title: Gastroretentive carbidopa/levodopa, DM-1992, for the treatment of advanced Parkinson's disease.
abstract: OBJECTIVE
  This study was undertaken to compare efficacy, tolerability, and pharmacokinetics of DM-1992, an extended-release formulation of carbidopa/levodopa (CD/L-dopa) with immediate-release (IR) CD/L-dopa in patients with advanced Parkinson's disease.
  
  
  METHODS
  This randomized, open-label, crossover study included a 3-d baseline and two 10-d treatment periods. Patients with daily OFF time of 2.5 h or more taking 400 mg or more L-dopa/d in four or more divided doses were titrated to stable regimens of DM-1992 2 times per day or CD/L-dopa IR 3 times to 8 times per day. Patients were allowed to take rescue CD/L-dopa as needed. Using home diaries, patients recorded OFF time and ON time with or without troublesome dyskinesia during baseline and treatment days 7 through 9. During 12-h clinic visits on day 10, plasma samples were collected for pharmacokinetics, and motor performance was assessed hourly.
  
  
  RESULTS
  Thirty-four patients were enrolled; mean baseline L-dopa dosage was 968 mg/d. After titration, CD/L-dopa IR was dosed 4.8 times per day and DM-1992, 2 times per day. Rescue CD/L-dopa IR was given 1.3 times during the DM-1992 arm and 0.2 times during the CD/L-dopa IR arm. The reduction from baseline in % OFF time was greater for DM-1992 compared with CD/L-dopa IR (-5.52% vs. +1.33%; P = 0.0471). At steady-state, compared with CD/L-dopa IR, DM-1992 exhibited a smoother plasma L-dopa concentration profile mostly because of a significantly higher (day 10) predose L-dopa concentration, associated with enhanced motor performance. Although more patients taking DM-1992 had one or more adverse events (AEs) than CD/L-dopa IR patients (35% vs. 15%), no pattern to the AEs was seen, nor any resulting discontinuations.
  
  
  CONCLUSIONS
  DM-1992 was associated with a reduction in %OFF time compared with CD/L-dopa IR despite a reduced dosing frequency. Although the open-label study design and the greater number of rescue doses during the DM-1992 arm call for caution in interpreting the results, the elevated predose plasma L-dopa concentration (12 h after DM-1992 administration) lends objective support to our findings, suggesting that phase 3 studies are warranted.
authors.affiliation: Rush University Medical Center, Chicago, IL, USA.
authors.forename: Leo
authors.initials: L
authors.lastname: Verhagen Metman
authors.affiliation: University of Alabama at Birmingham, AL, USA.
authors.forename: Natividad
authors.initials: N
authors.lastname: Stover
authors.affiliation: Depomed Inc., Newark, CA, USA.
authors.forename: Cuiping
authors.initials: C
authors.lastname: Chen
authors.affiliation: Depomed Inc., Newark, CA, USA.
authors.forename: Verne E
authors.initials: VE
authors.lastname: Cowles
authors.affiliation: Depomed Inc., Newark, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Sweeney
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000493:pharmacokinetics / Q000627:therapeutic use*; D002230:Carbidopa / Q000493:pharmacokinetics / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004338:Drug Combinations; D016503:Drug Delivery Systems; D005260:Female; D005500:Follow-Up Studies; D041981:Gastrointestinal Tract / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007980:Levodopa / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy*; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D004338:Drug Combinations; C009265:carbidopa, levodopa drug combination; D007980:Levodopa; D002230:Carbidopa
keywords: Parkinson's disease; carbidopa/levodopa; efficacy; gastroretention; pharmacokinetics