Parkinson’s Disease – Unmet Need – Detailed, Expanded Analysis: Unmet Need – Levodopa-Induced Dyskinesia (US/EU)

Levodopa-induced dyskinesia (LID) is a complication stemming from the long-term use of levodopa to treat Parkinson’s disease (PD); it causes abnormal involuntary movements. Surveyed neurologists in the United States estimate that nearly 30% of their PD patients currently experience motor complications and LID, both of which can be disabling and painful and greatly affect patients’ quality of life and activities of daily living. Currently, only a few options are available to treat PDLID, including amantadine IR, a long-standing generic drug that is not specifically approved for LID and has an unfavorable side-effect profile. In the United States, Supernus’s Gocovri (amantadine ER) is the only FDA-approved treatment for PDLID; third-to-market Osmolex ER (Supernus) is limited to off-label use. Nevertheless, the treatment of PDLID is evolving; new research suggests that Supernus’s Xadago has antiglutamatergic properties that may positively impact LID. In addition, the early- and late-phase pipeline is rich with new agents (e.g., dipraglurant [Addex], mesdopetam [IRLAB]). Understanding prescriber perceptions of the available options for PDLID and the drivers behind prescribers’ clinical decision-making for the indication can help drug developers identify levers for new product positioning and differentiation.


  • What clinical endpoints and drug attributes are most influential in prescribing for PDLID? How do neurologists rate the performance of amantadine, Gocovri, Osmolex ER, and Xadago on these attributes?
  • What are the prevailing areas of unmet need and opportunity in the treatment of PDLID?
  • Based on conjoint analysis and TPP simulation, what trade-offs among efficacy, safety, and price are neurologists willing to make for a hypothetical new drug for PDLID?


Provides quantitative insight into U.S. and European physician perceptions of key treatment drivers and goals and the current level of unmet need for a specific disease. Commercial opportunities are analyzed, and the extent to which emerging therapies may capitalize on these opportunities is evaluated.

Markets covered: United States, United Kingdom, France, Germany

Primary research: Survey of 61 U.S. and 31 European neurologists fielded in January 2023

Key companies: Supernus

Key drugs: amantadine IR, Xadago, Gocovri, Osmolex ER

launch Related Market Assessment Reports