Shortcomings of Gene Therapy - Reason 1 - It's All About Timing and Delivering An Effective Drug Dose
To be effective, there are 2 important requirements for gene therapy to be effective. First, an effective treatment requires that there are enough remaining viable cells that can be corrected. Unfortunately, by the time symptoms arise, a majority of cells have been destroyed by the genetic disease. Thus, gene therapy has to be given early in the course of a disease. Second, a sufficient dose of the corrected gene has to enter into a cell to replace the mutated gene. Nucleic acid is too big of a molecule to enter into a cell by itself and, thus, it requires a carrier system like a virus to deliver the gene into a cell. Under some circumstances, viral gene delivery poses a safety risk. To illustrate this point, click on the below link from a Forbes interview with a gene therapy pioneer that raises concerns about gene therapy.
Also, viruses requires a human cell to produce the gene therapy. Unlike bacterial, viruses cannot replicate on their own. The human cell to produce a gene therapy was developed from an aborted fetus in the 1970s.
Additionally, genetic diseases is associated with other secondary insults caused by inflammation. Thus, simply correcting a gene mutation is often insufficient to cure a genetic disease. In contrast, a stem cell offers anti-inflammatory features.
These are the major reasons why the Institute prefers cell therapy over gene therapy. Cell therapy is less sensitive to timing than gene therapy. Cell therapy does not require the need for viruses. Cell therapy also provides anti-inflammatory properties.