Nonrandomized Allocation of Steroid Therapy in Patients With Fukuyama Congenital Muscular Dystrophy: Study Protocol for a Phase II Clinical Trial

Aim: This study aimed to evaluate the efficacy and safety of steroid therapy in patients with Fukuyama congenital muscular dystrophy (FCMD). Methods: This is a noncontrolled, nonblinded, multicenter collaborative phase 2 trial in patients with a definite diagnosis of 3-kb insertion mutation homozygous or compound heterozygous FCMD based on genetic testing. The first part of the study evaluates efficacy; patients with homozygous FCMD were given oral prednisolone at a dose of 1 mg/kg on alternate days (0.5 mg/kg/day) for 24 weeks. The second part of the study evaluates safety; patients with homozygous and heterozygous FCMD were given oral prednisolone at a dose of 1 mg/kg on alternate days (0.5 mg/kg/day) for 48 weeks. Homozygous patients will be evaluated in the first part of the study for up to 24 weeks after prednisolone administration, after which they will continue receiving prednisolone in the second part for an additional 24 weeks. The primary endpoints were the changes in motor function evaluated using the gross motor function measure after treatment with prednisolone in the first part and the safety profiles based on the results of physical examination, vital signs, 12-lead electrocardiography (ECG), echocardiography, ophthalmic testing, SpO₂, laboratory tests, immunological tests, and adverse events in the second part. Discussion: Based on previous clinical research, prednisolone shows great potential as a therapeutic drug in patients with FCMD. To achieve this goal, we planned an investigator-initiated trial to confirm the effectiveness and safety of prednisolone.