This post intends to be a brief and readable overview on what monoclonal antibodies (mAbs) are and some examples of their clinical applications.
The following slideshow is a clear and accurate introduction on the topic:
(ignore the first slide error message and move to the second)
Download PPT file: “Antibodies as drugs”
The following image summarizes the latest drug developments on targeted therapy against cancer. The diagram shows the mechanism of action of several drugs, some of them are monoclonal antibodies while others are small molecules.
From the excellent article: Targeted Treatments: A New generation of Cancer Treatments. American Family Physician, 2008.
FDA-approved monoclonal antibodies for cancer treatment
|Name of drug||Type of cancer used to treat|
|Alemtuzumab (Campath)||Chronic lymphocytic leukemia.|
|Bevacizumab (Avastin)||Breast cancer.
|Cetuximab (Erbitux)||Colon cancer.
Head and neck cancers.
|Gemtuzumab (Mylotarg)||Acute myelogenous leukemia.|
|Ibritumomab (Zevalin)||Non-Hodgkin’s lymphoma.
Chronic lymphocytic leukemia.
|Panitumumab (Vectibix||Colon cancer.|
|Rituximab (Rituxan)||Non-Hodgkin’s lymphoma.|
|Tositumomab (Bexxar)||Non-Hodgkin’s lymphoma|
|Trastuzumab (Herceptin||Breast cancer|
Source: Mayo Clinic
Therapeutic antibodies in rheumatology
The monoclonal revolution has touched musculoskeletal diseases too. Infliximab and adalimumab have been approved by the FDA for the treatment of psoriasis, Crohn’s disease, ankylosing spondylitis, psoriatic arthritis, rheumatoid arthritis, sarcoidosis and ulcerative colitis. Etanercept is a fusion protein produced through expression of recombinant DNA with very similar indications. Recently (August 2009), the FDA added a boxed warning on the increased risk of lymphoma in TNF blockers users.
These three drugs share their mechanism of action: they reduce or even neutralize the effect of TNF (Tissue Necrosis Factor), they are known as TNF inhibitors. The image below shows the key role TNF plays in the pathogenesis of rheumatoid arthritis.
Source: Clinical Therapeutics: Tumor Necrosis Factor Inhibitors for Rheumatoid Arthritis. NEJM, 2006.
Some videos on the future of mAbs
This video shows how monoclonal antibodies can be used to the entry of influenza virus into the host cell.
From bench to bedside, Ron Levy, MD, professor of Medicine at Stanford discusses past and future of mAbs for the treatment of cancer. Wendy Harpham, a participant in the early clinical trials of Rituxan, provides a patient’s perspective.