Improved analysis of in vivo drug combination experiments with a comprehensive statistical framework and web-tool.

Drug combination therapy is often required to overcome the limited benefits of monotherapy in cancer treatment. While several tools exist for in vitro drug synergy screening and assessment, there is a lack of integrated methods for statistical analysis of in vivo combination experiments. To fill this gap, we present SynergyLMM, a comprehensive modeling and design framework for evaluating drug combination effects in preclinical in vivo studies. Unlike other methods, SynergyLMM accommodates complex experimental designs, including multi-drug combinations, and offers practical options for statistical analysis of both synergy and antagonism through longitudinal drug interaction analysis, including model diagnostics and statistical power analysis. These functionalities allow researchers to optimize study designs and determine an appropriate number of animals and follow-up time points required to achieve sufficient synergy and statistical power. SynergyLMM is implemented as an easy-to-use web-application, making it widely accessible for researchers without programming skills. We demonstrate the versatility and added value of SynergyLMM through its applications to various experimental setups and treatment experiments with chemo-, targeted- and immunotherapy. These case studies showcase its potential to improve robustness, statistical rigor and consistency of preclinical drug combination results, enabling a faster and safer transition from preclinical to clinical testing.