A Translational, Pharmacodynamic, and Pharmacokinetic Phase IB Clinical Study of Everolimus in Resectable Non-Small Cell Lung Cancer

Abstract

Purpose: The altered PI3K/mTOR pathway is implicated in lung cancer, but mTOR inhibitors have failed to demonstrate efficacy in advanced lung cancer. We studied the pharmacodynamic effects of everolimus in resectable non-small cell lung cancer (NSCLC) to inform further development of these agents in lung cancer.

Experimental design: We enrolled 33 patients and obtained baseline tumor biopsy and 2[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging followed by everolimus treatment (5 or 10 mg daily, up to 28 days), or without intervening treatment for controls. Target modulation by everolimus was quantified in vivo and ex vivo by comparing metabolic activity on paired PET scans and expression of active phosphorylated forms of mTOR, Akt, S6, eIF4e, p70S6K, 4EBP1, and total Bim protein between pretreatment and posttreatment tissue samples.

Results: There were 23 patients on the treatment arm and 10 controls; median age 64 years; 22 tumors (67%) were adenocarcinomas. There was a dose-dependent reduction in metabolic activity (SUVmax: 29.0%, -21%, -24%; P = 0.014), tumor size (10.1%, 5.8%, -11.6%; P = 0.047), and modulation of S6 (-36.1, -13.7, -77.0; P = 0.071) and pS6 (-41.25, -61.57, -47.21; P = 0.063) in patients treated in the control, 5-mg, and 10-mg cohorts, respectively. Targeted DNA sequencing in all patients along with exome and whole transcriptome RNA-seq in an index patient with hypersensitive tumor was employed to further elucidate the mechanism of everolimus activity.

Conclusions: This "window-of-opportunity" study demonstrated measurable, dose-dependent, biologic, metabolic, and antitumor activity of everolimus in early-stage NSCLC.

Fig. 1

Everolimus pharmacokinetic characteristics. Bar graphs showing a dose proportional increase in maximum concentration (C_max) of everolimus measured in whole blood on Days 1, 8 and 21. Blue and red bars represent the 5 mg and 10 mg doses of everolimus, respectively.

Fig. 2

Clockwise from top left: A: Percent change in maximum standardized uptake value (SUVmax) on paired PET/CT imaging in different patient groups with reduced metabolic activity in everolimus-treated patients and increased activity in the control group. B: Percent change in metabolic activity (measured as SUVmax). Waterfall plot of percent change in SUVmax on paired PET imaging for individual patients according to treatment group (C=control; E5=Everolimus 5 mg; E10=Everolimus 10 mg). C: Waterfall plot of change in tumor size (measured as maximum tumor diameter) for individual patients by treatment group (C=control; E5=Everolimus 5 mg; E10=Everolimus 10 mg). D: Changes in metabolic activity on paired PET imaging by RAS gene mutation status showing comparable activity of everolimus (10mg) in RAS mutant and non mutant tumors.

Fig. 3

Major pathologic response and near complete metabolic response in a patient with poorly differentiated, sarcomatoid NSCLC following 4 weeks of everolimus at 10mg daily dose. Left upper panel showing coagulative tumor necrosis in the resected specimen along with histologic sections from base line biopsy (left, 200×) and post-treatment surgical sections (right, 100×) from a patient with near complete metabolic response to everolimus (10mg daily for 21 days). Note the extensive tumor necrosis in the post treatment section. Insets showing sarcomatoid cellular morphology (400×) and positive pancytokeratin staining (400×) on immunohistochemistry. Right upper panel: Baseline (left) and post-treatment (right) FDG-PET and corresponding CT scan images showing near complete metabolic response in a sarcomatoid NSCLC patient treated with everolimus. Lower panel: Circos plots of exome and whole transcriptome RNA-seq of the post-treatment sample from the patient with near complete metabolic and pathologic response and another patient with sarcomatoid tumor that did not respond to everolimus (Non-Responder). 1. Outer circle depicts copy number derived from exome sequencing. The log2 ratio of total reads per exon divided by median reads across all samples, are shown on a Y-axis ranging from −1 to 1.5. Reads with log2 ratio of < −0.2 are red, those with log2 ratio of > 0.2 are blue and those between −0.2 and 0.2 are black. An orange line of the segmented copy number generated using the DNACopy algorithm overlays this data. 2. Green inner ring shows RNA-Seq gene expression presented as log10 (FPKM+1) values range from 0–6. 3. The inner circle, lists genes with coding mutations identified by exome sequence. Mutations had to be exonic, non-synonymous, indel or splice site mutation that had at least 20× coverage with >10% variant reads. This list was parsed to exclude SNPs, SNV that were not >1% of EVS or 1000 genomes, not in 100% of reads, and had to have a COSMIC ID. The full genomic data is available on the dbGAP database under the accession number phs000829.v1.p1 and is directly accessible at this URL: http://www.ncbi.nlm.nih.gov/projects/gap/cgibin/study.cgi?study_id=phs000829.v1.p1