Clinical trial of Madopar HBS in parkinsonian patients with fluctuating drug response after long-term levodopa therapy

Patient-specific in vitro drug release testing coupled with in silico PBPK modeling to forecast the in vivo performance of oral extended-release levodopa formulations in Parkinson's disease patients

Biorelevant in vitro release models are valuable analytical tools for oral drug development but often tailored to gastrointestinal conditions in 'average' healthy adults. However, predicting in vivo performance in individual patients whose gastrointestinal conditions do not match those of healthy adults would be of great value for optimizing oral drug therapy for such patients. This study focused on establishing patient-specific in vitro and in silico models to predict the in vivo performance of levodopa extended-release products in Parkinsońs disease patients. Current knowledge on gastrointestinal conditions in these patients was incorporated into model development. Relevant in vivo pharmacokinetic data and patient-specific in vitro release data from a novel in vitro test setup were integrated into patient-specific physiologically-based pharmacokinetic models. AUC, c_max and t_max of the computed plasma profiles were calculated using PK-Sim®. For the products studied, levodopa plasma concentration-time profiles modeled using this novel approach compared far better with published average plasma profiles in Parkinsońs disease patients than those derived from in vitro release data obtained from the 'average' healthy adult setup. Although further work is needed, results of this study highlight the importance of addressing patient-specific gastrointestinal conditions when aiming to predict drug release in such specific patient groups.

Madopar HBS and the decompensated phase of Parkinson disease

The most important current problem in the treatment of Parkinson disease in the so-called L-dopa long-term-treatment syndrome. We present here the results of our experience with Madopar HBS in the treatment of two groups of patients suffering from L-dopa long-term treatment syndrome. In the first study we replaced the standard Madopar with Madopar HBS. In the second study, after identifying the most disabling "off" periods, we added Madopar HBS to the previous treatment in such a way as to control these "off" phases. Our study suggests that Madopar HBS is useful in reducing typical fluctuation phenomena in the majority of patients.