Burden of non-motor symptoms in Parkinson's disease patients predicts improvement in quality of life during treatment with levodopa-carbidopa intestinal gel.

BACKGROUND AND PURPOSE: GLORIA, a registry conducted with 375 advanced Parkinson's disease patients treated with levodopa-carbidopa intestinal gel (LCIG) for 24 months in routine clinical care, demonstrated significant reductions from baseline in 'off' time and 'on' time with dyskinesia and improvements in the Non-Motor Symptom Scale (NMSS) total and individual domain scores, and in Parkinson's Disease Questionnaire 8 item (PDQ-8) total score. METHODS: Associations between baseline NMSS burden (NMSB), the multi-domain NMSS total score and the PDQ-8 total score were investigated for 233 patients. Baseline NMSB was assigned to five numerical categories defined by the NMSS total cutoff scores (0-20, 21-40, 41-60, 61-80 and >80). Pearson and Spearman correlations were calculated at month 24. RESULTS: The response of LCIG was assessed using validated criteria after 24 months. The proportion of patients decreasing ≥ 30 NMSS score points was 47% in the most affected NMSB category (NMSS total score > 80). A positive association was noted between baseline NMSB and NMSS total score (0.57, P < 0.0001), as well as between NMSS total score and PDQ-8 total score (0.46, P < 0.0001). Associations between improvements of the NMSS domain sleep/fatigue and PDQ-8 total score (0.32, P = 0.0001) as well as between the NMSS domain mood/cognition and PDQ-8 total score (0.37, P < 0.0001) were also shown. CONCLUSIONS: This analysis demonstrated positive associations between NMSS baseline burden and improvements of non-motor symptoms. Improvements of non-motor symptoms were associated with improved quality of life in advanced parkinsonian patients during a 2-year treatment with LCIG and reflect the long-term non-motor efficacy of this treatment.

Association of dopamine-related genetic loci to dopamine D3 receptor antagonist ABT-925 clinical response.

ABT-925, a selective dopamine D3 receptor (DRD3) antagonist, was tested in schizophrenia. A DRD3 gene polymorphism results in an S9G amino-acid change that has been associated with lower risk of schizophrenia, higher affinity for dopamine and some antipsychotics, and differential response to some antipsychotics. The effect of S9G genotype on response to ABT-925 was examined. DNA samples (N=117) were collected in a proof-of-concept, double-blind, randomized, placebo-controlled study of ABT-925 (50 or 150 mg QD) in acute exacerbation of schizophrenia. A pre-specified analysis assessed impact of genotype (SS versus SG+GG) on change from baseline to final evaluation for the Positive and Negative Syndrome Scale (PANSS) total score using analysis of covariance with genotype, treatment and genotype-by-treatment interaction as factors, and baseline score as covariate. Significant genotype-by-treatment interaction (P=0.015) was observed for change from baseline to final evaluation for the PANSS total score. Within subgroup analyses showed significant improvement from placebo in the SG+GG group treated with ABT-925 150 mg. More favorable clinical outcomes were observed in patients treated with ABT-925 150 mg who carried the DRD3 G allele than in those who carried the DRD3 SS genotype.