First FDA-Approved Trial Using Human Embryonic Stem Cells
Embryonic stem cells have been at the center of an intense national debate and in 2011 for the first time ever, doctors injected human embryonic stem cells into a patient with a spinal cord injury. This trial is only meant to assess the safety of using the stem cells, not the effectiveness of the technique at reversing the paralysis. This was the first such test approved by the FDA.
The patient was treated at the Shepherd Center in Atlanta that specializes in spinal cord and brain injuries and Geron Corp. of Menlo Park, Calif., which is sponsoring the research. While there are some clinics around the world offering therapies using human embryonic stem cells, this trial is the first to have been approved by a government entity. The FDA held up approval of the clinical trial for months, requesting extra animal safety studies and added steps for patient protection, primarily out of fears that the injected cells would grow into tumors or trigger extra pain.
In the animal trials, rats with spinal cord damage that had lost control of their hind limbs regained at least the partial ability to walk and run after treatments with the stem cells.
Although the hope is that these cells will help repair recent spinal cord injuries and restore some sensation and nerve function to enable patients to participate in physical therapy that could restore a degree of mobility, with the first patients, the goal is even more modest—to be certain the therapy doesn’t make things worse or cause unwanted side effects.
While a milestone in the technology, the drug candidate is still a long way from being proven and reaching the market. It still faces many years of testing for effectiveness if all goes well in the early stage study.
In addition to the Shepherd Center, Northwestern University near Chicago has been announced as a site for this phase of the trial, and up to seven centers ultimately may become involved.
Dr. Albrecht comments:
Embryonic cells, which can grow into any kind of tissue, hold the potential to repair or regenerate damaged organs. In spite of the hopes of medical advocates, research using human embryonic stem cells has been highly controversial.
The ethical concern is that human embryos will be produced for the sole purpose of creating embryonic stem cells. I too have a great concern about making human embryos solely for embryonic stem cells; however, there are literally thousands of unused embryos that might be put to a better use than merely taking up storage space in a liquid nitrogen container.
One of the problems with in vitro fertilization is that it is a highly unsuccessful process and therefore to maximize the chances for a pregnancy multiple eggs are utilized and consequently multiple embryos are produced. This approach serves patients who have a reduced chance for pregnancy because of age and or decreased ovarian reserve a better chance for pregnancy. However, by virtue of their decreased fertility potential, these patients rarely have excess embryos for freezing.
On the other hand, couples in whom the female partner is young and has excellent ovarian reserve numbers, excess embryos are frequently present. Patients are asked to make a disposition for these embryos. Their options include:
1 Discard extra embryos rather than freezing them. I do not recommend this option as I cannot guarantee any couple that they will achieve pregnancy on the fresh embryo transfer. In addition many couples desire to have more than one child and the frozen embryos give them that option without needing to go through the entire IVF process again.
2 Freeze them for future use by the couple. However, if the couple transferred two fresh embryos and became pregnant with twins, they may no longer want to use their embryos.
3 Give them to an embryo bank so that they can be adopted by another couple. Surprisingly, very few infertility couples are willing to allow another infertility couple to adopt their embryos and have their baby.
4 Store them in definitely at a yearly cost to the couple. Most programs require couples to make another disposition for the embryos by five years after freezing.
5 Thaw the embryos and let them die. This is an option that many couples wish to avoid, as they see it as destroying a potential life.
Couples may now have another option. They may be able to donate them to a program that will utilize them for embryonic stem cell research and development. Although this may still be controversy will, in my mind it at least provides one more option. One way of thinking about it is that it is similar to signing your driver’s license designating your body for donation for organ transplantation in the case that you die or become permanently vegetative due to an automobile accident. You are donating your organs so that someone else has the ability to live. The dream is that embryonic stem cells will also be able to allow someone to live because of the sacrifice of an embryo to develop those stem cells.
