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| Cancer other treatments |
Thalidomide | |
Thalidomide is an old drug. First used as an anxiolytic, it rapidly demonstrated major teratogenic effects (babies without limbs, other malformations). These malformations are due to a powerful negative effect on neovascularisation, which is necessary for normal foetal development. The idea to use this property in the antiangiogenic treatment of cancer emerged around ten years ago.
One of the indications of thalidomide is leprous erythema nodosum, which is an immune reaction with vascularitis due to circulating immune complexes. The precise mechanism of this rare infection may involve the Tumour Necrosis Factor alpha (TNFα).
Another indication is the treatment of very painful ulcers of the mouth, throat, vagina or rectum observed in AIDS or in Behcet syndrome. In such cases, involvement of Tumour Necrosis Factor alpha (TNFα) is also suspected.
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| Structure of thalidomide which exists as two enaniomeres
S(-) and R(+) and convert to each other physiologically. |
At present, the only cancer indication (validated in France) is the treatment of resistant multiple myeloma.
Given orally, the recommended dosage is around 200 mg/m2. Response can be spectacular with tumoral evolution stopped for long periods.
Thalidomide may provoke severe peripheral neuropathies, beginning with bilateral, symmetrical, distal, sensitive disorders. Electroneurophysiological studies (sensitive action potential and motor-evoked potential) together with strict monitoring during treatment should prevent this severe complication.
Due to the known teratogenic effects, the company heavily insists on the precautions to be taken to avoid any absorption by pregnant women. For the patient herself, such recommendations are superfluous since previous chemotherapies (and age!) prevent pregnancy.
Other side effects include somnolence, vertigo, headaches, mood disorders.
Other molecules, more or less related to thalidomide, are currently under experimentation. Certain new molecules may be more active and better tolerated than thalidomide, for instance in myeloma.
Other tumours are also being studied, in particular hormone refractory prostate cancer.
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