Advances in neuroprotection and treatments aimed at preventing motor complications attempt to slow this disabling disorder.
But for the one million American patients, including the actor Michael J. Fox and former Attorney General Janet Reno, PD still translates into dreaded "off" times when they become entombed in their own bodies. "Despite all the progress made in PD research and drug development, there are still patients with advanced disease who are beyond drugs and need someone to take care of them, and then there are those who are at the very beginning of their disease and are desperately searching for that magic pill to ward off progression," acknowledged Samy Ayoub, R.Ph., M.S., C.G.P., Pharm.D., assistant director for clinical services in the pharmacy department at Saint Barnabas Community Medical Center in Toms River, N.J.
It certainly appears that we have a long way to go in reaching the seemingly unattainable bliss of neuro-panacea-or even a therapeutic state close to it. But the good news is that some of these unresolved issues have become intertwined with the research being conducted on one investigational agent. And as many will agree, the quickest way to get research done is to team it with a drug headed for Food & Drug Administration approval.
Perhaps the most intriguing of the studies is the TEMPO (TVP-1012 in Early Monotherapy for Parkinson's Disease Outpatients) II trial, which evaluated whether rasagiline was able to modify the disease process. The study, published in a 2004 issue of Archives of Neurology, specifically compared the effects of early and later initiation of rasagiline on progression of disability in PD patients.
Four hundred patients with early disease, not requiring dopaminergic therapy, were randomized to receive rasagiline (1 mg or 2 mg daily) for one year, or placebo for six months, followed by rasagiline at 2 mg daily for six months. After one year, patients treated with rasagiline, 2 mg daily, experienced fewer symptoms (as indicated by a smaller increase in the Unified Parkinson's Disease Rating Scale [UPDRS] score), compared with those given placebo for six months followed by rasagiline, 2 mg daily for six months. The most frequently observed adverse events in the active treatment phase were infection, headache, dizziness, and accidental injury.
"When those patients given placebo were switched at six months to rasagiline, they showed improvement in their UPDRS scores; however, these improvements were only 50% of those seen in the continuous active treatment group," disclosed Lawrence W. Elmer, M.D., Ph.D., associate professor of neurology and director at the Center for Neurological Disorders at the Medical University of Ohio. He considers these data to be quite notable because they suggest that early, continuous treatment with rasagiline may have a disease-modifying effect. "The absence of an equivalent symptomatic benefit between two groups, differing only by six months of treatment duration, is provocative and intriguing," he noted.
So the question that this research seems to beg is whether rasagiline holds neuroprotective properties that may alter the disease process if started early in PD?