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Computer Science, Machine Learning

Human-Defined Reward Function Outperforms Predictive Models in Drug Discovery

Human-Defined Reward Function Outperforms Predictive Models in Drug Discovery

Drug discovery is a complex process that involves finding new medicines to treat various diseases. One of the biggest challenges in drug discovery is designing molecules that can effectively interact with biological systems, while also meeting other criteria such as safety and efficacy. To address this challenge, researchers have turned to artificial intelligence (AI) to help with the process. However, AI algorithms require a crucial component called reward functions to evaluate and rank potential drug candidates. In this article, we explore how AI can be used to improve drug discovery efficiency by developing better reward functions.
Section 1: The Problem of Reward Functions in Drug Discovery
Reward functions are essential for AI algorithms to prioritize compounds based on their potential as drugs. However, these functions are often created by humans, which can lead to biases and inconsistencies in the evaluation process. In drug discovery, chemists may have different opinions when it comes to prioritizing molecules, making it challenging for AI algorithms to learn an optimal reward function.

Section 2: Addressing the Problem with Machine Learning

To overcome the issue of human bias in reward functions, researchers have proposed using machine learning techniques to learn how to justify preferential rankings over molecules. By training a neural network to predict the reward function based on the input data, AI algorithms can adapt and improve their performance over time. This approach allows for the development of more accurate and robust reward functions, which are essential for efficient drug discovery.

Section 3: Validating the Approach with Case Studies

To demonstrate the effectiveness of the proposed method, researchers have conducted two case studies. In the first study, they simulated Design-Make-Test-Analyse (DMTA) cycles by alternating reward function updates and generative runs guided by that function. The results showed that the learned function adapts over time to yield compounds with high scores based on evaluation functions from the literature. In the second study, they applied their algorithm to historical data from four real drug discovery projects. The findings revealed that their algorithm yields reward functions that outperform human-defined functions, achieving an improvement of up to 0.4 in Spearman’s correlation against a ground truth evaluation function that encodes the target drug profile for that project.

Conclusion

In conclusion, AI has the potential to revolutionize drug discovery by improving efficiency and accuracy. By developing better reward functions using machine learning techniques, AI algorithms can prioritize compounds more effectively based on their potential as drugs. The proposed method demonstrates promising results in two case studies, validating its effectiveness in improving drug discovery efficiency. As the field of AI continues to evolve, we can expect even more innovative solutions to emerge that will accelerate the development of new medicines and improve human health.