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A Randomized, Double-Blind, Double-Dummy, Active-Controlled Study Comparing the Efficacy, Safety and Tolerability of ABBV-951 to Oral Carbidopa/Levodopa in Advanced Parkinson’s Disease Patients


Brief Summary:

Parkinson’s disease (PD) is a neurological condition, which affects the brain. PD gets worse
over time, but how quickly it progresses varies a lot from person to person. Some symptoms of
PD are tremors, stiffness, and slowness of movement. This study measures the efficacy,
safety, and tolerability of ABBV-951 versus oral Levodopa (LD)/Carbidopa (CD) [LD/CD] in
advanced PD participants to achieve reduction in motor fluctuations.

ABBV-951 is an investigational (unapproved) drug containing Levodopa Phosphate/Carbidopa
Phosphate (LDP/CDP) given subcutaneously (under the skin) for the treatment of Parkinson’s
Disease. The study has two treatment arms . In one arm, participants will be given ABBV-951
plus oral placebo (does not contain treatment drug). In the second arm, participants will be
given placebo solution and LD/CD tablets. Adult participants with advanced PD will be
enrolled. Approximately 130 participants will be enrolled in the study in approximately 80
sites across the world.

In one arm, participants will receive ABBV-951 solution as a continuous infusion under the
skin plus oral placebo capsules for LD/CD. In the second arm, participants will receive
placebo solution for ABBV-951 as a continuous infusion under the skin plus oral capsules
containing LD/CD tablets. The treatment duration is 12 weeks.

There may be higher treatment burden for participants in this trial compared to their
standard of care. Participants will attend regular visits during the course of the study at a
hospital or clinic. The effect of the treatment will be checked by medical assessments, blood
tests, checking for side effects, and completing questionnaires.


Inclusion Criteria:

– Diagnosis of idiopathic Parkinson’s Disease (PD) that is levodopa-responsive.

– Participants must be taking a minimum of 400 milligrams/day (mg/day) of Levodopa (LD)
equivalents and be judged by the investigator to have motor symptoms inadequately
controlled by current therapy, have a recognizable/identifiable “Off” and “On” states
(motor fluctuations), and have an average “Off” time of at least 2.5 hours/day over 3
consecutive PD Diary days with a minimum of 2 hours each day.

– Participant or caregiver, if applicable, demonstrates the understanding and correct
use of the delivery system, including the insertion of the cannula into the
participant’s abdomen, as assessed by the investigator or designee during the
Screening period.

Exclusion Criteria:

– Clinically significant, unstable medical conditions or any other reason that the
investigator determines would interfere with the participant’s participation in this
study or would make the participant an unsuitable candidate to receive study drug.

– History of allergic reaction or significant sensitivity to LD or constituents of the
study drug (and its excipients) and/or other products in the same class.


  • Parkinson’s and Movement /ID# 216705, Fountain Valley, California, United States, 92708
  • Neuro Pain Medical Center /ID# 216551, Fresno, California, United States, 93710-5473
  • University of California, San /ID# 216598, La Jolla, California, United States, 92093
  • Loma Linda University Medical /ID# 216500, Loma Linda, California, United States, 92354
  • Collaborative Neuroscience Net /ID# 216970, Long Beach, California, United States, 90806
  • University of California, Los Angeles /ID# 216674, Los Angeles, California, United States, 90095
  • SC3 Research Group – Pasadena /ID# 216821, Pasadena, California, United States, 91105-3149
  • Stanford University School of Med /ID# 216726, Stanford, California, United States, 94305-2200
  • Cedars-Sinai Medical Center – West Hollywood /ID# 216561, West Hollywood, California, United States, 90048
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