Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy
Condition: Myasthenia Gravis
MeSH terms: Myasthenia Gravis; Muscle Weakness
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of this trial is to determine if thymectomy combined with prednisone therapy is
      more beneficial in treating non-thymomatous myasthenia gravis than prednisone therapy alone.
    

Detailed description: 
      Myasthenia gravis (MG) is an autoimmune disease involving the thymus in which 85 percent of
      patients have antibodies to muscle acetylcholine receptors (AchR-Ab) that interfere with
      neuromuscular transmission. MG frequently causes severe disability that can be
      life-threatening. Thymectomy-a surgical procedure that removes thymus gland tissue from the
      chest cavity-has been an established therapy for non-thymomatous MG, or MG without thymoma,
      for more than 60 years (based on retrospective, non-randomized studies). Corticosteroids are
      now being used increasingly either as the sole treatment or in combination with thymectomy.
      Both therapies have associated adverse effects and indications for their use based on
      randomized trial data are lacking.

      The purpose of this 5-year trial is to determine if the surgical procedure, extended
      transsternal thymectomy (ETTX), combined with prednisone therapy is more beneficial in
      treating individuals with non-thymomatous MG than prednisone therapy alone. More
      specifically, this study will determine 1) if ETTX combined with prednisone results in a
      greater improvement in myasthenic weakness, compared to prednisone alone; 2) if ETTX combined
      with prednisone results in a lower total dose of prednisone, thus decreasing the likelihood
      of concurrent and long-term toxic effects, compared to prednisone alone; and 3) if ETTX
      combined with prednisone enhances quality of life by reducing adverse events and symptoms
      associated with the therapies, compared to prednisone alone.

      Learning that thymectomy results in a meaningful reduction of prednisone dosage or even full
      withdrawal or reduces side effects related to prednisone would support using the two
      treatments-thymectomy and prednisone-together. However, if no meaningful reduction of
      prednisone dosage or side effects is shown, the results would mean that using the two
      treatments together offers no advantages over prednisone treatment alone.

      After an initial screening, study participants will be randomized either to undergo the
      surgical procedure ETTX and receive prednisone treatment, or to receive prednisone treatment
      alone without surgery. Participants will be followed for at least 3 years.
    

Intervention name(s): thymectomy plus prednisone; prednisone alone
Intervention type(s): Procedure; Drug
Intervention description(s): The thymectomy will be performed as soon as possible after randomization.; Prednisone regimen will be every other day, starting at 10mg. The dose will increase by 10mg every 2 days to a target dose.
Other intervention name(s): Extended transsternal thymectomy plus prednisone; prednisolone
Intervention MeSH terms: Prednisone; Prednisolone
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: myasthenia gravis; thymectomy; prednisone; corticosteroid; extended transsternal thymectomy; ETTX; MG; thymus; thymoma