Assessing the outcomes of everolimus on renal angiomyolipoma associated with tuberous sclerosis complex in China: a two years trial

Background: Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder characterized by the development of numerous benign tumors. Renal angiomyolipoma (RAML) occur in up to 80% of TSC patients, which is a leading cause of TSC-related death in adult patients. The aim of the study was to evaluate the efficacy and safety profiles of everolimus in Chinese patients of TSC associated with RAML(TSC-RAML).

Methods: In this 2-years, nonrandomized, open-label trial, 18 patients of TSC-RAML, with at least one RAML 3 cm or larger in its longest diameter, were enrolled to assess the efficacy and safety of everolimus therapy in Chinese patients. Everolimus was administered for the first 12 months only. The primary endpoint was a reduction of 50% or more relative in RAML volume to the baseline in the absence of new RAML ≥1 cm and no RAML-related bleeding of grade ≥ 2. The secondary endpoints included: safety, lung function and skin lesions response rate. Serial computed tomography of RAML, magnetic resonance imaging of brain lesions and pulmonary-function tests were performed. Adverse events were investigated using CTCAE v4.0. All analyses used a significance level of 0.05 and were generated in SPSS19.0 software.

Results: The proportion of patients who achieved ≥50% reduction from baseline in the sum of volumes of target lesions increased from 52.94% at 3 months, to 58.82% and 66.67% at months 6 and 12, respectively. During the period of everolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 s (FEV1) increased by 276 ± 78 ml (P < 0.001), the forced vital capacity (FVC) increased by 433 ± 170 ml (P < 0.001), and the residual volume decreased by 408 ± 243 ml (P = 0.009), as compared with baseline values. The angiomyolipoma volume and the lung function approached, but did not completely return to, the baseline values. The skin lesions response rate was 37.5% after 12 months of therapy falling to 21.4% at 12 months after stopping everolimus. The most common adverse events were mucositis oral, irregular menstruation, abdominal pain, hypertriglyceridemia and headache. The most common grade 3 adverse events were irregular menstruation and mucositis oral. In addition, one patient died from RAML spontaneous haemorrhage during treatment with everolimus, even with reduction in RAML volume of 60.68% at 3 months. A second death was due to epithelioid RAML progression, with metastasis to multiple retroperitoneal lymph node, who died from severe infection one month after surgery.

Conclusions: Angiomyolipomas regressed somewhat during everolimus therapy but tended to increase in volume after the therapy was stopped. Everolimus was well tolerated and showed promising activity in Chinese patients with TSC-RAML, however, we should alert the life-threatening hemorrhage of large RAML in the early period and the lymph node metastasis of epithelioid RAML.

Trial registration: ChiCTR-OPC-14005488 . Registered November 17, 2014.