Cancer incidence in a trial of an antiapoptotic agent for Parkinson's disease.

We performed a placebo-controlled trial of CEP-1347, an inhibitor of neuronal apoptotic cell death, in patients with early Parkinson's disease (PD) to determine whether long-term therapy would slow disability progression. This also provided an opportunity to monitor cancer incidence in a large cohort of PD patients followed prospectively including periods before and after patients developed disability requiring dopaminergic therapy. This was a multicenter study of 806 patients with early PD, without disability requiring dopaminergic therapy, assigned randomly to placebo or one of three doses of CEP-1347. Patients were monitored for an average of 1.8 years (1,467 patient-years) with routine cancer screening evaluations and annual skin examinations by a dermatologist. There was no significant excess of cancers among patients taking CEP-1347 compared with placebo for any cancer type (all P > 0.1). Nonmelanoma skin cancers were the most common cancer type observed. The incidence of melanomas was 20.9 times that predicted in the general population. Most melanomas occurred in patients who had never taken dopaminergic therapy. We found no evidence that CEP-1347 affected cancer incidence within 2 years of follow-up. Melanoma occurrence in our PD patients was greater than predicted compared with the general population and was unrelated to dopaminergic therapy. Clinical surveillance of PD patients for melanoma may be warranted.

Serum urate as a predictor of clinical and radiographic progression in Parkinson disease.

OBJECTIVE: To determine whether concentration of serum urate, a purine metabolite and potent antioxidant that has been linked to a reduced risk of Parkinson disease (PD), predicts prognosis in PD. DESIGN: Prospective study. SETTING: The Parkinson Research Examination of CEP-1347 Trial (PRECEPT) study, which investigated the effects of a potential neuroprotectant on rates of PD progression, was conducted between April 2002 and August 2005 (average follow-up time 21.4 months). PARTICIPANTS: Eight hundred four subjects with early PD enrolled in the PRECEPT study. MAIN OUTCOME MEASURES: The primary study end point was progression to clinical disability sufficient to warrant dopaminergic therapy. Cox proportional hazards models were used to estimate the hazard ratio (HR) of reaching end point according to quintiles of baseline serum urate concentration, adjusting for sex, age, and other potential covariates. Change in striatal uptake of iodine I 123-labeled 2-beta-carbomethoxy-3-beta-(4-iodophenyl)tropane ([(123)I]beta-CIT), a marker for the presynaptic dopamine transporter, was assessed with linear regression for a subset of 399 subjects. RESULTS: The adjusted HR of reaching end point declined with increasing baseline concentrations of urate; subjects in the top quintile reached the end point at only half the rate of subjects in the bottom quintile (HR, 0.51; 95% confidence interval [CI], 0.37-0.72; P for trend < .001). This association was markedly stronger in men (HR, 0.39; 95% CI, 0.26-0.60; P for trend < .001) than in women (HR, 0.77; 95% CI, 0.39-1.50; P for trend = .33). The percentage of loss in striatal [(123)I]beta-CIT uptake also improved with increasing serum urate concentrations (overall P for trend = .002; men, P = .001; women, P = .43). CONCLUSIONS: These findings identify serum urate as the first molecular factor directly linked to the progression of typical PD and suggest that targeting urate or its determinants could be an effective disease-modifying therapy in PD. Trial Registration clinicaltrials.gov Identifier: NCT00040404.