Background Tomatoes contain carotenoids that have the potential to alter the effects of external ... more Background Tomatoes contain carotenoids that have the potential to alter the effects of external beam radiation therapy (EBRT). Objectives We hypothesized that dietary lyophilized tomato paste (TP) would reduce apoptosis within carotenoid-containing nonneoplastic tissues in EBRT-treated TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice. Methods Male TRAMP mice (n = 73) were provided an AIN-93G diet or a modified AIN-93G diet containing 10% TP (wt:wt) at 4 wk of age. Prostate tumor growth was monitored by ultrasound. The caudal half of the mouse was irradiated with 7.5 Gy (Rad) or 0 Gy (sham) at 24 wk of age or after the tumor volume exceeded 1000 mm3 with a Cobalt-60 source. Mice were euthanized 24 h postradiation. Carotenoids and α-tocopherol were measured by HPLC and compared by a t test. Tissues were assessed for radiation-induced changes (hematoxylin and eosin) and apoptosis [cleaved caspase-3 (CC3)] and compared by Kruskal–Wallis test or Freedman–Lane's permutati...
The immune system plays dual roles in response to cancer. The host immune system protects against... more The immune system plays dual roles in response to cancer. The host immune system protects against tumor formation via immunosurveillance; however, recognition of the tumor by immune cells also induces sculpting mechanisms leading to a Darwinian selection of tumor cell variants with reduced immunogenicity. Cancer immunoediting is the concept used to describe the complex interplay between tumor cells and the immune system. This concept, commonly referred to as the three E’s, is encompassed by 3 distinct phases of elimination, equilibrium, and escape. Despite impressive results in the clinic, cancer immunotherapy still has room for improvement as many patients remain unresponsive to therapy. Moreover, many of the preclinical results obtained in the widely used mouse models of cancer are lost in translation to human patients.To improve the success rate of immuno-oncology research and preclinical testing of immune-based anticancer therapies, using alternative animal models more closely r...
Supplementary Fig. 1 depicts the chronology of clinical trial visits and associated procedures fo... more Supplementary Fig. 1 depicts the chronology of clinical trial visits and associated procedures for dogs enrolled in this clinical trial.
Supplementary Fig. 2 shows the walk-in pharmacokinetics, both measured results and simulated valu... more Supplementary Fig. 2 shows the walk-in pharmacokinetics, both measured results and simulated values, for dogs treated with oral sirolimus in preparation for the definitive adjuvant trial.
Supplementary Table 2 contains the summary comparison of both the Intent-to-treat and Per-protoco... more Supplementary Table 2 contains the summary comparison of both the Intent-to-treat and Per-protocol analyses of clinical outcomes for dogs enrolled in Standard of Care (SOC) and Standard of Care + sirolimus
Purpose:Only one chemical class of topoisomerase I (TOP1) inhibitors is FDA approved, the camptot... more Purpose:Only one chemical class of topoisomerase I (TOP1) inhibitors is FDA approved, the camptothecins with irinotecan and topotecan widely used. Because of their limitations (chemical instability, drug efflux-mediated resistance, and diarrhea), novel TOP1 inhibitors are warranted. Indenoisoquinoline non-camptothecin topoisomerase I (TOP1) inhibitors overcome chemical instability and drug resistance that limit camptothecin use. Three indenoisoquinolines, LMP400 (indotecan), LMP776 (indimitecan), and LMP744, were examined in a phase I study for lymphoma-bearing dogs to evaluate differential efficacy, pharmacodynamics, toxicology, and pharmacokinetics.Experimental Design:Eighty-four client-owned dogs with lymphomas were enrolled in dose-escalation cohorts for each indenoisoquinoline, with an expansion phase for LMP744. Efficacy, tolerability, pharmacokinetics, and target engagement were determined.Results:The MTDs were 17.5 mg/m2 for LMP 776 and 100 mg/m2 for LMP744; bone marrow toxicity was dose-limiting; up to 65 mg/m2 LMP400 was well-tolerated and MTD was not reached. None of the drugs induced notable diarrhea. Sustained tumor accumulation was observed for LMP744; γH2AX induction was demonstrated in tumors 2 and 6 hours after treatment; a decrease in TOP1 protein was observed in most lymphoma samples across all compounds and dose levels, which is consistent with the fact that tumor response was also observed at low doses LMP744. Objective responses were documented for all indenoisoquinolines; efficacy (13/19 dogs) was greatest for LMP744.Conclusions:These results demonstrate proof-of-mechanism for indenoisoquinoline TOP1 inhibitors supporting their further clinical development. They also highlight the value of the NCI Comparative Oncology Program (https://ccr.cancer.gov/Comparative-Oncology-Program) for evaluating novel therapies in immunocompetent pets with cancers.
C87 There is great interest in the development of mTOR inhibitors as anti-cancer therapies. mTOR ... more C87 There is great interest in the development of mTOR inhibitors as anti-cancer therapies. mTOR functions as the nutrient sensor of the cell controlling protein translation, integral in cancer development and progression. The inhibition of mTOR is possible with Rapamycin, initially developed as an immunosuppressant for transplant patients, and novel analogues, known collectively as rapalogs. Although there are currently many treatment trials evaluating Rapamycin and rapalogs, the correlation of dose, pharmacodynamic modulation, response and benefit for these agents is poorly underestood. Furthermore, an understanding of optimal combinations of mTOR inhibitors with other cancer treatments is lacking. The complexity of questions related to the dose, exposure, dose-target, and benefit of a new cancer agent requires sophisticated and innovative model systems. Pet dogs that have naturally developed cancer may be such a model system. As such a preclinical dose escalation study in pet dogs with osteosarcoma was initiated to address questions of Rapamycin pharmacokinetics and its relationship to tumoral and PBMC correlative pharmacodynamics. This study was conducted through the Comparative Oncology Trials Consortium, a multi-institutional translational cancer therapy effort, led by the NCI, that integrates naturally occurring cancers seen in pet dogs into the development path of new cancer drugs. Dogs were administered paraenteral Rapamycin daily for an 8-day exposure starting at 0.01 mg/kg and finishing at 0.08 mg/kg. Biopsies were collected both pre and post treatment to assess mTOR pathway inhibition using modulation of 4EBP1 and S6K phosphorylation. Rapamycin was found to be safe and tolerable in tumor bearing dogs at doses relevant to typical human doses. There were two > grade 3 toxicities recorded but neither was attributable to the study drug. Hematologic and biochemical assessment was performed weekly for the 15-day study period and no significant toxicities reported. The tolerability of parenteral rapamycin in dogs will support the inclusion of dogs in future studies of mTOR inhibition. Pharmacokinetic and pharmacodynamic assessments are currently being performed. This study was designed as a necessary prequel for currently planned studies that will assess the activity of mTOR inhibition in osteosarcoma and future studies that will define optimal combinations of mTOR inhibition with both conventional and novel cancer treatments for sarcomas and other cancers.
Supplementary Data from Comparative Oncology Assessment of a Novel Inhibitor of Valosin-Containin... more Supplementary Data from Comparative Oncology Assessment of a Novel Inhibitor of Valosin-Containing Protein in Tumor-Bearing Dogs
Pet dogs with naturally occurring cancers play an important role in studies of cancer biology and... more Pet dogs with naturally occurring cancers play an important role in studies of cancer biology and drug development. We assessed tolerability, efficacy, and pharmacokinetic/pharmacodynamic relationships with a first-in-class small molecule inhibitor of valosin-containing protein (VCP/p97), CB-5339, administered to 24 tumor-bearing pet dogs. Tumor types assessed included solid malignancies, lymphomas, and multiple myeloma. Through a stepwise dose and schedule escalation schema, we determined the maximum tolerated dose to be 7.5 mg/kg when administered orally on a 4 days on, 3 days off schedule per week for 3 consecutive weeks. Adverse events were minimal and mainly related to the gastrointestinal system. Pharmacokinetic/pharmacodynamic data suggest a relationship between exposure and modulation of targets related to induction of the unfolded protein response, but not to tolerability of the agent. An efficacy signal was detected in 33% (2/6) of dogs with multiple myeloma, consistent with a mechanism of action relating to induction of proteotoxic stress in a tumor type with abundant protein production. Clinical trials of CB-5339 in humans with acute myelogenous leukemia and multiple myeloma are ongoing.
Supplementary Table 1 contains the inclusion and exclusion criteria for pet dogs considered for e... more Supplementary Table 1 contains the inclusion and exclusion criteria for pet dogs considered for enrollment into the SOC and SOC + S clinical trial arms.
Supplementary Table 3 contains a summary of the outcomes, with statistical comparisons, of the do... more Supplementary Table 3 contains a summary of the outcomes, with statistical comparisons, of the dogs enrolled in the SOC clinical trial arm. This includes the DFI and outcomes of the groups of dogs stratified by tumor location and ALP status.
Supplementary Table 4 contains a summary of the outcomes, with statistical comparisons, of the do... more Supplementary Table 4 contains a summary of the outcomes, with statistical comparisons, of the dogs enrolled in the SOC + sirolimus clinical trial arm. This includes the DFI and outcomes of the groups of dogs stratified by tumor location and ALP status.
Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stress... more Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stressors encountered during metastatic progression. We sought to test the hypothesis that enhanced efficiency of mRNA translation during periods of metastatic stress is required for metastatic competence of osteosarcoma and that this metastasis-specific adaptation is amenable to therapeutic intervention. Experimental Design: We employ novel reporter and proteomic systems that enable tracking of mRNA translation efficiency and output in metastatic osteosarcoma cells as they colonize the lungs. We test the potential to target mRNA translation as an antimetastatic therapeutic strategy through pharmacokinetic studies and preclinical assessment of the prototypic mTOR inhibitor, rapamycin, across multiple models of metastasis. Results: Metastatic osteosarcoma cells translate mRNA more efficiently than nonmetastatic cells during critical stressful periods of metastatic colonization of the lung. Rapamycin inhibits translational output during periods of metastatic stress, mitigates lung colonization, and prolongs survival. mTORinhibiting exposures of rapamycin are achievable in mice using treatment schedules that correspond to human doses well below the MTDs defined in human patients, and as such are very likely to be tolerated over long exposures alone and in combination with other agents. Conclusions: Metastatic competence of osteosarcoma cells is dependent on efficient mRNA translation during stressful periods of metastatic progression, and the mTOR inhibitor, rapamycin, can mitigate this translation and inhibit metastasis in vivo. Our data suggest that mTOR pathway inhibitors should be reconsidered in the clinic using rationally designed dosing schedules and clinical metrics related to metastatic progression.
Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stress... more Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stressors encountered during metastatic progression. We sought to test the hypothesis that enhanced efficiency of mRNA translation during periods of metastatic stress is required for metastatic competence of osteosarcoma and that this metastasis-specific adaptation is amenable to therapeutic intervention.Experimental Design: We employ novel reporter and proteomic systems that enable tracking of mRNA translation efficiency and output in metastatic osteosarcoma cells as they colonize the lungs. We test the potential to target mRNA translation as an antimetastatic therapeutic strategy through pharmacokinetic studies and preclinical assessment of the prototypic mTOR inhibitor, rapamycin, across multiple models of metastasis.Results: Metastatic osteosarcoma cells translate mRNA more efficiently than nonmetastatic cells during critical stressful periods of metastatic colonization of the lung. Rapamy...
Background Tomatoes contain carotenoids that have the potential to alter the effects of external ... more Background Tomatoes contain carotenoids that have the potential to alter the effects of external beam radiation therapy (EBRT). Objectives We hypothesized that dietary lyophilized tomato paste (TP) would reduce apoptosis within carotenoid-containing nonneoplastic tissues in EBRT-treated TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) mice. Methods Male TRAMP mice (n = 73) were provided an AIN-93G diet or a modified AIN-93G diet containing 10% TP (wt:wt) at 4 wk of age. Prostate tumor growth was monitored by ultrasound. The caudal half of the mouse was irradiated with 7.5 Gy (Rad) or 0 Gy (sham) at 24 wk of age or after the tumor volume exceeded 1000 mm3 with a Cobalt-60 source. Mice were euthanized 24 h postradiation. Carotenoids and α-tocopherol were measured by HPLC and compared by a t test. Tissues were assessed for radiation-induced changes (hematoxylin and eosin) and apoptosis [cleaved caspase-3 (CC3)] and compared by Kruskal–Wallis test or Freedman–Lane's permutati...
The immune system plays dual roles in response to cancer. The host immune system protects against... more The immune system plays dual roles in response to cancer. The host immune system protects against tumor formation via immunosurveillance; however, recognition of the tumor by immune cells also induces sculpting mechanisms leading to a Darwinian selection of tumor cell variants with reduced immunogenicity. Cancer immunoediting is the concept used to describe the complex interplay between tumor cells and the immune system. This concept, commonly referred to as the three E’s, is encompassed by 3 distinct phases of elimination, equilibrium, and escape. Despite impressive results in the clinic, cancer immunotherapy still has room for improvement as many patients remain unresponsive to therapy. Moreover, many of the preclinical results obtained in the widely used mouse models of cancer are lost in translation to human patients.To improve the success rate of immuno-oncology research and preclinical testing of immune-based anticancer therapies, using alternative animal models more closely r...
Supplementary Fig. 1 depicts the chronology of clinical trial visits and associated procedures fo... more Supplementary Fig. 1 depicts the chronology of clinical trial visits and associated procedures for dogs enrolled in this clinical trial.
Supplementary Fig. 2 shows the walk-in pharmacokinetics, both measured results and simulated valu... more Supplementary Fig. 2 shows the walk-in pharmacokinetics, both measured results and simulated values, for dogs treated with oral sirolimus in preparation for the definitive adjuvant trial.
Supplementary Table 2 contains the summary comparison of both the Intent-to-treat and Per-protoco... more Supplementary Table 2 contains the summary comparison of both the Intent-to-treat and Per-protocol analyses of clinical outcomes for dogs enrolled in Standard of Care (SOC) and Standard of Care + sirolimus
Purpose:Only one chemical class of topoisomerase I (TOP1) inhibitors is FDA approved, the camptot... more Purpose:Only one chemical class of topoisomerase I (TOP1) inhibitors is FDA approved, the camptothecins with irinotecan and topotecan widely used. Because of their limitations (chemical instability, drug efflux-mediated resistance, and diarrhea), novel TOP1 inhibitors are warranted. Indenoisoquinoline non-camptothecin topoisomerase I (TOP1) inhibitors overcome chemical instability and drug resistance that limit camptothecin use. Three indenoisoquinolines, LMP400 (indotecan), LMP776 (indimitecan), and LMP744, were examined in a phase I study for lymphoma-bearing dogs to evaluate differential efficacy, pharmacodynamics, toxicology, and pharmacokinetics.Experimental Design:Eighty-four client-owned dogs with lymphomas were enrolled in dose-escalation cohorts for each indenoisoquinoline, with an expansion phase for LMP744. Efficacy, tolerability, pharmacokinetics, and target engagement were determined.Results:The MTDs were 17.5 mg/m2 for LMP 776 and 100 mg/m2 for LMP744; bone marrow toxicity was dose-limiting; up to 65 mg/m2 LMP400 was well-tolerated and MTD was not reached. None of the drugs induced notable diarrhea. Sustained tumor accumulation was observed for LMP744; γH2AX induction was demonstrated in tumors 2 and 6 hours after treatment; a decrease in TOP1 protein was observed in most lymphoma samples across all compounds and dose levels, which is consistent with the fact that tumor response was also observed at low doses LMP744. Objective responses were documented for all indenoisoquinolines; efficacy (13/19 dogs) was greatest for LMP744.Conclusions:These results demonstrate proof-of-mechanism for indenoisoquinoline TOP1 inhibitors supporting their further clinical development. They also highlight the value of the NCI Comparative Oncology Program (https://ccr.cancer.gov/Comparative-Oncology-Program) for evaluating novel therapies in immunocompetent pets with cancers.
C87 There is great interest in the development of mTOR inhibitors as anti-cancer therapies. mTOR ... more C87 There is great interest in the development of mTOR inhibitors as anti-cancer therapies. mTOR functions as the nutrient sensor of the cell controlling protein translation, integral in cancer development and progression. The inhibition of mTOR is possible with Rapamycin, initially developed as an immunosuppressant for transplant patients, and novel analogues, known collectively as rapalogs. Although there are currently many treatment trials evaluating Rapamycin and rapalogs, the correlation of dose, pharmacodynamic modulation, response and benefit for these agents is poorly underestood. Furthermore, an understanding of optimal combinations of mTOR inhibitors with other cancer treatments is lacking. The complexity of questions related to the dose, exposure, dose-target, and benefit of a new cancer agent requires sophisticated and innovative model systems. Pet dogs that have naturally developed cancer may be such a model system. As such a preclinical dose escalation study in pet dogs with osteosarcoma was initiated to address questions of Rapamycin pharmacokinetics and its relationship to tumoral and PBMC correlative pharmacodynamics. This study was conducted through the Comparative Oncology Trials Consortium, a multi-institutional translational cancer therapy effort, led by the NCI, that integrates naturally occurring cancers seen in pet dogs into the development path of new cancer drugs. Dogs were administered paraenteral Rapamycin daily for an 8-day exposure starting at 0.01 mg/kg and finishing at 0.08 mg/kg. Biopsies were collected both pre and post treatment to assess mTOR pathway inhibition using modulation of 4EBP1 and S6K phosphorylation. Rapamycin was found to be safe and tolerable in tumor bearing dogs at doses relevant to typical human doses. There were two > grade 3 toxicities recorded but neither was attributable to the study drug. Hematologic and biochemical assessment was performed weekly for the 15-day study period and no significant toxicities reported. The tolerability of parenteral rapamycin in dogs will support the inclusion of dogs in future studies of mTOR inhibition. Pharmacokinetic and pharmacodynamic assessments are currently being performed. This study was designed as a necessary prequel for currently planned studies that will assess the activity of mTOR inhibition in osteosarcoma and future studies that will define optimal combinations of mTOR inhibition with both conventional and novel cancer treatments for sarcomas and other cancers.
Supplementary Data from Comparative Oncology Assessment of a Novel Inhibitor of Valosin-Containin... more Supplementary Data from Comparative Oncology Assessment of a Novel Inhibitor of Valosin-Containing Protein in Tumor-Bearing Dogs
Pet dogs with naturally occurring cancers play an important role in studies of cancer biology and... more Pet dogs with naturally occurring cancers play an important role in studies of cancer biology and drug development. We assessed tolerability, efficacy, and pharmacokinetic/pharmacodynamic relationships with a first-in-class small molecule inhibitor of valosin-containing protein (VCP/p97), CB-5339, administered to 24 tumor-bearing pet dogs. Tumor types assessed included solid malignancies, lymphomas, and multiple myeloma. Through a stepwise dose and schedule escalation schema, we determined the maximum tolerated dose to be 7.5 mg/kg when administered orally on a 4 days on, 3 days off schedule per week for 3 consecutive weeks. Adverse events were minimal and mainly related to the gastrointestinal system. Pharmacokinetic/pharmacodynamic data suggest a relationship between exposure and modulation of targets related to induction of the unfolded protein response, but not to tolerability of the agent. An efficacy signal was detected in 33% (2/6) of dogs with multiple myeloma, consistent with a mechanism of action relating to induction of proteotoxic stress in a tumor type with abundant protein production. Clinical trials of CB-5339 in humans with acute myelogenous leukemia and multiple myeloma are ongoing.
Supplementary Table 1 contains the inclusion and exclusion criteria for pet dogs considered for e... more Supplementary Table 1 contains the inclusion and exclusion criteria for pet dogs considered for enrollment into the SOC and SOC + S clinical trial arms.
Supplementary Table 3 contains a summary of the outcomes, with statistical comparisons, of the do... more Supplementary Table 3 contains a summary of the outcomes, with statistical comparisons, of the dogs enrolled in the SOC clinical trial arm. This includes the DFI and outcomes of the groups of dogs stratified by tumor location and ALP status.
Supplementary Table 4 contains a summary of the outcomes, with statistical comparisons, of the do... more Supplementary Table 4 contains a summary of the outcomes, with statistical comparisons, of the dogs enrolled in the SOC + sirolimus clinical trial arm. This includes the DFI and outcomes of the groups of dogs stratified by tumor location and ALP status.
Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stress... more Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stressors encountered during metastatic progression. We sought to test the hypothesis that enhanced efficiency of mRNA translation during periods of metastatic stress is required for metastatic competence of osteosarcoma and that this metastasis-specific adaptation is amenable to therapeutic intervention. Experimental Design: We employ novel reporter and proteomic systems that enable tracking of mRNA translation efficiency and output in metastatic osteosarcoma cells as they colonize the lungs. We test the potential to target mRNA translation as an antimetastatic therapeutic strategy through pharmacokinetic studies and preclinical assessment of the prototypic mTOR inhibitor, rapamycin, across multiple models of metastasis. Results: Metastatic osteosarcoma cells translate mRNA more efficiently than nonmetastatic cells during critical stressful periods of metastatic colonization of the lung. Rapamycin inhibits translational output during periods of metastatic stress, mitigates lung colonization, and prolongs survival. mTORinhibiting exposures of rapamycin are achievable in mice using treatment schedules that correspond to human doses well below the MTDs defined in human patients, and as such are very likely to be tolerated over long exposures alone and in combination with other agents. Conclusions: Metastatic competence of osteosarcoma cells is dependent on efficient mRNA translation during stressful periods of metastatic progression, and the mTOR inhibitor, rapamycin, can mitigate this translation and inhibit metastasis in vivo. Our data suggest that mTOR pathway inhibitors should be reconsidered in the clinic using rationally designed dosing schedules and clinical metrics related to metastatic progression.
Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stress... more Purpose: To successfully metastasize, tumor cells must respond appropriately to biological stressors encountered during metastatic progression. We sought to test the hypothesis that enhanced efficiency of mRNA translation during periods of metastatic stress is required for metastatic competence of osteosarcoma and that this metastasis-specific adaptation is amenable to therapeutic intervention.Experimental Design: We employ novel reporter and proteomic systems that enable tracking of mRNA translation efficiency and output in metastatic osteosarcoma cells as they colonize the lungs. We test the potential to target mRNA translation as an antimetastatic therapeutic strategy through pharmacokinetic studies and preclinical assessment of the prototypic mTOR inhibitor, rapamycin, across multiple models of metastasis.Results: Metastatic osteosarcoma cells translate mRNA more efficiently than nonmetastatic cells during critical stressful periods of metastatic colonization of the lung. Rapamy...
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