Date: 15-Jan-2021

Daiichi Announces Positive Results From Phase 1/2 Trial Of DS-5141 To Treat Duchenne Muscular Dystrophy

Daiichi Sankyo Company announced the results summary of the phase 1/2 clinical trial in Japan (hereafter, the study) of DS-5141 (hereafter, the drug) in patients with Duchenne muscular dystrophy (DMD), which Daiichi Sankyo is jointly developing with the Orphan Disease Treatment Institute Co., Ltd. (ODTI).

The study is a clinical trial to examine the safety and efficacy of the drug, which was administered subcutaneously once weekly for 12 weeks followed by once weekly subcutaneously administration for 48 weeks to patients with DMD.

No safety concerns, such as discontinuation or clinically significant adverse events, were observed in the study. Efficacy in terms of the production of messenger RNA with exon 45 skipping of the dystrophin gene (the trial’s secondary endpoint) was found in all patients, and the expression of dystrophin protein (the trial’s primary endpoint) showed a clear increase in several patients. Analysis of the trial result is currently ongoing.

Daiichi Sankyo will continue to investigate this study’s result in detail as part of its efforts to provide new treatment options for patients with DMD.

DS-5141, a nucleic acid drug expected to treat muscular dystrophy, skips exon 45 splicing, producing an incomplete but functional dystrophin protein during messenger RNA processing from the dystrophin gene in patient’s myocytes. In addition, it contains ENA oligonucleotide, Daiichi Sankyo’s proprietary modified nucleic acid, as an active ingredient, and received the SAKIGAKE designation in April 2017.

Duchenne muscular dystrophy is a severe rare hereditary disease with an incidence of about one in 3,500 male newborns regardless of ethnicity. It is caused by the deficiency of dystrophin protein production in the patient’s muscle cells, significantly limiting possible treatments and their effects