ErbB2/ErbB4 (neuregulin pathway)

Class

Recombinant neuregulin-1 biologic

ErbB2 and ErbB4 are receptor tyrosine kinases belonging to the epidermal growth factor receptor (EGFR/ErbB) family. In the heart, they are activated by neuregulin-1, a growth factor secreted by the endothelial cells lining cardiac blood vessels and chambers. Under normal physiology, neuregulin-1 signaling through ErbB4 and its obligate heterodimer partner ErbB2 supports cardiomyocyte survival, structural integrity, and contractile function. This axis has become a target for restorative cardiac therapy, where the strategy is to enhance rather than block receptor signaling: recombinant neuregulin-1 proteins and neuregulin-based biologics aim to reactivate this survival and repair pathway in stressed or failing heart muscle, with the goal of improving contractile performance and limiting adverse structural remodeling. This is a notable contrast to oncology, where the same ErbB2 receptor is more often a target for inhibition, since its amplification drives certain cancers; the cardiac application instead exploits the receptor's endogenous protective role. This dual biology also explains a recognized clinical phenomenon: therapies that block ErbB2 for cancer treatment can produce cardiac dysfunction as a side effect, underscoring how central this signaling axis is to maintaining healthy heart muscle independent of its role in tumor growth.