Response Profiles to High-concentration Capsaicin Desensitization in Patients with Peripheral Neuropathic Pain with or Without Allodynia: a Regional Multicenter Prospective Cohort

Overview

Prospective multicenter cohort to determine patient profiles (associated factors, including allodynia) with a better response to pain desensitization by capsaicin delivered in the form of a high concentration patch (8%), in a population of patients with peripheral neuropathic pain and followed up in a pain consultation in the Auvergne Rhône Alpes region.

Interventions

• Other Questionnaires
  In current practice, capsaicin patch treatment is offered to patients with a 24-hour average pain level measured by the EN numerical scale : EN scale is \> 4 Pain monitoring questionnaires will be completed by patients every 6 weeks : Neuropathic Pain Symptom Invetory (NPSI Score), Patients' Global Impression of Change (PGIC scale), Numerical pain scale

Primary outcome measures

• Factors (profiles) associated with a better initial response to pain desensitization by capsaicin [Time frame: 12 months]

Secondary outcome measures (9)

• Proportion [95% Confidence Interval (CI)] of patients "responder at 30%" at 1.5 months after each consecutive patch (e.g. at M4.5 for a second patch applied at M3) [Time frame: 1.5 months after each consecutive patch]
• Proportion [95% CI] of patients "initial responder" at 50% [Time frame: 12 months]
• Distribution of Neuropathic Pain Symptom Inventory (NPSI) score values over time: at inclusion, 3 months, 6 months, 9 months,12 months, and between inclusion and the end of follow-up [Time frame: Each 3 months and over 12 months]
• Distribution of NPSI subscores values (Q8, Q9, Q10) over time: at inclusion, 3 months, 6 months, 9 months,12 months, and between inclusion and the end of follow-up [Time frame: Each 3 months and over 12 months]
• Distribution of Patients' Global Impression of Change (PGIC) scale score values over time: at 1.5 months, 3 months, 4.5 months, 6 months, 7.5 months, 9 months,10.5 months, 12 months, and between inclusion and the end of follow-up [Time frame: Each 1.5 months and over 12 months]
• In the subpopulation of patients with allodynia (dynamic mechanical or static or thermal): proportion [95% CI] of "responders" at 7.5 months [Time frame: 7.5 months]
• In the subpopulation of initial responders at the 30% threshold: proportion [95% CI] of patients relapsing at 12 months, defined as pain scale (EN) > 4/10, indicating a new capsaicin patch [Time frame: 12 months]
• Number of new initiation of analgesic treatment, defined by the addition of a molecule to the treatment given at the time of application of the first capsaicin patch [Time frame: 12 months]
• Number of reduction of analgesic treatment, defined by the stop of a molecule compared to the treatment given at the time of the application of the first capsaicin patch [Time frame: 12 months]

Eligibility criteria

Inclusion criteria

• Patient over 18 years of age on the day of inclusion
• Patient who has been informed and has not expressed opposition to participating in the study,
• Patient with peripheral neuropathic pain (whatever the etiology), defined by :

• "Neuropathic Pain 4" score ("DN4" score) ≥ 4/10
• AND pain according to the numerical scale (EN) > 4/10,
• AND stable analgesic treatment for at least 1 month,
• AND with or without mechanical allodynia according to the Quantitative Sensory Testing (QST) : Brush test (dynamic), Von Frey test (static)
• AND with or without thermal allodynia to hot or cold as determined by a ROLLTEMP-II® (Rolltemp is a device designed for quick screening of temperature sensibility over large body areas).
• Patient responding to an indication of desensitization to high concentration capsaicin concentration and not presenting any contra-indication.
• Patient naïve of high concentration of Capsaicin on the concerned zone
• Patient understanding French

Non-inclusion Criteria:

• Patient with pain related to complex regional pain syndrome (criteria not meeting the indication for capsaicin)
• Patient with active cancer (underlying disease and treatments may modify pain perception),
• Patient receiving or having received in the last 3 months Botulinum toxin A on the concerned area (this treatment of neuropathic pain may modulate the effect of capsaicin and disturb the demonstration of causality),
• Patient with planned surgery within the next 12 months on the painful site (surgery may cause neuropathic damage and/or bias the pain assessment),
• Patient included in an interventional research protocol,
• Patient under guardianship or curators,
• Patient under legal protection

Exclusion criteria

None

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

France · 10 centers

• Centre Hospitalier Annecy Genevois — Annecy
• Hospices Civils de Lyon, Hôpital Pierre Wertheimer — Bron
• Centre Hospitalier Métropole Savoie — Chambéry
• Centre Hospitalier Universitaire de Clermont-Ferrand — Clermont-Ferrand
• Centre Hospitalier Universitaire Grenoble-Alpes — Grenoble
• Hospices Civils de Lyon, Hôpital de la Croix Rousse — Lyon
• Centre Léon Bérard — Lyon
• Centre Hospitalier Universitaire de Saint-Etienne — Saint-Etienne
• … and 2 more centers

Identifiers

NCT: NCT05817591 · 19-50

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗