Research progress on targeted drugs for vascular malformations

Vascular malformations, which mainly occur in the head and neck region, are a group of congenital disorders that cannot involute and dilate gradually as patients grow. Traditional therapeutic strategies for vascular malformations include laser therapy, sclerotherapy, interventional embolization, surgical resection, etc. However, for some cases with a relatively larger range of lesions, traditional therapeutic strategies might fall short of the goals. With the development of molecular genetics, gene mutations are currently recognized as the root cause of the occurrence of vascular malformations. The progression of vascular malformation lesions is further promoted by the activation of related pathways. Low-flow vascular malformations mainly involve activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, whereas high-flow vascular malformations mainly involve activation of the rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase kinase (MAPKK)/extracellular-signal regulated protein kinase (ERK) pathway. Targeted drugs against relevant gene mutations and signaling pathways have also been applied in the treatment of vascular malformations, and previous studies have shown that the mTOR inhibitor rapamycin is effective and now widely used in the treatment of low-flow vascular malformations. The PI3K inhibitor alpelisib is also promising in the treatment of venous malformations, and the MAPKK inhibitor trametinib has shown good results in the treatment of arteriovenous malformations. Therefore, traditional therapies supplemented by targeted drugs may bring new breakthroughs to the treatment of vascular malformations.