RareAgent: Self-Evolving Reasoning for Drug Repurposing in Rare Diseases
Lang Qin, Zijian Gan, Xu Cao, Pengcheng Jiang, Yankai Jiang, Jiawei Han, Kaishun Wu, Jintai Chen
TL;DR
RareAgent tackles rare-disease drug repurposing under the sparse-zero bipartite setting by reframing the task as active, evidence-seeking reasoning with a self-evolving multi-agent system. It builds task-specific evidence graphs (T-EGraphs) through adversarial debates among four agents, guided by textual feedback that refines policies and distills reasoning into transferable heuristics, yielding auditable reasoning trails. Empirically, RareAgent achieves state-of-the-art performance on rare-disease indication (AUPRC 0.438, AUROC 0.662, improved to 0.463 and 0.750 after self-evolution) and strong results on BioHopR (1-hop 33.87%, 2-hop 17.68%), outperforming reasoning baselines and large LLMs under budget constraints. The approach enhances interpretability and reliability in high-stakes drug discovery by grounding predictions in verifiable evidence and a growing repertoire of domain-specific heuristics.
Abstract
Computational drug repurposing for rare diseases is especially challenging when no prior associations exist between drugs and target diseases. Therefore, knowledge graph completion and message-passing GNNs have little reliable signal to learn and propagate, resulting in poor performance. We present RareAgent, a self-evolving multi-agent system that reframes this task from passive pattern recognition to active evidence-seeking reasoning. RareAgent organizes task-specific adversarial debates in which agents dynamically construct evidence graphs from diverse perspectives to support, refute, or entail hypotheses. The reasoning strategies are analyzed post hoc in a self-evolutionary loop, producing textual feedback that refines agent policies, while successful reasoning paths are distilled into transferable heuristics to accelerate future investigations. Comprehensive evaluations reveal that RareAgent improves the indication AUPRC by 18.1% over reasoning baselines and provides a transparent reasoning chain consistent with clinical evidence.
