A newly-tested treatment for multiple sclerosis reduces relapse and deterioration in patients, without many of the negative side effects associated with other treatments, a study said Wednesday.

A clinical study published Wednesday in the New England Journal of Medicine (NEJM) said that Cladribine was the first oral medication for patients suffering from MS, a complex neurological condition.

A team led by Gavin Giovanonni, a professor at Barts and The London School of Medicine and Dentistry in Britain, followed some 1,300 patients for nearly two years, monitoring them with MRI scans.

Patients were either given two or four short courses of Cladribine tablets over the course of a year or were administered a placebo.

The results were heartening, with those taking the Cladribine tablets over 55 percent less likely to suffer relapse and 30 percent less likely to suffer worsening in their disability due to MS.

The disease is a neurological condition that often begins in young adulthood and involves the body's immune system attacking its own central nervous system.

The damage done interferes with communications between the brain and other parts of the body, leading to disability.

Patients are often required to undergo regular injections and intravenous infusions, but Cladribine, which works by suppressing the immune system, only needs to be taken for between eight to 10 days a year to work effectively, the study found.

"The introduction of an oral therapy, particularly one that has no short-term side effects and is as easy to use as oral Cladribine, will have a major impact on the treatment of MS," Giovanonni said:

The new medication is produced by pharmaceutical group Merck Serono, a division of German group Merck KGaA.

Merck Serono's request to put the drug on the market was rejected by the US Food and Drug Administration at the beginning of December.

It is now in discussions with the US regulatory body and seeking to resubmit its application, according to a statement from the company.

MS usually affects people between 20 and 40 years old, and its symptoms can be serious and crippling.

It can affect almost all of the biological functions that control movement, sensory perception and memory.

An estimated one in 1,000 people are affected by the disease.