On Tuesday of this week, George had his 100 day post-transplant bone marrow biopsy (even though he was only 95 days post-transplant).

Everything went well and when he was wheeled back into the recovery room, he was OUT. He slept until it was time to leave. No graham crackers and juice for this guy!

Before we left the hospital, we stopped in at the cafe and got something to eat, because…that’s right…George can now eat restaurant food (no fast food though)!! We learned this at his appointment with Jackie prior to the bone marrow biopsy. We also learned that his tacrolimus (immunosuppressant drug) will be tapered down some more and because of that, his magnesium transfusion will go down by half. So he will only need to sit with the infusion bag for 2 hours instead of 4!



We are so happy with these steps in George’s treatment. Less time on the magnesium really frees up time in his day! Lowering the tacrolimus used to scare George, because once the immunosuppressant is lowered, the immune system is free to wake up a bit and the donor marrow cells could look around and see that it’s in this foreign body and attack it, causing Graft Vs Host Disease (gvhd). But, if you’ll remember, George was worried that his chimerism numbers had gone down. Jackie explained that it could be because the tacrolimus is holding them back. So, theoretically, backing off the tacrolimus may remove some restraint and allow George’s donor cells to start growing again, and George is excited by that prospect. He may develop a little gvhd, but almost everyone does and it’s treatable and manageable. So, it’s kind of a trade off. They did take labs on this visit to test for his chimerism numbers and we are anxiously awaiting the results. She also said if his chimerism numbers dip again, we may have to go back to the donor for more marrow for a boost! She said when the donor donated his marrow, he agreed to three requests. Again, BLESS HIM. That may be all that’s needed to get to that 100% chimerism, which is what we want and need!

So, why the pink tennis ball? It’s an image we now keep in our minds whenever we get a bone marrow biopsy taken. Dr. Loren explained to us that they have immense confidence in their testing procedures and the accuracy of them, but there’s always a slight chance that they could miss something. She explained it like this:
Imagine you have an Olympic sized swimming pool full of yellow-green tennis balls. But there are also one or two pink tennis balls in there. Whenever you do a bone marrow biopsy, it’s like taking an excavator and scooping up a sample of tennis balls. (The yellow-green tennis balls are good blood cells and the pink ones are leukemia cells, just to be clear!) It is entirely possible to take a sample of yellow-green balls that does not include a pink ball, giving you a false impression that you’re in full remission.
So, when we got the initial results below from George’s bone marrow biopsy, we were relieved, and cautiously optimistic. We are now awaiting the results of the cytogenetic analysis (analysis of his bone marrow on a molecular level).

So, for now while we are hoping there are only yellow-green tennis balls in George’s body and he started a treatment, called Xospata, to specifically target his FLT3 genetic mutation. People who have AML with certain FLT3 mutations often have aggressive disease and poor overall survival. It’s the main reason George had the bone marrow transplant instead of just being treated by chemo alone. The mutations in the FLT3 gene cause the FLT3 protein to always be active in leukemia cells, which can fuel their proliferation and survival. This is why researchers have considered FLT3 to be a good target for cancer treatment.

Gilteritinib (the generic name for Xospata),is a type of targeted cancer therapy called a tyrosine kinase inhibitor. It kills leukemia cells by binding to the mutant FLT3 protein and blocking its activity. It was just approved by the FDA in 2018 and became available in 2019, so we are very thankful this treatment is available to George! But more on that in the next blog.
Again – thanks to all those who follow, support, encourage and love George. It means the world
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