Thalidomide is a drug that used to be given to pregnant women to alleviate morning sickness. However, it was withdrawn from the market in 1961 after it was found to cause severe birth defects in children born to mothers who took it.
The drug caused deformity and other birth defects in thousands of babies across more than 46 nations. Thalidomide was the first example of a drug that passed legal specifications and regulations without full evaluation of its safety for use in pregnant and breastfeeding mothers. After 1961, drug regulatory authorities tightened their laws so that any new drug was screened for the potential to cause harm to the unborn baby.
Due to the immense negative publicity associated with the drug, research into its potential use ceased for a time. However, the immunomodulating properties of this drug were still studied in some parts of the world.
Studies have shown that tuberculosis increases the level of tumor necrosis factor-alpha (TNFα) which is involved in the promotion and progression of cancer. Research has shown that thalidomide exerts its anti-inflammatory effects through the inhibition of TNFα.
Thalidomide is given in combination with prednisolone and melphalan to treat myeloma in patients aged 65 or older who are not suitable for stem cell treatment. Researchers are still trying to elucidate the mechanism of this drug in treating myeloma but studies have shown that thalidomide can prevent the development of new blood vessels required to provide oxygen and nutrients to tumors. Without the formation of this new vasculature (angiogenesis) in place, tumors cannot grow larger than the size of a pinhead. Drugs that work in this way are referred to as anti-angiogenics or angiogenesis inhibitors.
Thalidomide is also used to treat a complication of leprosy referred to as erythema nodosum leprosum (ENL). The main effect of this drug in ENL is the reduction of fever and thalidomide has only been shown to have a limited effect in controlling neuritis, the main cause of disability in people with leprosy.
Some of the other areas being researched for the potential therapeutic effects of thalidomide include the following:
- Autoimmune skin diseases such as actinic prurigo
- Kaposi’s sarcoma in patients with AIDS
- Lesions and ulcers occurring in the mouth and esophagus of patients with AIDS
- Amyotrophic lateral sclerosis
- Behcet’s syndrome
- Certain cancers such as brain cancer, breast cancer, colon cancer, ovarian cancer, prostate cancer, non-small cell and small cell lung cancer, kidney cancer, thyroid cancer, blood cancers, Hodgkin’s disease, Non-Hodgkin’s lymphoma and malignant melanoma.
- Congestive heart failure
- Inflammatory bowel diseases such as Crohn’s disease
- Fibrodysplasia ossificans progressive
- Graft-versus-host disease
- Mycobacterium avium complex infection
- Prurigo nodularis
- Systemic lupus erythematosus
- Visceral Leshmaniasis
Reviewed by Sally Robertson, BSc