Real-world effects of foslevodopa/foscarbidopa on gait and balance in people with Parkinson's​

Introduction: Foslevodopa-foscarbidopa (Produodopa) is a new subcutaneous infusion run continuously over 24 hours for people with Parkinson’s (PwP). Foslevodopa is a prodrug for levodopa, the most effective treatment for Parkinson’s symptoms. Studies demonstrate that Produodopa improves symptom fluctuations (i.e. less OFF time & less troublesome dyskinesia) compared to oral medications. Gait and balance impairment are key risk factors for falls in advanced Parkinson’s and are less levodopa responsive. However, the impact of Produodopa on gait and balance has not yet been described.

Methods: PwP referred for Produodopa initiation at Charing Cross Hospital, following NICE treatment recommendations, were invited to participate. Testing occurred at baseline on oral medication (n=30), at 1-month (n=24) and 6-months (n=7) post-pump initiation; follow-up is ongoing. Testing included: a) questionnaires; b) motor examination (e.g. UPDRS-III & IV); c) instrumented gait & balance testing (including static posturography, timed-up-and-go, 7-metre walk and 720-degree turns), whilst wearing 6 APDM Opal sensors (both wrists; both ankles; sternum; lumbar).

Results: There was significant heterogeneity in objective and subjective measures within the group. Median age was 63 years (range 41-80), median disease duration was 11.5 years (range 5-17 years) and 33% were female. At 1-month, cadence was significantly raised, with other (non-significant) trends towards worse gait quality, and turning speed significantly reduced. This was despite significantly increased levodopa daily dosing. There were also significant improvements in balance confidence, though these changes did not persist at 6-months. Postural sway (on soft surface with eyes open) was significantly reduced. UPDRS-III and -IV were not significantly different.

Conclusion: Compared to oral medications, objective gait quality appeared worse (despite increased levodopa dosing) and balance improved after 1-month on Produodopa. A greater sample size and longer follow-up are required to make strong conclusions; data collection and analysis are ongoing. Next steps are to qualitatively explore the effects of Produodopa on quality-of-life, using semi-structured interviews with PwP and their caregivers.