Surgery is supposed to fix a problem, not leave a new one behind. Yet for millions of people each year, the operation ends but the pain does not. Nerves damaged or irritated during surgery can keep firing long after the wound has healed, producing burning, tingling, or stabbing pain around the scar that lasts for months or even years. Doctors call this post-surgical neuropathic pain, and it has long been one of the most frustrating problems in pain medicine: common, life-limiting, and poorly served by the treatments available.
On 27 October 2026, researchers presented new results that may change that picture. At the International Association for the Study of Pain (IASP) World Congress on Pain in Bangkok, Thailand, the drug company Grünenthal shared late-breaking data from its Phase III RISE trial of Qutenza, a high-strength capsaicin patch made from the compound that gives chilli peppers their heat. The headline result was positive: over the first 12 weeks, patients treated with the patch reported a significantly greater reduction in average pain than those given a control patch. But the full story is more mixed, and more interesting, than the headline alone. One of the trial's two main measures did not reach statistical significance, and the detailed numbers have so far been shared only as conference posters, not as a full peer-reviewed paper. This article explains what the trial tested, what it found, and what it did not prove.
When surgery leaves pain behind
Most surgical pain fades as tissues heal. Post-surgical neuropathic pain is different. It is defined as chronic pain with neuropathic features that develops or increases after surgery and persists beyond the normal healing process, thought to arise at least in part from nerve injury and pain sensitisation during the operation.
The symptoms can be distressing: pain from a light touch that should not hurt (allodynia), exaggerated pain from a mild stimulus (hyperalgesia), tingling, numbness, phantom sensations, and pain centred on the scar. Research cited by Grünenthal found patients reporting feeling extremely depressed or anxious and struggling with everyday activities.
Part of the problem is recognition. Grünenthal's chief scientific officer, Uli Brödl, described post-surgical neuropathic pain as "relatively understudied" and said it "continues to go under-recognised in clinical practice". A condition that is not recognised is not treated, and patients can spend years moving between clinics without a clear explanation for why they still hurt.
The scale is large. Grünenthal says the condition affects millions of patients every year. That figure, drawn from older pain-management literature, should be read as an estimate rather than a precise count, but even a fraction of it represents an enormous unmet need.
What is Qutenza, and how does it work?
Qutenza is a cutaneous patch containing 179 mg of capsaicin at 8% strength. Capsaicin is the active compound in chilli peppers, and it works on a receptor called TRPV1, found on pain-sensing nerve endings in the skin. In simple terms, a strong, controlled dose of capsaicin overstimulates those nerve endings and then "defunctionalises" them — it temporarily shuts down their ability to send pain signals while the nerve fibres recover. That is why a single patch application can provide relief for up to three months, rather than hours.
The patch is already an established medicine, just not for this condition. In Europe, it is approved for peripheral neuropathic pain in adults; in the United States, for nerve pain linked to shingles and for diabetic peripheral neuropathy of the feet. Post-surgical neuropathic pain would be a new use, which is why the RISE trial matters: it tests whether an existing, well-understood treatment works in a new group of patients.
It is worth being clear about what this treatment is not. It is not a chilli-pepper cream you can buy and rub on at home. The 8% patch is a prescription treatment applied in a clinic, typically for about an hour, by trained staff. It is a world away from mild over-the-counter capsaicin creams, and it should never be improvised at home.
Inside the RISE trial
The RISE trial (trial registration NCT04967664) was a Phase III, multi-centre, randomised, double-blind, parallel-group study sponsored by Averitas Pharma, Grünenthal's United States subsidiary. It enrolled 409 adults with moderate to severe post-surgical neuropathic pain.
To join the trial, participants needed a 24-hour average pain score of at least 4, pain lasting between 6 and 60 months after surgery, and a score of at least 3 on the DN4 questionnaire, a screening tool for neuropathic pain. The trial studied people with established, clearly neuropathic pain, not ordinary short-term pain straight after an operation.
Participants were randomly assigned to one of two patches, applied for 60 minutes. One group received the full-strength Qutenza patch (8% capsaicin). The other received a low-dose capsaicin control patch (0.04%). Using a very low dose of the same active ingredient as the control, rather than a fully inactive patch, is deliberate: capsaicin causes a warming, tingling sensation, so an inactive patch would quickly reveal who got the real treatment. The low-dose control helps keep the comparison honest.
The trial had two primary endpoints, both based on change in 24-hour average pain intensity from the start of the study: the average score across the whole period from week 2 to week 12, and the score at week 12 alone, the point at which patients would typically return for retreatment.
What the results actually showed
Here is where careful reading pays off, because the two endpoints told slightly different stories.
On the first endpoint, Qutenza won clearly. Over weeks 2 to 12, patients on the full-strength patch had a statistically significantly greater reduction in average pain intensity than those on the control patch. In plain language, the difference was large enough, and consistent enough across 409 patients, that it is unlikely to be a chance finding. This was one of the trial's pre-specified primary endpoints, so it is a genuine success, not a result fished out afterwards.
On the second endpoint, the picture was softer. At week 12 specifically, the numerical difference still favoured Qutenza, but it did not reach statistical significance. That does not mean the patch stopped working at week 12. Averaging pain over ten weeks smooths out the ups and downs of individual bad days; a single-week snapshot is noisier. Both readings can be true at once: sustained benefit over the period, with a less certain result at the final week.
The extension phase is where the results look most encouraging. Patients who continued could receive up to four retreatments, and over weeks 2 to 42, Qutenza again achieved a significantly greater reduction in average pain than the control. Professor Patrice Forget, clinical chair in anaesthesia at the University of Aberdeen, said the trial provides "encouraging evidence that Qutenza can deliver clinically meaningful and sustained pain reduction for up to 42 weeks".
On safety, the company reported findings consistent with previous Qutenza trials, with no new safety signals. That is reassuring, but the release does not publish rates of side effects or dropouts; those details will matter when the full data appear.
Why the result matters — and what it does not prove
The RISE results matter for three reasons. First, they address a condition with few good options. Many patients with nerve pain rely on daily tablets that can cause drowsiness or dizziness and do not work for everyone. A treatment applied once in a clinic, with effects lasting months, is a genuinely different kind of option.
Second, the benefit lasted. A significant advantage sustained over 42 weeks, with retreatments, suggests the effect is durable rather than a brief lift. That long horizon is exactly what patients with years-long pain need.
Third, the trial adds to a consistent body of evidence. Qutenza is not a new, untested molecule; it is an approved medicine being tested in a new population. That lowers, though it does not remove, the uncertainty around safety.
But honesty requires the caveats too. The results were presented as conference posters, not yet as a full peer-reviewed journal article, so independent experts have not yet been able to examine the complete dataset. The announcement does not report the size of the pain reduction in points on the pain scale, only that it was statistically significant, so readers cannot yet judge how large the benefit feels to a patient. And the week-12 single-point result falling short of significance is a reminder that the benefit, while real over the whole period, may vary from week to week.
There is a broader lesson here: long-term problems need long-term thinking. Readers interested in that wider picture may enjoy our report on how a nurse-led program is helping midlife adults cut dementia risk, which applies the same principle — structured, ongoing support rather than a one-off fix — to brain health. Our guide to the science of sleep debt explains why the brain cannot fully catch up on lost sleep at weekends, and poor sleep is a common companion of chronic pain. And for another treatment whose real challenge is what happens after the first success, see our look at the weight-regain problem after GLP-1 drugs.
What happens next
Grünenthal has not yet announced a regulatory filing for post-surgical neuropathic pain, and Qutenza is not currently approved for this use in Europe or the United States. The usual next steps would be publication of the full results in a peer-reviewed journal, followed by discussions with regulators. That process takes time, and approval is never guaranteed.
For patients living with pain after surgery today, the practical message is simpler: if pain persists well beyond healing, especially burning, tingling, or touch-sensitive pain around a scar, it is worth raising specifically with your doctor, and asking whether a neuropathic cause has been considered. This article is for information only and is not medical advice; treatment decisions should always be made with a qualified clinician who knows your history.
The bottom line
The RISE trial gives post-surgical neuropathic pain something it has rarely had: positive Phase III evidence for a treatment that works over months, not days. Qutenza met its main sustained-benefit endpoint in 409 patients, held its advantage over 42 weeks with retreatments, and showed no new safety concerns. The week-12 snapshot result and the absence of detailed effect sizes mean the story is incomplete, and the full published data will be the real test. But for people whose surgery ended long ago while their pain did not, this is a genuinely hopeful development.
This article is for general information only and is not medical advice. If you are living with persistent pain after surgery, speak to your doctor or another qualified health professional about your options.