How is response defined in blood cancers such as leukemia?
For leukemia, the word used is remission, as opposed to tumor response. For example, the drug Gleevec is effective in the treatment of chronic myelogenous leukemia (CML). Someone with CML can have a partial remission, which means that the bone marrow is cleared of a given percentage of tumor cells. With Gleevec and CML, the landmark study showed that you can see complete response, meaning you can look at the bone marrow and not see any leukemic cells. But what’s more important is that you can actually take a look at the cells and determine their genetics, or so-called cytogenetics. A complete cytogenetic response means that instead of having 10 percent of cells with the abnormal chromosome that causes CML, the Philadelphia chromosome, it’s totally gone. We think a cytogenetic response is biologically very important because the cells that are responsible for this leukemia are gone. Although it’s too early to say long-term, this is a benefit that could translate into cure. Are “benefit”
