Foslevodopa–Foscarbidopa subcutaneous infusion in Parkinson’s disease: a cross-cultural/cross-racial international multicentre comparative tolerability study (CRIM-FOS study)

Advanced Parkinson's disease (APD) often presents challenges such as irregular gastric absorption and delayed gastric emptying, leading to significant and unpredictable fluctuations in both motor and non-motor symptoms. Our study is a real-world, open-label study of the tolerability and efficacy of subcutaneous infusion of Foslevodopa/Foscarbidopa (FL/FC) focus on comparing White Caucasian patients and non-White patient cohorts. A database of 50 patients with APD across four international centers, for the FL/FC therapy program was examined and analysed for racial/ethnicity breakdown, motor, nonmotor and quality of life measures and tolerability using established criteria. Participants underwent assessments at 6 and 12 months, making this one of the largest global cross-racial Caucasian (62%) and non-Caucasian patients (38%) Statistical analyses were performed using IBM SPSS Statistics version 31, with significance set at p < .05. In 50 patients (48% men, 38% of non-caucasian origin) with APD, Motor (UPDRS III) scores significantly declined from a baseline mean of 40.26 (SD = 10.21) to 24.84 (SD = 6.67) at 12 months (p < .001). Health-related quality of life, measured by the PDQ-8, improved significantly, with a mean difference of 6.11 (p < .001). The dropout rate was low at 10%, with an average time to dropout of 3 months (range: 2-4 months), primarily due to dose-limiting adverse effects like severe dyskinesias and financial constraints. Subcutaneous infusion of FL/FC significantly improves motor function and sleep quality in advanced Parkinson's patients, reduces caregiver burden, enhances quality of life and effective across racial backgrounds. Our study underscores the importance of careful patient selection and monitoring during dose adjustments to optimize long-term outcomes.