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PUB012 Inhibition of the Colony-Stimulating-Factor-1 Receptor Affects the Resistance of Lung Cancer Cells to Cisplatin
S1452
1.65, 95%CI: 1.04-2.61) independently predicted poor DFS. Conclusion: In patients undergoing VATS lobectomy for NSCLC, EBL was the only modifiable predictor of poor DFS. The results of this study should be cautiously interpreted and needs to be furtherly validated in larger data sets.
Keywords: Gender differences, intraoperative estimated blood loss (EBL), non-small cell lung cancer; NSCLC, Disease free survival (DFS)
PUB011 A Potent, VEGFR2-Sparing RET Kinase Inhibitor for Treating Patients with RET-Dependent Lung Cancers Stephen Rothenberg Loxo Oncology, Stamford/CT/ United States of America Background: Activating mutations and fusions of the RET receptor tyrosine kinase have been identified in several cancer types, including fusions in w 2% of lung adenocarcinomas. Furthermore, tyrosine kinase inhibitors (TKIs) that inhibit RET have activity in patients with RET-dependent cancers. However, current TKIs are only moderately potent against RET, cause toxicity through stronger inhibition of other kinases (e.g. KDR/VEGFR2) and poorly inhibit secondary resistance (e.g. gatekeeper) mutations. We aimed to design an inhibitor that targets diverse RET fusions and potential resistance mutations, with sparing of anti-targets and excellent drug-like properties. Methods: Lead RET inhibitor candidates were selected by determining: (1) activity against KIF5B- and CCDC6RET fusions found in lung cancer and and V804 gatekeeper substitutions that casue acquried resistance to
Journal of Thoracic Oncology
Vol. 12 No. 1S
multikinase inhibitors; and (2) selectivity against a broad panel of kinase and other anti-targets. Activity in vivo was determined by measuring both pharmacodynamic target modulation and efficacy in diverse RETdependent tumor models, including cancer cell line and patient-derived mouse xenografts (PDX). Results: Our lead RET candidates possess nanomolar potency against diverse RET fusions and potential acquired resistance mutations, including challenging V804 gatekeeper substitutions. Furthermore, each is and at least 100-fold selective for the majority of kinases analyzed in vitro, and this high degree of selectivity is maintained against critical anti-targets in live cells, including KDR. These properties lead to significant efficacy in vivo in lung cancer xenografts harboring endogenous RET alterations and a RET-fusion PDX with acquired resistance to multikinase inhibitors mediated by V804M. Finally, daily oral dosing of mouse xenografts for more than three months produces continued tumor regression, without the development of acquired resistance or toxicity. The unique combination of high potency, broad activity against diverse RET alterations and minimal activity against anti-targets indicates the potential for continuous dosing, long-term efficacy and a wide therapeutic index in the clinic. Conclusion: We have developed potent and specific RET kinase inhibitors with favorable pharmaceutical properties and potent activity against diverse RET alterations in vitro and in vivo, including founder genetic alterations and resistance mutations that may arise following treatment with multikinase inhibitors. Together with significant sparing of other kinase and non-kinase antitargets, they are predicted to robustly inhibit RET in patients at clinically relevant doses, and therefore offer the potential for more effective and safe treatment of patients with RET-dependent cancers. Loxo Oncology will be initiating clinical development of its lead RET inhibitor in patients with RET-fusion lung cancers in the coming months. Keywords: RET, Targeted therapy, Acquired resistance, VEGFR2-sparing
PUB012 Inhibition of the Colony-StimulatingFactor-1 Receptor Affects the Resistance of Lung Cancer Cells to Cisplatin Mario Cioce, Carmencita Lavilla, Chandra Goparaju, Harvey Pass NYU Langone Medical Center, New York/ United States of America
January 2017
Background: Colony-Stimulating-Factor Receptor-1 (CSF-1R) is a type III receptor tyrosine kinase (RTK) responsible for promoting the differentiation, survival and homing of the monocyteemacrophage cell lineages. Here we provide evidence for the existence of cisplatinresistant, lung cancer cell subpopulations expressing the Colony Stimulating Factor Receptor -1 (CSF-1R).
Abstracts
S1453
resulting in the persistence of CSF-1R expressing cells in cisplatin-treated samples, in vitro and in vivo. Keywords: CSF1-R, Chemoresistance, TKI, ALDH
PUB013 Randomized Phase II Study of Methods: CSF-1 and IL-34 secreted from A549, NCIPembrolizumab after SBRT versus H1299, H1975, CALU-1, NCI-H157, NCI-H358, NCI-H460 was measured. ALDH-positive cells were defined as cells Pembrolizumab Alone in Patients with that displayed greater fluorescence compared with a Advanced NSCLC, Preliminary Results control staining reaction containing the ALDH inhibitor, DEAB upon addition of synthetic ALDH substrate BAAA. siRNA CSF-1 and siRNA IL-34 were transfected into lung cancer cells. JNJ-40346527a “clinical trial” grade CSF-1R tyrosine kinase inhibitor (TKI) was provided by Janssen Research & Development. Results: QPCR of all but one cell line expressed detectable amounts of CSF-1R and IL-34. Western blotting with anti-CSF-1R antibodies confirmed extracellular and intracellular forms of the receptor in six out of seven cell lines. ELISA revealed detectable levels of secreted CSF-1 and no detectable IL-34. QPCR of mRNA obtained from H1975, NCI-H1299, A549 and Calu-1 revealed that both the receptor and the ligand CSF-1 mRNAs were increased by cisplatin treatment, and conditioned medium from the same cells revealed increased levels of CSF-1 from cisplatin treated ones.Significantly impaired colony formation in cells transfected with siRNAs directed towards CSF-1 or CSF-1R occured and was strongly increased by cisplatin treatment at subtoxic doses. Co-treatment of the cells with increasing doses of cisplatin and JNJ-40346527 revealed a strong potentiation of cisplatin cytotoxicity. FACS analysis revealed 4/4 representative lung cancer cell lines contained ALDHbright cells and exhibited increased number of ALDHbright cells upon cisplatin treatment, and JNJ-40346527 decreased significantly the number of ALDHbright cells. This effect was much stronger when the TKI was administered to the cells in combination with cisplatin.Treatment of tumor bearing mice with JNJ-40346527 produced strong chemo-sensitizing effects in vivo and this correlated with a reduced number of CSF-1Rpos cells in tumors excised from the treated mice. Depletion of the CD45pos cells within the treated tumors did not, apparently, play a major role in mediating the therapeutic response to the TKI. Conclusion: Inhibition of CSF-1R impairs chemoresistance of the lung cancer cell lines and in vivo. A CSF1R TKI inhibitor shows synergy with cisplatin in vivo. This correlates with the observation that the CSF-1/CSF-1R system is stimulated by stress einduced chemotherapy
Willemijn Theelen, Ferry Lalezari, Michel Van Den Heuvel, Paul Baas, Heike Peulen Nki, Amsterdam/Netherlands Background: Immune checkpoint inhibitors have provided long-lasting responses in recurrent non-small cell lung cancer (NSCLC) patients, but the majority of patients do not benefit with response rates of < 25%. To test if stereotactic body radiation therapy (SBRT) on a single metastasis preceding pembrolizumab, an anti PD1 antibody, is safe and will lead to an increased tumor specific immune response, we initiated the multicenter phase II PEMBRO-RT study. Methods: Patients with advanced NSCLC with all histologies, second line or further, regardless of PD-L1 status were randomized (1:1) between receiving iv. pembrolizumab (200mg q3w) alone or iv. pembrolizumab (200mg q3w) after SBRT (3x8Gy) on a single metastasis. Biopsies were taken from a non-irradiated tumor site at baseline and after two cycles of pembrolizumab. The primary endpoint was an improvement of the overall response rate (ORR) from 20% to 50% at 12 weeks in the pembrolizumab alone vs the combination arm respectively. Results: From July 2015 to June 2016, 38 patients were randomized and 28 patients were evaluable for the primary endpoint: 13 in the pembrolizumab alone arm vs 15 patients in the combination arm. ORR at 12 weeks was 23.1% in the pembrolizumab alone arm vs 33.3% in the combination arm. In the pembrolizumab alone arm three patients had a confirmed partial response (PR); two had stable disease (SD) and eight showed progressive disease (PD). In the combination arm five patients had a confirmed PR; four had SD and six showed PD. There were no treatment related toxicities leading to discontinuation of the pembrolizumab and SBRT did not result in higher toxicity. Conclusion: SBRT on a single metastasis directly followed by pembrolizumab shows a promising ORR advantage in this preliminary analysis without an increase in toxicity. Keywords: brolizumab
Immunotherapy,
NSCLC,
SBRT,
pem-
1.65, 95%CI: 1.04-2.61) independently predicted poor DFS. Conclusion: In patients undergoing VATS lobectomy for NSCLC, EBL was the only modifiable predictor of poor DFS. The results of this study should be cautiously interpreted and needs to be furtherly validated in larger data sets.
Keywords: Gender differences, intraoperative estimated blood loss (EBL), non-small cell lung cancer; NSCLC, Disease free survival (DFS)
PUB011 A Potent, VEGFR2-Sparing RET Kinase Inhibitor for Treating Patients with RET-Dependent Lung Cancers Stephen Rothenberg Loxo Oncology, Stamford/CT/ United States of America Background: Activating mutations and fusions of the RET receptor tyrosine kinase have been identified in several cancer types, including fusions in w 2% of lung adenocarcinomas. Furthermore, tyrosine kinase inhibitors (TKIs) that inhibit RET have activity in patients with RET-dependent cancers. However, current TKIs are only moderately potent against RET, cause toxicity through stronger inhibition of other kinases (e.g. KDR/VEGFR2) and poorly inhibit secondary resistance (e.g. gatekeeper) mutations. We aimed to design an inhibitor that targets diverse RET fusions and potential resistance mutations, with sparing of anti-targets and excellent drug-like properties. Methods: Lead RET inhibitor candidates were selected by determining: (1) activity against KIF5B- and CCDC6RET fusions found in lung cancer and and V804 gatekeeper substitutions that casue acquried resistance to
Journal of Thoracic Oncology
Vol. 12 No. 1S
multikinase inhibitors; and (2) selectivity against a broad panel of kinase and other anti-targets. Activity in vivo was determined by measuring both pharmacodynamic target modulation and efficacy in diverse RETdependent tumor models, including cancer cell line and patient-derived mouse xenografts (PDX). Results: Our lead RET candidates possess nanomolar potency against diverse RET fusions and potential acquired resistance mutations, including challenging V804 gatekeeper substitutions. Furthermore, each is and at least 100-fold selective for the majority of kinases analyzed in vitro, and this high degree of selectivity is maintained against critical anti-targets in live cells, including KDR. These properties lead to significant efficacy in vivo in lung cancer xenografts harboring endogenous RET alterations and a RET-fusion PDX with acquired resistance to multikinase inhibitors mediated by V804M. Finally, daily oral dosing of mouse xenografts for more than three months produces continued tumor regression, without the development of acquired resistance or toxicity. The unique combination of high potency, broad activity against diverse RET alterations and minimal activity against anti-targets indicates the potential for continuous dosing, long-term efficacy and a wide therapeutic index in the clinic. Conclusion: We have developed potent and specific RET kinase inhibitors with favorable pharmaceutical properties and potent activity against diverse RET alterations in vitro and in vivo, including founder genetic alterations and resistance mutations that may arise following treatment with multikinase inhibitors. Together with significant sparing of other kinase and non-kinase antitargets, they are predicted to robustly inhibit RET in patients at clinically relevant doses, and therefore offer the potential for more effective and safe treatment of patients with RET-dependent cancers. Loxo Oncology will be initiating clinical development of its lead RET inhibitor in patients with RET-fusion lung cancers in the coming months. Keywords: RET, Targeted therapy, Acquired resistance, VEGFR2-sparing
PUB012 Inhibition of the Colony-StimulatingFactor-1 Receptor Affects the Resistance of Lung Cancer Cells to Cisplatin Mario Cioce, Carmencita Lavilla, Chandra Goparaju, Harvey Pass NYU Langone Medical Center, New York/ United States of America
January 2017
Background: Colony-Stimulating-Factor Receptor-1 (CSF-1R) is a type III receptor tyrosine kinase (RTK) responsible for promoting the differentiation, survival and homing of the monocyteemacrophage cell lineages. Here we provide evidence for the existence of cisplatinresistant, lung cancer cell subpopulations expressing the Colony Stimulating Factor Receptor -1 (CSF-1R).
Abstracts
S1453
resulting in the persistence of CSF-1R expressing cells in cisplatin-treated samples, in vitro and in vivo. Keywords: CSF1-R, Chemoresistance, TKI, ALDH
PUB013 Randomized Phase II Study of Methods: CSF-1 and IL-34 secreted from A549, NCIPembrolizumab after SBRT versus H1299, H1975, CALU-1, NCI-H157, NCI-H358, NCI-H460 was measured. ALDH-positive cells were defined as cells Pembrolizumab Alone in Patients with that displayed greater fluorescence compared with a Advanced NSCLC, Preliminary Results control staining reaction containing the ALDH inhibitor, DEAB upon addition of synthetic ALDH substrate BAAA. siRNA CSF-1 and siRNA IL-34 were transfected into lung cancer cells. JNJ-40346527a “clinical trial” grade CSF-1R tyrosine kinase inhibitor (TKI) was provided by Janssen Research & Development. Results: QPCR of all but one cell line expressed detectable amounts of CSF-1R and IL-34. Western blotting with anti-CSF-1R antibodies confirmed extracellular and intracellular forms of the receptor in six out of seven cell lines. ELISA revealed detectable levels of secreted CSF-1 and no detectable IL-34. QPCR of mRNA obtained from H1975, NCI-H1299, A549 and Calu-1 revealed that both the receptor and the ligand CSF-1 mRNAs were increased by cisplatin treatment, and conditioned medium from the same cells revealed increased levels of CSF-1 from cisplatin treated ones.Significantly impaired colony formation in cells transfected with siRNAs directed towards CSF-1 or CSF-1R occured and was strongly increased by cisplatin treatment at subtoxic doses. Co-treatment of the cells with increasing doses of cisplatin and JNJ-40346527 revealed a strong potentiation of cisplatin cytotoxicity. FACS analysis revealed 4/4 representative lung cancer cell lines contained ALDHbright cells and exhibited increased number of ALDHbright cells upon cisplatin treatment, and JNJ-40346527 decreased significantly the number of ALDHbright cells. This effect was much stronger when the TKI was administered to the cells in combination with cisplatin.Treatment of tumor bearing mice with JNJ-40346527 produced strong chemo-sensitizing effects in vivo and this correlated with a reduced number of CSF-1Rpos cells in tumors excised from the treated mice. Depletion of the CD45pos cells within the treated tumors did not, apparently, play a major role in mediating the therapeutic response to the TKI. Conclusion: Inhibition of CSF-1R impairs chemoresistance of the lung cancer cell lines and in vivo. A CSF1R TKI inhibitor shows synergy with cisplatin in vivo. This correlates with the observation that the CSF-1/CSF-1R system is stimulated by stress einduced chemotherapy
Willemijn Theelen, Ferry Lalezari, Michel Van Den Heuvel, Paul Baas, Heike Peulen Nki, Amsterdam/Netherlands Background: Immune checkpoint inhibitors have provided long-lasting responses in recurrent non-small cell lung cancer (NSCLC) patients, but the majority of patients do not benefit with response rates of < 25%. To test if stereotactic body radiation therapy (SBRT) on a single metastasis preceding pembrolizumab, an anti PD1 antibody, is safe and will lead to an increased tumor specific immune response, we initiated the multicenter phase II PEMBRO-RT study. Methods: Patients with advanced NSCLC with all histologies, second line or further, regardless of PD-L1 status were randomized (1:1) between receiving iv. pembrolizumab (200mg q3w) alone or iv. pembrolizumab (200mg q3w) after SBRT (3x8Gy) on a single metastasis. Biopsies were taken from a non-irradiated tumor site at baseline and after two cycles of pembrolizumab. The primary endpoint was an improvement of the overall response rate (ORR) from 20% to 50% at 12 weeks in the pembrolizumab alone vs the combination arm respectively. Results: From July 2015 to June 2016, 38 patients were randomized and 28 patients were evaluable for the primary endpoint: 13 in the pembrolizumab alone arm vs 15 patients in the combination arm. ORR at 12 weeks was 23.1% in the pembrolizumab alone arm vs 33.3% in the combination arm. In the pembrolizumab alone arm three patients had a confirmed partial response (PR); two had stable disease (SD) and eight showed progressive disease (PD). In the combination arm five patients had a confirmed PR; four had SD and six showed PD. There were no treatment related toxicities leading to discontinuation of the pembrolizumab and SBRT did not result in higher toxicity. Conclusion: SBRT on a single metastasis directly followed by pembrolizumab shows a promising ORR advantage in this preliminary analysis without an increase in toxicity. Keywords: brolizumab
Immunotherapy,
NSCLC,
SBRT,
pem-