GNPX 2017 Annual Report

17 Inhibition of Colony Formation by a Combination of TUSC2 and Erlotinib In the graphs above, “EV” means DOTAP: cholesterol (DC)—empty vector (EV) complex (the Oncoprex nanovesicle without the TUSC2 gene), “PBS” means phosphate-buffered saline, and “EV + PBS” means EV and PBS, acting as a control; “ER” means erlotinib; “*” means p<0.05; and “**” means p<0.01. TUSC2-Erlotinib Combination Significantly Inhibits Tumor Growth and Metastasis and Induces Apoptotic Activity In another preclinical study, MD Anderson researchers analyzed the effect of the combination of TUSC2 and erlotinib on inhibiting tumor growth and metastasis in two NSCLC mouse xenograft models. Mice with established flank tumors of equal volumes were divided into different treatment groups: PBS, used as a control; DC-TUSC2 complex (Oncoprex), referred to in the graphs below as “Fus1” or “TUSC2”; erlotinib alone, referred to in the graphs as “Erlo” or “ER”; DOTAP:cholesterol (DC)—empty vector (EV) complex with erlotinib, referred to as “EV + Erlo” or “EV + ER”; and Oncoprex plus erlotinib, referred to as “Combo,” “TUSC2 + ER” or “TUSC2 + Erlo.” In the H322 subcutaneous xenograft model, the combination of intravenous Oncoprex and erlotinib was significantly superior (p<0.05) in reducing tumor volumes than either agent alone, as shown by graph A below. With adjustment for multiple comparisons, the tumor growth rate of Oncoprex and erlotinib combination was the only group significantly smaller than the PBS control group (p<0.01). The mean tumor volume was 421.25±89.27 mm3, compared with 1082.50±338.69 mm3, 801.25±144.60 mm3, 675.00±228.80 mm3, and 875.00±267.85 mm3, in their counterparts receiving PBS, Oncoprex, erlotinib, or EV + erlotinib, respectively. In terms of tumor size, the posterior probability of cooperative effect was 0.9928, which means that there were less than 100 in 10,000 chances that the effect of TUSC2-erlotinib combination was not cooperative. MD Anderson researchers also developed a lung metastasis xenograft mouse model, using the human TUSC2-defective, EGFR negative A549 NSCLC cell line. Animals were treated with the same protocol as their subcutaneous counterparts. The number of tumor nodules on lung surfaces was reduced by 82% after TUSC2-erlotinib treatment, compared to 41% and 54%, for TUSC2 alone or erlotinib treatment alone, respectively, as shown in graph B below. The overall difference of the tumor nodule count among the five groups was significant (p<0.0001), as was the difference between the Oncoprex and erlotinib combination group compared to each of the other groups (p<0.01). As shown in graph C below, in resected tumor tissues assayed by TUNEL, the average number of apoptotic cells in the TUSC2 + erlotinib group was many times higher than in any of the other groups, including the groups receiving erlotinib alone and USC2- nanovesicles alone.