Results of two clinical trials have shown that a drug called ruxolitinib improves quality of life for people with myelofibrosis - a rare form of blood cancer.

The drug has been approved by the US Food and Drug Administration, and the European Medicines Agency is also considering whether to give it a green light, after the two trials, published in the New England Journal of Medicine, showed it eased symptoms.

Myelofibrosis - which affects about one in 100,000 people - is a rare blood cancer that causes scar tissue (fibrosis) to accumulate in the bone marrow, affecting blood cell production. Patients diagnosed with this type of cancer have an average life expectancy of five years.

The new research, carried out in both Europe and the US, found that patients started to feel better after a couple of days of taking ruxolitinib, with the spleen shrinking noticeably. After 48 weeks, patients' spleens had shrunk by more than half (56 per cent) on average, compared with only four per cent for the best current therapy.

Some patients were even judged so improved that they returned to work, with most becoming more active. The majority were also able to eat more and suffered less abdominal pain, night sweats, itching and bone pain.

Bone marrow transplants are the only cure for the condition. But they are generally only considered suitable for patients who are younger and fitter, and most myelofibrosis patients are in their 60s or 70s.

This means that the emergence of ruxolitinib could prove important, as existing drugs have limited effects on relieving symptoms, do not address the underlying causes, and can cause leukaemia among patients who already have a high risk of developing the disease.

The European study was led by researchers at Guy's and St Thomas's NHS Foundation Trust, led by Dr Claire Harrison.

"This is a huge step forward for patients," she said.

"It's the biggest breakthrough I've had in my career - it's very gratifying to give your patient a drug and have them feel dramatically better within a couple of days. That doesn't happen often in medicine."

Martin Ledwick, head of Cancer Research UK's information nurse team, said it was good to see new treatments being developed for a rare condition.

"When myelofibrosis is advanced, its symptoms are debilitating and difficult to bear. So developing new approaches which might help improve quality of life and perhaps, in the future, be found to improve life expectancy has to be a good thing," he added.

Symptoms of the disease include bone pain, excessive itchiness, fatigue, night sweats and severe anaemia.

People with the disease also experience an enlarged spleen, which can affect walking and stretches the stomach so much that it causes gastrointestinal problems.

Source: CRUK