In continuation of my update on antisense oligonucleotides
Sarepta Therapeutics, Inc. the leader in precision genetic medicine for rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has approved Amondys 45 (casimersen). Amondys 45 is an antisense oligonucleotide from Sarepta’s phosphorodiamidate morpholino oligomer (PMO) platform, indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients with a confirmed mutation amenable to exon 45 skipping. This indication is based on a statistically significant increase in dystrophin production in skeletal muscle observed in patients treated with Amondys 45, which is reasonably likely to predict clinical benefit for those patients who are exon 45 amenable. Consistent with the accelerated approval pathway, the continued approval of Amondys 45 may be contingent on confirmation of a clinical benefit in confirmatory trials.
The ESSENCE trial – a placebo-controlled confirmatory trial to support the Amondys 45 approval – is ongoing and expected to conclude in 2024.
Although kidney toxicity was not observed in the clinical studies with Amondys 45, kidney toxicity, including potentially fatal glomerulonephritis, has been observed after administration of some antisense oligonucleotides. Kidney function should be monitored in patients taking Amondys 45. In the clinical trial, the most common adverse reactions observed in at least 20% of patients treated with Amondys 45 and at least 5% more frequently than in placebo were (Amondys 45, placebo): upper respiratory tract infections (65%, 55%), cough (33%, 26%), fever (33%, 23%), headache (32%, 19%), joint pain (21%, 10%), and pain in mouth and throat (21%, 7%).
“This is an important day for Sarepta and, far more importantly, for the patients that we serve. After years of scientific commitment, investment and development, the approval of Amondys 45, Sarepta’s third approved RNA therapy, offers treatment to the 8% of the DMD community who have a confirmed exon 45 amenable mutation,” said Doug Ingram, president and chief executive officer, Sarepta. “Along with our other approved RNA therapies, we can now offer treatment options for nearly 30% of Duchenne patients in the U.S. And our commitment to bring therapies to the greatest percentage of the DMD community as soon as possible continues.”
“Decades of research and commitment have fueled and now accelerate our progress towards new treatments for Duchenne,” said Marissa Penrod, founder of Team Joseph and parent of an 18-year old with Duchenne. “The extraordinary diligence and persistence of the Duchenne community – patients and families, clinicians and researchers – have led us to today’s approval, where we now have exon-skipping treatments for almost a third of those with Duchenne.”
