For this blog I will be discussing the drug alemtuzumab (Campath), a monoclonal antibody. A monoclonal antibody is an antibody that has been synthesized from the clones of B cells from an immune animal. Since B cells only make antibodies for one specific antigen, therefore monoclonal antibodies can only recognize one specific epitope. Campath is a drug that is used to treat B-cell chronic lymphocytic leukemia by slowing or stopping the growth of cancer cells. It can also help with relapses of multiple sclerosis, making the relapses occur less frequently. I think monoclonal antibodies such as Campath are a great medical development. Some people’s immune systems do not function as they should, so getting monoclonal antibodies for the antigen that infects them is the next best thing. However, the development of monoclonal antibodies is expensive and hard, so monoclonal antibodies are only made for common diseases.
Campath works by binding to CD52, an antigen present on the surface of almost all B and T cells, and many other cells in the immune system, as well as some bone marrow cells and male reproductive tissue. After the antibody binds to the surface of leukemic cells, the cancerous cells undergo antibody-dependent lysis. Possible side-effects may include:
- Hematologic Toxicity: Serious pancytopenia/ marrow hypoplasia, autoimmune idiopathic thrombocytopenia, and autoimmune hemolytic anemia have occurred in patients
- doses of more than 30 mg in one dose or 90 mg per week have been linked to higher incidence of pancytopenia
- Infusion Reactions: it can cause serious infusion reactions, patients should be closely monitored during infusion
- Infections, Opportunistic Infections: Serious bacterial, viral, fungal, and protozoan infections have been reported
- Fever, chills, flushing, dizziness, shortness of breath, nausea, vomiting, or mild rash/itching
- Depression/anxiety, muscle pain, numbness in extremities, irregular heartbeat, weight change
- May increase of getting progressive multifocal leukoencephalopathy brain infection
All of these side-effects are bad, however the autoimmune complications are directly related to the treatment that the drug provides. Since the antibody attacks all immune cells with a CD52 glycoprotein, this can cause the destruction of cancerous cells as well as healthy immune cells. Low counts of blood cells lead to the complications of pancytopenia, marrow hypoplasia and autoimmune idiopathic thrombocytopenia. I think this drug does have a lot of risks associated with it, therefore I think any doctor that would prescribe it must believe that the benefits outweigh the risks of side effects; this drug is mainly used to fight cancer so that makes sense.
Since this drug attacks the cells of the immune system and the bone marrow, it will make anyone who takes it more susceptible to infection. This drug attacks cells of the both the innate and acquired immune system, T cells, B cells, macrophages, dendritic cells, NK cells, monocytes and more. Therefore, the drug should NOT be taken if the patient has HIV, had a vaccine recently or has tuberculosis. I think the development of monoclonal antibodies will continue to progress and they will become more widely used. Hopefully the cost of production will decrease and the developmental process will become more efficient. If that happens, lots of people will be able to get antibodies for illnesses that their body does not already have and more people will survive serious diseases.
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