Monoclonal antibodies such as rituximab, alemtuzumab, and ofatumumab may be used to treat CLL. These drugs are given as infusions into a vein (IV), usually over several hours. They may be given in a doctor's office, chemotherapy clinic, or in the outpatient department of a hospital. These drugs can sometimes cause allergic reactions while they are being infused, which in some people may be serious. You may get medicines before the infusion to lower the chance of an allergic reaction.
Depending on the specific drug, you may get treatment as often as several times a week or as infrequently as once a month. In some cases, these drugs may be given along with chemotherapy.
The main side effects of monoclonal antibody therapy are fever and chills during the treatment. The fever may be high, but usually goes down or away when the infusion is slowed or stopped. Some people may have rashes as well. In rare cases, people may have more serious problems, including trouble breathing and low blood pressure. These problems are most common during the first time a person gets the drug.
You may also get an infection more easily because the antibodies damage your immune system cells. This problem can sometimes be serious with alemtuzumab, which can cause very low white blood cell counts. You may get a special treatment ahead of time to reduce the impact of these side effects.
Less common but potentially serious side effects can include blockage in the intestines, low blood platelet counts (with increased risk of bleeding),and reactivation of viral hepatitis. In rare cases, tumor lysis syndrome can be induced. This occurs when the drug kills the cancer cells at such a rapid rate that the body cannot get rid of the breakdown products of the dead cells fast enough.