- US Food and Drug Administration Holds Hearing on Parkinson’s Drug
- New Hope For Parkinson’s Stem Cell Therapy
US Food and Drug Administration Holds Hearing on Parkinson’s Drug
On October 17, an advisory committee to the United States Food and Drug Administration (FDA) met to hear public commentary on the request by Teva Pharmaceutical Industries, the manufacturer of rasagiline (Azilect®), for a label change indicating that the drug “slows the clinical progression of Parkinson’s.” The manufacturer based its request on two large-scale research studies that it says indicate the medication does more than ease the symptoms of Parkinson’s.
The hearing included a day of debate amongst doctors, scientists, and people living with Parkinson’s about the scientific evidence presented by the FDA and the study sponsor. PDF Research Advocate Jackie Hunt Christensen, who lives with Parkinson’s, served as the committee’s patient advocate. Three other PDF Research Advocates contributed written and oral testimony.
PDF and five other Parkinson’s organizations prepared written testimony recommending against the proposed label change, which included this passage:
“While we are encouraged by the evidence presented to date, it appears to our community that the data surrounding Azilect as a therapy that slows clinical progression of Parkinson’s are not yet definitive, and that additional information is required to completely determine the impact of Azilect on clinical disease progression.”
The committee recommended to the FDA that there was not enough scientific evidence provided to show that the medication is effective in slowing the clinical progression of Parkinson’s. The FDA will take this recommendation and others factors into account when making its final decision, though when this will happen is not yet known.
What Does it Mean?
All Parkinson’s medications currently on the market have been proven to ease the symptoms of the disease. However, none of these has yet been proven to slow or reverse its course. Thus, an action supporting the “clinical progression” indication would have immense implications for people with Parkinson’s. While such an indica- tion would be great news for the community, it is the position of PDF and the other organizations that such a decision must be based firmly on the science — and this, we believe, does not yet support this case for Azilect.
We will advise you when the FDA makes its final decision. In the meantime, Azilect will remain on the market, with or without the proposed new indication. People whose doctors have prescribed Azilect to ease their symptoms will be able to continue using this treatment.
New Hope For Parkinson’s Stem Cell Therapy
Scientists funded in part by the Parkinson’s Disease Foundation announced in the November issue of Nature, that they have made an important step towards stem cell treatment for Parkinson’s disease (PD). Pluripotent stem cells, such as those derived from embryos and more recently induced from adult skin cells, have the potential to develop into nearly any cell type. For this reason, they could potentially serve as unlimited sources of healthy new cells to treat diseases including Parkinson’s. However, scientists have had trouble transforming stem cells into the neurons lost in Parkinson’s. So researchers led by Lorenz Studer, M.D., at the Memorial Sloan-Kettering Cancer Center worked out the precise conditions needed to do so. They also transplanted the neurons into the brains of animals with brain lesions reminiscent of those observed in Parkinson’s.
- The researchers made cultured human pluripotent stem cells differentiate into dopamine neurons.
- The dopamine neurons produced by this method had the same characteristics as dopamine neurons from the brain region affected by Parkinson’s.
- When transplanted into the brains of mice and rats, the neurons survived for at least four and a half months and did not form tumors.
- The transplanted dopamine neurons improved the performance of mice and rats in motor function tests.
- Dopamine neurons transplanted into the brains of rhesus monkeys survived for at least one month.
What Does it Mean?
Pluripotent stem cells hold great promise, but scientists have struggled with transforming stem cells into working dopamine neurons. For the first time, Dr. Studer and his colleagues appear to have identified the correct conditions necessary to transform pluripotent stem cells exclusively into dopamine neurons that resemble those lost from the same brain region affected by Parkinson’s, that perform well in animals, and that do not produce tumors. The fact that these transplanted neurons reduced some Parkinson’s symptoms in animals is a good sign for potential therapeutic applications in people living with the disease. Before stem cell therapy for Parkinson’s becomes a reality, significant challenges remain. Until then, this new protocol will be helpful to screen and test new potential drug therapies.
*The two science stories in this issue of News & Review are abbreviated. See full stories.