What types of responses can p... Video Transcript

Participants

, Michael Mauro MD, Gwen L. Nichols MD

Summary

The goal of treatment for chronic myeloid leukemia (CML) is remission. The three levels of remission are hematologic (good), cytogenetic (better) and molecular (best). Learn what they may mean long-term.

Webcast Transcript

When patients respond to CML therapy, we have different levels of response or different levels of remission. The first level of response is a hematologic or blood remission. Fortunately, that's easy to achieve with current treatment options, and fortunately it's been something we've been able to achieve with even older therapies.

Now, that really translates into mitigation of signs and symptoms, so patients always usually feel better when their blood counts are normalized and their spleen is no longer enlarged.

The second level of response is a cytogenetic remission, or a cytogenetic response, and it's defined at different levels. It can either be a complete response, where by those standard bone marrow testing, cytogenetics and FISH, we don't see any Philadelphia chromosome, or a major response where the majority of the cells are normal. That historically has changed the natural history of CML. So if someone was in the chronic phase and it got that type of response, it meant that three- to five-year timeline they were thinking of without good treatment really changes.

The complete cytogenetic response and low levels by molecular testing or PCR historically carries the best prognosis. The good news is that most of the patients with Gleevec treatment have gotten complete cytogenetic remission, about two thirds, 70 to 80 percent, and a good number of patients have very deep molecular remission. So that clearly should translate into a survival advantage.

What we can tell now is that it translates into less risk of progression to the advanced phase of CML. That's what we can clearly say from the studies we've done so far. But if we look at what we did with older therapies, like interferon, I think it's a lot—one could logically conclude that we're looking at a very good chance for changing the natural history of CML in a dramatic way to the type of responses we've had with Gleevec.