Copaxone (glatiramer acetate injection) is a disease-modifying therapy approved by the U.S. Food and Drug Administration (FDA) for the treatment of relapsing forms of multiple sclerosis (MS). This includes clinically isolated syndrome (CIS), relapsing-remitting multiple sclerosis (RRMS), and active secondary progressive multiple sclerosis (SPMS). Teva Pharmaceuticals markets the treatment.
How does Copaxone work?
MS is a progressive neurodegenerative disorder in which the immune system mistakenly targets the myelin protein. Myelin is the main component of the protective sheath that insulates nerve fibers. This triggers inflammation and causes damage to the brain and spinal cord, leading to a wide range of symptoms.
Copaxone is a small synthetic protein that mimics a fragment of myelin. It consists of four amino acids, the building blocks of proteins, that make up myelin.
The exact mechanism of how Copaxone reduces the frequency of relapses is not known. However, researchers think that the medication modifies the immune attack against myelin. For example, Copaxone may act to increase the immune system’s tolerance to myelin through repeated exposure, in a similar way to a vaccine.
Another mechanism could be that Copaxone may alter which immune cells are active. For example, it may be able to induce a type of immune cells called suppressor T-cells that secrete anti-inflammatory proteins and prevent damage. Copaxone may also act to prevent the activation of T-cells that target and attack myelin.
Copaxone can reduce the rate of relapses and slow the progression of MS. However, it cannot reverse the damage that MS already caused or cure the disease.
Copaxone in clinical trials
Researchers studied Copaxone in several clinical trials.
The key clinical trial that led to Copaxone’s approval for marketing was the so-called the Copolymer 1 multiple sclerosis study, carried out in the 1990s. The randomized, double-blind, placebo-controlled Phase 3 trial enrolled 251 patients with RRMS. During the trial, participants received either Copaxone or a placebo daily for two years.