10 AI for Drug Design
Why Drug Design Needs AI
Drug discovery is extremely expensive, slow, and risky. On average, developing a new drug costs over $1.3 billion and takes more than 10 years.
Drug Discovery as an AI Problem
Drug discovery can be formulated as a set of AI tasks across multiple biological scales.
Key AI Tasks
- Target Identification – identify disease-related genes or proteins
- Molecule Generation – generate candidate drug molecules
- Structure & Property Prediction – predict binding, toxicity, solubility
- Clinical Outcome Prediction – predict trial success
Multi-scale Biological Systems
Biological systems span multiple scales: molecule → cell → tissue → organ → disease.
Biological Foundations (Minimal)
English:
- DNA stores genetic information
- RNA transfers information
- Proteins perform biological functions
Molecules as Data
Molecules as Sequences
English: Molecules and proteins can be represented as discrete sequences (e.g., SMILES, amino acids).
Molecules as Graphs
English: Atoms are nodes, bonds are edges → Graph Neural Networks (GNNs).
Molecules as 3D Objects
English: 3D geometry is critical for molecular function.
Generative Models for Drug Design
English: Generative models can directly create new molecules instead of selecting from databases.
Main Generative Paradigms
- Autoregressive Models (LMs)
- Graph Generation
- Diffusion Models (state-of-the-art)
Diffusion Models (Key Idea)
English: Diffusion models generate data by gradually denoising random noise.
MARS: Small Molecule Drug Generation
English: MARS uses MCMC-style iterative graph editing to optimize multiple objectives.
EnzyGen: Generative Enzyme Design
English: EnzyGen is a unified generative model for enzyme sequence-structure-function co-design.
PPDiff: Protein–Protein Complex Design
English: PPDiff performs diffusion in hybrid sequence–structure space for protein complex design.
Key Challenges in AI Drug Design
English:
- Multiple objectives must be satisfied simultaneously
- Data is scarce and noisy
- Novelty is hard to achieve
- Physical and biological constraints are strong