Sore neck/lower back muscles/joints with AML ?

Hello,  My wife was diagnosed with AML for 2nd time and is being treated with a drug called Viadazza until a bone marrow donor is found.   She has been experiencing really bad sore muscles in the neck and lower back.  Has anyone who had AML ever experienced this?  I don't know if it's because the drug Viadazza, Nuepogen that she is given to help WBC or the disease it self or just random with sleeping wrong?  Any information would be much appreciated.   Thank You!