Blocking the activin IIB receptor with bimagrumab (BYM338) increases walking performance: A meta‐analysis

Aim Diseases and bed rest may result in decreased muscle size and function. While exercise is recommended as a countermeasure, there are times when diseases or injuries make it difficult for the patient to partake in an exercise intervention. Pharmaceutical interventions using a myostatin inhibitor, BYM338, have been investigated as a way to increase or maintain muscle function. Of interest in the present analysis was the 6‐min walk test. The 6‐min walk test was selected, as there is an association between walking ability and the ease of performing activities of daily living. Thus, our aim was to investigate the effects of BYM338 on walking performance relative to a placebo. Methods A meta‐analysis using a random effects model was conducted in April 2021. Results Four studies were included with a total sample size of 244 participants receiving BYM338 and 114 participants receiving a placebo. The average age of the participants included was 68 years. The main analysis produced a weighted mean effect size of 10 m (SE 5) ( P = 0.05) for BYM338 over a placebo. Excluding the lowest dosage (1 mg/kg) provided similar results (12 m [SE 5], P = 0.033). Of note, the weighted mean effect with or without the lowest dosage is surrounded by a large degree of uncertainty. Conclusions Our results suggest that BYM338 is a viable drug for improving 6‐min walk test in populations associated with impaired function. Geriatr Gerontol Int 2021; 21: 939–943 .