Early treatment with a key drug to fight multiple sclerosis (MS) nearly halves the risk of progression to the full-blown disease, according to a study published online on Wednesday by The Lancet.
The treatment, glatiramer acetate, marketed as Copaxone, was tested in 16 countries among 481 patients with a tell-tale lesion in the central nervous system called clinically isolated syndrome.
The volunteers either received the drug or a dummy lookalike for up to three years.
Copaxone reduced the risk of developing "clinically definite" MS by 45 percent compared with a placebo.
In addition, the time it took for 25 percent of patients to develop the full-scale disease was more than doubled in the Copaxone group, at just under two years on average compared with just under one year in the placebo group.
Around a million people around the world are affected by MS, a degenerative disease in which the immune system attacks myeline, the fatty sheath that protects nerve fibres.
As a result, signals between nerve cells are delayed, disrupted or even blocked, rather like a poor connection in an electrical wire.
This causes worsening problems in coordination and balance, as well as blurred vision and slurred speech.
"This study establishes glatiramer acetate as an option for patients with clinically isolated syndrome who choose to start treatment early to improve control of the underlying disease process," says the new paper.
The study was led by Giancarlo Comi, a professor of neurology at Milan's Vita-Salute University in Italy.
Copaxone is currently approved for treating "relapsing-remitting" forms of MS.