Eribulin (Halaven®): A Comprehensive Monograph on a Novel Microtubule Dynamics Inhibitor for Advanced Malignancies

1.0 Executive Summary

Eribulin is a potent antineoplastic agent belonging to the halichondrin class of microtubule dynamics inhibitors. It is a fully synthetic, structurally simplified analogue of halichondrin B, a complex natural product originally isolated from the marine sponge Halichondria okadai.[1] Marketed under the brand names Halaven® and Mevlyq®, eribulin represents a significant achievement in medicinal chemistry, translating a rare and complex natural lead into a viable therapeutic drug.[2]

The primary mechanism of action is unique among microtubule-targeting agents. Eribulin binds to high-affinity sites at the positive (+) ends of β-tubulin, inhibiting the growth phase (polymerization) of microtubules while leaving the shortening phase (depolymerization) unaffected.[2] This "end-poisoning" mechanism sequesters tubulin into non-productive aggregates, leading to the disruption of mitotic spindles, an irreversible G2/M cell-cycle blockade, and subsequent apoptosis.[1] In addition to these cytotoxic effects, eribulin exerts non-mitotic actions on the tumor microenvironment, including vascular remodeling to improve tumor perfusion and phenotypic changes consistent with the reversal of epithelial-mesenchymal transition (EMT), which may contribute to its observed survival benefits.[2]