The results of the world’s first Phase 3 trials, of a new drug Gefapixant, show that it can ease the often distressing symptoms of chronic cough, with minimal side effects.
Professor Jacky Smith, who led the study, Honorary Consultant at Wythenshawe Hospital, part of Manchester University NHS Foundation Trust (MFT), and Director of the NIHR Manchester Clinical Research Facility (CRF), which supported the delivery of the study, says Gefapixant has the potential to have a significant impact on the lives of thousands of sufferers.
Chronic coughing is defined as a cough lasting more than eight weeks, and is thought to affect between four per cent and 10 per cent of the population, some of whom cough thousands of times a day, over many years.
While many patients improve with the treatment of associated conditions such as asthma, gastroesophageal reflux disease, and nasal disease, many do not.
The condition can cause abdominal pain, urinary incontinence in women, as well as anxiety, depression and difficulty sleeping.
The two Phase 3 trials – called Cough 1 and Cough 2 recruited 2,044 participants from 156 sites in 17 countries who had been suffering from chronic cough for an average of 11 years.
In the Cough 1 trial, 730 participants were given either Gefapixant 45mg, 15 mg, or a placebo and in the Cough 2 trial, 1,314 participants in the were given either Gefapixant 45 mg, 15mg, or a placebo.
The study results, published in The Lancet, show that Gefapixant 45 mg demonstrated an 18.5 per cent reduction in 24-hour cough frequency relative to placebo in Cough 1 and a 14·6 per cent reduction in Cough 2.
Professor Smith also leads the NIHR Manchester Biomedical Research Centre (BRC), Improving Respiratory Symptoms Programme, which is helping to reduce disease progression and symptoms for people with respiratory conditions by working towards earlier diagnosis and a more targeted approach.
Professor Smith said:
“These global trials have confirmed that this drug has exciting potential for patients who suffer from chronic cough, an often distressing condition.
“Effective treatments for cough are a significant unmet clinical need and no new therapies have been approved in over 50 years.
“Billions of pounds are spent annually on over-the-counter cough and cold medicines despite a lack of evidence to support their efficacy, concerns about the potential for abuse and risk of harm in overdose.”
The study monitored the impact of Gefapixant – which can target P2X3receptors in the nerves that control coughing – using a special cough monitoring system originally developed in Manchester to counts coughs.
The drug was initially developed as a painkiller, until the researchers discovered it had a significant impact on chronic cough.
Retired journalist Nick Peake, from Warrington, was a previous cough study participant at Manchester CRF, at Wythenshawe Hospital.
Nick, who was a television director at ITV and the BBC, has been suffering from chronic cough for 25 years said: “Coughing has blighted my life. Every day without fail I cough for the first two hours, soon after I wake up, often every 30 seconds. It wears me out.
“It comes and goes through the day, usually after a meal, or when I have a change of atmosphere – out of warm into cold, or if I exercise too hard.
“It often stops me getting to sleep at night, but then I might wake up at three or four o’clock in the morning and start coughing.
He added: “The coughing interferes with conversations, sometimes it stops me singing which I love to do. It’s embarrassing when I’m with people – I find myself apologising a lot, and I have no control over it.
“So I’m often in despair about it and it can make me miserable. How my wife has put up with it all this time I don’t know.
“It’s been going on for so long and I’m thoroughly fed up with it, and desperate for a cure to be found.”
Professor Smith, who is also Professor of Respiratory Medicine at The University of Manchester, added: “We can’t say this drug is a cure for chronic cough, but it can, and often does, reduce the frequency of coughing substantially.
“Now these the phase 3 trials have been successful, we feel this is a major step towards this treatment becoming available for our patients with chronic cough.
“That could make a big difference to patients who often struggle with this condition which can make such a big impact on their lives.”