RESUMEN
RRx-001 is a pan-active, systemically nontoxic epigenetic inhibitor under investigation in advanced non-small cell lung cancer, small-cell lung cancer and high-grade neuroendocrine tumors in a Phase II clinical trial entitled TRIPLE THREAT (NCT02489903), which reexposes patients to previously effective but refractory platinum doublets after treatment with RRx-001. The purpose of this case study is first to report a partial response to carboplatin and etoposide in a patient with small-cell lung cancer pretreated with RRx-001, indicating episensitization or resensitization by epigenetic mechanisms, and second to discuss the literature related to small-cell lung cancer and episensitization.
RESUMEN
We present the case of a 49-year-old male with metastatic epidermal growth factor receptor (EGFR) mutation-positive adenocarcinoma of the lung that continues to outlive stage IV diagnosis of non-small cell lung cancer after treatment with RRx-001, an experimental anticancer agent with epigenetic and immunologic activity, in the context of a phase II clinical trial called TRIPLE THREAT. Currently, no adequate treatment options exist for patients with EGFR mutation-positive tumors who have failed a 1st-generation tyrosine kinase inhibitor (erlotinib or gefitinib) treatment and do not develop a resistant mutation. Biopsy of a large pancreatic metastasis after RRx-001 demonstrated extensive necrosis with CD3+ and CD8+ immune cell infiltration that appears to correlate with prolonged survival despite end-stage disease. These results suggest that the mode of action of RRx-001 is related to immune stimulation in addition to epigenetic inhibition.
RESUMEN
RRx-001, an experimental systemically non-toxic epi-immunotherapeutic agent, which potentiates the resensitization of resistant cancer cells to formerly effective therapies, is under active investigation in several clinical trials that are based on sequential or concomitant rechallenge to resistant first- or second-line regimens. One of these trials is designated TRIPLE THREAT (NCT02489903), because it explores the conditioning or priming effect of RRx-001 on three tumor types - non-small cell lung cancer (NSCLC), small cell lung cancer and high-grade neuroendocrine tumors - prior to re-administration of platinum doublets. In follow-up to a recent case study, which describes early monotherapeutic benefit with RRx-001 in a refractory EGFR-mutated NSCLC tumor, we present subsequent evidence of a radiological partial response to reintroduced platinum doublets after RRx-001. For the 50% of patients with EGFR-mutated NSCLC who progress on EGFR-tyrosine kinase inhibitors (without evidence of a T790M mutations) as well as platinum doublets and pemetrexed/taxane, no other clinically established treatment options exist. A retrial of these therapies in EGFR-positive NSCLC patients via priming with epigenetic agents such as RRx-001 constitutes a strategy to 'episensitize' tumors (i.e. reverse resistance by epigenetic means) and to extend overall survival.
RESUMEN
Inhibition of vascular endothelial growth factor (VEGF) signaling, an initiator of tumor angiogenesis, inhibits tumor growth and invasion. Bevacizumab, a monoclonal antibody to VEGF, in common use as an adjunct to standard chemotherapy like irinotecan in advanced colorectal cancer, also affects the normal (nontumor) vasculature. Dysphonia or voice changes have been anecdotally reported in patients that have been exposed to antiangiogenics. In this case report, we present an occurrence of severe dysphonia in a 60-year-old male with metastatic colorectal cancer after reintroduction of irinotecan and bevacizumab. To our knowledge, this is the first case of dysphonia associated with bevacizumab rechallenge.
RESUMEN
Neuroendocrine tumors (NET) are a heterogeneous group of neoplasms defined by the presence of cells with secretory granules and the potential to produce and release high levels of vasoactive peptides into the circulation, leading to severe flushing and diarrhea, which may adversely affect quality of life. This report presents the case of a 64-year-old man with chronic refractory diarrhea due to pulmonary NET treated with the experimental anticancer agent RRx-001 in a phase II trial called TRIPLE THREAT with subsequent resolution of his diarrhea.
RESUMEN
As early as the 1920s, the eminent physician and chemist, Otto Warburg, nominated for a second Nobel Prize for his work on fermentation, observed that the core metabolic signature of cancer cells is a high glycolytic flux. Warburg averred that the prime mover of cancer is defective mitochondrial respiration, which drives a switch to an alternative energy source, aerobic glycolysis in lieu of Oxidative Phosphorylation (OXPHOS), in an attempt to maintain cellular viability and support critical macromolecular needs. The cell, deprived of mitochondrial ATP production, must reprogram its metabolism as a secondary survival mechanism to maintain sufficient ATP and NADH levels for macromolecule production, membrane integrity and DNA synthesis as well as maintenance of membrane ionic gradients. A time-tested method to identify and disrupt criminal activity is to "follow the money" since the illicit proceeds from crime are required to underwrite it. By analogy, strategies to target cancer involve following and disrupting the flow of ATP and NADH, the energetic and redox "currencies" of the cell, respectively, since the tumor requires high levels of ATP and NADH, not only for metastasis and proliferation, but also, on a more basic level, for survival. Accordingly, four broad ATP reduction strategies to impact and potentially derail cancer energy production are highlighted herein: 1) small molecule energy-restriction mimetic agents (ERMAs) that target various aspects of energy metabolism, 2) reduction of energy 'subsidization' with autophagy inhibitors, 3) acceleration of ATP turnover to increase energy inefficiency, and 4) dietary energy restriction to limit the energy supply.