GNPX 2017 Annual Report

7 While next generation TKIs show promise in targeting resistant EGFR positive tumors that carry a mutation known as T790M, only about one-half of EGFR positive patients (5% to 7.5% of all NSCLC patients of North American and European descent and 15% to 25% of NSCLC patients of Asian descent) carry the T790M mutation. This leaves a significant majority of NSCLC patients—those who are EGFR negative and those who are EGFR positive but have become resistant to erlotinib and do not have the T790M mutation—without a targeted therapy for their cancer. Our clinical and preclinical data indicate that the combination of our lead product candidate, Oncoprex, with erlotinib and other EGFR TKIs may increase anti-tumor activity in cancers with or without the EGFR mutations and in cancers that have become resistant to erlotinib therapy, thus expanding the number of patients who could benefit from those drugs. TUSC2, the Active Agent in Oncoprex TUSC2, which is the active agent in Oncoprex, is a multifunctional gene that plays a vital role in cancer suppression and normal cell regulation. Key TUSC2 anti-cancer mechanisms of action include the inactivation of multiple oncogenic kinases, the induction of apoptosis, the control of cell signaling and inflammation, and modulation of the immune system to fight cancer. Oncoprex has also been shown to block mechanisms that create drug resistance. Our data indicate that Oncoprex in combination with both EGFR TKIs and with immunotherapies achieve results more favorable than results achieved with either Oncoprex or such other therapies alone, and may make those drugs effective for patients who would not otherwise benefit from them. Normal TUSC2 function is inactivated at the early onset of cancer development, making TUSC2 a potential target for all stages of cancer, including metastatic disease. The TUSC2 protein is reduced or absent in approximately 85% of lung cancers. In patients with NSCLC, the loss of TUSC2 expression has been associated with significantly worse overall survival than when TUSC2 expression is not impaired. Studies show TUSC2 protein functions as a key mediator in the Apaf1-mediated mitochondrial apoptosis pathway by recruiting and directing cytoplasmic Apaf1 protein to a critical cellular location and activating it in situ and by up-regulating activity of other proapoptotic effectors. Normal TUSC2 function mediates apoptosis in cancer cells through interaction with Apaf1 and down-regulates multiple tyrosine kinases including EGFR, AKT, PDGFR, c-Kit, and c-Abl. TUSC2 mediates apoptosis in cancer cells but not normal cells through its interaction with Apaf1 and down-regulates tyrosine kinases including EGFR, PDGFR, c-Kit, and c-Abl. In normal cells, the proteins involved in the PI3K/AKT pathway (also called the mTOR pathway), in which PI3K, a kinase, generates messenger molecules required to translocate AKT, another protein kinase, to the cell’s plasma membrane where it is phosphorylated and activated, play an important role in cellular function and cellular trafficking. These proteins are often found to be aberrantly active in cancers, causing cells to lose their ability to control cell growth, proliferation, and differentiation. Thus, mutations in PI3K (overexpression) and its upstream receptors, EGFR, have been associated with many forms of cancers. Similarly, proteins in the Ras/MAPK pathway, which is a signal transduction pathway that transduces signals to the cell nucleus where specific genes are activated for cell growth, division and differentiation, play a critical role in cellular responses to various stress stimuli, including osmotic stress, DNA damage, and proinflammatory factors. As shown in the figures below, the TUSC2 protein, a potent pan-kinase inhibitor, blocks multiple cell signaling pathways downstream of the receptor (EGFR in the figures), leading to cell cycle interruption and thereby preventing cancer cell proliferation and survival.