Isis' Gene Silencing Drug Approved by FDA

The promise of antisense technology, a gene silencing technique aimed at treating genetic disorders, may finally be coming to fruition. After two decades of research and a number of false hopes for commercially viable drugs, the U.S. Food and Drug administration announced Tuesday the approval of Kynamro, marketed to treat an inherited cholesterol disorder.

The Isis Pharmaceuticals’ drug has been shown to effectively treat homozygous familial hypercholesterolemia (HoFH), affecting roughly one in a million people in the U.S. The inherited disease renders sufferers unable to remove LDL-C, or “bad” cholesterol, from the blood, ultimately resulting in increased risk of heart attack and death before patients see their 30th birthday.

“Kynamro, an injection given once a week, works with other lipid-lowering medications and diet to impair the creation of the lipid particles that ultimately give rise to LDL-C,” Eric Colman, M.D., deputy director of the Division of Metabolism and Endocrinology Products at the FDA’s Center for Drug Evaluation and Research, said in a released statement.

Antisense Therapy and the Creation of the SOD1 Protein

The Carlsbad, California-based pharmaceuticals company has poured nearly $2 billion into researching antisense technology since its founding in 1989. Founder and chief executive Stanley T. Crooke said in an interview Tuesday, “I told people it would be at least 20 years and $2 billion before we knew if the technology would work. We think it’s a seminal day for the technology and the company.”

Researchers active in the pursuit of antisense technology are hesitant to believe the drug will find widespread use, saying it’s still too early to tell. Though antisense drugs should theoretically be able to easily shut down any number of targeted genes, in reality, difficulties have arisen regarding sufficient potency and lack of toxicity making it to cells.

Currently, Isis is working on developing similar drugs to treat spinal muscular atrophy, lower triglycerides and reduce scarring from operations.

Sanofi’s Genzyme division will market the drug, with experts estimating treatment at $235,000-$295,000 a year.