Diagnosis: Acute Myeloid Leukemia (AML). A Journey

Ok, so maybe they are more like peach or salmon colored. They are called gilteritinib (Xospata) and they are used to as a targeted therapy against the FLT3 mutation in leukemia patients.

I talked a little about FLT3 in my previous post, but as a refresher, 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. FLT3 is the most common gene change, or mutation, in leukemia cells. The FLT3 gene contains instructions for a protein called FLT3, which helps white blood cells grow. Mutations in the FLT3 gene cause the FLT3 protein to always be active in leukemia cells, which can fuel their proliferation and survival. The FLT3 gene is expressed in normal bone marrow cells and regulates the orderly growth of blood cells in response to daily demands. When the gene is mutated in a leukemia cell, however, the cancer cells grow in an uncontrolled manner unless the function of FLT3 is turned off by drugs like gilteritinib.

If you read about gilteritinib (Xospata) online, you’ll read that it’s used to treat relapsed or refractory cases of AML with FLT3 mutation. George has neither. But, Jackie told us they prescribe it post-transplant as maintenance therapy for anyone with FLT3. She said it’s considered “standard of care” and it’s approved by the FDA, which is great because it’s not cheap and we definitely need the insurance to approve and cover it! Jackie said George will probably take it for 3-5 years!

When we first got the report of George’s molecular analysis from his first bone marrow biopsy in January 2022 and the doctor told us he had the FLT3 mutation, they said that he went from a good risk to a poor risk and that was hard to hear. Without transplant, survival rates are about 20%, compared to 50% for leukemia without the mutation. Knowing there is a targeted therapy against this mutation that was just approved in 2018 gives us some hope and comfort should George’s leukemia return, which we are praying it never, ever does!

Obviously, a lot of the information about FLT3 and the clinical trials that led to the Xospata George is taking is above my pay grade! But I have gathered enough to know a few things, besides what I wrote above.

• This is a type of chemo, but it will not attack all his fast growing cells like traditional chemo, so he won’t lose his hair, etc.
• Like other chemo treatments, it will cause his white blood cell and platelet counts to drop, which we have already seen.
• George’s team is on the ball…they know all the latest research data and the drug gilteritinib was actually tested by researchers, led by Dr. Alexander Perl, at UPenn! You can read about his findings in an easy to read fashion here: https://www.pennmedicine.org/news/news-releases/2019/april/targeted-drug-for-leukemia-tested-at-penn-medicine-helps-patients-live-longer