Influence of Minimally Invasive Thymectomy on the Subsequent Clinical Course of Myasthenia Gravis

• Conditions: Myasthenia Gravis
• Interventions: Procedure: thymectomy (robotic-assisted thoracoscopic, minimally-invasive thymectomy); Procedure: no thymectomy (control); Procedure: thymectomy by means of median sternotomy (transsternal)

• Registration Number: NCT04158661
• Lead Sponsor: Charite University, Berlin, Germany

Brief Summary

The aim of this study is to investigate whether minimally invasive thymectomy achieves comparable efficacy and safety results compared to open thymectomy in patients with myasthenia gravis. The planned investigation is a multicenter observational study based on retrospective (present patient data) and prospective data (questionable outcome data).

Primary hypothesis: Minimally invasive thymectomy is not inferior to open thymectomy in terms of efficacy and safety (non-inferiority study).

Detailed Description

Based on large cohort studies of the last decades, the thymectomy has become a central component of the immunomodulating therapy in MG patients without thymoma detection. Because randomized studies were missing, remained a residual uncertainty on the importance of Thymectomy. In the study "Randomized Trial of Thymectomy in Myasthenia Gravis" (MGTX-study) published 2016 the effectiveness of thymectomy by patients without thymoma detection has been indisputable confirmed. A significant improvement of the patient's complaints and the reduction of the immunosuppressive drugs were particularly evident by early onset MG (EOMG) two to three years after performing a complete resection of the thymic tissue.

While the MGTX study (with an open operative procedure) was being done, the minimally-invasive thymectomy has gained more and more acceptance. From a surgical point of view, the minimally invasive thoracoscopic procedure represents a gentler alternative. According to the momentaneous clinical-scientific point of view, further studies are necessary to compare both procedures. Furthermore, the MGTX study included only patients with generalized MG and positive anti-Acetylcholine Receptor (AChR)-antibodies, who were younger than 65 years, so that the relevance of thymectomy in other important subgroups, such as late onset MG (LOMG), the ocular MG (OMG), as well as the patients without detected antibodies (seronegative MG patients), who represent about 10 % of whole population of MG patients, is still not clear.

Study Timeline

• Study First Submitted: 2019-11-07
• Study First Submitted QC: 2019-11-07
• Study First Posted: 2019-11-12
• Study Start: 2020-04-20
• Primary Completion: 2020-11-30
• Status Verified: 2021-09
• Last Update Submitted: 2021-09-23
• Last Update Posted: 2021-09-24
• Study Completion: 2022-06-30

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 248

Inclusion Criteria

• Patients with Myasthenia Gravis
• Age ≥18 years

Exclusion Criteria

• a proper communication with the patient is not possible
• an informed consent could not be signed
• a patient reject a participation or requires breaking up

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Tmin-group	thymectomy (robotic-assisted thoracoscopic, minimally-invasive thymectomy)	* confirmed seropositive ocular or generalized MG \[detection of antibodies (Abs) targeting the AChR, muscle-specific tyrosine kinase (MuSK) or Titin\] or seronegative ocular or generalized MG * age ≥ 18 years * thymectomy ≥ three years
T0-group	no thymectomy (control)	* confirmed seropositive ocular or generalized MG \[detection of antibodies (Abs) targeting the AChR, muscle-specific tyrosine kinase (MuSK) or Titin\] or seronegative ocular or generalized MG * a very long disease history OR * age ≥ 18 years * rejecting a thymectomy or have contraindications for thymectomy
MGTX-group ("historical control group")	thymectomy by means of median sternotomy (transsternal)	from MGTX-trial ("Randomized Trial of Thymectomy in Myasthenia Gravis")

Primary Outcome Measures

Name	Time	Method
Mean daily prednisone dose	three years after thymectomy

Trial Locations

Locations (3)

NeuroCure Clinical Research Center (NCRC), Charité University, Berlin; 🇩🇪 Berlin-Mitte, Germany

Sana Klinikum Lichtenberg; 🇩🇪 Berlin, Germany

Department of Surgery Charité University; 🇩🇪 Berlin-Mitte, Germany