A Japanese multicentre, placebo-controlled phase II/III trial has shown that 6 g/day of extended-release sialic acid for 48 weeks is effective on upper limb muscle strength in GNE myopathy.
- Of the 19 participants who completed the study, 15 were on sialic acid and four on placebo.
- The difference in loss of upper limb strength over 48 weeks between the two groups was significant (5.1 kg in the placebo group and 0.1 kg in the treated group).
These results confirm those of the phase II trial published in 2016, but contradict the negative results of the subsequent international phase III trial. According to the authors, these contrasting results could be due to less heterogeneity in the genetic background of the participants in the Japanese trial. A three-year international natural history study, published in 2021, suggested that Bulgarian patients had more severe symptoms and disease progression.