Migraine sufferers have been offered new hope after trials showed a designer drug cuts the number of attacks in half. The once-a-month injection, which can be delivered at home, blocks brain molecules linked to migraine, and is the first new preventative therapy in 20 years.

Around 8.5 million people in Britain suffer migraines, and there are 200,000 attacks every day in the UK. Symptoms can be so severe that lying in a darkened room is the only relief for the throbbing pain and nausea.

However the new drug, called Erenumab, appears to slash in half the number of days lost to the condition for many patients, a breakthrough which charities said marked ‘the start of a real change’ for sufferers.

Dr Peter Goadsby, Professor of Neurology at King’s College London, who led the Phase III clinical trial, said: “It clearly shows that blocking this pathway can reduce the impact of migraine.

“The results represent a real transition for migraine patients from poorly understood, repurposed treatments, to a specific migraine-designed therapy.

“It represents an incredibly important step forward for migraine understanding and migraine treatment.”

Migraine usually involves severe head pain and often brings symptoms including nausea, vomiting and sensitivity to light or sound. It affects one in every five women and around one in every 15 men. Around half of all sufferers have a close relative with the condition, suggesting that it may be genetic.