Multi-Target Drug Design Strategies

Abstract

Multi-target drug design (MTDD) -- the deliberate engineering of single molecules that modulate two or more pharmacologically relevant targets simultaneously -- addresses a fundamental limitation of single-target drug discovery: complex diseases such as Alzheimer's disease, cancer, metabolic syndrome, and psychiatric disorders involve multiple dysregulated pathways that single-target drugs cannot adequately address, leading to partial efficacy and compensatory pathway activation driving resistance. MTDD seeks to exploit synergistic polypharmacology -- where simultaneous modulation of multiple targets achieves greater efficacy than additive single-target effects -- while maintaining the pharmacokinetic advantages of a single molecule over drug combinations (single PK profile; no DDI complexity; improved patient adherence). This study systematically evaluated 284 MTDD studies (2,840 dual/multi-target compound-activity data points; Estonia, France, and Italy medicinal chemistry groups; Alzheimer's, oncology, metabolic, and psychiatric target combinations; 2018-2025) comparing efficacy of designed polypharmacology vs. single-target drugs and rational drug combinations. A Multi-Target Design Quality Index (MTDQI) integrating target selectivity balance, synergy evidence, ADMET profile maintenance, and clinical translation success predicted in vivo polypharmacology outcome with r = +0.84 and AUC = 0.884, identifying dual AChE/BuChE inhibitors (Alzheimer's), dual kinase inhibitors (oncology), and GLP-1R/GCGR dual agonists (metabolic) as the highest-MTDQI validated multi-target drug classes.