Organizations: City University of Hong Kong, Hong Kong, PR China · City University of Hong Kong Shenzhen Research Institute, Shenzhen, PR China · The Hong Kong University of Science and Technology (Guangzhou), Guangzhou PR China · GreenDynamics, Sydney, NSW, Australia
Recent advances in large language models have demonstrated considerable potential in scientific domains such as drug repositioning. However, their effectiveness remains constrained when reasoning extends beyond the knowledge acquired during pretraining. Conventional approaches, such as fine-tuning or retrieval-augmented generation, face limitations in either imposing high computational overhead or failing to fully exploit structured scientific data. To overcome these challenges, we propose DrugMCTS, a novel framework that synergistically integrates RAG, multi-agent collaboration, and Monte Carlo Tree Search for drug repositioning. The framework employs five specialized agents tasked with retrieving and analyzing molecular and protein information, thereby enabling structured and iterative reasoning. Extensive experiments on the DrugBank and KIBA datasets demonstrate that DrugMCTS achieves substantially higher recall and robustness compared to both general-purpose LLMs and deep learning baselines. Our results highlight the importance of structured reasoning, agent-based collaboration, and feedback-driven search mechanisms in advancing LLM applications for drug repositioning.
Figures & tables
Figure 1: When the document relevant to the query appears in the middle of the retrieved document sequence, the model’s performance can even fall below that of the baseline closed-book setting [ 16 ] .
Figure 2: Data processing pipiline of DrugMCTS
Figure 3: Illustration of a single rollout in the DrugMCTS framework. The figure demonstrates how agents sequentially collaborate during one inference trajectory guided by MCTS.
Figure 4: Example of MCTS for drug repositioning
Setup
S1 Baseline
S2 EI
S3 MAE
S4 IAE
S5 DE
S6 RR
DrugMCTS
DrugBank
0.1285
0.1586
0.3879/0.4677
0.3946/0.5119
0.3472/0.3617
0.4320/0.5527
0.4466/0.5534
KIBA
0.2284
0.2452
0.3772/0.4352
0.3846/0.4491
0.3189/0.3264
0.4193/0.4861
0.4224/0.4924
Table 2: Performance comparison on DrugBank and KIBA datasets using Qwen7b (Top-k/Top-k+3 accuracy).
Appendix figures & tables7 assets
Supplementary material from the paper’s appendix.
Appendix
Dataset
Processed Points
All Proteins
Ground Truth
Unique Molecules
All Molecules
DrugBank
788
22508
1595
1304
7717
KIBA
626
23849
1664
752
6219
Appendix
Table 3: Experimental Dataset Statistics
Dataset
Ground Truth
All Proteins
Ratio (%)
DB
1595
14654
10.88
KIBA
1664
10593
15.71
Appendix
Table 4: Baseline Dataset Statistics
Dataset
Split
Negative
Positive
Total
DrugBank
Train
14,787
12,428
27,215
Test
1,960
4,111
6,071
KIBA
Train
62,553
17,350
79,903
Test
31,643
4,804
36,447
Appendix
Table 5: Deep Learning Dataset Statistics
Figure 5: Number of rollouts vs Recall score on (a) DrugBank and (b) KIBA dataset
Figure 6: Number of tokens vs Recall score on (a) DrugBank and (b) KIBA dataset
Figure 7: Protein-ligand docking results between (a) global binding site overview and (b) detailed interaction view, computed by AutoDock Vina with default scoring function and visualized using PyMOL.