PIK3CA/PTEN-altered Advanced Breast Cancer Treated With MEN1611 Monotherapy or in Combination With Eribulin

MEN1611 is a potent, orally bioavailable selective inhibitor of the class I phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) with a novel structure which exhibits a strong inhibitory activity especially against the PI3K catalytic subunit alpha (PIK3CA), with potential antineoplastic activity. PI3K alpha inhibitor MEN1611 selectively binds to and inhibits PIK3CA and its mutated forms in the PI3K/Akt (protein kinase B)/mammalian target of rapamycin (mTOR) pathway.

Eribulin mesylate (eribulin), a non-taxane inhibitor of microtubule dynamics of the halichondrin class of antineoplastics, suppresses microtubule growth and sequesters tubulin into nonfunctional aggregates, preventing mitotic spindle formation with subsequent G2-M stop and apoptosis.