Gene Therapy: 25 Years Later
The promise of gene therapy has been circulating for nearly a quarter of a century, and the best that can be said of this time of intense research is that its results have been very modest, and sometimes tragic. In 1999, American teenager Jesse Gelsinger died in a clinical trial of gene therapy. One year later, a team of French researchers treated 11 children with a severe immunodeficiency (SCID, the famous bubble children), achieving a very successful partial success, but two of the patients developed leukemia because of the virus (a retrovirus) used for Introduce the correct gene into your cells. And, despite the great efforts of scientists, little has been said. So far, because, as you can read in Matter, The United States will approve the first gene therapy for commercial use in September. It will be against leukemias that do not respond to another treatment, and this time the technique, developed by Novartis, is backed by good results in an international clinical trial.
The keys to success are interesting for the future. The first is the vector virus, which is a manipulated version of HIV, the AIDS virus. Like the viruses most commonly used so far, HIV is a retrovirus (extracts copies of its genome and integrates them into the human genome), but of a special genus called lentivirus. And, unlike traditional retroviruses, modified lentiviruses have been shown to be incapable of causing leukemia, as was the case with the children’s bubble.
The only injection is given to the patient costs between 250,000 and 500,000 euros.
The second key is that leukemia is a disease of lymphocytes, or white blood cells, which are the incarnation of the immune system. This avoids having to infect a solid organ, such as the liver or the lung, with the virus carrying the correct gene, which is extremely difficult. Instead, the lymphocytes are removed from the patient and transported to Novartis laboratories where virus infection is carried out with full assurance. The cells are then selected and injected back into the patient. Two-thirds of them remain cancer-free two years after treatment. These are serious numbers.
The main obstacle is now the economic one. The only injection given to the patient costs between 250,000 and 500,000 euros, according to unofficial estimates. And here is a fact that can be scandalous. If the patient heals, he does not need the medication again. This is just the nightmare of any financial department of Big Pharma, and is often expressed with a macabre outside: curing a disease is not profitable.
And this, unfortunately, going to be the big problem with the great advances in drug research – not only in génica- therapy is now waiting for their turn in the pipe production industry. They are increasingly effective medicines, but also more expensive. In Spain, we have lived a prologue of this situation with drugs against hepatitis C, which some administrations have resisted tooth and nail to fund despite its proven effectiveness against this serious disease. This economic theme is going to be our daily bread, and public health managers should already be doing a master’s degree in which they are coming. They are the lights and shadows of the future.