Glatiramer Acetate - Mechanism of Action

Mechanism of Action

Glatiramer acetate is a random polymer (average molecular mass 6.4 kD) composed of four amino acids that are found in myelin basic protein. The mechanism of action for glatiramer is unknown, although several have been proposed. Administration of glatiramer shifts the population of T cells from pro-inflammatory Th1 cells to regulatory Th2 cells that suppress the inflammatory response. Given its resemblance to myelin basic protein, glatiramer may also act as a sort of decoy, diverting an autoimmune response against myelin. The integrity of the blood–brain barrier, however, is not appreciably affected by glatiramer, at least not in the early stages of treatment. Glatiramer acetate has been shown in clinical trials to reduce the number and severity of exacerbations.

The mechanism(s) by which glatiramer acetate exerts its effects in patients with Multiple Sclerosis (MS) is (are) not fully elucidated. However, it is thought to act by modifying immune processes that are currently believed to be responsible for the pathogenesis of MS. This hypothesis is supported by findings of studies that have been carried out to explore the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a condition induced in several animal species through immunization against central nervous system derived material containing myelin and often used as an experimental animal model of MS. Studies in animals and in vitro systems suggest that upon its administration, glatiramer acetate-specific suppressor T-cells are induced and activated in the periphery.