RRx-001, A novel dinitroazetidine radiosensitizer.

The 'holy grail' in radiation oncology is to improve the outcome of radiation therapy (RT) with a radiosensitizer-a systemic chemical/biochemical agent that additively or synergistically sensitizes tumor cells to radiation in the absence of significant toxicity. Similar to the oxygen effect, in which DNA bases modified by reactive oxygen species prevent repair of the cellular radiation damage, these compounds in general magnify free radical formation, leading to the permanent "fixation" of the resultant chemical change in the DNA structure. The purpose of this review is to present the origin story of the radiosensitizer, RRx-001, which emerged from the aerospace industry. The activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews

RRx-001, A novel dinitroazetidine radiosensitizer

The ‘holy grail’ in radiation oncology is to improve the outcome of radiation therapy (RT) with a radiosensitizer—a systemic chemical/biochemical agent that additively or synergistically sensitizes tumor cells to radiation in the absence of significant toxicity. Similar to the oxygen effect, in which DNA bases modified by reactive oxygen species prevent repair of the cellular radiation damage, these compounds in general magnify free radical formation, leading to the permanent “fixation” of the resultant chemical change in the DNA structure. The purpose of this review is to present the origin story of the radiosensitizer, RRx-001, which emerged from the aerospace industry. The activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews

Sensitization of neuroendocrine prostate cancer by RRx-001.

280 Background: RRx-001 is a first-in-class dinitroazetidine nontoxic anticancer agent. Its actions include upregulation of oxidative stress, depletion of GSH and NADPH, anti-angiogenesis, epigenetic modulation and induction of viral mimicry. In a phase II clinical study (NCT02489903), RRx-001 reversed resistance to reintroduced platinum doublets in small cell lung cancer (SCLC) and other tumor types. RRx001 demonstrated clinical activity with a complete metabolic response of metastatic castration-resistant neuroendocrine prostate cancer (NEPC) after treatment with RRx-001 and reintroduced platinum doublets. Here, we used a preclinical model to further investigate RRx-001 sensitization of NEPC to platinum therapy. Methods: NCI-H660 spheroids were pre-treated with 1 mM RRx-001 or vehicle prior to treatment with carboplatin or docetaxel and cell proliferation was assessed. Cells were also pre-treated with both 1 mM RRx-001 and 10 mM N-acetyl cysteine (NAC) or 1 mM Buthionine-S,R-sulfoximine (BSO) to investigate the role of reactive oxygen species (ROS) in RRx-001 activity. NCI-H660 xenografts were pre-treated with RRx-001 (mimicking clinical activity) or vehicle prior to treatment with carboplatin, and tumor volume and body weight were monitored. Results: RRx-001 pre-treatment significantly decreased the IC50 of carboplatin from ~86 mM to 36 mM in vitro, whereas no significant effect was observed on the IC50 of docetaxel. The ROS inhibitor NAC reversed &gt; 70% of RRx-001 sensitization to carboplatin, while co-pre-treatment with the ROS generator BSO significantly enhanced RRx-001 activity. In vivo, pre-treatment with RRx-001 prior to carboplatin significantly decreased tumor volume compared to vehicle, with ~50% greater reduction in mean tumor volume at 30 days. Body weight was not affected by RRx-001. Conclusions: This preclinical study supports the concept that “priming” with RRx-001 may be an effective therapeutic strategy to resensitize NEPC to initially highly effective platinum doublets. A phase 3 trial is planned, and studies with additional preclinical NEPC models will identify the mechanism of action of RRx-001. </jats:p

Abstract C138: Anti-αv integrin monoclonal antibody intetumumab (CNTO 95) enhances the therapeutic efficacy of radiation therapy and reduces metastasis of human cancer xenografts in nude rats

Abstract Radiation therapy is used to treat cancer in over 50% of all cancer patients. Interaction of tumor cells with the extracellular matrix via adhesion molecules is important for survival of cancer stem cells, and may play a role in resistance to radiation therapy. Preclinical and clinical studies from our lab and others have demonstrated that a fully human anti- v integrin monoclonal antibody intetumumab (CNTO 95) may enhance the therapeutic index of radiotherapy by selective targeting of upregulated integrins on tumor cells and vascular endothelial cells of tumors. We previously reported that intetumumab is a radiosensitizer in mice with xenograft tumors. However, since intetumumab does not cross-react with mouse integrins, but has limited cross-reactivity with rat integrins, we next studied the potential of combined use of fractionated local tumor radiation therapy and intetumumab in human cancer xenograft models in nude rats in order to assess effects on both tumor cells and vasculatures. We found that intetumumab alone had a moderate effect on tumor growth in human head and neck cancer and non-small cell lung cancer xenograft models. When combined with fractionated radiation therapy, intetumumab significantly inhibited tumor growth and produced a tumor response rate that was significantly better than with radiation therapy alone (P &amp;lt; 0.01). The total tumor response rate (complete response and partial response) was 67% in A549 NSCLC model for intetumumab plus radiotherapy compared with 17% for radiotherapy alone. Treatment with intetumumab reduces the lung metastasis by inhibiting the homing of A549 NSCLC cells, as well as spontaneous metastasis to lung from subcutaneous tumors in A549 NSCLC xenograft model. The blood perfusion and blood volume in xenograft tumors measured by micro-bubble enhanced ultrasound image was substantially improved by treatment of intetumumab. Immunohistochemistry staining of xenograft tumor sections demonstrated that the combined use of intetumumab and radiation therapy significantly reduced the microvessel density and increased apoptosis in tumor cells and the tumor microenvironment. The oxygenation and hypoxic status of tumors treated with intetumumab with or without radiotherapy is under investigation and will be presented. Furthermore, intetumumab alone and in combination with radiation was well-tolerated and did not produce any obvious signs of systemic toxicity. An in vivo toxicity study of crypt stem cell survival in the gastrointestinal tract demonstrated that treatment with intetumumab did not alter the number of surviving crypt stem cells of duodenum, jejunum, or ileum following irradiation, suggesting that intetumumab did not sensitize the sensitive GI epithelium to the effect of radiation therapy. These results demonstrate that intetumumab can potentiate the efficacy of fractionated radiation therapy in human cancer xenograft tumors in nude rats. These findings are promising and may have high translational relevance for the treatment of patients with solid tumors. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C138.</jats:p

Darbepoetin alfa Radiosensitizes Tumors Independent of Anemia or the Correction of Anemia.

Abstract Darbepoetin alfa (DA) is a FDA approved long acting erythropoietic protein. We hypothesized that correction of anemia in tumor-bearing mice by DA would secondarily increase the tumor pO2 and potentiate radiation-induced cell killing of tumor cells. To test this hypothesis, we used total body irradiation (TBI) to induce anemia in C3H mice. Murine squamous cell carcinoma tumor (SCC VII) and fibrosarcoma (RIF-1) models were used to study tumor responses to radiation in vivo. DA (30μg/kg) was administered i.p. either every two weeks or weekly. EPO-R RNA levels were measured in tumors from normal, anemic and DA treated mice in both tumor models. Tumors were locally irradiated with daily fractions of 250 cGy for 5 days. Following 500 cGy TBI, hemoglobin levels decreased and reached a nadir of 7.0 ± 0.9 gm/dL 14 days post TBI. Administration of DA reduced the depth and duration of anemia and improved the general health condition of anemic animals as evidenced by accelerated recovery of body weight following the TBI and maintenance of normal levels of activity compared to similarly irradiated animals not treated with DA. Mice treated with DA on the same day as the TBI had elevated hemoglobin levels with a nadir of 11.1 gm/dL on day 14 after TBI. Systemic administration of DA alone did not stimulate tumor growth in TBI-induced anemic mice. When combined with fractionated local tumor irradiation, administration of DA at any of the time points studied (18, 11, 4 and 0 days before initiation of local tumor irradiation) delayed tumor growth and increased the tumor growth delay time from 2.7 days for irradiation alone to 7.3 – 10.6 days for DA treated animals (p &lt; 0.01). There was no statistically significant difference between tumor growth delay times for groups of mice treated with DA at various times before tumor irradiation. Although DA effectively corrected anemia in tumor-bearing mice and significantly decreased the number of hypoxic cells in the tumors as shown by EF5 staining, radiosensitization by DA was independent of the correction of anemia. EPOR RNA expression was barely detectible in tumors cultured in vitro. There were no differences in EPO-R RNA levels in tumors from anemic or DA treated mice (1–2 fold increase), although EPO-R transcription was upregulated in tumors grown in vivo compared to control tumors lines grown in vitro (40–80 fold increase). This may be due to hypoxic induction of EPO-R by tumors in vivo or expression of EPO-R by endothelial cells or infiltrating macrophages. Results from an experiment in non-anemic mice with RIF-1 tumors suggest that DA can sensitize tumor cells in non-anemic mice to radiation as well. These results support the idea that radiosensitization by DA is independent of hemoglobin and tumor pO2. It has long been assumed that anemia causes decreased tumor oxygenation and increased tumor radioresistance, and that correction of anemia would therefore increase tumor pO2, and result in enhanced radiosensitivity. However, the data presented here challenge this presumed relationship. These findings are promising and may have relevance to the treatment of patients with a variety of tumor types with radiation therapy.</jats:p

Darbepoietin Alfa Potentiates the Efficacy of Radiation Therapy in Mice with Corrected or Uncorrected Anemia

Abstract Darbepoietin alfa (DA) is a long-acting analogue of erythropoietin that has reduced receptor affinity and enhanced biological activity. Experiments were done to test the hypothesis that correction of anemia in tumor-bearing mice by DA would increase tumor oxygenation and potentiate radiation-induced tumor cell killing. A SCC VII tumor model was used to study tumor responses to fractionated radiation therapy in mice with anemia induced by total body irradiation. Administration of DA reduced the extent and duration of anemia and associated tumor hypoxia, protected the bone marrow cells and prevented the body weight loss from the effect of irradiation, and facilitated the recovery in a time-dependent manner, with the administration of DA prior to total body irradiation having the greatest protective effect. When combined with fractionated radiation therapy, DA increased the tumor growth delay time from 2.7 days for irradiation alone to 7.3 to 10.6 days for combination of DA and irradiation. The effect of DA on tumor responses to fractionated radiation therapy was observed when DA was given 18 to 4 days before starting radiation therapy, but DA was also equally effective as a radiosensitizer when given only 2 hours before fractionated irradiation therapy. Weekly dosing of DA was as efficacious for the enhancement of radiation responses of tumors as biweekly dosing. Similar results were obtained in the RIF-1 fibrosarcoma tumor model. These studies show that DA can effectively correct anemia in tumor-bearing mice and sensitize tumor cells to fractionated radiation therapy. Importantly, DA was also able to sensitize tumors to radiation in mice with uncorrected anemia and hypoxia, suggesting that the effect of DA on radiosensitivity was independent of these factors and a different mechanism of action may be responsible for this effect.</jats:p

Telehealth System Based on the Ontology Design of a Diabetes Management Pathway Model in China: Development and Usability Study

BackgroundDiabetes needs to be under control through management and intervention. Management of diabetes through mobile health is a practical approach; however, most diabetes mobile health management systems do not meet expectations, which may be because of the lack of standardized management processes in the systems and the lack of intervention implementation recommendations in the management knowledge base. ObjectiveIn this study, we aimed to construct a diabetes management care pathway suitable for the actual situation in China to express the diabetes management care pathway using ontology and develop a diabetes closed-loop system based on the construction results of the diabetes management pathway and apply it practically. MethodsThis study proposes a diabetes management care pathway model in which the management process of diabetes is divided into 9 management tasks, and the Diabetes Care Pathway Ontology (DCPO) is constructed to represent the knowledge contained in this pathway model. A telehealth system, which can support the comprehensive management of patients with diabetes while providing active intervention by physicians, was designed and developed based on the DCPO. A retrospective study was performed based on the data records extracted from the system to analyze the usability and treatment effects of the DCPO. ResultsThe diabetes management pathway ontology constructed in this study contains 119 newly added classes, 28 object properties, 58 data properties, 81 individuals, 426 axioms, and 192 Semantic Web Rule Language rules. The developed mobile medical system was applied to 272 patients with diabetes. Within 3 months, the average fasting blood glucose of the patients decreased by 1.34 mmol/L (P=.003), and the average 2-hour postprandial blood glucose decreased by 2.63 mmol/L (P=.003); the average systolic and diastolic blood pressures decreased by 11.84 mmHg (P=.02) and 8.8 mmHg (P=.02), respectively. In patients who received physician interventions owing to abnormal attention or low-compliance warnings, the average fasting blood glucose decreased by 2.45 mmol/L (P=.003), and the average 2-hour postprandial blood glucose decreased by 2.89 mmol/L (P=.003) in all patients with diabetes; the average systolic and diastolic blood pressure decreased by 20.06 mmHg (P=.02) and 17.37 mmHg (P=.02), respectively, in patients with both hypertension and diabetes during the 3-month management period. ConclusionsThis study helps guide the timing and content of interactive interventions between physicians and patients and regulates physicians’ medical service behavior. Different management plans are formulated for physicians and patients according to different characteristics to comprehensively manage various cardiovascular risk factors. The application of the DCPO in the diabetes management system can provide effective and adequate management support for patients with diabetes and those with both diabetes and hypertension

Abstract 4371: RRx-001 modulates intratumor blood flow in SCCVII and U87 tumors

Abstract The tumor-specific provascular effects of the anti-cancer agent RRx-001, a novel nitrogen oxide donor and allosteric hemoglobin modifier in Phase 1 clinical trials were investigated using contrast enhanced ultrasound (CEUS) and whole tissue section quantitative immunohistological staining. Changes in tumor blood flow by CEUS in SCCVII tumor bearing mice following RRx-001 (3, 6, 12 mg/kg) were dose and time dependent, reaching maximum perfusion 6 h after treatment, returning to baseline within 72 h. Microregional effects of RRx-001 (15 mg/kg) on tumor blood flow and oxygenation by immunohistological staining were studied in mouse SCCVII and human U87 tumors. SCCVII tumors exhibited regions of intermittent perfusion exemplified by co-localization of vessels with the hypoxia marker pimonidazole commonly occurring throughout the tissue. Only 21% of vessels showed perfusion after a bolus dose of the perivascular stain DiOC7. This increased to 28% 12 h post RRx-001. Paradoxically, an increase in tissue oxygenation was not seen while modestly increased pimonidazole binding was observed. However, preliminary radiobiological assessment suggested tumors were radiosensitized when irradiated 10 min after 12 mg/kg RRx-001. In the U87 tumor a decrease in vessel perfusion at 90 min post RRx-001 administration was observed. Blood flow over large areas of treated tumors was completely shut down. These areas stained positive for CD31 and tissue did not appear necrotic. Analysis indicated 25% reduction in the fraction of perfused vessels and un-perfused tissue by area at 90 min returning to near normal levels at 12 h. There was no significant increase in the fraction of necrosis at 12 h suggesting that the large un-perfused regions seen at 90 min had recovered rather than become necrotic. No significant change in tumor hypoxia was seen at 90 min or 12 h. For both tumor types, RRx-001 appeared to cause the loss of perfusion in large regions of the tumor however, at the 12 h time point, both tumor types showed increase in vessel perfusion but no significant decrease in hypoxia. These data suggest a redistribution of blood flow in both tumor types while differences between the tumors were related to tumor architecture and distribution of α-SMA. RRx-001 shows promise for short-term blood flow redistribution in tumors with a pericyte-rich vasculature with contractile proteins such as α-SMA. Expression of α-SMA in tumor vasculature could therefore be useful for predicting tumor response to RRx-001. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4371. doi:1538-7445.AM2012-4371</jats:p

Anti–αv Integrin Monoclonal Antibody Intetumumab Enhances the Efficacy of Radiation Therapy and Reduces Metastasis of Human Cancer Xenografts in Nude Rats

Abstract We previously reported that intetumumab (CNTO 95), a fully human anti–αv integrin monoclonal antibody, is a radiosensitizer in mice with xenograft tumors. Because intetumumab does not cross-react with mouse integrins, but has cross-reactivity with rat integrins, we next studied the potential combined use of radiation therapy and intetumumab in human cancer xenograft models in nude rats to assess effects on both tumor cells and the tumor microenvironment. Nude rats bearing human head and neck cancer and non–small cell lung cancer (NSCLC) xenografts were treated with intetumumab and fractionated local tumor radiotherapy. Effects on tumor growth and metastasis, blood perfusion, oxygenation, and gastrointestinal toxicity were studied. Intetumumab alone had a moderate effect on tumor growth. When combined with fractionated radiation therapy, intetumumab significantly inhibited tumor growth and produced a tumor response rate that was significantly better than with radiation therapy alone. Treatment with intetumumab also significantly reduced lung metastasis in the A549 NSCLC xenograft model. The oxygenation and blood perfusion in xenograft tumors measured by microbubble-enhanced ultrasound imaging were substantially increased after treatment with intetumumab. The combined use of intetumumab and radiation therapy reduced the microvessel density and increased apoptosis in tumor cells and the tumor microenvironment. Toxicity studies showed that treatment with intetumumab did not cause the histopathologic changes in the lungs and did not sensitize the sensitive gastrointestinal epithelium to the effect of radiation therapy. Intetumumab can potentiate the efficacy of fractionated radiation therapy in human cancer xenograft tumors in nude rats without increased toxicity. Cancer Res; 70(19); 7591–9. ©2010 AACR.</jats:p