are FLIT3 inhibitors that we often use in patients who've had a stem cell transplant with a FLIT3 mutation and after the transplant we give them FLIT3 inhibitors to maintain the remission and there are certain settings that even if you don't have a transplant, we might give a FLIT3 inhibitor as a maintenance treatment. So they're usually less intensive drugs. Azacitidine, this is a hypomethylene agent that can be used in the frontline treatment of MDS or AML. For AML it's now used in combination with venetoclax if you're using it in the frontline, but in the maintenance setting it's used by itself and at lower doses or longer intervals in between and one of the newer types of treatments is an oral form of azacitidine so you can take it as a pill form. You don't have to get it as an injection as it's usually given for the treatment of AML or MDS. There are also some other targeted agents being tested such as FLIT3 inhibitors, but I would say the most common one in use or being tested is the azacitidine or other hypomethylene agents. So the best studied and most established at this time and the only FDA approved agent is oral azacitidine or the brand name is Onyureg. This drug was approved a few years ago for patients in a very very particular niche. So folks who had received induction therapy or some sort of a more intensive therapy but then were ineligible to go forward with allogeneic stem cell transplantation. This drug in particular has good effects in terms of improving overall survival in patients who cannot have this more aggressive therapy. Whether they have a low level of disease that we call minimal residual disease or not, so in both settings, but there are other drugs as well in other niche populations. For example, there is a maintenance agent called seraphenib that has been around for a long time but is primarily used in the post transplant setting to try and avoid recurrence of FLIT3 mutated AML.