New drug treatment reduces chronic pain following shingles

A new drug treatment has been found to be effective against chronic pain caused by nerve damage, also known as neuropathic pain, in patients who have had shingles.

The researchers hope that the might also be effective against other causes of , such as diabetes, HIV, nerve injury and , as it targets a mechanism that is not targeted by any existing therapies and has fewer .

Drugs available now have limited success at treating neuropathic and often have unpleasant or disabling side effects.

It is estimated that around 190,000 people in the UK get shingles every year, most of them aged over 50. It is caused when a dormant viral infection of a nerve is reactivated, resulting in a painful rash. In most cases, the shingles rash lasts a few weeks, but in some cases the permanent caused by the virus results in a chronic neuropathic pain called post-herpetic neuralgia. Around one in 10 people with shingles experiences post-herpetic neuralgia and, once established, it usually causes life-long suffering.

In a study involving 183 with post-herpetic neuralgia in six countries, the new drug EMA401 was found to reduce pain and did not cause any serious side effects. The findings are published in The Lancet.

Lead author Professor Andrew Rice, from the Department of Surgery and Cancer at Imperial College London, said: "Conventional painkillers don't tend to help people with severe chronic neuropathic pain and most available treatments have modest efficacy and/or are limited by side effects. We are therefore keen to find new ways of providing these people with some relief.

"A positive trial like this in such a challenging condition as post-herpetic neuralgia, for a drug that acts in a new way, is unusual and very exciting. We hope that the new drug will ultimately offer hope for patients who aren't helped by current treatments."

The study, a phase 2 trial, compared EMA401 with a placebo, with participants taking two pills a day for four weeks. Fifty-eight per cent of participants taking the drug found it effective, reducing pain by at least 30 per cent.

Spinifex Pharmaceuticals, which owns the drug, now plans to conduct a larger trial, possibly testing higher doses of the drug for longer periods of time.

"We are looking forward to seeing how EMA401 performs in a larger trial in people with post-herpetic neuralgia, where we will explore higher doses, and in trials where we will analyse its efficacy in other conditions. Identifying the characteristics of the patients who do get good pain relief from EMA401 will also be an important avenue for research," added Professor Rice.

Tom McCarthy, CEO of Spinifex Pharmaceuticals, said: "There is a clear need for new treatments that bring patients pain relief with fewer side effects. In addition to post-herpetic neuralgia, we see broad potential for EMA401 to treat a range of chronic painful conditions such as pain due to osteoarthritis and diabetes. We look forward to delivering on the further development of EMA401."

Spinifex's clinical program for EMA401 includes a clinical trial in the treatment of neuropathic pain in patients after cancer chemotherapy, which is being conducted by Professor Praveen Anand at Imperial College London. Professor Anand's group also conducted key clinical tissue research which led up to the trials.

Professor Rice works with patients with at Chelsea and Westminster Hospital, where he is a Consultant in Pain Medicine. He has worked with Spinifex through Imperial Consultants on the pre-clinical development of the new drug since 2005.

More information: A.S.C. Rice et al. 'EMA401, an orally administered highly selective angiotensin II type 2 receptor antagonist, as a novel treatment for postherpetic neuralgia: a randomised, double-blind, placebo-controlled phase 2 clinical trial.' The Lancet, 5 February 2014 dx.doi.org/10.1016/S0140-6736(13)62337-5

Related Stories

Positive news for shingles pain sufferers

date Aug 29, 2012

A new treatment from a University of Queensland start-up company, Spinifex Pharmaceuticals, could bring hope to shingles sufferers experiencing nerve pain.

How does exercise affect nerve pain?

date Jun 01, 2012

Exercise helps to alleviate pain related to nerve damage (neuropathic pain) by reducing levels of certain inflammation-promoting factors, suggests an experimental study in the June issue of Anesthesia & Analgesia, offici ...

Drug may reduce chronic pain for spinal cord injuries

date Oct 31, 2013

(Medical Xpress)—Researchers have discovered that a known neurotoxin may cause chronic pain in people who suffer from paralysis, and a drug that has been shown to remove the toxin might be used to treat ...

Recommended for you

Niger battles deadly meningitis epidemic

date 38 minutes ago

Parents cradling sick children in their arms streamed into a treatment centre in Niger's capital Niamey, the victims of a meningitis epidemic that has claimed over 100 lives and appears to be accelerating.

Long lasting anti-hemophilia factor safe in kids

date 5 hours ago

Children with hemophilia A require three to four infusions each week to prevent bleeding episodes, chronic pain and joint damage. The effect on quality of life can be significant, due to time and discomfort associated with ...

Missouri detective battles flesh-eating infection

date 9 hours ago

Friends and loved ones of Lee's Summit, Mo., Police Detective Joshua Ward are praying for the 34-year-old married father of three who, even after five surgeries in as many days, remained in critical condition Monday at St. ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.