Successful treatment of a patient with statin-induced myopathy and myotonic dystrophy type II with proprotein convertase subtilisin/kexin type 9 inhibitor, alirocumab (Praluent)

Presently there are limited treatment options for hypercholesterolemia in patients with statin intolerance and myotonic dystrophy. A 74 year-old male presented to endocrine clinic with hypercholesterolemia (serum LDL-C 210 mg/dL), hypogonadism, insulin-controlled type 2 diabetes mellitus, and minimally elevated serum creatine kinase (CK) levels (184 U/L, ref. range 38-174). Shortly after simvastatin treatment, patient developed severe myalgias in the proximal lower and upper extremities; and serum CK increased to 317 U/L. Subsequently patient was treated with various statins including rosuvastatin with similar outcomes. Patient was also treated with bile acid binding resin and ezetimibe without improvement. At this time, a diagnosis of myotonic dystrophy type 2 was confirmed. Patient was then treated with alirocumab, a PCSK9 inhibitor 75 mg subcutaneously every 2 weeks with significant improvement in LDL-C (90 mg/dL) and myalgias. In conclusion, PCSK9 inhibitors such as alirocumab may be an excellent lipid lowering agent in patients with statin intolerance and myotonic dystrophy.