Doctors released new information in June on the effectiveness of a currently available medication for multiple sclerosis.1 The drug is known as Copaxone, also known by its generic name, glatiramer acetate injection.
Copaxone is indicated to reduce the number of relapses in people with relapsing MS. While it's not known exactly how the drug works, it's believed it stimulates pro-inflammatory immune cells to switch to anti-inflammatory cells. The immune cells then encounter damage in the central nervous system and apparently reduce inflammation at the site of the lesion.2
Another Perspective
Omar Khan, MD, an associate professor of Neurology at Wayne State University, led a small study of 18 people with relapsing-remitting multiple sclerosis to more closely determine how the medication helped people with MS recover.
Each patient underwent an imaging procedure known as magnetic resonance spectroscopy (MRS). This is a type of magnetic resonance imaging; it provides chemical rather than anatomical information. The chemicals can give radiologists clues about how MS may influence chemical processes in the brain.3
MRS imaging was used in this study to prove that Copaxone exerts its effect inside the brain and spinal cord, Khan told Priority Healthcare, in an e-mail interview.
One of the chemicals measured in the study is known as n-acetylaspartate (en-uh-see-till-uh-SPAR-tate), or NAA, an indicator that neurons in the brain are functioning normally. An increase in levels of NAA in the brain relative to another chemical known as creatinine (kree-AA-tuh-neen) can serve as an indicator that injured nerve cells or neurons in the brain are recovering. (The relationship between NAA and creatinine on MRS readings is written as NAA/Cr ratios.)
In fact, this was the first study of Copaxone to use this diagnostic measurement as an indicator of the drug's effectiveness, Khan explained.
In MS, it is nerve cells and the fatty sheath known as myelin that protects them that are the key targets in the disease process. For as yet unknown reasons, the body's immune system mistakenly attacks myelin and nerve cells, damaging or destroying them, and thus, causing the symptoms that crop up in MS.4
'Improved Recovery'
"Copaxone treatment led to increased NAA/Cr ratios, suggesting improved cerebral axonal recovery in relapsing-remitting MS patients, indicating a potential benefit on the pathways of electrical conduction in the brain," explained Khan, who is also Director of Experimental Therapeutics and Clinical Research at Wayne State University's Multiple Sclerosis Center.
Axons are the connections in the brain by which nerve cells communicate with each other. They can also be damaged when MS strikes. Preventing or minimizing damage to nerve cells is critical in reducing long-term disability in MS, the research team pointed out.
Patient Follow-Up
In their open-label study (meaning both clinical staff and patients knew the name of the medication being tested), Khan and his colleagues followed most of the patients for a three-year period while they were taking the drug. In addition, four patients in an untreated group were followed for the first two years, and half of those began therapy with Copaxone in the study's third year. Each patient underwent both MRI and MRS exams before therapy began and then yearly afterwards. Every six months, the investigators also measured each patient's level of disability to determine if they had relapsed at any time. The results, presented at a neurology conference in Europe, involved new data from the ongoing study.
"NAA/Cr ratio remained stable during the third year, and significantly improved compared to baseline and the untreated group," Khan's team reported. The patients in the non-treated group who later began therapy also showed improvements in the ratio of these two chemicals compared to their levels at the start of the study. Two patients who remained untreated had continued declines in their NAA/Cr ratio, the investigators found.
"These MRS data suggest an action of Copaxone in the central nervous system, resulting in a sustained beneficial effect on cerebral axonal injury," said Khan. "No other approved treatment for relapsing-remitting MS has been shown to have a beneficial effect on MRS scans over a three-year period."
Benefits of Early Therapy
In a similar, but unrelated study,5 doctors in Italy compared the effectiveness of Copaxone begun immediately versus its effectiveness when treatment was delayed. The researchers enrolled 142 patients in an open-label extension trial of an earlier MRI study, and assigned them to two groups. One group received Copaxone at the start of the extension study and the second group received the medication after taking a placebo for the first 9 months, and then switched to the drug.
The researchers found that a greater number of patients in the group taking Copaxone from the beginning did not reach significant disability—defined in the study as needing intermittent or constant assistance like a cane, crutch or brace—compared to patients who were given the drug on a delayed basis.
The results suggest that starting Copaxone treatment early for people with active relapsing MS may have a positive impact on long-term disease evolution by slowing the progression to serious disability, the investigators concluded.
1. Khan O, Shen Y, Hu J et al. Sustained effect of glatiramer acetate on cerebral axonal recovery in relapsing-remitting MS: results after three years of serial brain magnetic resonance spectroscopy examination. 15th Meeting of the European Neurological Society. 2004 Jun 18-22. Vienna, Austria.
2. Teva Pharmaceutical Industries. About Copaxone. Available at: http://www.mswatch.com/therapy/section.aspx?SectionId=789eabf5-3a07-4dff-a7ee-0d4ad1381a6d. Accessed July 8, 2005.
3. University of Arkansas Medical Sciences. Department of Radiology. College of Medicine. Magnetic Resonance Spectroscopy (MRS): Introduction. Available at: http://www.uams.edu/radiology/info/research/mrs/. Accessed July 8, 2005.
4. National Multiple Sclerosis Society. What is Multiple Sclerosis? Available at: http://www.nationalmssociety.org/What%20is%20MS.asp. Accessed July 8, 2005.
5. Rovaris M, Comi G, Rocca M et al. Long-term follow-up of patients treated with glatiramer acetate: a multi-centre, multi-national extension of the European/Canadian double-blind, placebo-controlled, MRI-monitored trial. 15th Meeting of the European Neurological Society. 2004 Jun 18-22. Vienna, Austria.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
