Clinical Trials for Complex Regional Pain Syndrome
There are currently 4 ongoing clinical trials investigating treatments for Complex Regional Pain Syndrome across Europe. These studies are exploring different approaches including monoclonal antibodies, botulinum toxin injections, anesthetic medications, and vitamin supplementation to help manage this challenging chronic pain condition.
Clinical trial locations
- Denmark
- France
- Netherlands
Study on Fremanezumab for Pain Relief in Patients with Complex Regional Pain Syndrome
This trial is investigating whether fremanezumab, a monoclonal antibody medication, can help reduce pain in people living with Complex Regional Pain Syndrome. The study compares the effects of fremanezumab against a placebo over an eight-week treatment period.
Who can participate: The trial is open to adults between 18 and 75 years old who have been diagnosed with CRPS according to the Budapest criteria. Participants must have had symptoms for 3 to 18 months and experience significant pain levels, with an average daily pain score of at least 4 out of 10 during the baseline week.
Who cannot participate: The trial excludes patients with other medical conditions beyond CRPS, those outside the specified age range, people who cannot give informed consent, individuals currently in another clinical trial, those with allergies to the study medication, pregnant or breastfeeding women, and patients with certain medical conditions or recent medication use that could interfere with results.
Treatment approach: Fremanezumab is given as an injection under the skin using a pre-filled syringe at a dose of 225 mg. The medication works by blocking a specific protein involved in transmitting pain signals. Throughout the trial, participants track their daily pain levels using a scale from 0 (no pain) to 10 (worst possible pain) to measure changes in pain intensity.
Study of perineural incobotulinumtoxinA treatment for patients with Complex Regional Pain Syndrome type I or II affecting one side of the body
This research examines whether injections of incobotulinumtoxinA (Xeomin), a purified form of botulinum toxin, can help manage pain when injected near the affected nerves. The study aims to determine if this treatment method is practical and safe for people with CRPS affecting one arm or leg.
Who can participate: Adults aged 18 or older with CRPS type I or II affecting one limb are eligible. The condition must meet the Budapest Research Criteria and have been present for at least 6 months. Participants must have CRPS as their main pain condition, have been on stable pain medication for at least one month, and agree to maintain the same medication throughout the study. Women of childbearing age must use effective contraception, and all participants must be able to communicate in Danish.
Who cannot participate: The trial excludes people younger than 18 or older than 65, pregnant or breastfeeding women, those with previous allergic reactions to botulinum toxin, active infections at the injection site, blood clotting disorders, those taking blood thinners, individuals with neuromuscular junction disorders, people currently using other botulinum toxin products, those who had major surgery in the affected area within 6 months, participants in other recent trials, people with severe psychiatric conditions, and those with other chronic pain conditions that could affect results.
Treatment approach: Participants receive up to 200 units of Xeomin injected near the nerves in the affected limb. The medication works by blocking nerve signals that cause muscle contractions and pain transmission. The treatment period may last up to 12 months, and the study will monitor pain levels and any symptoms that occur after the injections.
Study on Esketamine for Long-term Pain Relief in Patients with Complex Regional Pain Syndrome
This trial is testing whether a series of esketamine infusions given every two weeks for three months is as effective as the standard treatment, which involves continuous administration over six days in a hospital setting. The goal is to find out if this less intensive approach can provide similar pain relief.
Who can participate: The trial is open to adults aged 18 or older who meet the Budapest Criteria for CRPS or have “CRPS with Remission of Some features.” Participants must have CRPS affecting one arm or one leg, be receiving planned (non-emergency) treatment, and have an adequate understanding of Dutch to follow study instructions.
Who cannot participate: Patients without a CRPS diagnosis, those younger than 18 or older than 65, and individuals considered part of a vulnerable population cannot participate.
Treatment approach: Esketamine is administered through intravenous infusion in a day treatment setting every two weeks for three months. The medication is provided in two strengths (25 mg/ml and 5 mg/ml) under the brand name Ketanest S. Esketamine works by blocking NMDA receptors in the brain, which are involved in pain perception. The study monitors pain intensity, inflammation markers, side effects, and changes in the need for other pain medications throughout the three-month treatment period and continues observations for up to twelve months after surgery.
Study on the Effect of Vitamin C and Microcrystalline Cellulose on Reducing Complex Regional Pain Syndrome in Patients Undergoing Upper Limb Surgery
This trial investigates whether taking Vitamin C around the time of upper limb surgery can reduce the risk of developing CRPS Type I after the procedure. The study represents a preventive approach rather than treatment of existing CRPS.
Who can participate: Patients over 18 years old who are scheduled for major surgery of the upper limb (such as the arm or hand) are eligible. Participants must be able to give informed consent to follow the treatment and monitoring plan and must have social security coverage.
Who cannot participate: The trial excludes patients outside the specified age range, those not undergoing upper limb surgery, patients without CRPS type 1 (also known as algoneurodystrophy), and individuals considered part of a vulnerable population.
Treatment approach: Participants take l-ascorbic acid (Vitamin C) orally in capsule form, starting before surgery and continuing for six months. Vitamin C is believed to work by reducing oxidative stress and inflammation, which may help prevent the onset of CRPS. The study monitors participants for up to twelve months after surgery to check for signs of CRPS Type I and evaluates how well participants tolerate the vitamin and follow the treatment plan.
Summary
The current clinical trials for Complex Regional Pain Syndrome demonstrate diverse research approaches across Europe, with studies taking place in Denmark, the Netherlands, and France. Two trials are being conducted in Denmark, each exploring different treatment methods: one using a monoclonal antibody that blocks pain signaling proteins, and another using botulinum toxin injections near affected nerves.
The trials reveal two main research directions: treating existing CRPS symptoms and preventing CRPS development after surgery. Three trials focus on managing established CRPS using different mechanisms including pain signal blockers, nerve-targeted injections, and NMDA receptor antagonists. One trial takes a preventive approach by testing whether Vitamin C supplementation around the time of upper limb surgery can reduce the risk of developing CRPS.
Notably, all trials focus on CRPS affecting the limbs, with specific attention to single-limb involvement. The studies range from small feasibility trials to larger comparative effectiveness studies, and they employ various assessment methods including pain intensity scales and inflammation markers. Treatment durations vary from eight weeks to twelve months of monitoring, reflecting both the chronic nature of the condition and the need for long-term safety data.
