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

Phase 2

Not yet recruiting

• Conditions: Post-Mastectomy Neuropathic Pain Syndrome
• Interventions: Drug: Capsaicin 8% Patch; Procedure: Serratus Plane Block; Procedure: Botulinum Toxin A

• Registration Number: NCT06807164
• Lead Sponsor: Centre Oscar Lambret

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.

Study Timeline

• Study First Submitted: 2025-01-29
• Study First Submitted QC: 2025-01-29
• Status Verified: 2025-02
• Study Start: 2025-02-01
• Study First Posted: 2025-02-04
• Last Update Submitted: 2025-02-04
• Last Update Posted: 2025-02-06
• Primary Completion: 2027-02-01
• Study Completion: 2027-08-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 123

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Capsaicin 8% Patch (Control)	Capsaicin 8% Patch	Participants in this arm will receive an 8% capsaicin patch in a single treatment session. This treatment is intended as a second-line therapy for chronic neuropathic pain associated with post-mastectomy syndrome. If pain persists, the capsaicin patch application may be repeated at 12 weeks.
Serratus Plane Block (SPB)	Serratus Plane Block	Participants in this arm will undergo a Serratus Plane Block (SPB), a local anesthetic injection administered by a trained anesthesiologist. 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
Botulinum Toxin A (Botox-A) Injection	Botulinum Toxin A	This arm involves administration of Botulinum Toxin A (Botox-A) at the site of pain. 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.

Primary Outcome Measures

Name	Time	Method
Pain assessment using Numerical Pain Scale (END)	8 weeks after treatment initiation, or the closest measurement within +/- 1 week if the 8-week data is missing.	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.

Secondary Outcome Measures

Name	Time	Method
Success of Pain Control	Assessed at 8 weeks post-treatment.	Defined as a reduction in pain of 3 points or more on the Numerical Pain Scale (END) at 8 weeks, with failure indicated in other cases.
Evolution of Pain Scores	Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.	Change in pain levels as self-reported by the patient using the END at 1, 2, 4, 6, 8, and 24 weeks after treatment (and at 13, 14, 16, and 18 weeks if treatment is repeated at 12 weeks).
Neuropathic Component Evaluation	Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.	Change in neuropathic symptoms assessed via the Neuropathic Pain Symptom Inventory (NPSI) at 1, 2, 4, 6, 8, and 24 weeks after treatment (and at 13, 14, 16, and 18 weeks if treatment is repeated at 12 weeks).
Early Treatment Failure	Assessed at 7 and 14 days post-treatment	Early failure of local analgesic treatment defined by failure to perform the procedure (due to intolerance or technical issues) or failure to control pain as evaluated at 7 and 14 days post-procedure.
Introduction of New Analgesic Treatment	Assessed at multiple time points: 1, 2, 4, 6, 8, and 24 weeks.	Documentation of any new analgesic treatments (e.g., antiepileptics, antidepressants, opioids) introduced, with dosages collected at 1, 2, 4, 6, 8, and 24 weeks after treatment (and at 13, 14, 16, and 18 weeks if treatment is repeated).
Adverse Events	From study treatment to 24-weeks follow-up	Monitoring of adverse events possibly related to the treatment (capsaicin, botulinum toxin type A, or SBP block) during and after the local procedure, graded according to NCI-CTCAE v5.0.
HADS Scale Evaluation	Assessed at baseline, 8 weeks, and 24 weeks.	Assessment of anxiety and depression using the Hospital Anxiety and Depression Scale (HADS) at baseline, 8 weeks, and 24 weeks.
Quality of Life Assessment	Assessed at baseline, 8 weeks, and 24 weeks.	Evaluation of health-related quality of life using the SF12 scale at baseline, 8 weeks, and 24 weeks.
Patient General Impression of Change (PGIC)	Assessed at 8 weeks and 24 weeks	Self-assessment of change in condition from 1 (no change or worse) to 7 (considerable improvement) measured at 8 weeks and 24 weeks.

Trial Locations

Locations (1)

Centre Oscar Lambret; 🇫🇷 Lille, Hauts-de-France, France