What is an exon skipping drug?

What is an exon skipping drug?

Exon skipping uses small drugs called antisense oligonucleotides to help cells skip over a specific exon during splicing. This allows cells to join a different set of exons together to produce a protein that is shorter than usual but may have some function.

What does Amondys 45 do?

Amondys 45 (casimersen) is an antisense oligonucleotide indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients who have a confirmed mutation of the DMD gene that is amenable to exon 45 skipping.

What is exon skipping and how does it work?

In molecular biology, exon skipping is a form of RNA splicing used to cause cells to “skip” over faulty or misaligned sections (exons) of genetic code, leading to a truncated but still functional protein despite the genetic mutation.

When was Amondys 45 approved?

Sarepta Therapeutics Announces FDA Approval of AMONDYS 45™ (casimersen) Injection for the Treatment of Duchenne Muscular Dystrophy (DMD) in Patients Amenable to Skipping Exon 45. February 25, 2021 14:10 ET | Source: Sarepta Therapeutics, Inc. Sarepta Therapeutics, Inc.

Does exon skipping work?

Because the deletion of different exons along the length of the DMD gene can cause Duchenne, mRNA patches for a given exon will not work for all patients. For example, exon 51 skipping will only work in about 13% of DMD patients, because the disease in these people is amenable to masking exon 51.

What is exon inclusion?

It allows a gene to be transcribed into multiple isoforms (or mRNA transcripts) and hence increases the phenotypic complexity of an organism without increasing its genetic complexity. The exon-inclusion ratio, also known as percent spliced in (PSI), is a popular statistic for measuring alternative splicing events (2).

When was Casimersen approved?

Casimersen received its first approval on 25 February 2021, in the USA, for the treatment of DMD in patients who have a confirmed mutation of the DMD gene that is amenable to exon 45 skipping.

Is Exondys 51 approved?

The U.S. Food and Drug Administration today approved Exondys 51 (eteplirsen) injection, the first drug approved to treat patients with Duchenne muscular dystrophy (DMD).

Is exon skipping considered gene therapy?

Exon skipping is one of the most promising gene therapy approaches for the treatment of DMD.

What is the life expectancy of Duchenne muscular dystrophy?

In the past, most people with DMD did not live beyond their early 20s. Improvements in treatment have meant that life expectancy has increased. At present, average life expectancy for people with DMD is 27 years.

Can gene therapy cure muscular dystrophy?

So far, there is no effective treatment but new gene-based therapies are currently being developed with particular noted advances in using conventional gene replacement strategies, RNA-based approaches, or cell-based gene therapy with a main focus on Duchenne muscular dystrophy (DMD).

Who discovered exon skipping?

The proof of concept of the exon-skipping therapy for DMD was first demonstrated by Pramono et al. (18) in lymphoblastoid cells and by Dunckley et al. (19) in cultured mouse cells in vitro.

What are Sarepta’s exon 45 and exon 53 skipping drugs?

This study is a stage 3 trial of Sarepta’s exon 45 and exon 53 skipping drugs. Exon skipping drugs use a small piece of genetic material to skip over the part of the dystrophin gene with a mutation. The part of the dystrophin gene with a mutation varies between patients.

How do exon skipping drugs work?

Exon skipping drugs use a small piece of genetic material to skip over the part of the dystrophin gene with a mutation. The part of the dystrophin gene with a mutation varies between patients. Therefore, exon skipping trials are mutation specific. This trial requires you to be amenable to the skipping of exon 45 or 53.

How many patients are amenable to exon 45 skipping?

The study will enrol approximately 126 patients, with a planned minimum target of 45 patients amenable to exon 45 skipping and 45 patients amenable to exon 53 skipping.

Are casimersen and vyondys 53 (golodirsen) effective for exon 45 skipping?

The global, double-blind study is evaluating the safety and efficacy of casimersen and Vyondys 53 (golodirsen) in patients with mutations amenable to exon 45 skipping in the case of casimersen, and to exon 53 skipping with Vyondys 53.