Scientists in Dublin have made a major breakthrough in the fight against multiple sclerosis (MS) and other major diseases.

Researchers have led an international study that has succeeded in identifying that a drug developed to fight arthritis may be able to halt the progression of MS, Alzheimer’s and other inflammatory conditions.

Initial tests revealed that the drug – the result of three decades of research at the Trinity Biomedical Sciences Institute – could instantly block MS and the effects of blood poisoning in mouse models.

The drug, called MCC950, was also found to effectively block a condition 'Muckle-Wells syndrome,' a disorder characterized by episodes of skin rash, fever and joint pain and which can trigger hearing loss and kidney damage.

The Irish Times reports that the drug stops a very early trigger that sets off the inflammatory response to infection. The paper also notes that while inflammation is good during infections, it can cause a wide range of serious diseases if the inflammation remains in place.

Prof Luke O'Neill, chairman of biochemistry at the Trinity Biomedical Sciences Institute, said: "This is exciting, one of the biggest discoveries we have had. It is fantastic, the thing we have been looking for for 30 years. This could be the missing compound."

The findings, which were published in the journal Nature Medicine, suggest the researchers' main discovery was to identify the pathway that allows the drug to block the action of a pro-inflammatory substance in the body, called NLRP3.

Prof O'Neill also revealed his team's tests on mice confirmed that inflammatory diseases all share a common process, even though parts of the body becoming inflamed might differ.

"It really showed that it could work in humans," he said.

Prof O'Neill, the co-senior author of the study, also collaborated with experts from the Universities of Michigan, Massachusetts, Queensland and Bonn, for the research.

He said that pharmaceutical giant Pfizer had developed the original compound about 20 years ago, knowing at the time the drug was anti-inflammatory, but without the knowledge of being able to establish its 'pathway.'

O'Neill said: "It was serendipity. I knew they had an interesting drug back in 2001 and I wondered if it targeted the pathway we were looking at."

As the drug formula was in the public domain, O'Neill asked his Queensland counterpart, Prof Matt Cooper, to make the drug so it could be analyzed and tested in Dublin.

He recalled: "The results began to roll in. It was one of those rare occasions where everything we did seemed to come out positive."

He said a light bulb moment came when he observed how it "worked wonders" in curing mice of MS and in blood poisoning where the whole body becomes inflamed.

"That really told me we have a common pathway for all of these diseases," he said.

He also told of his belief that Muckle-Wells syndrome "could be the first disease to be cured in humans using the drug."

"It may not cure all conditions, but it would certainly halt their progression. It is the escalation of those diseases that causes all the problems."

He also revealed that he and Prof Cooper are now considering setting up a company to develop the drug further, adding: "We seem to have got there first with a small molecule that can block inflammation."

Several unique forms of the drug based on the original formula – and which can be patent protected – have been developed by Prof Cooper.

Funding for the research was made available by Science Foundation Ireland and the European Research Council.