How do I know treatment is working?

How do I know treatment is working? The easiest way to see whether or not treatment for myelodysplastic syndrome is working is to look at the blood counts. If a person starts out with anemia and all of a sudden the hemoglobin rises from 8 to 9 to 10 to 11 to 12, you know the treatment is probably working and a person will feel that. Some of my patients will reflect back to me that they feel normal for the first time in months or even a year as their hemoglobin starts to rise. That actually happened just a couple days with a patient of mine in clinic. Another way we check to see if a treatment is working is by checking another bone marrow biopsy, particularly patients who have too many blasts in their bone marrow to start with. It's normal to have less than 5% blasts. Some people with myelodysplastic syndromes may have 5, 10, 15% blasts in the bone marrow. If we check another bone marrow after treatment and that blast percentage shrinks to less than 5%, we know that a treatment is working as well. So MDS as opposed to AML, the treatment can take a little while longer to work. So now specifically talking about azacytidine, another thing that we commonly see is the treatment is not tried long enough. So it can take up to four cycles of treatment. These are monthly cycles, so it's given for typically seven days. After that it takes another 21 days. So if you go for around 28 days or a month for the complete treatment to finish, so it would be four months of those before we might expect to see a response. So there's even evidence that some patients respond after that, so up to six cycles. I think what we see, I quoted that 60% response rate from the clinical trials, but in actual practice we see a little bit lower responses and that may be from the cases where it's stopped too early and if the treatment had been continued for at least four cycles, but if able to get to six just to exclude that there's going to be any response, I think we would see more similar to the clinical trials of a 60% response rate. So yeah, it does take a little while longer. This azacytidine, it's an epigenetic drug and so we know with epigenetic drugs they can take a while longer to actually show the response. So we talked a little bit about genetics. These are mutations seen in the DNA of the leukemia cells. Genetics literally means above the DNA, so these are not changes to the DNA, they're marks on the DNA, we call it methylation, or on the organization of the DNA, the chromatin. If there's changes in those, those can impact the DNA expression, so when I say epigenetic it means something that's targeting those mechanisms, not directly the mutations themselves.