The Center for Biologics Evaluation and Research (CBER) regulates cellular therapy products, human gene therapy products, and certain devices related to cell and gene therapy. CBER uses both the Public Health Service Act and the Federal Food Drug and Cosmetic Act as enabling statutes for oversight. Cellular therapy products include cellular immunotherapies, and other types of both autologous and allogeneic cells for certain therapeutic indications, including adult and embryonic stem cells. Human gene therapy refers to products that introduce genetic material into a persons DNA to replace faulty or missing genetic material, thus treating a disease or abnormal medical condition. Although some cellular therapy products have been approved, CBER has not yet approved any human gene therapy product for sale. However, the amount of cellular and gene therapy-related research and development occurring in the United States continues to grow at a fast rate. CBER has received many requests from medical researchers and manufacturers to study cellular and gene therapies and to develop cellular and gene therapy products. In addition to regulatory oversight of clinical studies, CBER provides proactive scientific and regulatory advice to medical researchers and manufacturers in the area of novel product development. Read more from the original source: … Continue reading →

Gene therapy is a way of inserting genes into a patient's cells and replacing the preexisting alleles, or gene variants, to perform some therapeutic function. It has been used thus far primarily to replace mutant defective genes, or alleles, with normal alleles, but could in theory be used to edit the human genome arbitrarily. If gene therapy were applied to reproductive cells in the gonads (the germline), these genetic changes would be heritable. This process has never been performed, but it has a name: germline genetic engineering. Since the early 1980s, gene therapy has been used to produce medicines. Say that a human being needs a certain protein as a medicine. This therapy uses a viral vector, that is, a virus modified to contain the DNA to be introduced. Large quantities of the virus are injected to the target area, or, sometimes tissue is removed, infected with the virus, and then implanted again. The viruses are modified such that the vast majority are not capable of independent self-replication - providing little chance for pathogenic infection. The virus introduced the new DNA into the genome of human cells, much in the same way normal viruses introduce their own genetic material into … Continue reading →

Germline Gene Transfer Gene transfer represents a relatively new possibility for the treatment of rare genetic disorders and common multifactorial diseases by changing the expression of a person's genes. Typically gene transfer involves using a vector such as a virus to deliver a therapeutic gene to the appropriate target cells. The technique, which is still in its infancy and is not yet available outside clinical trials, was originally envisaged as a treatment of monogenic disorders, but the majority of trials now involve the treatment of cancer, infectious diseases and vascular disease. Human gene transfer raises several important ethical issues, in particular the potential use of genetic therapies for genetic enhancement and the potential impact of germline gene transfer on future generations. Gene transfer can be targeted to somatic (body) or germ (egg and sperm) cells. In somatic gene transfer the recipient's genome is changed, but the change is not passed on to the next generation. In germline gene transfer, the parents' egg and sperm cells are changed with the goal of passing on the changes to their offspring. Germline gene transfer is not being actively investigated, at least in larger animals and humans, although a great deal of discussion is … Continue reading →

Viral vectors have natural host cell populations that they infect most efficiently. Retroviruses have limited natural host cell ranges, and although adenovirus and adeno-associated virus are able to infect a relatively broader range of cells efficiently, some cell types are refractory to infection by these viruses as well. Attachment to and entry into a susceptible cell is mediated by the protein envelope on the surface of a virus. Retroviruses and adeno-associated viruses have a single protein coating their membrane, while adenoviruses are coated with both an envelope protein and fibers that extend away from the surface of the virus. The envelope proteins on each of these viruses bind to cell-surface molecules such as heparin sulfate, which localizes them upon the surface of the potential host, as well as with the specific protein receptor that either induces entry-promoting structural changes in the viral protein, or localizes the virus in endosomes wherein acidification of the lumen (anatomy) induces this refolding of the viral coat. In either case, entry into potential host cells requires a favorable interaction between a protein on the surface of the virus and a protein on the surface of the cell. For the purposes of gene therapy, one might … Continue reading →