DMD Therapy DS-5141b Wins Japanese SAKIGAKE Fast-Track Designation

Japan has put Duchenne muscular dystrophy (DMD) drug candidate DS-5141b on its SAKIGAKE list, a designation to the U.S. Food and Drug Administration’s Fast Track Designation. United States’ fast tract. Daiichi Sankyo, the drug’s developer, announced the decision in a press release.

An open-label Phase 1/2 clinical trial (NCT02667483), currently recruiting participants, is evaluating DS-5141b’s safety, tolerability, efficacy and pharmacokinetics in boys with DMD. Up to six boys, ages 5 through 10 years old with a confirmed diagnosis of DMD, will receive the treatment for 12 weeks.

The trial, currently underway in Japan, also hopes to determine what dosage of DS-5141b to use in subsequent clinical trials.

DS-5141b induces exon 45 skipping of a dystrophin mRNA to promote incomplete but functional dystrophin production, and therefore, might be effective as a treatment for DMD. DS-5141b also contains the active ingredient ENA oligonucleotide, a modified nucleic acid made using proprietary technology owned by Daiichi Sankyo.

The company co-developed its drug with Japan’s Orphan Disease Treatment Institute and the Innovation Network. Daiichi Sankyo said in February that it expects to win manufacturing and marketing approval for DS-5141b by the end of 2020.

SAKIGAKE is a regulatory procedure of the Japanese Ministry of Health, Labor and Welfare that promotes research and development strategies in Japan, with the goal of getting innovative pharmaceutical products, medical devices and regenerative medicines on the market quickly. The system also aims to accelerate the practical application of unapproved/off-label use of drugs for serious and life-threatening diseases.

DMD is a genetic disorder characterized by progressive muscle degeneration and weakness, and affects one in 3,500 newborn males regardless of ethnicity. DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells functional. Symptom onset is in early childhood, usually between ages 3 and 5. The disease primarily affects boys. Families with DMD boys lack available treatment options, and the drugs now on the market have only limited effectiveness.