What is a monoclonal antibody?
Antibodies are a natural part of your
immune system. The body makes antibodies to attack certain foreign substances
that enter the body and threaten its health. The antibody attaches itself to the
antigen (foreign substance)
and marks it for destruction by your immune system.
A monoclonal antibody (MAb)
is an antibody that has been created in a laboratory. Monoclonal antibodies are
designed to target only certain specific cells for destruction. Unlike traditional
chemotherapy, MAbs attach themselves to specific antigens found on the surface of
Like a natural antibody, this lab-created antibody binds to a specific antigenlike
a key sliding inside a lockand destroys it.
What is Campath and how does it destroy cancer cells?
Campath has been approved by the US Food and Drug Administration as a single medication
for treating the blood disease known as B-cell chronic lymphocytic leukemia, also
known as B-CLL. Although there is currently no cure for B-CLL, Campath is the first
and only monoclonal antibody that has been approved to treat it.
Campath targets the CD52 molecule, an antigen that is found on the surface of many
cells, including leukemia cells. This allows Campath to turn on the body's immune
system to help attack the leukemia.
Who should not take Campath?
Campath is approved as therapy for anyone with B-CLL; however, women who are pregnant
should take Campath only if it is clearly needed; your doctor can help you with
this determination. Also, mothers who are nursing babies should discuss with their
doctors whether to stop taking Campath or to stop nursing.
WARNING: CYTOPENIAS, INFUSION REACTIONS, and INFECTIONS
Cytopenias: Serious, including fatal, pancytopenia/marrow hypoplasia, autoimmune idiopathic thrombocytopenia, and autoimmune hemolytic anemia can occur in patients receiving Campath. Single doses of Campath greater than 30 mg or cumulative doses greater than 90 mg per week increase the incidence of pancytopenia.
Infusion Reactions: Campath administration can result in serious, including fatal, infusion reactions. Carefully monitor patients during infusions and withhold Campath for Grade 3 or 4 infusion reactions. Gradually escalate Campath to the recommended dose at the initiation of therapy and after interruption of therapy for 7 or more days.
Infections: Serious, including fatal, bacterial, viral, fungal, and protozoan infections can occur in patients receiving Campath. Administer prophylaxis against Pneumocystis jiroveci pneumonia (PCP) and herpes virus infections.
In clinical trials, the frequency of infusion reactions was highest in the first week of treatment. The following serious, including fatal, infusion reactions have been identified in post-marketing reports: syncope, pulmonary infiltrates, acute respiratory distress syndrome (ARDS), respiratory arrest, cardiac arrhythmias, myocardial infarction, acute cardiac insufficiency, cardiac arrest, angioedema, and anaphylactoid shock.
Prolonged myelosuppression have been reported in patients receiving Campath. Campath treatment results in severe and prolonged lymphopenia with a concomitant increased incidence of opportunistic infections. Assess CD4+ counts after treatment until recovery to ≥ 200 cells/µL. Obtain complete blood counts (CBC) at weekly intervals during Campath therapy and more frequently if worsening anemia, neutropenia, or thrombocytopenia occurs. Withhold Campath for severe cytopenias (except lymphopenia). Discontinue for autoimmune cytopenias or recurrent/persistent severe cytopenias (except lymphopenia).
Administer only irradiated blood products to avoid transfusion associated Graft versus Host Disease (TAGVHD), unless emergent circumstances dictate immediate transfusion.
Routinely monitor patients for CMV infection during Campath treatment and for at least 2 months following completion of treatment. Withhold Campath for serious infections and during antiviral treatment for CMV infection or confirmed CMV viremia. Initiate therapeutic ganciclovir (or equivalent) for CMV infection or confirmed CMV viremia.
Do not administer live viral vaccines to patients who have recently received Campath.
The most common adverse reactions (≥ 10%) were infusion reactions, cytopenias, cytomegalovirus (CMV) and other infections, nausea, emesis, diarrhea, and insomnia.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
For important risk and use information, please see full Prescribing Information (PDF).