Real-World Data and Causal Machine Learning to Enhance Drug Development.

The current paradigm of clinical drug development, which predominantly relies on traditional randomized controlled trials (RCTs), is increasingly challenged by inefficiencies, escalating costs, and limited generalizability. Concurrent advancements in biomedical research, big data analytics, and artificial intelligence have allowed for the integration of real-world data (RWD) with causal machine learning (CML) techniques to address some of these limitations. This manuscript reviews the emerging role of RWD/CML in enhancing clinical research and drug development programs. By leveraging diverse data sources — including electronic health records, wearable devices, and patient registries — CML methods facilitate robust drug effect estimation, enable precise identification of responders, and support adaptive trial designs. Approaches such as advanced propensity score modelling, outcome regression, and Bayesian inference can help mitigate confounding and biases inherent in observational data, thereby strengthening the validity of causal inference. However, these innovative methodologies also face significant challenges related to data quality, computational scalability, and the absence of standardized validation protocols. Furthermore, ethical and regulatory concerns regarding model transparency and validity, data privacy, and possible algorithmic biases stress the importance of multidisciplinary collaboration and rigorous oversight. Our analysis underscores that while RWD/CML integration can enhance clinical development programs by generating more comprehensive evidence and accelerating drug innovation, its successful adoption depends on overcoming technical, operational, and scientific hurdles while maintaining a transparent approach with regulatory agencies.