Serratus Plane Block (SPB) Versus Capsaïcine Versus Botox-A for Chronic Neuropathic Pain in Post-mastectomy Syndrome

NCT06807164 | Recruiting Phase 2

• 2 other identifiers: SerCaBot-23022024-517420-20-00
• Study Type: interventional
• Target: 123
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this phase II clinical trial is to study the effectiveness of a treatment with Serratus Plane Block (SPB) or Botox-A in comparison with capsaicin for the control of chronic neuropathic pain of post-mastectomy syndrom, that is not adequately managed by systemic treatment alone. The primary outcome will be the pain evaluation at 8 weeks. 123 patients with chronic neuropathic pain of post-mastectomy syndrom insufficiently relieved by systemic treatment alone will be recruited over 24 months at the Centre Oscar Lambret. Patients will be randomly assigned to one of three treatment groups (41 patients per group): Capsaicin Botulinum toxin A SPB Patients will be followed for 24 weeks after the study treatment. The follow-up will include remote evaluation and 2 medical visits during which pain and quality of life will be assessed.

Conditions

Post-Mastectomy Neuropathic Pain Syndrome

Keywords

Breast cancer; Chronic neuropathic pain; Post-mastectomy pain; Serratus Plane Block (SPB); Capsaicin; Pain management; Botulinum toxin type A

Outcome Measures

Primary Outcomes (1)

• Pain assessment using Numerical Pain Scale (END)

  The primary outcome measure is pain assessed by self-evaluation using the Numerical Pain Scale (END) ranging from 0 (no pain) to 10 (worst pain imaginable) at rest, evaluated 8 weeks after treatment (or 9 weeks after randomization if treatment was not performed). The patient's self-assessment reflects individual treatment efficacy. In case of treatment interruption due to immediate intolerance or technical issues, the baseline END will be considered for the primary analysis.

  8 weeks after treatment initiation, or the closest measurement within +/- 1 week if the 8-week data is missing.

Secondary Outcomes (9)

• Success of Pain Control

  Assessed at 8 weeks post-treatment.

• Evolution of Pain Scores

  Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.

• Neuropathic Component Evaluation

  Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.

• Early Treatment Failure

  Assessed at 7 and 14 days post-treatment

• Modification of introduction of New Analgesic Treatment

  Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.

Study Arms (3)

Capsaicin 8% Patch (Control)

ACTIVE COMPARATOR

Participants in this arm will receive an 8% capsaicin patch in a single treatment session in addition to a systemic treatment that has been ongoing for at least 4 weeks. If pain persists, the capsaicin patch application may be repeated at 12 weeks.

Drug: Capsaicin 8% Patch

Serratus Plane Block (SPB)

EXPERIMENTAL

Participants in this arm will undergo a Serratus Plane Block (SPB), a local anesthetic injection administered by a trained anesthesiologist, in addition to a systemic treatment that has been ongoing for at least 4 weeks. The SPB can be repeated every two weeks up to a maximum of four sessions within the initial 8-week period if pain persists. A repeat treatment may be considered at 12 weeks if further pain control is needed. This intervention aims to provide extended pain relief for neuropathic pain in post-mastectomy patients

Procedure: Serratus Plane Block

Botulinum Toxin A (Botox-A) Injection

EXPERIMENTAL

This arm involves administration of Botulinum Toxin A (Botox-A) at the site of pain, in addition to a systemic treatment that has been ongoing for at least 4 weeks. If pain remains unresolved, the injection may be repeated at 12 weeks. Botox-A is used here as a local, long-lasting analgesic intervention aimed at reducing chronic neuropathic pain in patients post-mastectomy.

Procedure: Botulinum Toxin A

Interventions

Capsaicin 8% Patch DRUG

One or two capsaicin patch (8%) are applied for 60 minutes to the site of neuropathic pain, in day-hospital. An oral, antalgic pre-medication may be done with one of the following medications (alone or association): paracetamol 1g, nefopam 30 mg, tramadol 100 mg, morphine 10mg, oxycodone 5mg. Capsaicin will be administered in addition to a systemic treatment that has been ongoing for at least 4 weeks. If pain persists, the capsaicin patch application may be repeated at 12 weeks.

Also known as: Qutenza®

Capsaicin 8% Patch (Control)

Serratus Plane Block PROCEDURE

The Serratus Plane Block (SPB) is a nerve block performed by a trained anesthesiologist to provide localized pain relief. It involves the injection of a local anesthetic: Maximum 150 mg naropeine combined with 150 μg clonidine hydrochloride into the serratus anterior plane under ultrasound guidance. An anesthesiologist will perform the procedure in a post-interventional recovery room, with light sedation.The SBP will be carried out in addition to a systemic treatment that has been ongoing for at least 4 weeks. The SPB may be repeated every two weeks up to four times in the initial 8-week period, with an additional repeat at 12 weeks if pain control remains insufficient.

Also known as: SPB

Serratus Plane Block (SPB)

Botulinum Toxin A PROCEDURE

Botulinum Toxin A (Botox-A) is injected into the affected area, with a total of 300 units administered across up to 60 injection sites. An anesthesiologist will perform the procedure in a post-interventional recovery room, with light sedation. This intervention will be carried out in addition to a systemic treatment that has been ongoing for at least 4 weeks, and is aimed at providing prolonged pain relief for post-mastectomy neuropathic pain. Light sedation is provided, and injections may be repeated at 12 weeks if necessary.

Also known as: Botox-A, Botox

Botulinum Toxin A (Botox-A) Injection

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Women aged ≥ 18 years;
• Unilateral breast cancer treated by total or partial mastectomy:
• with sentinel lymph node technique (SLN) or axillary dissection;
• with or without immediate reconstruction using a prosthesis;
• associated or not with radiotherapy and/or chemotherapy;
• Presenting moderate to severe chronic neuropathic pain, defined by:
• Numerical Pain Scale (NPS) ≥ 3 and DN4 ≥ 4,
• on a localised aera ((≤ 240 cm²), at the surgical site, in the axillary hollow, or on the inner side of the ipsilateral arm,
• between 3 and 9 months after breast surgery,
• with indication of additional locoregional treatment in complement to a systemic treatment of chronic neuropathic pain, as recommended by the SFETD - French Society for the Study and Treatment of Pain (tricyclic antidepressants or IRSNA or gabapentinoid PLUS lidocaine patch, at the appropriate dosage) and implemented for at least 4 weeks;
• Patient affiliated with a health insurance plan;
• Patient informed and having consented to participate in the trial.

You may not qualify if:

• Ipsilateral breast cancer recurrence, regardless of the first treatment;
• History of breast or thoracic surgery prior to mastectomy with residual pain;
• Painful polyneuropathy related to chemotherapy requiring treatment;
• Ongoing or planned loco-regional adjuvant radiotherapy within the next 8 weeks;
• Treatment area not suitable for potential botulinum toxin type A treatment;
• Breast reconstruction using flap or lipomodelling;
• Indication for breast reconstruction within the next 8 weeks;
• Chronic pain of another etiology such as:
• Neuropathic pain secondary to a neuroma (localized pain),
• Radiodermatitis,
• Phantom breast pain,
• Lymphedema,
• Complex regional pain syndrome,
• Adhesive capsulitis,
• Fibromyalgia;

Sponsors & Collaborators

• Centre Oscar Lambret: lead
• Ligue contre le cancer, France: collaborator
• Santelys Association: collaborator
• CTD-CNO, Caen: collaborator

Study Sites (1)

Centre Oscar Lambret

Lille, Hauts-de-France, 59000, France

RECRUITING

MeSH Terms

Conditions

Breast Neoplasms; Agnosia

Interventions

Capsaicin; Transdermal Patch; Botulinum Toxins, Type A

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Perceptual Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Polyunsaturated Alkamides; Amides; Organic Chemicals; Alkenes; Hydrocarbons, Acyclic; Hydrocarbons; Catechols; Phenols; Benzene Derivatives; Hydrocarbons, Aromatic; Hydrocarbons, Cyclic; Solanaceous Alkaloids; Alkaloids; Heterocyclic Compounds; Fatty Acids, Monounsaturated; Fatty Acids, Unsaturated; Fatty Acids; Lipids; Equipment and Supplies; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Hydrolases; Enzymes; Enzymes and Coenzymes; Metalloproteases; Bacterial Proteins; Proteins; Amino Acids, Peptides, and Proteins; Bacterial Toxins; Toxins, Biological; Biological Factors

Study Officials

• Didier DELBROUCK, Anesthesiologist

  Centre Oscar Lambret

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Julien THERY, Project manager

CONTACT

+33 (0)3 20 29 59 18; j-thery@o-lambret.fr

Victor DESTEIRDT, Clinical Research Associate-M

CONTACT

+33 (0)3 20 29 59 18; v-desteirdt@o-lambret.fr

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: N/A (since the study is open label)
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Phase 2, randomized clinical trial, open-label, evaluating 3 interventions : Capsaicin, Botox-A, SPB

Study Record Dates

• First Submitted: January 29, 2025
• First Posted: February 4, 2025
• Study Start: March 31, 2026
• Primary Completion (Estimated): August 30, 2027
• Study Completion (Estimated): December 30, 2027
• Last Updated: March 27, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)