Myleran

Myleran is an oral anticancer medication approved to improve the quality of life and relieve cancer symptoms (palliative care) for people with chronic myelogenous leukemia (CML). It’s a type of medication called an alkylating agent. It works by damaging the cancer cells’ genetic material, leading to cell death. Since there are newer medications available, Myleran is no longer a recommended treatment option for CML.

Myleran is only FDA approved for use in CML. Although it’s not approved for any other purpose, some providers might consider using Myleran to treat two rare blood conditions (myeloproliferative neoplasms) that haven’t responded to first-choice options. These conditions include essential thrombocythemia (where your body produces too many platelets) and polycythemia vera (where your body produces too many red blood cells). But Myleran isn’t a standard treatment for these conditions because of its potential risk of causing secondary cancers. This is when a different cancer develops while you’re taking medication for a condition that you already have. If you have either of these two blood conditions, discuss with your provider about your options.

These two medications both contain busulfan as its active ingredient. Myleran is an oral tablet that’s no longer recommended for CML. On the other hand, busulfan (Busulfex) is an injection that’s given through the vein (intravenous or IV). The injectable form is FDA approved and used more commonly in chemotherapy regimens given before a stem cell transplant for CML.

Yes, taking Myleran can have serious risks. Most commonly, Myleran can cause your red blood cell, white blood cell, and platelet counts to drop, especially with higher doses of this medication. When the number of these cells are lower than normal, you’re at risk of developing anemia, infections, and bleeding or bruising. Your blood cell counts typically go back to normal, but in some cases, this can take a long time. This is because your chemotherapy medications can weaken your bone marrow and affect its ability to make new blood cells like normal. Your provider will closely monitor your blood counts through routine lab work while you’re taking Myleran. If your blood counts are low, you might have to stop taking this medication. Let your provider know as soon as possible if you experience fevers, chills, tiredness, or bleeding and bruising that doesn’t stop or go away.

In rare cases, Myleran can cause lung damage and scarring (pulmonary fibrosis). This can take several months to years to develop after starting the medication. Notify your provider right away if you start experiencing a cough or difficulty breathing. In addition, some people taking Myleran have developed secondary cancers. This is when a cancer (like a different blood cancer or solid tumor) develops while you’re taking medication for a condition that you already have. Some people have also had seizures while taking this medication. Before starting Myleran, make sure to tell your provider if you have a history of seizures, head injury, or take medications that can make you more likely to have a seizure. Also, Myleran can lower your ability to have a baby (infertility), so discuss with your provider if you have any concerns about family planning.