Continuous Low-Dose Everolimus Shrinkage Tuberous Sclerosis Complex-Associated Renal Angiomyolipoma: A 48-Month Follow-up Study

Abstract

Tuberous sclerosis complex (TSC) is a rare disease that causes multisystem benign neoplasm, induced by dysregulation of the mammalian target of the rapamycin pathway (mTOR). This study aimed to examine the effects of continuous low-dose everolimus, a potent and selective inhibitor of mTOR, on the treatment of TSC-associated renal angiomyolipoma (AML). Between July 2013 and August 2017, 11 patients with TSC-AML were enrolled for an everolimus therapy protocol. An oral everolimus dose starting at 2.5 mg daily was gradually increased to 5.0 mg daily. All patients were evaluated using MRI or CT scanning at baseline, 12, 24, 36 and 48 months after the start of treatment for measuring changes of renal AML mass volume. Everolimus therapy resulted in significant shrinkage of TSC-AML volume after 48 months follow-up. Serum levels of everolimus were subdivided into group I (<8 ng/mL, n=6) and group II (>8 ng/mL, n=5). The volume reduction rates were 10.6%–65.2% in group I and 42.5%–70.6% in group II. To evaluate the response to treatment, three of six (50%) were responders in group I, and all the patients in group II (5/5, 100%) were responders. The differences in AML volume reduction between the groups were statistically significant at 12 months (p=0.011), 24 months (p=0006), 36 months (p=0.014) and 48 months (p=0.05). These results suggest that continuous low-dose everolimus therapy (2.5–5 mg daily) might be effective in shrinking TSC-AML volume and minimizes adverse effects and subsequent reducing medical costs.