Nonsense mutation DMD is a subset of DMD. Usually, the inability to produce dystrophin is caused by a variety of mutations that cause deletions, duplications or single point mutations that disrupt the coding reading frame of the dystrophin gene. Of these single point mutations, 10% to 15% are categorized as “nonsense mutations” that are caused by an alteration of a single base in the DNA, which ends the translation of a gene into a protein. Nonsense mutation DMD cases are not treatable by the exon-skipping technology employed by treatments from Sarepta and Prosensa.
PTC’s trial is intended to be much larger than either Glaxo or Sarepta’s groups, with 220 patients at 50 global investigational sites. The company intends to test the safety of varying doses of the drug and use the six-minute walk test to determine efficacy. The trial will be double-blind and placebo-controlled.
A Foolish final thought
Even though these new DMD treatments sound promising, Sarepta Therapeutics Inc (NASDAQ:SRPT), Prosensa, and PTC all fall under the textbook classification of speculative biotechs. These three companies don’t have any approved treatments on the market and, therefore, no real source of earnings growth. GlaxoSmithKline plc (ADR) (NYSE:GSK) is the only established company in the field, but the success or failure of its DMD treatment won’t have a huge impact on its top line growth.
All three companies have promising pipelines, with additional treatments for DMD, influenza, Huntington’s disease, and cystic fibrosis in the works, but these treatments are all in the very early stages. For now, what matters most for these three companies is bringing a successful DMD treatment to the market. If one of them is successful, it will not only save children’s lives, but also reward the true believers and backers of these companies.
The article Could This DMD Treatment Become a Blockbuster Drug? originally appeared on Fool.com and is written by Leo Sun.
Leo Sun has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned.
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