Have a 77 yo M patient with history of JAK2 positive myelofibrosis diagnosed in 2014 and treated with ruxolitinib. He presented with worsening constitutional symptoms, leukocytosis from 16 to 111, and worsening anemia and thrombocytopenia. Bone marrow biopsy showed progression of myelofibrosis with JAK2, ASX1, and TET2 mutations. He was started on pacritinib now (platelets 38). However, karyotype interestingly showed a 9;22 translocation. Unclear if MF can obtain this translocation or new CML has developed. Can MF obtain this mutation and if so, should it be treated by adding an agent such as Imatinib?
This sounds like he’s developed new CML on top of MF. Would continue JAK inhibitor if possible and add second generation TKI. We have a few of these patients that have MF and CML and we treat the two almost independently. Often, they can be challenging cases but first step is to see what kind of response you get with adding TKI. The TKI won’t take care of JAK driven signs/symptoms and the JAK inhibitor won’t help with the CML.
