BindGPT: A Scalable Framework for 3D Molecular Design via Language Modeling and Reinforcement Learning

Generating novel active molecules for a given protein is an extremely challenging task for generative models that requires an understanding of the complex physical interactions between the molecule and its environment. In this paper, we present a novel generative model, BindGPT which uses a conceptually simple but powerful approach to create 3D molecules within the protein's binding site. Our model produces molecular graphs and conformations jointly, eliminating the need for an extra graph reconstruction step. We pretrain BindGPT on a large-scale dataset and fine-tune it with reinforcement learning using scores from external simulation software. We demonstrate how a single pretrained language model can serve at the same time as a 3D molecular generative model, conformer generator conditioned on the molecular graph, and a pocket-conditioned 3D molecule generator. Notably, the model does not make any representational equivariance assumptions about the domain of generation. We show how such simple conceptual approach combined with pretraining and scaling can perform on par or better than the current best specialized diffusion models, language models, and graph neural networks while being two orders of magnitude cheaper to sample. Recent research has demonstrated the capability of deep generative models to generate novel molecular compounds directly in 3D, with the flexibility to incorporate protein pocket and ligand subfragment conditions. Among these, diffusion models such as EDM (Hoogeboom et al., 2022) and DiffDock (Corso et al., 2023) initiate the generation process with an arbitrary spatial distribution of atoms and progressively refine their positions to yield physically