Locoregional recurrence after transanal total mesorectal excision: an emotional rollercoaster

Transanal total mesorectal excision is a complex technique that should be performed in expert centers.

NKTR-255, a novel polymer-conjugated rhIL-15 with potent antitumor efficacy

BACKGROUND

NKTR-255 is a novel polyethylene glycol-conjugate of recombinant human interleukin-15 (rhIL-15), which was designed to retain all known receptor binding interactions of the IL-15 molecule. We explored the biologic and pharmacologic differences between endogenous IL-15 receptor α (IL-15Rα)-dependent (NKTR-255 and rhIL-15) and IL-15Rα-independent (precomplexed rhIL-15/IL-15Rα) cytokines.

METHODS

In vitro pharmacological properties of rhIL-15, NKTR-255 and precomplex cytokines (rhIL-15/IL-15Rα and rhIL-15 N72D/IL-15Rα Fc) were investigated in receptor binding, signaling and cell function. In vivo pharmacokinetic (PK) and pharmacodynamic profile of the cytokines were evaluated in normal mice. Finally, immunomodulatory effect and antitumor activity were assessed in a Daudi lymphoma model.

RESULTS

NKTR-255 and rhIL-15 exhibited similar in vitro properties in receptor affinity, signaling and leukocyte degranulation, which collectively differed from precomplexed cytokines. Notably, NKTR-255 and rhIL-15 stimulated greater granzyme B secretion in human peripheral blood mononuclear cells versus precomplexed cytokines. In vivo, NKTR-255 exhibited a PK profile with reduced clearance and a longer half-life relative to rhIL-15 and demonstrated prolonged IL-15R engagement in lymphocytes compared with only transient engagement observed for rhIL-15 and precomplexed rhIL-15 N72D/IL-15Rα Fc. As a consequent, NKTR-255 provided a durable and sustained proliferation and activation of natural killer (NK) and CD8+ T cells. Importantly, NKTR-255 is more effective than the precomplexed cytokine at inducing functionally competent, cytotoxic NK cells in the tumor microenvironment and the properties of NKTR-255 translated into superior antitumor activity in a B-cell lymphoma model versus the precomplexed cytokine.

CONCLUSIONS

Our results show that the novel immunotherapeutic, NKTR-255, retains the full spectrum of IL-15 biology, but with improved PK properties, over rhIL-15. These findings support the ongoing phase 1 first-in-human trial (NCT04136756) of NKTR-255 in participants with relapsed or refractory hematologic malignancies, potentially advancing rhIL-15-based immunotherapies for the treatment of cancer.

Bempegaldesleukin (BEMPEG; NKTR-214) efficacy as a single agent and in combination with checkpoint-inhibitor therapy in mouse models of osteosarcoma

Survival of patients with relapsed/refractory osteosarcoma has not improved in the last 30 years. Several immunotherapeutic approaches have shown benefit in murine osteosarcoma models, including the anti-programmed death-1 (anti-PD-1) and anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) immune checkpoint inhibitors. Treatment with the T-cell growth factor interleukin-2 (IL-2) has shown some clinical benefit but has limitations due to poor tolerability. Therefore, we evaluated the efficacy of bempegaldesleukin (BEMPEG; NKTR-214), a first-in-class CD122-preferential IL-2 pathway agonist, alone and in combination with anti-PD-1 or anti-CTLA-4 immune checkpoint inhibitors in metastatic and orthotopic murine models of osteosarcoma. Treatment with BEMPEG delayed tumor growth and increased overall survival of mice with K7M2-WT osteosarcoma pulmonary metastases. BEMPEG also inhibited primary tumor growth and metastatic relapse in lungs and bone in the K7M3 orthotopic osteosarcoma mouse model. In addition, it enhanced therapeutic activity of anti-CTLA-4 and anti-PD-1 checkpoint blockade in the DLM8 subcutaneous murine osteosarcoma model. Finally, BEMPEG strongly increased accumulation of intratumoral effector T cells and natural killer cells, but not T-regulatory cells, resulting in improved effector:inhibitory cell ratios. Collectively, these data in multiple murine models of osteosarcoma provide a path toward clinical evaluation of BEMPEG-based regimens in human osteosarcoma.

5G-assisted telementored surgery

Safe and effective implementation of remote surgery and telementoring can have significant limitations. Fifth-generation (5G) wireless networks could be useful in overcoming these drawbacks. As a proof of concept, the authors present technical and clinical details of two procedures assisted by telementoring using 5G that were also broadcast live. Secure remote access advice.

Abstract 3265: NKTR-255, a polymer-conjugated IL-15 enhances anti-tumor NK cell responses and synergizes with monoclonal antibodies to provide long-term survival in human lymphoma model

Background: IL-15 is a cytokine that activates and provides survival benefit to NK cells. Exploiting the therapeutic value of native IL-15 has been challenging due to its unfavorable pharmacokinetic properties and tolerability. NKTR-255 is a polymer-conjugated human IL-15 that retains binding affinity to the alpha subunit of IL-15 receptor and exhibits reduced clearance to thereby provide a sustained pharmacodynamics response. NKTR-255 has potential for providing an enhanced immunotherapeutic effect when combined with monoclonal antibodies that mediate tumor killing by antibody dependent cellular cytotoxicity (ADCC). Here we investigate the pharmacological properties of NKTR-255 on NK cells and the therapeutic effect of NKTR-255 when combined with tumor-directed monoclonal antibodies in a B cell lymphoma model.

Methods: KHYG-1 cells (human NK cell line) were used to measure phosphorylated STAT5 (pSTAT5) and cell proliferation. Human PBMCs were stimulated with NKTR-255 and/or daratumumab for in vitro NK cell characterization. In the cytotoxic assay, mice received single IV doses of 0.3 mg/kg of NKTR-255 and splenic NK cells were co-cultured with YAC-1 cells (mouse T lymphoma cell line) to measure cytotoxic function. In the Daudi lymphoma model, 1x107 Daudi cells were inoculated IV on Day 0. NKTR-255 (0.03, 0.1 or 0.3 mg/kg SC) was administered on Days 14, 21 and 28 and antibody treatment was administered on Day 14 (daratumumab 0.5 mg/kg IP) or on Days 14 and 17 (rituximab 40 mg/kg IP). Survival rate was determined by onset of hindlimb paralysis as a surrogate parameter.

Results: NKTR-255 dose-dependently induced pSTAT5 and proliferation in KHYG-1 cells (EC50 values for pSTAT5: 0.2 ng/ml, proliferation: 5 ng/ml). NKTR-255 also resulted in enhanced pSTAT5 and NKG2D surface expression on human primary NK cells. In addition NKTR-255 increased NK cell degranulation in co-culture experiments with U266 cells (myeloma cell line) with/without daratumumab (anti-human CD38 antibody), as determined by enhanced CD107a surface expression. In vivo pretreatment with NKTR-255 resulted in sustained cytotoxic function of NK cells in both ex vivo and in vivo studies. Finally, NKTR-255 synergistically provided long-term survival benefit in a dose-dependent manner when administered with daratumumab or rituximab (anti-human CD20 antibody) in the Daudi B cell lymphoma model.

Conclusions: NKTR-255 is an immune stimulator of NK cells that provides a dose-dependent effect in the proliferation and activation of NK cells. This property of NKTR-255, when administered with daratumumab or rituximab, translates into enhanced therapeutic efficacies of the antibodies in a B cell lymphoma model. These results indicate that combining NKTR-255 with a tumor-directed antibody having an ADCC mechanism can provide a synergistic effect for treating cancers.

Citation Format: Takahiro Miyazaki, Saul Kivimäe, Rhoneil Pena, Peiwen Kuo, Marlene Hennessy, Murali Addepalli, Neha Dixit, Wildaliz Nieves, Sara Sheibani, Mekhala Maiti, Laurie VanderVeen, Joanna Wilczek, Loui Madakamutil, Jonathan Zalevsky. NKTR-255, a polymer-conjugated IL-15 enhances anti-tumor NK cell responses and synergizes with monoclonal antibodies to provide long-term survival in human lymphoma model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3265.

Abstract 3755: Comprehensive antitumor immune activation by a novel TLR7/8 targeting agent NKTR-262 combined with CD122-biased immunostimulatory cytokine NKTR-214

Background: NKTR-262 is a novel therapeutic, which delivers intratumoral engagement of the TLR 7/8 pathway, promoting an immune stimulatory environment and local injection site tumor antigen release. When NKTR-262 is administered in combination with NKTR-214, a CD122-biased cytokine agonist currently in clinical trials as a monotherapy and in combination with nivolumab, the combined effect of innate immune stimulation and enhanced antigen presentation with sustained T cell activation leads to systemic tumor immunity. Materials and methods: Ten subcutaneous syngeneic mouse tumor models with diverse histologies were assessed for NKTR-262 and NKTR-214 combination treatment efficacy. Once established, tumors were treated with a single peritumoral dose of NKTR-262, while NKTR-214 was administered i.v. on q9dx3 schedule. A subset of tumor models were inoculated bilaterally to assess abscopal effect of the combination treatment. Regression of injected tumors and the abscopal effect in contralateral untreated tumors was assessed by tumor size measurements. In bilateral models immune cell activation in both tumors was assessed by flow cytometry. Cytokine induction was measured in plasma and tumors in select models. Results: Combination treatment with NKTR-262 and NKTR-214 showed efficacy in all tested tumor models. Efficacy varied from significant tumor growth inhibition to up to 100% complete responses in multiple models. Synergistic efficacy was demonstrated in select models where single agent NKTR-262 or NKTR-214 activity was compared to the combination treatment. Immune cell phenotyping showed that combining NKTR-262 with NKTR-214 induced a two-step immune response in treated and abscopal tumors. At early timepoints, accumulation of activated granulocytes correlated with tumor cell death and dendritic cell activation. The innate response was followed by selective tumor infiltration by CD8 T cells and a reduction of immunorepressive cells. Single agent treatment showed only a subset of the cellular changes observed in the combination. Immune cell activation was shown to correlate with immune stimulatory cytokine release in NKTR-262 treated tumors. Conclusions: We present a designed combination therapy that mimics a natural immune response by activating a broad immune cell network in multiple nonclinical tumor models independent of tissue origin. Combining NKTR-262 and NKTR-214 engages the entire immune activation cascade required for systemic tumor clearance from local tumor antigen production to a sustained systemic T cell response. Unlike treatments that stimulate downstream components of select immune pathways without eliciting systemic tumor immunity, a comprehensive anti-tumor immune activation by coordinated engagement of innate and adaptive immune cells may increase the success of immune therapy for patients.

Citation Format: Saul Kivimae, Marlene Hennessy, Rhoneil Pena, Yolanda Kirksey, Wildaliz Nieves, Phi Quatch, Janet Cetz, Zhongxu Ren, Haiying Cai, BoLiang Deng, Wen Zhang, John L. Langowski, Christie Fanton, Neel K. Anand, Werner Rubas, Steve Doberstein, Jonathan Zalevsky. Comprehensive antitumor immune activation by a novel TLR7/8 targeting agent NKTR-262 combined with CD122-biased immunostimulatory cytokine NKTR-214 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3755.

Abstract B057: The CD122-biased immunostimulatory cytokine NKTR-214 combined with checkpoint blockade leads to mobilization of antitumor immunity and synergistic activity

Background: NKTR-214 is a novel immunostimulatory cytokine which provides a sustained and biased activation signal through the heterodimeric IL-2R receptor (IL2Rbg or CD122), resulting in significant expansion of CD8+ T and NK cells relative to regulatory T cells in the tumor microenvironment. As a single agent in preclinical tumor models, NKTR-214 significantly increases the intratumoral CD8T/Treg ratio (>400). Here we examine activity and pharmacodynamic effects of NKTR-214 alone and combined with immune checkpoint blockade in both a murine tumor model and in a human in vitro co-culture system. Methods: Mice bearing subcutaneous CT26 colon tumors were treated with single agent NKTR-214 (q9d), murine anti-CTLA-4 or anti-PD-1 (twice-weekly), or combinations of these agents. Serum cytokines were assessed by multiplex ELISA (Quansys). T cell clonality and infiltration were assessed in tumors 7 days after treatment initiation, with TCR V and J beta usage determined by ImmunoSEQ (Adaptive Biotechnologies). Effects on human cytokine and chemokine expression were examined by the BioMAP Combo ELECT (DiscoverX) in vitro system utilizing human fibroblasts or endothelial cells, PBMCs and either HT29 colon adenocarcinoma or HT1299 NSCLC cell lines. 1-PEG-IL2, the most active species of the NKTR-214 prodrug, or Keytruda (anti-PD-1) was added over a range of concentrations alone or in combination, with biomarkers assessed 48 hours later. Results: In tumor-bearing mice, NKTR-214 led to increases in serum IFNg as well as increases in the chemokine MCP-1 (CCL2), a chemoattractant of CD4 T, CD8 T and NK cells. Single-agent NKTR-214 led to significant tumor growth inhibition and 10% tumor free animals, while single-agents anti-CTLA-4 or anti-PD-1 lacked efficacy. Combination of NKTR-214 with checkpoint blockade was synergistic and led to greater tumor-free animals (67% in combination with anti-CTLA-4, 90% with anti-PD-1). NKTR-214 combined with anti-PD-1 was also more efficacious than the combination of anti-CTLA-4 and anti-PD-1. TCR repertoire analysis demonstrated superior increases in TIL clonality and infiltration with NKTR-214 compared to either anti-CTLA-4 or anti-PD-1 alone. NKTR-214 combined with either mode of checkpoint inhibition led to significant increases in both parameters, with the greatest effect occurring when combined with anti-PD-1. In the human BioMAP system, NKTR-214 active species led to significant increases in granzyme B, IFNg, IL-6, IL-17A and TNFa, while these markers were only modestly induced by Keytruda alone. When NKTR-214 was combined with Keytruda, additive and synergistic increases in these factors were found. In addition, the combination significantly decreased uPA in the fibroblast-HT29 system and MDC in the endothelial-HT1299 system, both factors associated with tumor progression. Conclusions: NKTR-214 delivers sustained signaling of the IL-2 pathway. Analysis of multiple immune markers in mice and human tumor-immune cell cultures provide mechanistic rationale for the increased T and NK cell activation in the tumor microenvironment after treatment with NKTR-214. When combined with anti-PD-1, significant increases in T cell receptor clonality, tumor infiltration and immune activation biomarkers are achieved - a significant finding, given that concomitant increase in clonality and infiltration has been correlated with favorable responses in the clinic. In vitro studies with human cells demonstrate the potentiation of immune activation markers associated with anti-tumor effects in combination with anti-PD-1, further suggesting these findings may be translatable from mouse to human. NKTR-214 is currently in a Phase 1 clinical trial to evaluate the pharmacokinetics, pharmacodynamics and activity in an outpatient setting.

Citation Format: John L. Langowski, Murali Addepalli, Laurie VanderVeen, Rhoneil Pena, Ravikumar Nutakki, Yolanda Kirksey, Ute Hoch, Jonathan Zalevsky, Stephen K. Doberstein, Deborah H. Charych. The CD122-biased immunostimulatory cytokine NKTR-214 combined with checkpoint blockade leads to mobilization of antitumor immunity and synergistic activity [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B057.

Abstract 558: Durable antitumor activity of the CD122-biased immunostimulatory cytokine NKTR-214 combined with immune checkpoint blockade

Background: While immune checkpoint blockade is a promising therapeutic approach, combination with agents that modulate complementary pathways may improve responses. Interleukin-2 (IL-2) immunotherapy leads to long-term responses in a small percentage of cancer patients, but systemic toxicity limits its use. In addition, IL-2 expands T regulatory cells, antagonizing antitumor immunity. NKTR-214 is a novel CD122-biased immunostimulatory cytokine which combines biased activation of the IL-2R beta receptor, greatly favoring activation of effector over regulatory T cells in the tumor microenvironment, with improved pharmacokinetics and tolerability compared to Proleukin® (aldesleukin) in non-clinical models. Here we examine the efficacy and mechanism of NKTR-214 combined with checkpoint blocking antibodies in murine tumor models.

Methods: Mice bearing subcutaneous B16, LLC, CT26 or EMT6 tumors were treated with single agent NKTR-214 (q9d), aldesleukin (bid or qd), murine anti-CTLA-4 or anti-PD-1 (twice-weekly), or combinations of these agents. Tumor volume was measured before, during and after treatment. Immune cells were profiled by flow cytometry; CD8 or NK requirements for efficacy were assessed by in vivo depletion through serial anti-CD8 or anti-asialo-GM1 antibody injections, respectively. Antitumor memory and specificity was assessed in complete responders by challenging with EMT6 or CT26 followed by observation with no additional test article treatments.

Results: In the B16 model, superior single-agent efficacy was achieved by NKTR-214 with a 10-fold lower dose than aldesleukin, yet significantly increased CD8/Treg ratio in the tumor (>400). In the EMT6 model, while both aldesleukin and NKTR-214 synergized with anti-CTLA-4, a greater percentage of complete responders were consistently observed with NKTR-214 (73% versus 44%). Antitumor immunity induced by the combination required both NK and CD8 T cell activity, and was durable and specific with mice remaining tumor-free after re-challenge with an EMT6 but not CT26 implant. Finally, NKTR-214 combined with anti-PD-1 provided superior activity in the CT26 model compared with the combination of anti-CTLA-4 and anti-PD-1 (90% versus 60% tumor-free, respectively).

Conclusions: NKTR-214 enables access to the potent IL-2 pathway, providing a mechanism of action complementary to checkpoint inhibition. Favorable pharmacokinetics of NKTR-214 allows sustained tumor exposure and dosing schedules commensurate with antibody therapies. The nonclinical results support the ongoing Phase 1 trial of NKTR-214 in patients with solid tumors.

Citation Format: John L. Langowski, Rhoneil Pena, Yolanda M. Kirksey, Murali K. Addepalli, Ute Hoch, Jonathan Zalevsky, Stephen K. Doberstein, Deborah H. Charych. Durable antitumor activity of the CD122-biased immunostimulatory cytokine NKTR-214 combined with immune checkpoint blockade. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 558.

Abstract B015: Antitumor activity of the CD122-biased immunostimulatory cytokine combined with immune checkpoint blockade requires innate and adaptive immunity

Background: While immune checkpoint blockade is a promising therapeutic approach, combination with agents that modulate complementary pathways may improve responses. Interleukin-2 (IL-2) immunotherapy leads to long-term responses in a small percentage of cancer patients, but systemic toxicity limits its use. In addition, IL-2 expands T regulatory cells, antagonizing antitumor immunity and resulting in a poorer clinical outcome. NKTR-214 is a novel CD122-biased immunostimulatory cytokine which combines biased activation of the IL-2R beta receptor subunit, greatly favoring activation of effector over regulatory T cells, with improved pharmacokinetics and tolerability compared to Proleukin in non-human models. Here we examine the efficacy and mechanism of NKTR-214 combined with anti-CTLA-4 in murine tumor models.

Methods: Mice bearing subcutaneous EMT6 mammary tumors were treated with NKTR-214 q9d, murine anti-CTLA-4 or anti-PD-1 twice-weekly, or both in combination. Immune cell profiling was assessed by flow cytometry following treatment. CD8 or NK cells were depleted in vivo by serial anti-CD8 or anti-asialo-GM1 antibody injections, respectively. Antitumor memory and specificity was assessed in complete responders by challenging with EMT6 or CT26 colon carcinoma implants with no additional treatment.

Results: While NKTR-214 and anti-CTLA-4 were not as efficacious individually, their combination was synergistic and well-tolerated with 83% of test animals tumor-free. Combination treatment increased NK and memory effector CD8 cells in both tumor and spleen. Antitumor immunity by the combination was durable and specific as 70% and 100% of mice remained tumor-free after challenge with a second and third EMT6 implant, but not after a subsequent CT26 implant. NKTR-214 combined with anti-PD-1 also proved synergistic with 40% of animals remaining tumor free following treatment. In vivo depletion of either CD8 effector or NK cells abrogated efficacy suggesting both contribute to the response.

Conclusions: The mechanism of NKTR-214 antitumor immunity is complementary to checkpoint inhibition. Favorable pharmacokinetics of NKTR-214 allows sustained tumor exposure and dosing schedules commensurate with other therapies. This new therapeutic combination of NKTR-214 and checkpoint inhibition may similarly enable durable responses in humans.

Citation Format: John L. Langowski, Seema S. Kantak, Rhoneil Pena, Yolanda Kirksey, Murali Addepalli, Steve Lee, Ute Hoch, Deborah H. Charych, Stephen K. Doberstein. Antitumor activity of the CD122-biased immunostimulatory cytokine combined with immune checkpoint blockade requires innate and adaptive immunity. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B015.

Abstract 5032: Synergy between an engineered cytokine, NKTR-214, and CTLA-4 blockade in murine colon and breast tumor models

Background: Immunotherapy offers the potential for durable responses in a growing list of cancer indications. NKTR-214 is comprised of the cytokine IL2 conjugated o multiple PEG units. Upon in vivo administration some of these PEG molecules are released to leave activated IL2-conjugates that bind selectively at the IL2 receptor beta subunit (IL2Rβ). The active IL-2-conjugates favor proliferation of tumor-killing CD8+ memory T cells (CD8T) over immunosuppressive regulatory T cells (Treg) in the tumor microenvironment (Charych, JCO 2013, 31:15, Suppl. 1).We have also shown that NKTR-214 results in sustained exposure of drug in the tumor and robust immune system activation that translates between rodents and monkeys at safe doses, (AACR; Mol Cancer Ther 2013;12 (11 Suppl): Abstract B296). The receptor selectivity and improved pharmacokinetic profile leads to substantially improved single-agent efficacy and safety over the original IL-2 cytokine. Combinations of different checkpoint blockade antibodies have shown great promise clinically and in preclinical tumor models, highlighting the importance of targeting multiple immune activation pathways. Here we examine the combination of NKTR-214 with anti-CTLA4 antibody in murine breast and colon tumor models to explore the interaction of two mechanisms of action: checkpoint inhibition and direct CD8T cell activation via the IL-2 receptor beta.

Methods: Female BALB/c mice bearing established tumors implanted with CT-26 (Murine Colon Carcinoma) or EMT6 (Murine Mammary Carcinoma) cells were treated with single agent NKTR-214, murine anti-CTLA-4 antibody or the two agents in combination. NKTR-214 was administered at 0.8 mg/kg i.v. and anti-CTLA-4 at 100 μg/mouse i.p.

Results: In both the EMT6 breast and the CT-26 colon models, the combination of NKTR-214 with anti-CTLA-4 yielded significantly better tumor growth inhibition compared to either agent dosed alone. In the EMT6 model 10/12 animals were tumor free by day 20 in the combination arm and stayed tumor free until the end of study (60 days). Similarly in the CT-26 model, 8/12 animals were tumor free by day 25 in the combination arm and stayed tumor free until the end of study (day 60). Single agent anti CTLA-4 or NKTR-214 did not show significant tumor inhibition in either model. No toxicities were observed when NKTR-214 was combined with anti CTLA-4 antibody.

Conclusions: NKTR-214 is a highly differentiated immunotherapy with a new mechanism of action that shows efficacy both as a single agent (as previously shown in a mouse melanoma model) and in combination. Combining NKTR-214 mediated T cell activation with CTLA-4 blockade is highly synergistic in murine models of cancer and holds the promise for durable responses in patients.

Citation Format: Steve Lee, Murali Addepalli, Ute Hoch, Rhoneil Pena, Payal Shirsat, Yolanda Kirksey, Stephen K. Doberstein, Deborah Charych, Seema Kantak. Synergy between an engineered cytokine, NKTR-214, and CTLA-4 blockade in murine colon and breast tumor models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5032. doi:10.1158/1538-7445.AM2014-5032

An engineered immunotherapy (NKTR-214) with altered selectivity toward the IL2 receptor: Efficacy and tolerability in a murine tumor model

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Background: Cytokine-based immunotherapy has been successful for the treatment of cancer, with potential for durable responses in multiple indications. One approach towards stimulating the immune system is to target the heterotrimeric interleukin2 receptor, IL2R. NKTR-214 uses polymer technology to alter receptor subunit selectivity to favor expansion of CD8+ memory effector T cells (CD8T) in the tumor over CD4+ regulatory T cells (Treg). In addition, polymer conjugation is designed to improve exposure and enhance tumor localization, significantly improving efficacy, modulating vascular leak syndrome (VLS) and allowing flexible dosing regimens. Methods: C57BL/6 mice bearing established subcutaneous B16F10 melanoma were treated with NKTR-214 at a variety of doses (0.25-4.0 mg/kg) and schedules (q5dx3 to q14dx2). Mice treated with clinically validated IL2 were administered 3mg/kg, bidx5 for 2 cycles. Efficacy was measured by monitoring tumor volumes. Tolerability was evaluated by survival. VLS was measured by injection of Evans Blue dye followed by colorimetry in lungs. Tumor immunotyping, by flow cytometry. Results: Tumors from mice receiving NKTR-214 had a CD8/Treg ratio of over 1,000 versus 14 for IL2. NKTR-214 administered at 2 mg/kg, q9dx3 was identified as the optimal regimen and showed tumor growth delay of 26 days compared to 9 days for optimally dosed IL2. 90% of NKTR-214 treated mice tolerated treatment compared to 67% for IL2. VLS was completely resolved prior to administration of the next dose of NKTR-214, unlike IL2. NKTR-214 was well tolerated in rats at two schedules, at MTD. Conclusions: NKTR-214 is a highly differentiated cytokine with a new mechanism of action that may provide options for cancer immunotherapy. Polymer conjugation of a clinically validated cytokine alters the IL2R selectivity to favor expansion of tumor killing immune cells (CD8T) over regulatory immune cells (Treg) in the tumor. The conjugate is also designed to improve exposure and enhance tumor localization, offering more options of dose and schedule. The optimal dose and schedule is cytokine-sparing, provides substantial tumor growth delay, and reduces toxicity.

Assessment of a process to degrade metal working fluids using Pseudomonas stutzeri CECT 930 and indigenous microbial consortia

The development of a novel biological process to treat metal working fluids (MWFs)-containing effluents at bioreactor scale was pursued in this work. The bacteria Pseudomonas stutzeri CECT 930 was investigated for the first time as an alternative agent for MWF degradation. An adequate medium design and mixing and aeration system, as well as an appropriate microorganism proved to be crucial for reaching high levels of degradation by P. stutzeri and by an indigenous consortium (about 70% and 50% of reduction in total petroleum hydrocarbon content in less than 2 wk, respectively). Additionally, as there is no information in literature trying to kinetically characterize an MWF-polluted effluent degradation process, all the experimental data were fitted to logistic and Luedeking and Piret models, that allowed to elucidate the growth-associated character of the biodegradation process.

Conformational analysis and crystal structure of {[1-(3-chloro-4-fluorobenzoyl)-4-fluoropiperidin-4yl]methyl}[(5-methylpyridin-2-yl)methyl]amine, fumaric acid salt

{[1-(3-Chloro-4-fluorobenzoyl)-4-fluoropiperidin-4yl]methyl}[(5-methylpyridin-2-yl)methyl]amine, fumaric acid salt (C(20)H(22)ClF(2)N(3)O, C(4)H(4)O(4)) (1) was synthesized and characterized by the complete (1)H, (13)C and (19)F NMR analyses. The conformation of the piperidin ring, in the solution state, was particularly studied from the coupling constants determined by recording a double-quantum filtered COSY experiment in phase-sensitive mode. (1)H NMR line-shape analysis was used, at temperatures varying between -5 and +60 degrees C, to determine the enthalpy of activation of the rotational barrier around the CN bond. Compound 1 crystallizes in the triclinic space group P1 with a=8.517(3) Angstrom, b=12.384(2) Angstrom, c=12.472(3) Angstrom, alpha=70.88(2) degrees, beta=82.04(2) degrees, gamma=83.58(2) degrees. The results strongly indicate that the solid and solution conformations are similar. Thermal stability and phases transitions were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Furthermore polymorphism screening was studied from recrystallization of 1 performed in seven solvents and by slurry conversion in water. The X-ray powder diffraction (XRPD) and differential scanning calorimetry results suggested that 1 crystallizes into one crystalline form which melts at 157 degrees C (DeltaH=132 J g(-1)).

[Crystalline polymorphism of eflucimibe]

The importance, in therapeutics, of the concept of bioavailability and on-going quality research in the formulation of a drug has prompted us to examine the crystalline polymorphism of eflucimibe as from the research phase. This study has been carried out by re-crystallization of the product in organic solvents having a different polarity in a variety of experimental temperature and pressure conditions, then, subsequently, by re-cooling the previously dissolved substance. The analytical methods applied to identify and then describe the polymorphic forms are thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray powder diffraction from synchrotron radiation (XRPD), infrared spectrometry (IR), solid-state nuclear magnetic resonance spectrometry (SSNMR) and lastly maximum solubility measurements. By means of XRPD, two polymorphic forms called A and B have been clearly identified at ambient temperature. These two crystalline forms were obtained in a reproducible way, then described by DSC, XRPD, IR and SSNMR. Differential scanning calorimetry analysis has shown for polymorphic form A two endothermic phenomena with low energy at about 35 masculine and 118 degrees C attributed by XRDP to conformational polymorphism. The complex endothermic event that extends between 75 masculine and 105 degrees C appears to correspond to successive alterations of a lamellar structure. The solid-solid transition observed at 110 degrees C is due to a change of crystalline phase, then the melting point occurring at about 130 degrees C. For form B, two changes of crystalline phase are clearly observed at about 80 masculine and 120 degrees C. The reversibility of these changes was observed by thermomicroscopy in polarized light. Form A, which is less soluble in absolute ethanol than form B, is the more stable thermodynamically in the temperature range from 25 masculine to 50 degrees C where the data have been obtained. The Van't Hoff diagram layout for each polymorphic form appears to reveal an A<-->B transition temperature in a temperature range lower than 25 degrees C. This study, undertaken as from the research phase, has enabled us to highlight the polymorphism of this new chemical entity by means of XRDP by explaining the nature of the endothermic phenomena observed by DSC, and lastly identify the thermodynamically more stable polymorphic form, thus contributing to a better knowledge of this future drug.

Prolidase deficiency with hyperimmunoglobulin E: a case report

Prolidase deficiency is a rare, inherited disorder characterized by ulceration of the skin, mental retardation, and massive urinary excretion of imidodipeptides. Most patients also have recurrent infections, an unusual facial appearance, and splenomegaly. We describe a girl presenting with chronic dermatitis, recurrent respiratory tract infections since her first months of life, and facial features characteristic of prolidase deficiency. The diagnosis of prolidase deficiency was made at 4.5 months of age. The immunologic study in this patient showed an extreme and progressive increase of total immunoglobulin E (IgE) in serum (reaching the value of 77,600 IU/l) and defective chemotactic function of the neutrophils. Treatment with a hyper-proteic diet supplemented with ascorbic acid, manganese chlorite, and topical proline resulted in reduction of the frequency and severity of the infections and significant improvement of the skin lesions. The authors discuss the immunologic alterations and the favorable evolution with treatment in this patient.

An ice test for the diagnosis of myasthenia gravis

OBJECTIVE

To determine whether ice application to a ptotic eyelid can differentiate myasthenic from nonmyasthenic ptosis.

DESIGN

Prospective, multicenter, nonrandomized, comparative trial.

PARTICIPANTS

Twenty patients with myasthenia gravis (MG) and ptosis were evaluated in the neuro-ophthalmology service. CONTROL SUBJECTS: Twenty patients with nonmyasthenic ptosis evaluated in the same locale.

METHODS

Palpebral fissures were measured before and immediately after a 2-minute application of ice to the ptotic eyelid.

MAIN OUTCOME MEASURES

The difference in palpebral fissures in millimeters before and after ice application. Two or more millimeters of improvement after ice application was considered a positive ice test result.

RESULTS

A positive ice test result was noted in 16 of the 20 (80%) patients with MG and in none of the 20 patients without MG (P < 0.001). Of the 4 patients with MG and complete ptosis, 3 had a negative ice test result.

CONCLUSIONS

The ice test is a simple, short, specific, and relatively sensitive test for the diagnosis of myasthenic ptosis. The sensitivity of the ice test in patients with complete ptosis decreases considerably.

PTCA, thrombolysis or atherectomy: rational treatment of recently occluded saphenous vein grafts

Recently occluded saphenous vein grafts (SVG) contain abundant thrombus. Distal embolization and myocardial infarction often occur when recanalization of such SVG is attempted. In 80 patients with occluded SVG, we employed transcatheter devices to lyse, compress or extract thrombus. Primary treatment for these SVG was performed in the following manner; PTCA 29, intragraft urokinase 12, TEC atherectomy 39. Following urokinase or atherectomy, adjunctive PTCA was performed to diminish the residual stenosis. All patients had class III or IV angina. Clinically, SVG occlusions were 3 days to 3 months old. TIMI flow was grade 0, and occlusion length was greater than 6 cm for all SVG. Each strategy resulted in a similar procedure success rate. However, when used as a primary treatment, TEC may be associated with lower rates of distal embolization and myocardial infarction.

Development of a community intervention programme on miners' health and working environment in Nicaragua

Since 1983, a broad research and development programme has been carried out with the support of Sweden through the Swedish Agency for Research Cooperation in Developing Countries (SAREC). One of the medical research and development projects deals with the environment and state of health of the population of an entire village, and is referred to as the Abdon Vega project. It is pursued by the Department of Social and Preventive Medicine of the University of León, Nicaragua, with the support of the Department of Social Medicine at the Karolinska Institute in Stockholm. The project comprises two stages. The first one centres on the state of health of the workers and the mining environment. This article reports on the objectives of the project and the study area. It presents experience from the development work up to now and the difficulties encountered.

Renal and extrarenal rhabdoid tumors in children: a clinicopathologic study of 14 patients

The clinical and pathologic features of 14 children with rhabdoid tumors are presented. Eight patients had primary renal neoplasms and six had extrarenal tumors. The eight renal rhabdoid tumors were identified among 514 primary renal neoplasms collected at four pediatric institutions. Six patients were under 1 year of age; five children died of tumor-related causes, four of them within 4 months of diagnosis and one 17 months postnephrectomy. Another patient died of sepsis 12 days postnephrectomy. One is alive 13 months postnephrectomy, and one was lost to follow-up evaluation. The most common sites of metastasis were the lymph nodes (seven children) and the lungs (three patients). Three infants with renal rhabdoid tumors had, in addition, intracranial masses, two of which manifested clinically before the detection of the renal tumors, in one confirmed to be a primitive neuroectodermal tumor. Five of the 6 extrarenal tumors were identified among 155,926 surgical pathology specimens examined in the same children's hospitals over the same period of time; the remaining extrarenal rhabdoid tumor was received in consultation from a community hospital. The extrarenal rhabdoid tumors occurred in the dorsum of the right foot, liver, soft tissue of the right chest wall, left temporal lobe, left leg, and left thoracic paraspinal region. The ages ranged from 6 weeks to 15 years and two months. Three patients died of tumor-related causes within 4 months of diagnosis; one was a term stillborn. Two are alive, 1 month and 70 months postdiagnosis. Common sites for metastases included the lungs (three patients), and liver and lymph nodes (two children each). Patients with renal and extrarenal rhabdoid tumors are of similar age, have a similar clinical course, with early metastases and poor response to therapy. Primitive neuroectodermal intracranial tumors have been identified in several reported patients with renal rhabdoid tumors; similar brain tumors have not been documented in patients with extrarenal rhabdoid tumors. The histogenesis of this tumor remains unknown.

Clear cell sarcoma of the kidney: a clinicopathologic study of 21 patients with long-term follow-up evaluation

The clinical and pathologic features of 21 children with clear cell sarcoma of the kidney are presented. These cases were identified among 517 primary renal tumors collected from four pediatric institutions. Abdominal mass and hematuria were the usual presenting signs. The male to female ratio was 1.3 to 1. Although the mean age at diagnosis was 3 years, the sarcomas were diagnosed earlier in boys (2 years, 7 months) than in girls (3 years, 7 months). Tumor size and weight may have accounted for this difference, since the average tumor weights were 899 g for boys and 635 g for girls. Right kidney locations predominated (14 cases). The most common site for metastasis was the skeleton (12 patients), and the skull was almost invariably involved (10 children). Bone metastases preceded the development of metastases elsewhere in nine patients, in five of whom the involvement was polyostotic. Of the 12 patients with osseous metastases, nine died within five years of diagnosis, and one died eight years and nine months after diagnosis; the remaining two patients were successfully treated with a combination of surgery, radiotherapy, and actinomycin D, vincristine, cyclophosphamide, and Adriamycin. Eight of the nine patients with lung metastases died within five years of diagnosis. Until substantial proof is found that clear cell sarcoma of the kidney is related to nephroblastoma, its identification as a non-Wilms' sarcoma would seem to be appropriate. This tumor is not the only sarcoma of the kidney, but it appears to be the most common renal sarcoma of childhood.

Noiles total knee replacement procedure

We report preliminarily on 32 Noiles total knee replacements performed during a 32month period, with a detailed account of those results, including 11 cases (9 patients) followed up for 24 to 32 months, and an illustrative case report. We had excellent results in 31 cases. The Noiles prosthesis function met the standards of function reported by Wilson and Venters,1 using a system developed at the University of North Carolina for evaluating the results of total knee replacement, and also passed the standards referred to by Kettlekamp and Nasca.2.

Comparison of anesthetic solutions used in lumbar and caudal peridural anesthesia

Clinical observations on peridural anesthesia were made in 466 patients. The spread of various concentrations of anesthetics injected into the lumbar and caudal peridural space were followed by plotting analgesia-time profiles. Onset of anesthesia and the volume required to provide one dermatome of anesthesia varied little among different anesthetics given in different concentrations. The sequence of appearance of analgesia was also similar, with longer times being required to block larger roots. Quality of anesthesia was judged by the penetration of anesthestic solutions into the largest spinal nerve root (S1); rate of penetration depended on the type of drug and concentration. No drug concentration combination included all the ideal characteristics for block: minimal mass of anesthetic, maximum spread, long duration (minutes of anesthesia per milligram of drugs per segment), low incidence of failure, and fast stabilization time. However, depending on the surgical needs and the characteristics of the patients, some drugs and concentrations may be preferred. Stabilization and onset were slower and drug requirements larger for caudal than for lumbar peridural anesthesia.