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Levodopa/Carbidopa (LD/CD)

AbbVie · Phase 3 active Small molecule ✓ Verified May 2026

Levodopa/Carbidopa (LD/CD) is a Dopamine precursor with peripheral decarboxylase inhibitor Small molecule drug developed by AbbVie. It is currently in Phase 3 development for Parkinson's disease, Restless legs syndrome (off-label use).

Levodopa is converted to dopamine in the brain to replace deficient neurotransmitter levels, while carbidopa inhibits premature conversion in the periphery, allowing more levodopa to reach the central nervous system.

Levodopa/Carbidopa (LD/CD) is a medication used to treat Parkinson's Disease, specifically motor fluctuations in advanced cases. It works by inhibiting the enzyme aromatic-L-amino-acid decarboxylase, which is involved in the breakdown of levodopa.

Likelihood of approval
58.3% vs 58.3% industry baseline
If approved by FDA: likely 2028–2030
Steps remaining: NDA/BLA submission
Confidence: High
Why this estimate
  • Baseline phase 3 → approval rate +58.3pp
    Industry-wide phase 3 drugs reach approval ~58.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
  • CNS / neurology attrition -3.0pp
    CNS drugs have historically high Phase 3 failure rates (notably in Alzheimer disease + major depression).
  • Big-pharma sponsor +3.0pp
    AbbVie is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.
Predicted approval windows by jurisdiction (conditional on FDA approval)
Regulator Country Likely year Lag vs FDA
FDA US 2028–2030
EMA EU 2029–2031 +0.7 yr
MHRA GB 2029–2031 +0.7 yr
Health Canada CA 2029–2032 +0.9 yr
TGA AU 2029–2032 +1.2 yr
PMDA JP 2029–2032 +1.5 yr
NMPA CN 2030–2033 +2.3 yr
MFDS KR 2029–2032 +1.4 yr
CDSCO IN 2029–2033 +1.8 yr
ANVISA BR 2030–2033 +2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic nameLevodopa/Carbidopa (LD/CD)
SponsorAbbVie
Drug classDopamine precursor with peripheral decarboxylase inhibitor
TargetDopamine pathway; aromatic L-amino acid decarboxylase (carbidopa component)
ModalitySmall molecule
Therapeutic areaNeurology
PhasePhase 3

Mechanism of action

Levodopa (L-DOPA) is a precursor to dopamine that can cross the blood-brain barrier, unlike dopamine itself. Carbidopa is a peripheral decarboxylase inhibitor that prevents levodopa from being converted to dopamine outside the brain, thereby increasing the amount of levodopa available for conversion to dopamine in the CNS. This combination restores dopaminergic neurotransmission in Parkinson's disease patients who have progressive loss of dopamine-producing neurons.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

Frequently asked questions about Levodopa/Carbidopa (LD/CD)

What is Levodopa/Carbidopa (LD/CD)?

Levodopa/Carbidopa (LD/CD) is a Dopamine precursor with peripheral decarboxylase inhibitor drug developed by AbbVie, indicated for Parkinson's disease, Restless legs syndrome (off-label use).

How does Levodopa/Carbidopa (LD/CD) work?

Levodopa is converted to dopamine in the brain to replace deficient neurotransmitter levels, while carbidopa inhibits premature conversion in the periphery, allowing more levodopa to reach the central nervous system.

What is Levodopa/Carbidopa (LD/CD) used for?

Levodopa/Carbidopa (LD/CD) is indicated for Parkinson's disease, Restless legs syndrome (off-label use).

Who makes Levodopa/Carbidopa (LD/CD)?

Levodopa/Carbidopa (LD/CD) is developed by AbbVie (see full AbbVie pipeline at /company/abbvie).

What drug class is Levodopa/Carbidopa (LD/CD) in?

Levodopa/Carbidopa (LD/CD) belongs to the Dopamine precursor with peripheral decarboxylase inhibitor class. See all Dopamine precursor with peripheral decarboxylase inhibitor drugs at /class/dopamine-precursor-with-peripheral-decarboxylase-inhibitor.

What development phase is Levodopa/Carbidopa (LD/CD) in?

Levodopa/Carbidopa (LD/CD) is in Phase 3.

What are the side effects of Levodopa/Carbidopa (LD/CD)?

Common side effects of Levodopa/Carbidopa (LD/CD) include Nausea, Dyskinesia, Orthostatic hypotension, Dizziness, Hallucinations, Confusion.

What does Levodopa/Carbidopa (LD/CD) target?

Levodopa/Carbidopa (LD/CD) targets Dopamine pathway; aromatic L-amino acid decarboxylase (carbidopa component) and is a Dopamine precursor with peripheral decarboxylase inhibitor.

Related

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing