Peggy Willocks was 44 when she was diagnosed with Parkinson’s disease. It progressed quickly, forcing her to retire four years later from her job as a primary-school principal in Elizabethton, Tennessee. Soon, her condition had deteriorated so much that she was often unable to dress and feed herself, take care of basic hygiene or walk unaided across a room.
Willocks enrolled in a trial for an experimental therapy called Spheramine, developed by Titan Pharmaceuticals, a biotechnology company in South San Francisco, California. Spheramine consists of cultured human retinal epithelial cells bound to specialized man-made carrier molecules. The cells are implanted into the brain, where it is hoped that they will produce the dopamine precursor levodopa, which can reduce the symptoms of Parkinson’s disease. In August 2000, Willocks became the second person ever to receive the treatment. After having a steel halo — a stereotactic frame — bolted to her skull, she was put under general anaesthesia. Surgeons then used the frame and coordinates obtained from numerous magnetic resonance imaging (MRI) scans to pinpoint the location at which to drill. They then snaked a catheter through her brain’s white matter to deliver the cells into the striatum.
At first there was no effect, but Willocks says that after 6–8 months she began to feel better. The changes were always moderate and gradual, except for once, about nine months after her surgery, when she showed what her doctor called a “radical” improvement in balance. By a year after the treatment, she and the five other patients in the phase I trial showed an improvement in motor ability of 48%, and those gains largely held 4 years later.
Ten years on, she says she notices her condition worsening, but is still doing much better than she was before her operation. She has no doubt that the treatment works. Investigators disagree…