According to a report on the BBC News web site today, the European Commission has — for the very first time anywhere in the Western world — given final approval to market a gene therapy that corrects an inborn error of metabolism for the treatment of any type of human genetic disorder.

The new treatment, known as alipogene tiparvovec (Glybera^®), will apparently be made available in Europe in 2013 to treat adult patients with a condition known as familial lipoprotein lipase deficiency (LPLD) — a rare genetic disorder in which affected patients are unable to digest certain types of fats in their diet. About 1 or 2 persons in a million is born with damaged copies of the gene that codes for expression of the enzyme lipoprotein lipase. Insufficient expression of this gene leads to the accumulation of lipoproteins in the bloodstream, abdominal pain, and potentially life-threatening inflammation of the pancreas (pancreatitis). Historically, the only way to manage LPLD has been through the use of very low-fat diets.

As with many other types of gene therapy that have been tried in the past and/or are under investigation today, this new treatment uses a viral carrier (a modified adenovirus) to infect human tissues (in this case human muscle cells) with a working copy of the LPLD gene. Glybera is initially approved only for treatment of adult patients with familial LPLD who are affected by severe or multiple attacks of pancreatitis despite dietary fat restrictions. The diagnosis of LPLD will need to be confirmed by genetic testing, and patients must also have detectable levels of lipoprotein lipase.

The developer of Glybera — a Dutch company known as uniQure — has already stated that it intends to apply for regulatory approval of this product in the US and Canada. Click here to see the company’s own statement about the approval.

Several other web sites have also commented on this approval, which is clearly a very important step in the ability of companies to bring gene replacement therapies to market in Europe and potentially in the rest of the Western world. Some of that comment has noted that the cost for treatment with Glybera may be of the order of US$1.6 million per person, which is going to raise all sorts of other questions about the “value” of such treatments. However, once again, the proof of concept is what is going to be really important to the rare disease community. We now know that the European regulatory authorities are willing to approve gene therapies for very rare disorders … and we hope that the FDA is going to be able to take the same step soon, whether it is with alipogene tiparvovec for the treatment of familial LPDP or some other gene therapy for a quite different genetic disorder.