Fetal Therapy With Mtor Inhibitors in Cardiac Rhabdomyoma and Lymphatic Malformations Publisher Pubmed



Zargarzadeh N ; Rashidian P ; Shah T ; Ryan G ; Afshar Y
Source: Best Practice and Research: Clinical Obstetrics and Gynaecology Published:2025

Abstract

Fetal therapy has advanced with novel pharmacological approaches to address congenital tumors and malformations, including cardiac rhabdomyomas and lymphatic malformations (LMs). Cardiac rhabdomyomas, often associated with tuberous sclerosis complex (TSC), can lead to significant morbidity due to arrhythmias, left or right ventricular outflow tract obstruction and heart failure, particularly in neonates. LMs, resulting from abnormal development of the lymphatic system, can cause considerable morbidity, including airway obstruction, disfigurement, recurrent infections, bleeding into cysts, and impaired function of affected organs, depending on location. Recent therapies involving mammalian target rapamycin (mTOR) inhibitors, such as everolimus and sirolimus, offer promising interventions for these conditions. As mTOR inhibitors target dysregulated cell growth and angiogenesis, they can effectively reduce the size of both cardiac rhabdomyomas and LMs in-utero . Clinical studies in the pediatric population have shown that mTOR inhibitors promote regression of cardiac rhabdomyomas, leading to improved cardiac function, and similarly reduce the size of lymphatic malformations, thereby decreasing the need for surgical or interventional procedures. Sirolimus has also shown efficacy in treating complex LMs and is increasingly being used as a first line agent alone as well as in conjunction with other treatment modalities like surgery and sclerotherapy. Despite potential side effects, including gastrointestinal discomfort and an increased risk of infection, the risk–benefit ratio should be carefully evaluated on an individual patient basis. This review examines current evidence supporting the use of mTOR inhibitors in fetal therapy, highlighting their ability to mitigate postnatal complications and improve long-term outcomes. Further research is needed to optimize dosing protocols and assess the long-term safety of these therapies in the fetal population. © 2025 Elsevier B.V., All rights reserved.