ANNOUNCER: And while that's not a cure, studies with other drugs show this so-called "cytogenetic response" corresponds to longer survival. But data on Gleevec is preliminary, and doctors are still debating how and when it's best used.
GWEN NICHOLS, MD: The tough question is, if we start with that therapy or transplantation.
STEPHEN O'BRIEN, MD: It's fairly clear if you're at the extremes of the spectrum. So for example, if you're 20 and you had a related donor that matched very well, and you were fit and healthy, I suspect myself and most other doctors would recommend a bone marrow transplant.
If you're 60 and whether or not you have a donor that age, I think the risks of transplant are excessive perhaps, and then drug therapy would clearly indicated.
For the middle ground, I think one has to discuss the options with the patients and provide as much data as one can, and then it's a very personal choice for the physician and the patient in their particular circumstances.
ANNOUNCER: Another difficult decision is what a patient should do who is taking Gleevec, and who shows a good response.
STEVE MACKINNON, MD: My own opinion, and I'm a bone marrow transplant physician, is that if I have a patient who's on Gleevec. I would want them to continue on the drug. On the other hand, for patients who don't have good responses to Gleevec, if they're young enough, those patients can then proceed with the transplant.
But one of the great unknowns nowadays days is will prior Gleevec therapy effect the results of transplant subsequently? And that could happen in a number of ways.
ANNOUNCER: One concern is that delaying a transplant might increase risk. It's possible that the drug itself might lead to complications. And a patient who fails medical therapy, like Gleevec, might face a transplant with more advanced disease.
But it's also possible that using Gleevec may improve results in later transplants.
STEVE MACKINNON, MD: And the last thing to bear in mind is that Gleevec may put patients into remission prior to transplantation. And that has a possibility of actually improving the results of transplantation.
ANNOUNCER: No doctor is ready to call Gleevec a cure for CML. But if research shows Gleevec prolongs survival, doctors say many CML patients may enjoy long, symptom-free lives, without the trauma and risk of a bone marrow transplant.