As reported recently in Medscape, forty-eight patients with myotonic dystrophy type 1 (DM1), were identified by way of the DM-Scope registry, which is the largest collection of data for the DM population. The investigational drug in the study was Metformin, a well-known diabetic medication.
About DM1
DM1, a multisystem disease, affects smooth muscle and skeletal muscle. DM1 affects the heart, eyes, and endocrine system which release hormones that control growth, metabolism, reproduction, and development. Several patients were marked as non-eligible due to various test results leaving forty evaluable patients.
Between February 2014 and May 2015, thirty-eight patients in the intent to treat (ITT) population were administered one or more doses of Metformin. All patients in this group received a 3mg (per day) dose of metformin. However, fifteen patients were eliminated from the ITT group. Ten were treated and five received placebo.
Four patients withdrew from the treated group due to metformin-induced adverse events in the gastrointestinal tract that could not be remedied by usual therapies.
Regarding the primary outcome, the placebo group demonstrated stable values from the baseline to the Week 52 examination. In comparison, the metformin group demonstrated increased performance in each evaluation.
The analyses found that the metformin group showed progression in per-protocol analysis, which deletes data from any patient who did not comply with the protocol. However, the analyses did not reach significant levels even with higher estimates in the metformin group.
Visits to patients at weeks sixteen and twenty-eight produced similar numbers. The metformin group continued to show significant improvement as of Week sixteen.
The secondary outcome showed similar clinical parameters ignoring the differences in being treated or not treated with metformin. Biological samples were similar in the two groups. The clinical parameters were muscle function and strength, electrocardiogram (ECG), quality of life, and signs of myotonia (muscle spasms).
About Secondary Outcomes
Eventually, biological samples within the two groups did not differ. The outcome did not depend on whether patients were or were not treated with metformin. The clinical parameters included myotonia indices, strength and muscle function, ECG, and quality of life.
About Safety
A total of 280 adverse reactions occurred in 38 participants. The metformin group reported 163, and the control group reported 117. Sixty-eight percent of the 280 events, according to administrators, were not related to the treatment. Further analysis of adverse events attributes 53% to the metformin group and 88% to the control group.
An additional four participants reported serious adverse events, with one being in the control group and three in the metformin group.
The most common adverse symptoms were gastrointestinal disorders. Asthenia (weakness and lack of energy) occurred in eight patients in the metformin group and three patients in the control group.
Sixteen patients in the control group reported benign infections while nine cases of benign infections were reported in the metformin group.
Metformin did not appear to have affected ECG parameters or lab assessments. Nor were there any cases of hypoglycemia or lactic acidosis (lactic acid buildup in the bloodstream).
Looking Forward
Myotonic dystrophy is considered a disorder that is yet unchallenged. Metformin offers a good toxicity profile and may improve patients’ mobility.
