Bioequivalence of Foslevodopa/Foscarbidopa continuous subcutaneous infusion to arm, thigh, or flank versus abdomen in healthy and advanced Parkinson's disease individuals.

Background: Foslevodopa/foscarbidopa (LDp/CDp) are soluble prodrugs of levodopa/carbidopa delivered as a continuous subcutaneous infusion (CSCI) via a portable pump to provide continuous levodopa exposures. Objective: To assess the safety of LDp/CDp and the relative bioavailability of levodopa/carbidopa following LDp/CDp 24-hour CSCI administration to the arm, thigh, and flank versus the abdomen. Methods: Two open-label, randomized crossover studies (healthy adult volunteers [HV]; adults with advanced Parkinson's disease [aPD]; NCT05094050) evaluated 24-hr CSCI of LDp/CDp to different infusion sites (abdomen, arm, thigh, flank), each designated as a study regimen. Participants in the aPD study had levodopa-responsive idiopathic Parkinson's disease with ≥2.5 h of "Off" time/day. In the HV study, each LDp/CDp regimen was administered over 24 h, with 72-hour washout periods between regimens. In the aPD study, LDp/CDp was administered for 2 consecutive days at each infusion site, with no washout between regimens. Results: For both levodopa and carbidopa, the 90% confidence intervals for both exposure measures (AUC and C Conclusions: The pharmacokinetics of levodopa and carbidopa demonstrated that the abdomen, arm, thigh, and flank are interchangeable sites for CSCI of LDp/CDp. There were no concerning patterns of adverse events.