In case you missed it, earlier this month medical technology crossed a major milestone. Glybera (alipogene tiparvovec) became the first gene therapy drug to be approved for commercial use. The European Commission, which is considered to be more open to genetic therapies than the United States’ Food and Drug Administration, approved the drug on November 2 following a final review of clinical trials results. The Dutch firm uniQure plans on making Glybera available at specialized medical centers throughout the European Union in early 2013 and is currently seeking regulatory approval in the US, Canada, and other markets. Gendicine and H101 have been approved in China as gene therapies for cancer and have so far shown limited success.
Now, what does Glybera do and how does it work? It’s been approved for patients with the rare (one in 1,000,000 people) autosomal recessive lipoprotein lipase (LPL) deficiency. Without LPL, these patients have significantly increased levels of chylomicrons that carry fat throughout the body. Accumulation of these chylomicrons in the pancreas can lead the the often painful and potentially fatal condition pancreatitis.
When an important enzyme is missing, one option is to periodically deliver an exogenously produced replacement, which is what millions of people with diabetes do each day. The other, more permanent option, is to induce one’s own cells to produce the enzyme. Glybera is capable of doing this by encasing the correct LPL gene in an adeno-associated virus (AAV) which hones in on muscle cells. When the AAVs reach their target, they deliver the gene and within a few weeks functional protein is being produced. In clinical trials uniQure found that the therapy was well-tolerated by 27 LPLD patients and within 3-12 weeks after a single-dose injection nearly all of their patients had lower serum lipid concentrations and reduced incidence of pancreatitis.
Given how rare LPLD is, it is unfortunately very likely that the orphan drug will be exceedingly expensive. This cost may drop if Glybera is approved for other diseases; it is also under investigation for the treatment of more common disorders such as hyperlipoproteinemia, Syndrome X, and non-alcoholic steatohepatitis. Hopefully Glybera continues to be a successful implementation of gene therapy, both for the sake of the LPLD patients and for the field in general.
Flashbacks: Personalized Medicine Getting Closer: the LPL DNA Chip; Hope for Hemophiliacs: Gene Therapy Stops the Bleeding
Product page: Glybera (alipogene tiparvovec)
