Emerging Therapeutic Strategies for Targeting Hyaluronan in Metabolic Disease from Molecular Design to Clinical Translation

Hyaluronan (HA) is increasingly implicated as a contributor to metabolic disease; however, the strongest causal evidence still derives from preclinical models, and no HA-directed treatment has reached the metabolic clinic. That gap points to a weakness in the underlying therapeutic logic. Clinical results for systemic removal of HA have been mixed rather than uniformly negative. In the phase II HALO-202 trial, PEGPH20 improved progression-free survival in patients with hyaluronan-high pancreatic tumors, whereas the phase III HALO-301 trial, which enrolled only hyaluronan-high patients, showed no overall survival benefit; depletion alone was therefore insufficient, and this outcome cannot be attributed to unselected treatment or to molecular size. Its biological activity is not determined by molecular size alone. Concentration, preparation purity, receptor context, tissue location, and the balance between high-molecular-weight HA (HMW-HA, generally above 1000 kDa) and smaller fragments, which range from oligosaccharides of about ten saccharides or fewer to low-molecular-weight HA in between, jointly influence whether the matrix mainly protects or injures metabolic tissues. The argument here is that the field should move away from bulk depletion and toward precision delivery and biomarker-guided patient selection. The therapeutic landscape is organized around four strategies: pharmacological inhibition of HA synthesis, enzymatic degradation, HA-based biomaterials, and defined-molecular-weight HA fragments. Throughout, we distinguish interventions that modify endogenous HA biology from platforms that use HA as a carrier or scaffold, because improved drug delivery or wound healing does not by itself demonstrate correction of pathological HA signaling. Their translational obstacles are then assessed, including patient stratification by HA size and CD44 signature, standardization of size-resolved HA quantification, thromboembolic risk, manufacturing and regulatory hurdles for drug–device combinations, and the design of trials with composite metabolic endpoints. HA is best viewed as an amplifier of metabolic stress rather than a bystander, and the route to clinical translation lies in restoring the equilibrium between HA synthesis and degradation rather than eliminating the molecule, a goal that remains a translational hypothesis rather than a demonstrated clinical outcome.