When people first start taking CML medication like Gleevec, their blood count must be monitored relatively often to make sure it doesn't get too low.
"The first milestone that we want to see is a complete hematologic remission by three months," says Dr. Kalaycio. "That means that we want the blood count to be normal and the spleen not to be felt. Now that's not what's happening in the bone marrow necessarily, at this stage, it's just in the blood."
Patients who don't achieve that milestone are often switched to another medicine.
"At six months, we want to see some degree of suppression of the Philadelphia chromosome in a bone marrow test," explains Dr. Kalaycio. "It doesn't have to be complete suppression, but it has to be something. We continue to check bone marrow biopsies every six months until the Philadelphia chromosome is no longer present."
Patients who achieve complete cytogenetic remission by six months, meaning that the Philadelphia chromosome is not longer present in a blood or bone marrow test, have a high chance of keeping their CML in remission forever.
"By 18 months of therapy, we need to see no Philadelphia chromosome in a bone marrow test. If it is still present at 18 months, that means therapy hasn't gone as well as we would have liked and we would consider either switching drugs or we consider a stem cell transplant because the pills just simply aren't working that well."
Patients who don't get a complete cytogenic remission by 18 months are unlikely to do so, according to Dr. Kalaycio, and are at increased risk of the disease progressing to accelerated or blast crisis phase.
The current recommendation for women who are on Gleevec is not to become pregnant.
"There are reports of healthy babies being born from patients on Gleevec, but there are also reports of unhealthy babies being born on Gleevec," says Dr. Kalaycio. "So the recommendation is not to do it."
Obviously, that can be difficult news for women who wish to conceive and are on Gleevec. But there are ways to allow for a pregnancy under certain circumstances.
"I would recommend consultation with a leukemia doctor who has experience in working in these situations before just stopping the pill and trying to get pregnant," advises Dr. Kalaycio.
People who have achieved remission of CML with drugs such as Gleevec, should be aware of and on the lookout for two important issues, according to Dr. Kalaycio.
The first issue is medication compliance — you've got to keep taking your medicine for the rest of your life, even if you feel better.
"The biggest problem we have with Gleevec is the person not taking their medicine," says Dr. Kalaycio. "If treatment milestones [like those mentioned above] aren't being met, my first question is, 'Are you taking your medicine?'"
In Dr. Kalaycio's experience, common reasons people who stop taking their medicine include the cost of treatment, that the person feels better and that they think because their disease is in remission they can discontinue treatment.
The second issue is that Gleevec can negatively interact with other drugs, especially some cholesterol-lowering drugs like statins. The toxicity of other drugs can be increased when you're on Gleevec, says Dr. Kalaycio. Be sure to tell every physician who is treating you that you are currerntly taking Gleevec and also inform your leukemia doctor of any new drugs you have been prescribed.
"Unlike other leukemias, there is no immune deficiency in CML, so you don't have to worry about excess risk of infection," says Dr. Kalaycio. With CML, your immune system is perfectly intact and no additional precautions need to be taken to prevent infection, such as wearing a mask in public.
No. CML is not hereditary. So even if your parent has CML, you are not necessarily more likely to develop the disease. And because the disease is relatively rare and does not typically present symptoms in its early phase, screening is unnecessary.