Hi Linda.
Here is some basic information about Mylotarg:
Mylotarg is the tradename for gemtuzumab ozogamicin. It's given to patients with the CD33 antigen. Do you know if your mother's blood cells have been examined to see if she has the CD33 receptor?
It's a fairly new drug (approved in 2000 for AML treatment), so there aren't likely to be many statistics available. An FDA report titled Approval summary: gemtuzumab ozogamicin in relapsed acute myeloid leukemia discussed a study of 142 patients where the response rate was 26% among patients over age 60, but that report is over 5 years old and was for AML patients, not specifically those with MDS. Protocols for administration and success rates can change from year to year as doctors look for the ideal way to use the drug, so I don't think that report is directly applicable to your mother's case.
This description of Mylotarg at cancer.org from 2004 is easy to understand and lists possible side effects.
There is a large trial (about 2000 patients) in progress to study Mylotarg's use in combination with chemo drugs for patients with MDS.
What did the doctor say this evening?