Clinical trial NCT06807164: Serratus Plane Block (SPB) Versus Capsaïcine Versus Botox-A for Chronic Neuropathic Pain in Post-mastectomy Syndrome
Official title: Serratus Plane Block (SPB) Versus Capsaïcine Versus Botox-A for Chronic Neuropathic Pain in Post-mastectomy Syndrome
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: PHASE2
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
Lead sponsor: Centre Oscar Lambret
Sponsor class: OTHER
Collaborators: name: Ligue contre le cancer, France
name: Santelys Association
name: CTD-CNO, Caen
First posted: 2025-02-04
Enrollment: 123
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Phase 2, randomized clinical trial, open-label, evaluating 3 interventions : Capsaicin, Botox-A, SPB
Primary purpose: TREATMENT

Brief summary: The goal of this phase II clinical trial is to study the effectiveness of a second line treatment with Serratus Plane Block (SPB) or Botox-A in comparison with capsaicin for the control of chronic neuropathic pain of post-mastectomy syndrom. The primary outcome will be the pain evaluation at 8 weeks.

123 patients with chronic neuropathic pain of post-mastectomy syndrom in failure of a first-line 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. The follow-up will include evaluation of pain and quality of life.

Detailed description: SerCaBot is a randomized, open-label, phase II clinical trial designed to evaluate the efficacy of a second-line treatment with Serratus Plane Block (SPB) or Botox-A compared to capsaicin for the control of chronic neuropathic pain of post-mastectomy syndrome.

123 patients with will be recruited over 24 months at the Centre Oscar Lambret.

This clinical trial will be proposed to patients with chronic neuropathic pain of post-mastectomy syndrome in failure of a first-line treatment.

After consent, an inclusion assessment will be carried out including clinical examination, anamnesis, pain evaluation (questionnaires PCS, NPS, DN4, NPSI and collect of antalgic treatment) and evaluation of quality of life (questionnaire SF12) and depression (questionnaire HADS).

Patients will then be randomly assigned to one of three treatment groups : Capsaicin, Botox-A, SPB (41 patients per group). The randomization will be balanced 1:1:1, controlled by minimisation (with a random factor set at 0.8) for the distribution of the following factors:

* Pain level at enrolment (continuous NPS)
* Duration of pain (\<3 months vs. ≥3 months) ;
* Axillary dissection (yes vs. no)
* Loco-regional adjuvant radiotherapy (yes vs. no)

The study treatment will be administered 1 to 2 weeks after randomization. Treatment will be stopped prematurely in the event of unacceptable toxicity or complication. In each group, a repeat of the treatment may be considered after 12 weeks if further pain control is required. In the SPB group, a repeat is also possible every 2 weeks.

Patients will be followed for 24 weeks after the study treatment. Follow-up will include:

* 2 medical visits at 8 weeks and at 24 weeks including pain assessment (questionnaires NPS, NPSI, record of antalgic treatment), record of adverse events related to study treatment and assessment of quality of life (SF12 questionnaire) and depression (questionnaire HADS).
* remote assessment at week-1, week-2, week-4 and week-6 including assessment of pain (questionnaires NPS, NPSI, record of antalgic treatment) and record of adverse events.

Patients will withdraw from the study after the 24 week medical visit. Early withdrawal will be possible in case of patient's decision of withdrawal, breast surgery during follow-up, or death.

Eligibility criteria: Inclusion Criteria :

1. Women aged ≥ 18 years;
2. 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;
3. 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,
   * after failure (ineffectiveness or intolerance) of a first-line treatment for chronic neuropathic pain, as recommended by the SFETD - French Society for the Study and Treatment of Pain (IRSNA or venlafaxine or gabapentin or tricyclic antidepressants PLUS lidocaine patch, at the appropriate dosage) and implemented for at least 4 weeks;
4. Patient affiliated with a health insurance plan;
5. Patient informed and having consented to participate in the trial.

Exclusion Criteria :

1. Ipsilateral breast cancer recurrence, regardless of the first treatment;
2. History of breast or thoracic surgery prior to mastectomy with residual pain;
3. Painful polyneuropathy related to chemotherapy requiring treatment;
4. Ongoing or planned loco-regional adjuvant radiotherapy within the next 8 weeks;
5. Treatment area not suitable for potential botulinum toxin type A treatment;
6. Breast reconstruction using flap or lipomodelling;
7. Indication for breast reconstruction within the next 8 weeks;
8. 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;
9. Hypersensitivity or allergy to anesthetics, capsaicin, naropein, clonidine hydrochloride, an amide-type local anesthetic, botulinum toxin type A, or any excipient contained in the preparations;
10. Infection or inflammation at the injection site;
11. Therapeutic/effective anticoagulation;
12. Clinical signs or medical history leading to the diagnosis of:

    * Hemostasis disorder,
    * Local infection,
    * Severe renal insufficiency (creatinine clearance \< 30 mL/min),
    * Thrombocytopenia \< 50,000 platelets/mm3;
13. Generalized muscle activity disorders (e.g., myasthenia, Lambert-Eaton syndrome);
14. Heart rate lower than 60/minute;
15. Severe bradyarrhythmia due to sick sinus syndrome or second or third-degree atrioventricular block;
16. State of depression (HADS score ≥ 11);
17. Other contraindication to any of the study treatments;
18. Inability for the patient to follow the study schedule;
19. Inability for the patient or the healthcare team to perform the treatment within 2 weeks;
20. Pregnant or breastfeeding women, women who are able to conceive and who do not use a highly effective method of contraception during the trial and for at least 1 month after the end of treatment ;
21. Patient under guardianship or curatorship.

Primary outcomes:
measure: Pain assessment using Numerical Pain Scale (END)
timeFrame: 8 weeks after treatment initiation, or the closest measurement within +/- 1 week if the 8-week data is missing.
Secondary outcomes:
measure: Success of Pain Control
timeFrame: Assessed at 8 weeks post-treatment.
measure: Evolution of Pain Scores
timeFrame: Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.
measure: Neuropathic Component Evaluation
timeFrame: Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.
measure: Early Treatment Failure
timeFrame: Assessed at 7 and 14 days post-treatment
measure: Introduction of New Analgesic Treatment
timeFrame: Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.
measure: Adverse Events
timeFrame: From study treatment to 24-weeks follow-up
measure: HADS Scale Evaluation
timeFrame: Assessed at baseline, 8 weeks, and 24 weeks.
measure: Quality of Life Assessment
timeFrame: Assessed at baseline, 8 weeks, and 24 weeks.
measure: Patient General Impression of Change (PGIC)
timeFrame: Assessed at 8 weeks and 24 weeks
Other outcomes:
Locations:
city: Lille
country: France
facility: Centre Oscar Lambret
state: Hauts-de-France
Study officials:
affiliation: Centre Oscar Lambret
name: Didier DELBROUCK, Anesthesiologist
role: PRINCIPAL_INVESTIGATOR
References: