| Activity Number: | 539 
                            	- SPEED: Bayesian Methods and Applications in the Life and Social Sciences | 
                    
                        | Type: | Contributed | 
                    
                        | Date/Time: | Wednesday, August 1, 2018 : 11:35 AM to 12:20 PM | 
                    
                        | Sponsor: | Section on Bayesian Statistical Science | 
                
                    
                        | Abstract #332686 |  | 
                    
                        | Title: | A Novel Bayesian PK/PD Model for Synergy: Challenges and Opportunities for Sequential Knowledge Integration | 
                
                
                    | Author(s): | Fabiola La Gamba* and Tom Jacobs and Helena Geys and Christel Faes | 
                
                    | Companies: | and Janssen R&D and Janssen R&D and Hasselt University | 
                
                    | Keywords: | Bayesian inference; 
                            Nonlinear Mixed Models; 
                            Pharmacodynamics; 
                            Pharmacokinetics; 
                            Sequential integration; 
                            Meta-analysis | 
                
                    | Abstract: | 
                            Studies on pharmacodynamic interactions are usually performed in an in-vitro setting. In this work the co-administration of a novel molecule with a marketed treatment is studied through in-vivo studies performed sequentially. The body temperature change over time is expressed through a turnover model where a virtual pharmacokinetic profile of the marketed treatment drives the effect. A pharmacodynamic interaction is assumed at IC50. The aim of this work is to discuss the implications of performing the model in a Bayesian sequential manner, so that the posteriors resulting from a study are used to determine the priors of the next study. The assessed modelling aspects are: 1.Impact of prior elicitation; 2.Specification of random effect; 3.Impact of different Bayesian sequential integrations. The model worked well with informative priors, random baseline and when a wide dose range was investigated in each study. The integration of studies where one or few dose combinations were assessed produced biased results. This highlights the importance of a careful design of experiment for a successful sequential integration.   
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                    Authors who are presenting talks have a * after their name.