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Biological therapies use man-made versions of substances normally made
by the immune system. These substances may kill lymphoma cells, slow
their growth, or activate the patient's own immune system to more
effectively fight the lymphoma.
Monoclonal Antibodies
Antibodies are proteins normally made by the immune system to
help fight infections. Man-made versions, called monoclonal antibodies,
can be designed to attack a specific target, such as a substance on the
surface of lymphocytes (the cells in which lymphomas start).
Several monoclonal antibodies are now being used to treat
lymphoma.
Rituximab (Rituxan) is an antibody that recognizes and
attaches to a substance called CD20 found on the surface of some types
of lymphoma cells. This attachment seems to cause the lymphoma cell to
die. Patients usually get intravenous (IV) infusions each week for 4
weeks. The treatments can be given in the doctor's office or clinic.
Common side effects are usually mild but may include chills, fever,
nausea, rashes, fatigue, and headaches. Even if these symptoms occur
during the first rituximab infusion, it is very unusual for them to
recur with later doses.
Newer forms of monoclonal antibodies are similar to rituximab
but have radioactive molecules attached to them, which may help them
work better.
- Ibritumomab tiuxetan (Zevalin) is another antibody directed
at CD20, but this one has radioactive yttrium attached to it.
- Tositumomab (Bexxar), which is also an antibody directed at
CD20, although this one has radioactive iodine attached to it.
While these drugs may eventually prove to be more powerful than
rituximab, they are somewhat harder for doctors to give (because of the
radiation dosing involved). Another limitation is that they cannot be
used with chemotherapy because they also lower blood counts. At this
time they are generally used if chemotherapy and/or rituximab are no
longer working.
Alemtuzumab (Campath) is an antibody directed at the CD52
antigen. It is useful in some cases of chronic lymphocytic leukemia
(CLL) and also some types of peripheral T-cell lymphomas.
Interferon
Interferon is a hormone-like protein made by white blood cells
to help the immune system fight infections. Some studies have suggested
that giving man-made interferon can cause some types of non-Hodgkin
lymphomas to shrink or stop growing.
The side effects of this treatment include fatigue, fever,
chills, headaches, muscle and joint aches, and mood changes. Because of
these side effects, interferon is not used very often. It may be given
to some patients in addition to chemotherapy.
Last Revised: 08/29/2007
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