In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 15_suppl ( 2012-05-20), p. 10619-10619
Abstract:
10619 Background: The efficacy and safety of everolimus, an oral mTOR inhibitor, was assessed in two randomized, double-blind, placebo-controlled, phase 3 trials: EXIST-1 (NCT00789828) and EXIST-2 (NCT00790400). EXIST-1 examined everolimus for the treatment of subependymal giant cell astrocytoma (SEGA) associated with TSC and EXIST-2 for the treatment of renal angiomyolipoma (AML) associated with either TSC or sporadic lymphangioleiomyomatosis. In each instance, everolimus was superior to placebo for the primary endpoints, SEGA and renal AML response rates. Inhibitors of mTOR have antiangiogenic effects on tumor growth in vitro and in vivo. Methods: Patients were randomized to receive everolimus (n=78) starting at 4.5 mg/m 2 /day (target trough, 5-15 ng/mL) or placebo (n=39) in EXIST-1 and 10 mg/day everolimus (n=79) or placebo (n=39) in EXIST-2. Plasma samples were taken at baseline and pre-dosing on day 1 of weeks 4, 12, 24, 36, and 48 of treatment. Angiogenic markers of interest were vascular endothelial growth factor (VEGF)-A and -D, placental growth factor (PlGF), soluble VEGF receptor-1 (sVEGFR1), soluble VEGF receptor 2 (sVEGFR2), c-Kit, and collagen type IV. Results: Compared with placebo, a sustained ~30% and ~60% increase in VEGF-A was observed in the everolimus arm of EXIST-1 and EXIST-2, respectively. A concomitant decrease in collagen type IV (~25% EXIST-1; ~45% EXIST-2) and sVEGFR2 (~25% both trials) was also observed in the everolimus arm. A sustained decrease (~60%) in VEGF-D was observed in the everolimus arm of EXIST-2, but not EXIST-1. In both studies, no change was observed in PlGF, sVEGFR1, or c-Kit plasma concentrations in the everolimus arm or any biomarkers evaluated in the placebo arm. Baseline sVEGFR2 and VEGF-D were ~40% and ~4-fold higher, respectively, while VEGF-A was ~50% lower in EXIST-2 compared with EXIST-1. A similar baseline plasma concentration for the other biomarkers was noted in both studies. Conclusions: Patients presenting with SEGA or renal AML associated with TSC had a reduction in plasma concentrations of sVEGFR2, collagen type IV, and VEGF-D (AML only) and an increase in VEGF-A. Everolimus may have antiangiogenic properties in TSC patients.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2012.30.15_suppl.10619
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2012
detail.hit.zdb_id:
2005181-5
