Sporadic Angiomyolipomas Growth Kinetics While on Everolimus: Results of a Phase II Trial

Everolimus decreases tumor volume of renal angiomyolipomas in patients with tuberous sclerosis. No prospective data are available regarding the effect of everolimus on the growth kinetics in patients with sporadic angiomyolipomas. We sought to determine the safety and efficacy of everolimus in the volumetric reduction of sporadic angiomyolipomas.

This multi-institutional, prospective, phase II trial, enrolled patients with 3 cm or larger sporadic angiomyolipomas who were candidates for surgical resection or percutaneous angioembolization. Patients received 10 mg everolimus daily for 4 planned 28-day cycles. Response was defined as a 25% or greater volumetric reduction of patient angiomyolipoma. Baseline, 4, 6 and 12-month volumetric analyses were performed using magnetic resonance imaging. Everolimus was discontinued in those with less than 25% volumetric reduction after 4 cycles. Those with 25% or greater volumetric reduction received 2 additional cycles. The primary outcomes were the efficacy of everolimus in the volumetric reduction of angiomyolipomas by 25% or more, and the safety and tolerability of everolimus.

Overall 20 patients were enrolled at 5 centers. Of these patients 11 (55%) completed 4 cycles and 7 (35%) completed 6 cycles. Efficacy was demonstrated, with 10 of 18 (55.6%) patients exhibiting a 25% or greater reduction in tumor volume at 4 months (median 58.5%) and 10 of 14 (71.4%) patients exhibiting a 25% or greater reduction in tumor volume at 6 months (median 58.2%). Four (20%) patients were withdrawn due to protocol defined toxicities and 8 (40%) self-withdrew from the study due to side effects.

Everolimus was effective in causing volumetric reduction of angiomyolipomas by 25% or greater in most patients but was associated with a high rate of treatment discontinuation.