A MULTIPLE sclerosis sufferer who postponed an assisted suicide after pinning his hopes on a breakthrough new drug has spoken of his disappointment after missing out on a clinical trial for the new treatment.

Colin Campbell, 57, said it was a "bitter blow" as he now no longer feels well enough to travel to Switzerland to end his life. He stressed that his predicament underlined the case to legalise assisted suicide in Scotland to prevent other terminally ill patients facing the same dilemma.

Mr Campbell had originally planned to end his life at the LifeCircle clinic in Basel on June 15, but deferred it after friends encouraged him to pursue a stem cell transplant abroad. When neurologists advised that the high-risk treatment probably would not be effective for him, he pinned his hopes on ocrelizumab instead.

The drug is the first in the world to be licensed for the treatment of primary-progressive MS, a rarer form of the disease where symptoms steadily deteriorate over time without any periods of remission.

It was licensed in the United States in March and is currently being reviewed for use in Europe by the European Medicines Agency. Approval is expected to be granted later this year, after which the manufacturer could apply to the Scottish Medicines Consortium to have the ocrelizumab prescribed on the NHS in Scotland - where rates of MS are among the highest in the world.

The process is slow, however, and it is unlikely the drug will become available until 2018. Mr Campbell said his health is "not good" and he had hoped to get ocrelizumab earlier through a global clinical trial.

However, he said he has been told that the trial has closed to new candidates amid fierce competition for places. It has recruited just two participants from Scotland.

Mr Campbell said: "I've just not got the stamina to be challenging neurologists. If they said 'no', that's fine. I think a younger person would probably not be satisfied with that. If I was 37 instead of 57 I'd probably say 'come on, this isn't very good'. What's the basis for selection? Why aren't people with these illnesses being contacted?"

Mr Campbell, who moved from Inverness to Greenock in June after being unable to get a ground-floor flat in supported accommodation in the Highlands, added that he had now abandoned plans for a voluntary assisted suicide in Switzerland. He said: "I'm no longer physically capable of getting to Switzerland - I wouldn't make it. I'm really just taking it a day at a time."

Mr Campbell first came to public attention backing a campaign to legalise assisted suicide for terminally ill people in Scotland. He said it was unfair that people who wanted assisted suicide had to end their lives prematurely just to ensure they were fit enough to travel abroad.

He said: "This is not a topic that's going to go away. It's absolutely going to become even more urgent as a topic because you've got the problems of an ageing population and insufficient treatment available for people. It's cruel and it's a form of abuse, I think, to force people to carry on in pain, with no quality of life and no hope of ever getting better."

It comes as the High Court in London considers a right-to-die case brought by Noel Conway, who has motor neurone disease. He is calling for an assisted dying law in England and Wales which would allow people with less than six months to live the right to be prescribed a fatal dose of medication which they could self-administer. A decision is expected in October.

A spokeswoman for campaigners, Dignity in Dying Scotland, said: "Dying people in Scotland deserve better than to be faced with the choice of going to Switzerland to end their lives too soon or facing a death they do not wish here. Colin's case highlights some of the problems we have created by outsourcing this problem.

"We are calling on the Scottish Parliament to pass compassionate legislation, supported by the majority of people in Scotland, that would allow dying people to choose what is right for them and when. An Assisted Dying law would allow people to live at the end of their life free from the worry that their suffering may become unbearable."