Yesterday, during The Cold Spring Harbor International Conference in China, GSK announced a statistically significant improvement in walking distance in Duchenne muscular dystrophy patients treated with drisapersen for one year.
Drisapersen, which was developed by Prosensa then GSK, is a synthetic antisense oligonucleotide that skips exon 51 of the dystrophin gene. The initial development of drisapersen was supported by the AFM-telethon.
The clinical phase II trial included 53 patients aged 5 years and older, five of whom were followed up at the Institute of Myology, which is supported and financed by the AFM-Telethon. Patients were separated into three groups; one group received a continuous dose of treatment, the second was treated intermittently, and the third group received a placebo. The primary outcome measure was the distance walked in six minutes (six-minute walk test, or 6MWT) 24 weeks after treatment.
Improved walking ability
After 24 weeks of treatment, patients who received the continuous dose of drisapersen showed a significant improvement in the distance walked compared to the placebo group (average of 35.09 meters), in contrast to those treated intermittently. After a year, the distance walked in six minutes increased for both groups compared to patients who received the placebo: an average of 35.84 metres for the continuous treatment group and 27.08 metres for the intermittent treatment group. However, there was no difference in muscle strength compared to placebo for either drisapersen regimen.
GSK concluded that “drisapersen, may represent an important treatment option for boys with DMD having mutations correctable by exon 51 skipping.” In fact, this treatment is currently undergoing a phase III trial in which the Institute of Myology is participating.