A literature review and expert consensus statement on diagnostics in suspected metal implant allergy

BACKGROUND

Although rare, allergic reactions to metal implants represent a diagnostic challenge in view of missing guidelines.

OBJECTIVES

To develop an European expert consensus on characteristics of metal allergy reactions and the utility of various diagnostic tools in suspected metal implant allergy.

METHODS

A nominal group technique (NGT) was applied to develop consensus statements. Initially an online literature database was created on a secure server to enable a comprehensive information. Twenty-three statements were formulated on potential aspects of metal implant allergy with a focus on diagnostics and grouped into five domains. For the consensus development, the panel of 12 experts initially did refine and reformulate those statements that were ambiguous or had unclear wording. By face-to-face (9/12) or virtual participation (3/12), an anonymous online voting was performed.

RESULTS

Consensus (≥80% of agreement) was reached in 20/23 statements. The panel agreed that implant allergy despite being rare should be considered in case of persistent unexplained symptoms. It was, however, recommended to allow adequate time for resolution of symptoms associated with healing and integration of an implant. Obtaining questionnaire-aided standardized medical history and standardized scoring of patient outcomes was also considered an important step by all experts There was broad consensus regarding the utility/performance of patch testing with additional late reading. It was recognized that the lymphocyte transformation test (LTT) has to many limitations to be generally recommended. Prior to orthopaedic implant, allergy screening of patients without a history of potential allergy to implant components was not recommended.

CONCLUSIONS

Using an expert consensus process, statements concerning allergy diagnostics in suspected metal implant allergy were created. Areas of nonconsensus were identified, stressing uncertainty among the experts around topics such as preoperative testing in assumed allergy, histological correlate of periimplant allergy and in vitro testing, which underscores the need for further research.

Invasive electrical stimulation in the treatment of avascular osteonecrosis of the femoral head - mid-term results

The study aimed to evaluate the outcomes of osteonecrosis of the femoral head (ONFH) in adults after surgical treatment including invasive electromagnetic osteostimulation (E-Stim). Further, the influence of disease stage and several comorbidities on the joint preservation rate should be examined. Sixty patients (66 hip joints) with ONFH were included in this retrospective cross-sectional analysis (mean follow-up: 58 months, 19-110 months). Potential ONFH risk factors and comorbidities (ONFH stage, age, sex, alcohol, smoking, cortisone medication, chemotherapy) were recorded. The influence of specific parameters on the joint preservation rates was evaluated by a multivariate logistic regression analysis. Finally, patients with preserved hip joints underwent an assessment of their last available X-rays. The joint preservation rate depended on the initial ONFH Steinberg stage (I+II: 82.8%, III: 70.8%, ≥ IVa: 38.5%). Initially collapsed ONFH (p ≤ 0.001) and cortisone therapy (p = 0.004) significantly decreased the joint preservation rates. In case of progressed ONFH, the presence of ≥ 2 risk factors resulted in higher THA conversion rates (stage III: OR 18.8; stage ≥IVa: OR 12). In 94% of the available X-rays, the ONFH stage improved or did not progress. No complications could be attributed to the E-Stim device or procedure. The present surgical protocol including minimally invasive E-Stim revealed high joint preservation rates for non-collapsed ONFH after mid-term postoperative follow-up. Especially in progressed ONFH, the-risk profile seems to be crucial and hence, for joint preserving surgery, careful patient selection is recommended.

The Bispecific Tumor Antigen-Conditional 4-1BB x 5T4 Agonist, ALG.APV-527, Mediates Strong T-Cell Activation and Potent Antitumor Activity in Preclinical Studies

4-1BB (CD137) is an activation-induced costimulatory receptor that regulates immune responses of activated CD8 T and natural killer cells, by enhancing proliferation, survival, cytolytic activity, and IFNγ production. The ability to induce potent antitumor activity by stimulating 4-1BB on tumor-specific cytotoxic T cells makes 4-1BB an attractive target for designing novel immuno-oncology therapeutics. To minimize systemic immune toxicities and enhance activity at the tumor site, we have developed a novel bispecific antibody that stimulates 4-1BB function when co-engaged with the tumor-associated antigen 5T4. ALG.APV-527 was built on the basis of the ADAPTIR bispecific platform with optimized binding domains to 4-1BB and 5T4 originating from the ALLIGATOR-GOLD human single-chain variable fragment library. The epitope of ALG.APV-527 was determined to be located at domain 1 and 2 on 4-1BB using X-ray crystallography. As shown in reporter and primary cell assays in vitro, ALG.APV-527 triggers dose-dependent 4-1BB activity mediated only by 5T4 crosslinking. In vivo, ALG.APV-527 demonstrates robust antitumor responses, by inhibiting growth of established tumors expressing human 5T4 followed by a long-lasting memory immune response. ALG.APV-527 has an antibody-like half-life in cynomolgus macaques and was well tolerated at 50.5 mg/kg. ALG.APV-527 is uniquely designed for 5T4-conditional 4-1BB-mediated antitumor activity with potential to minimize systemic immune activation and hepatotoxicity while providing efficacious tumor-specific responses in a range of 5T4-expressing tumor indications as shown by robust activity in preclinical in vitro and in vivo models. On the basis of the combined preclinical dataset, ALG.APV-527 has potential as a promising anticancer therapeutic for the treatment of 5T4-expressing tumors.

Relationship between emotional expressions and lifestyle changes among university students during COVID-19 lockdown in Lebanon

INTRODUCTION

Emotional expressivity plays an important role in terms of communication and interpersonal relationships in the context of society. Our research aims at assessing the perception of emotional expressivity and its association with lifestyle changes during COVID-19 lockdown among university students in Lebanon.

METHODOLOGY

A total of 742 participants completed an anonymous online questionnaire including socio-demographic characteristics, lifestyle habits, and emotional expression evaluated through the Berkeley Expressivity Questionnaire (BEQ). Participants also reported their perception of the relationship between emotional expressivity and lifestyle changes experienced during lockdown.

RESULTS

The expression of positive emotions was decreased among students who have a weight loss from decreased eating during lockdown. Moreover, significantly lower negative emotions and increased positive emotions were found to be associated respectively with the increase in quality and quantity of distance learning, which emphasizes the psychological investment in education. In terms of extensive time spent on TV and social media, results point towards increased emotional expressivity, particularly positive emotions and impulse facets. Finally, changes in social interaction during this period impacted all facets of emotional expressivity.

CONCLUSIONS

In the context of lockdown due to the pandemic, emotional aspects were associated by university students with lifestyle changes. Our research highlights the beneficial role of social networking, distance learning, physical activity, and well-balanced nutrition on emotional regulation in this particularly stressful situation, thus the importance of a global approach to emotional expressivity including the social aspects and biological ones.

Characteristics and care of chronic hepatitis C treated with direct-acting antivirals in migrants

BACKGROUND AND AIMS

Hepatitis C is poorly documented in migrants. The published studies mainly concern the screening in this population and are limited to some countries in Europe and North America. This study aimed to evaluate the characteristics and care of chronic hepatitis C in this population compared to the nonmigrant population, in the era of direct-acting antivirals (DAAs).

METHOD

We performed a retrospective analysis based on data presented at the multidisciplinary team meetings of our tertiary care center between 2015 and 2019.

RESULTS

We included 277 migrant- and 1390 nonmigrant patients mono-infected with hepatitis C virus (HCV) and treated with DAAs. The majority of the migrants were from Eastern European countries. In multivariable analysis, BMI classes associated with more obesity (OR = 1.84; 95% CI, 1.37-2.49; P < 0.001) and therapeutic patient education (OR = 3.91; 95% CI, 2.38-6.49; P < 0.001) were positively associated with migrant status, whereas age (OR = 0.92; 95% CI, 0.90-0.94; P < 0.001), female gender (OR = 0.46; 95% CI, 0.28-0.74; P = 0.002), modes of contamination with less drug use, transfusion history or nosocomial risk, as well more unknown mode (OR = 0.70; 95% CI, 0.50-0.96; P = 0.031), alcohol consumption (OR = 0.48; 95% CI, 0.29-0.73; P = 0.001), types of structures with less care in a general hospital or health network of general practitioners and more care in a university hospital or primary addictology center (OR = 0.78; 95% CI, 0.60-0.99; P = 0.046) and opioid substitution therapy (OR = 0.25; 95% CI, 0.08-0.68; P = 0.008) were negatively associated with migrant status. The substained virologic response 12 was close to 97% in both groups.

CONCLUSION

Despite multiple differences in characteristics and therapeutic care between the two populations, the chances of healing hepatitis C were the same among migrant- compared with nonmigrant patients.

Novel approach to estimate distraction forces in distraction osteogenesis and application in the human lower leg

PURPOSE

In distraction osteogenesis (DO) of long bones, new bone tissue is distracted to lengthen limbs or reconstruct bone defects. However, mechanical boundary conditions in human application such as arising forces are mainly based on limited empirical data. Our aim was the numerical determination of the callus distraction force (CDF) and the total distraction force (TDF) during DO in the tibia of adults to advance the understanding of callus tissue behavior and optimize DO procedures.

METHOD

We implemented a mathematical model based on an animal experiment to enable the calculation of forces arising while distracting callus tissue, excluding the influence of surrounding soft tissue (muscles, skin etc.). The CDF progression for the distraction period was calculated using the implemented model and varying distraction parameters (initial gap, area, step size, time interval, length). Further, we estimated the CDF based on reported forces in humans and compared the results to our model predictions. In addition, we calculated the TDF based on our CDF predictions in combination with reported resisting forces due to soft tissue presence in human cadavers. Finally, we compared the progressions to in vivo TDF measurements for validation.

RESULTS

Due to relaxation, a peak and resting CDF is observable for each distraction step. Our biomechanical results show a non-linear degressive increase of the resting and peak CDF at the beginning and a steady non-linear increase thereafter. The calculated resting and peak CDF in the tibial metaphysis ranged from 0.00075 to 0.0089 N and 0.22-2.6 N at the beginning as well as 20-25 N and 70-75 N at the end of distraction. The comparison to in vivo data showed the plausibility of our predictions and resulted in a 10-33% and 10-23% share of resting CDF in the total resting force for bone transport and elongation, respectively. Further, the percentage of peak CDF in total peak force was found to be 29-58% and 27-55% for bone transport and elongation, respectively. Moreover, our TDF predictions were valid based on the comparison to in vivo forces and resulted in a degressive increase from 6 to 125 N for the peak TDF and from 5 to 76 N for the resting TDF.

CONCLUSION

Our approach enables the estimation of forces arising due to the distraction of callus tissue in humans and results in plausible force progressions as well as absolute force values for the callus distraction force during DO. In combination with measurements of resisting forces due to the presence of soft tissue, the total distraction force in DO may also be evaluated. We thus propose the application of this method to approximate the behavior of mechanical callus properties during DO in humans as an alternative to in vivo measurements.

Subject specific finite element modelling of periprosthetic femoral fractures in different load cases

Periprosthetic femoral fractures (PFF) around total hip replacements are one of the biggest challenges for orthopaedic surgeons. To understand the risk factors and formation of these fractures, the development of a reliable finite element (FE) model incorporating bone failure is essential. Due to the anisotropic and complex hierarchical structure of bone, the mechanical behaviour under large strains is difficult to predict. In this study, a state-of-the-art subject specific FE modelling technique for bone is utilised to generate and investigate PFF. A bilinear constitutive law is applied to bone tissue in subject specific FE models of five human femurs which are virtually implanted with a straight hip stem to numerically analyse PFF. The material parameters of the models are expressed as a function of bone ash density and mapped node wise to the FE mesh. In this way the subject specific, heterogeneous structure of bone is mimicked. For material mapping of the parameters, computed tomography (CT) images of the original fresh-frozen femurs are used. Periprosthetic fractures are generated by deleting elements on the basis of a critical plastic strain failure criterion. The models are analysed under physiological and clinically relevant conditions in two different load cases re-enacting stumbling and a sideways fall on the hip. The results of the analyses are quantified with experimental data from previous work. With regard to fracture pattern, stiffness and failure load the simulations of the load case stumbling delivered the most stable and accurate results. In general, mapping of material properties was found to be an appropriate way to reproduce PFF with finite element models.

Abstract 1637: A fully human anti-vista antibody as a promising therapy against poorly immunogenic tumors

V-domain Immunoglobulin Suppressor of T cell Activation (VISTA/PD-1H) is an immune checkpoint regulator of the B7 family. VISTA can be found on the cell surface of some tumor types, however for the majority of cancers, VISTA is highly expressed in the immunological myeloid cell compartment in the tumor microenvironment (TME). VISTA has been shown, in vitro and in vivo, to inhibit T cell activation and prevent T cell recruitment into tumors. In patients, high VISTA expression is associated with poor prognosis and is also a potential mediator of resistance to anti-CTLA-4 and anti-PD-(L)1 therapies. Therefore, VISTA is a very attractive new target for cancer immunotherapy. Kineta has selected a lead candidate anti-VISTA monoclonal antibody after a deep screen of 107 fully human and highly diverse antibodies directed against the VISTA extracellular domain. The candidate exhibits high potency in the subnanomolar range and is characterized by a long constant of dissociation evaluated by ELISA and Octet binding. It targets human and cynomolgus monkey VISTA on a unique epitope. Cross reactivity against other B7 family members has also been evaluated, and the lead candidate demonstrates high specificity against VISTA. The candidate antibody also efficiently induces T cell activation, proliferation and IFNg secretion on a Staphylococcal EnterotoxinB assay, as well as in a coculture experiment with a cell line overexpressing VISTA. The candidate promotes maturation of Antigen Presenting Cells with an increase of CD80 and HLA-DR surface expression as well as CXCL10 secretion in a monocyte activation assay. The mechanism of action is mediated in part by NK cells. This anti-VISTA antibody also prevents the immunosuppressive function of differentiated MDSCs in vitro against T cells. In Knock-In-human VISTA mice, anti-VISTA antibody treatment mediates single-agent antitumor activity in vivo in multiple syngeneic tumor models and shows enhanced efficacy in combination with either anti-PD-(L)1 or anti-CTLA-4 treatment. Finally, anti-VISTA antibody treatment was well-tolerated in exploratory toxicology studies in cynomolgus monkey and has a half-life consistent with other monoclonal antibodies. Our results strongly support the continued development of our anti-VISTA antibody for the treatment of colder, less immunogenic tumors.

Citation Format: Thierry Guillaudeux, Eric Tarcha, Robert Bader, Benjamin Dutzar, Nathan Eyde, Emily Frazier, David Jurchen, Remington Lance, Cristina Loomis, Kurt Lustig, Yulia Ovechkina, David Peckham, Jeff Posakony, Shaarwari Sridhar, Mei Xu, Shawn Iadonato. A fully human anti-vista antibody as a promising therapy against poorly immunogenic tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1637.

Abstract PR005: Highly potent fully human anti-VISTA antibodies – A new target checkpoint inhibitor against immunosuppressive myeloid cells

V-domain Immunoglobulin Suppressor of T cell Activation (VISTA/PD-1H) is a B7 family ligand expressed on circulating and intratumoural myeloid cells as well as Treg and NK cells. It has been shown to inhibit T cell responses in vitro and in preclinical models. In patients, VISTA is also a potential mediator of resistance to anti-CTLA-4 and anti-PD1 therapies and therefore is a valuable new target for cancer immunotherapy. Kineta has analyzed 107 fully human ScFv antibodies directed against VISTA. Our lead candidates exhibit high potencies in the subnanomolar range and are also characterized by a long kDis. They specifically target human and cynomolgus monkey VISTA on a singular unique epitope. In a Staphylococcus Enterotoxin B T-cell activation assay, Kineta’s anti-VISTA antibodies efficiently induce IFNg secretion. They also promote strong maturation of Antigen Presenting Cells with an increase of CD80 and HLA-DR surface expression as well as CXCL10 secretion. The mechanism of action is mediated in part by NK cells. We demonstrated that myeloid cells acquire a high level of VISTA expression during MDSC or M2 differentiation in vitro and that Kineta’s anti-VISTA antibodies prevent the differentiation of MDSC as well as their immunosuppressive activity against T cells. Anti-VISTA antibodies mediate single-agent antitumor effects in syngeneic tumor models in wild-type mice and show enhanced activity in combination with anti-PD1 and anti-CTLA-4 treatment. Candidate anti-VISTA antibodies have also been evaluated in exploratory tolerability and PK studies in cynomolgus monkey. These studies demonstrated that multiple weekly doses of antibodies are well-tolerated with appropriate PK for lead selection and optimization. Our results strongly favor further characterization and continued development of selected lead antibodies for the potential treatment of colder, less immunogenic tumors.

This abstract is also being presented as PO035.

Citation Format: Thierry Guillaudeux, Eric Tarcha, Robert Bader, Benjamin Dutzar, Nathan Eyde, Emily Frazier, David Jurchen, Remington Lance, Cristina Loomis, Kurt Lustig, Yulia Ovechkina, David Peckham, Jeff Posakony, Shaarwari Sridhar, Mei Xu, Shawn Iadonato. Highly potent fully human anti-VISTA antibodies – A new target checkpoint inhibitor against immunosuppressive myeloid cells [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PR005.

Novel method for determining bone dimensions relevant for longitudinal and transverse distraction osteogenesis and application in the human tibia and fibula

BACKGROUND

In distraction osteogenesis (DO) of long bones, new bone tissue is formed and distracted to lengthen limbs or reconstruct bone defects. However, certain anthropometric quantities relevant for biomechanical modelling of DO are unknown, such as areas where new bone tissue is formed. We developed a novel method to facilitate the determination of these distraction areas (DA), which we applied in the tibia and fibula of adults for longitudinal and transverse DO to advance knowledge of anatomical boundary conditions.

METHODS

CT data sets of 21 adult human tibiae and 24 fibulae were selected for investigation. Volumetric models were created utilizing image segmentation. The DA for longitudinal DO was determined in a CAD environment using the total bone cross section in the proximal, central and distal diaphysis of the tibia and fibula. Additionally, the medullary canal area was determined in the fibula. Furthermore, we measured the total DA and medullary canal DA for transverse distraction using a longitudinally split fibula with an osteotomy length of 8, 12, 16 and 20 cm. The osteotomy plane was oriented in medial and anteromedial direction. Finally, Spearman analyses were conducted to assess the correlation between bone length and DA.

RESULTS

For longitudinal DO, the mean total DAs were 878, 535 and 482 mm² in the tibia and 132, 153, 124 mm² in the fibula for the proximal, central and distal diaphysis, respectively. Regarding transverse distraction, the mean total DAs for a medial and anteromedial osteotomy plane orientation were 962, 1423, 1868 and 2306 mm² as well as 925, 1387, 1844, 2279 mm² for an osteotomy length of 8, 12, 16 and 20 cm, respectively. Weak, positive, and non-significant correlations were observed when correlating bone length and DA in the tibia and fibula.

CONCLUSIONS

Quantification of DAs and hence distracted callus tissue in DO advances anatomical knowledge and improves biomechanical modelling by adding a parameter which cannot be approximated based on bone length.

Numerical simulation of the electric field distribution in an electrical stimulation device for scaffolds settled with cartilaginous cells

Electrical stimulation is a promising approach to enhance cell viability and differentiation. We aim to develop a stimulation device for the investigation and realization of cartilaginous cell engineering. The stimulation setup is capable of applying well-defined electric fields to several scaffolds at the same time. The setup consists of a flat plate with multiple test tubes for the scaffolds. A flexible printed circuit board containing a separate pair of electrodes for each tube is fixed at the bottom of the plate. In this context, numerical simulation using Finite Element Method (FEM) is a valuable tool to gain a better understanding of the electric field distribution in such devices. The thin insulating layer of the flexible printed circuit board allows sufficient field strength to be achieved at moderate input voltages but presents challenges for modelling. In simulations, thin layers would usually require a fine discretization with many degrees of freedom (DOF). This leads to large models, which are expensive regarding memory and computation time. Based on the 'contact impedance' boundary condition available in COMSOL Multiphysics® 5.4, an alternative approach is proposed that can model thin layers in capacitively coupled setups. The resulting electric field distribution in the new stimulation setup is presented and discussed.

Improvement of Human Sperm Vacuolization and DNA Fragmentation Co-Cultured with Adipose-Derived Mesenchymal Stem Cell Secretome: In Vitro Effect

Background and Objectives

Oxidative stress (OS) is known to be an important factor of male infertility. Adipose-derived mesenchymal stem cells (AD-MSCs) are known to have immune-modulatory and anti-oxidant effects through their secretions, hence raising the idea of their potential benefit to improve sperm parameters. This study aims at investigating the effect of AD-MSCs conditioned medium (CM) on human sperm parameters in the presence and absence of H₂O₂-induced OS.

Methods and Results

Sperm samples were collected from 30 healthy men and divided into two groups: non-stressed and H₂O₂-stressed. Isolated AD-MSCs from healthy donors undergoing liposuction were cultured and CM was collected at 24, 48 and 72 h. Both sperm groups were cultured with CM and a time course was performed followed by an evaluation of sperm parameters. The incubation of non-stressed and stressed sperm samples with AD-MSCs-CM for 24 h was found to have the optimum impact on sperm vacuolization, DNA fragmentation and OS levels in comparison to other incubation timings, while preserving motility, viability and morphology of cells. Incubation with CM improved all sperm parameters except morphology in comparison to the non-treated group, with the best effect noted with CM collected at 24 h rather than 48 or 72 h for sperm vacuolization and DNA fragmentation. When compared to fresh semen parameters (T0), samples cultured with CM 24 h showed a significant decrease in sperm vacuolization and DNA fragmentation while keeping other parameters stable.

Conclusions

AD-MSCSs-CM improves sperm quality, and hence can be used in treating infertility and subsequently enhancing IVF outcomes.

Abstract 2380: Preclinical safety and efficacy of a tumor-directed T cell activating 4-1BB x 5T4 ADAPTIR™ bispecific antibody

The ability to induce potent anti-tumor activity by stimulating 4-1BB (CD137), a key co-stimulatory receptor, makes 4-1BB an attractive immunotherapeutic target. However, a clinically tested, 4-1BB targeting monospecific antibody has been hampered by dose-limiting hepatic toxicities. To improve safety of 4-1BB targeting therapies we have developed a 4-1BB x 5T4 bispecific antibody designed to direct tumor-specific T cell responses to the tumor by stimulating 4-1BB only when co-engaged with 5T4, a tumor-associated antigen. The preclinical dataset presented here provides an overview of the mechanism of action and the efficacy and safety profile of ALG.APV-527, supporting its advancement into the clinic. ALG.APV-527 was built using the ADAPTIR™ platform with binding domains from the ALLIGATOR-GOLD® human scFv library. Its 5T4-dependent agonistic function was assessed using primary CD8+ T cells or NK cells in the presence of 5T4-expressing cells. Secretion of IFN-γ or granzyme B was measured at 72 hrs using ELISA. To measure proliferation, PBMCs were labelled with Cell Trace™ and gated CD8+ T cells were analyzed using flow cytometry. For tumor inhibition studies, the human 5T4-expressing colon carcinoma HCT116 xenograft model was used. 5T4 expression was evaluated in normal human tissues and different human tumors by immunohistochemistry. The preclinical safety profile of ALG.APV-527 was evaluated in a single and repeated dose, dose-range finding toxicology study in non-human primates (NHP). The study design included all the standard repeated dose toxicity parameters and in addition, pharmacokinetics, immunogenicity, and pharmacodynamic end-points. ALG.APV-527 induces a 5T4-dependent increase in IFN-γ and granzyme B production and enhances proliferation of T cells and NK cells. Furthermore, ALG.APV-527 inhibits tumor growth in a human 5T4-expressing colon carcinoma xenograft model. 5T4 is overexpressed in multiple solid tumors, potentially directing the activity of 4-1BB induced by ALG.APV-527 to 5T4-expressing tumors, improving the risk/benefit profile. Four doses (administered once weekly) did not cause any adverse events in the NHP toxicity study. In conclusion, ALG.APV-527 induces potent CD8+ T cell and NK co-stimulation but only in the presence of 5T4. Based on its efficacy and preclinical safety profile, ALG.APV-527 is a promising anti-cancer therapeutic for the treatment of multiple 5T4-expressing solid tumors.

Citation Format: Anna Dahlman, Michelle Nelson, Jeannette Bannink, Starrla Johnson, Doreen Werchau, Anneli Nilsson, Lill Ljung, Gabriele Blahnik-Fagan, Robert Bader, Adnan Deronic, Peter Ellmark, Maria Askmyr, Gabriela Hernandez-Hoyos, Cathy McMahan, Sara Fritzell. Preclinical safety and efficacy of a tumor-directed T cell activating 4-1BB x 5T4 ADAPTIR™ bispecific antibody [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 2380.

Impact of alexithymia on glycemic control among Lebanese adults with type 2 diabetes

Purpose

Alexithymia, defined as the inability of a person to identify, describe and express emotions, has been found to influence glycemic control in type 2 diabetes patients (D2). The characteristics and influencing factors of alexithymia and the association of this psychological construct with D2 has not yet been studied in Lebanon where 14.6% of adults are diagnosed with the disease. This study aims at evaluating the prevalence of alexithymia and its relationship with glycemic control among Lebanese adults with D2.

Methods

Alexithymia was assessed in 104 patients diagnosed with D2 and 100 healthy controls using the 20-item Toronto Alexithymia Scale (TAS-20). The impact of alexithymia on glycemic control was evaluated using HbA1c values, fasting blood glucose levels, number of severe hyperglycemic episodes and hospitalizations for hyperglycemia within the past months.

Results

Alexithymia prevalence was significantly higher in D2 patients compared to controls (35.5% vs 15%). Patients with alexithymia showed higher levels of HbA1c and glucose in comparison to those without alexithymia. Consistently, significant positive correlations were found between the TAS-20 total and subscale scores and both HbA1c and glucose levels. Alexithymic patients had three times more severe hyperglycemic episodes and five times more hospitalizations for hyperglycemia compared to those without alexithymia. According to multivariate regression analysis, lifestyle factors alone were not found predictive of alexithymia in D2 patients.

Conclusion

Given the impact of alexithymia on D2 regulation, screening of alexithymia in case of D2 and appropriate psychological follow-up are important for a better prognosis, management and treatment of the disease.

The Carrot Not The Stick: Creating Incentives for Voluntary Enforcement of Smoke-Free Policies Through Smoke-Free Zone Certification

Background and context: Jordan's Public Health Law bans smoking in public places. However, law-enforcement mechanisms are lagging and Jordanians continue to be exposed to second-hand smoke. The Global Tobacco Control Report 2017 rates enforcement at 2/10 dropping even below the previous 3/10 rating of 2015. Aim: Our intervention aims to provide alternative routes for protection from exposure to second-hand smoke. Strategy/Tactics: The intervention builds on results from a 2012 survey which indicated that 85% of the public supports banning smoking in healthcare institutions, schools, and work places. In 2013 King Hussein Cancer Foundation and Center launched the Smoke-free Zone Certificate Program in collaboration with Global Smoke-free Worksite Challenge. The program, currently in its fifth round, recognizes institutions that voluntarily enforce smoke-free environments. Program/Policy process: Interested institutions submit an application requesting certification. Applications go through a screening process to confirm initial alignment with the program criteria. Institutions passing the initial screening are physically inspected for compliance through unannounced spot-check visits. Those passing the inspection receive certification. To qualify, an institution should meet two criteria. The first is enforcing a 100% smoke-free policy within all indoor premises. Designated smoking areas are not allowed. For schools, the criteria require that the smoke-free policy extends to cover both indoor and outdoor premises. The second criterion is that the smoke-free policy should be in effect for a minimum of 9 months on the day of certification. The appeal of the program builds on (1) the institution's belief in the importance of providing a safe and healthy environment, (2) the association of the program with the name of a well-respected national organization, and (3) the media exposure that the certified institutions receive. Active promotion of the program is performed during the application period to recruit additional applicants. Outcomes: Fig. 1 depicts the growth in numbers of applications and of certified organizations. On average 67% of applicants receive certification. Interest varies by category with schools outweighing all other applicants (62%). What was learned: Incentives for voluntary enforcement of smoke-free policies have the potential to support law enforcement. The growing interest and the modifications that institutions undergo to meet the program criteria are a testimony to our success. Several institutions went through three rounds of applications prior to receiving certification, indicating the ability of the program to motivate compliance. There is a need to continue to grow the number of applicants especially in the 'restaurants' and 'healthcare' categories. Sensitization about the benefits of smoke-free environments, technical assistance to interested institutions, and additional media exposure can help.

[Figure: see text]

Multicentric Evaluation of a New PT Reagent Based on Recombinant Human Tissue Factor and Synthetic Phospholipids

A new PT reagent based on recombinant human tissue factor and synthetic phospholipids (phosphatidyl choline and phosphatidyl serine) with defined fatty acid side chains was calibrated against BCT/253 and CRM 149R. A small but consistent bias in the International Sensitivity Index (ISI) value was obtained using either the human or rabbit brain reference material. ISI values were around 1.0 or slightly lower depending on the respective instrument. Mixing studies with factor deficient plasmas showed a high factor sensitivity especially for factor VII as compared to commercial rabbit brain or human placenta thromboplastin. In an international field trial the reagent was tested using fully or semi automated Electra™ coagulometers in 4 different laboratories. Results with normal samples were in excellent agreement among the different laboratories. Mean values were 10.9, 10.9, 11.0, 11,7 s with a range of 9.5 to 12.5 s. Results of males and females were not different. In patients with liver disease very similar PT activities were found as compared to sensitive rabbit brain or human placental thromboplastins. In normals and patients with oral anticoagulation INR values correlated very well against BCT (r = 0.98, regression line y =-0.07 + 0.9 x). The distribution of samples was linear over the whole range. In the comparison against sensitive rabbit brain thromboplastin or human placental thromboplastin similar correlations were found. In a few cases higher INR values were observed for the recombinant reagent especially in patients with intensive treatment. Factor assays in those patients showed at least the strong reduction of one vitamin Independent coagulation factor. Over all the linearity was better against the rabbit brain reagent than against the human placental reagent which is slightly less factor VII sensitive as shown in mixing studies with normal and factor VII deficient plasma. Precision studies in the 4 laboratories showed excellent reproducibility of lyophilised controls or local patient plasma pools for all reagents with a better performance of the recombinant reagent. C. V. values from day to day ranged from 1.3% to 5% for normal and abnormal controls.

These results show that the recombinant PT reagent, especially in conjunction with a precise automated instrument, may improve the results of PT testing and thus may lead to better patient care.

Abstract 1786: APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR™ molecule for redirected T-cell cytotoxicity, induces potent T-cell activation, proliferation and cytotoxicity with limited cytokine release

Introduction: Depletion of CD123 over-expressing malignant cells provides a potential new treatment option which may improve patient outcomes in several hematological malignancies. CD123 is over-expressed in AML, MDS, ALL, CML, HCL and BPDCN and infrequently expressed by normal cells making it an attractive target which is being pursued using a number of different approaches including T-cell engaging immunotherapy. Cytokine release syndrome is a significant concern with T-cell activating therapeutics which has led to severe complications in clinical trials. We have developed APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR molecule for redirecting T-cell cytotoxicity to CD123-expressing tumor cells. A potential advantage of the ADAPTIR platform is reduced cytokine release upon T-cell engagement compared to other formats (Mol Cancer Ther. 2016 Sep;15(9):2155-65). Here we present in vitro and in vivo activity of APVO436 and compare the activity of APVO436 to another anti-CD123 x anti-CD3 bispecific containing the amino acid sequence of MGD006.Methods: Binding, T-cell activation and proliferation were assessed using multi-color flow cytometry. Cytotoxic activity was determined using chromium release assays and flow cytometry. PBMC samples were obtained from normal donors and AML patients. In vivo studies were performed using NSG mice transplanted with human PBMC's. The CD123 and CD3 binding domain sequences for flotuzumab (MGD006) were obtained from patent W02015026892 engineered in Macrogenic's dual-affinity re-targeting format as reported in Sci Transl Med. 2015 May 27;7(289):289ra82.Results: Dose-dependent cytotoxicity of CD123 expressing tumor cell lines and primary AML cells was induced by APVO436 at low effector to target ratios, accompanied by T-cell activation and proliferation. APVO436 induced significantly lower levels of several T-cell cytokines including IFNγ, IL-2, and TNFα compared to the molecule in the dual-affinity re-targeting format. In vivo, APVO436 significantly reduced established tumor burden in xenograft murine models.Conclusions: APVO436 potently induces T-cell activation, proliferation and CD123+ cell depletion with AML and normal donor samples and CD123 expressing tumor cell lines with limited levels of T-cell cytokine release compared to another CD123 x CD3 targeting bispecific format suggesting a potential safety advantage. APVO436 inhibits tumor-growth in sub-cutaneous tumor models with IV-implanted human T cells, indicating migration and engagement of T cells at the tumor site. These data are supportive of further investigation of APVO436 as a potential treatment option for AML and other hematological malignancies. GLP toxicology studies have been completed in non-human primates and APVO436 is advancing to clinical testing.

Citation Format: Michael R. Comeau, Robert E. Miller, Robert Bader, Rebecca Gottschalk, Mollie Daugherty, Toddy Sewell, Lynda Misher, Lara Parr, Melissa DeFrancesco, David Bienvenue, Catherine J. McMahan, Gabriela H. Hoyos, Jane A. Gross. APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR™ molecule for redirected T-cell cytotoxicity, induces potent T-cell activation, proliferation and cytotoxicity with limited cytokine release [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 1786.

Activation of the CD137 Pathway in T cells by a CD137 × 5T4 bispecific ADAPTIR Molecule Requires Co-engagement of CD137 and 5T4

CD137 (4-1BB) is a key costimulatory immune receptor (member of the TNFR-superfamily) that is expressed primarily on activated CD8+ T and NK cells. Stimulation of CD137 leads to enhanced proliferation, increased survival, intensified cytolytic activity of T cells and induced IFN-γ production. CD137 monoclonal antibody therapies have shown promising anti-tumor effects in the clinic, but systemic immune stimulation have induced dose-limiting hepatic toxicities. A novel bispecific antibody (ALG.APV-527) was developed based on ADAPTIR™ technology to direct the activation of T cells and NK cells to the tumor area, thereby minimizing systemic toxicity. ALG.APV-527 contains binding domains to the costimulatory molecule CD137 and the tumor-associated antigen 5T4. 5T4 is a tumor antigen expressed on a variety of solid tumor types. ALG.APV-527 was generated with binding domains from the Alligator-Gold® human scFv library, and has been optimized for binding and function. ALG.APV-527 increased CD8+ T-cell activation, as measured by IFN-γ production, but only in the presence of 5T4-expressing cells. Additionally, the CD137 ×5T4 bispecific antibody enhanced proliferation of primary T cells and increased potency in an NF-κB reporter assay. Of importance, the binding affinity and function of ALG.APV-527 retained a low Ec50 (nM range) regardless of the level of 5T4 expression on target cells. In conclusion, we have developed a novel ADAPTIR™ bispecific molecule that, based on preclinical data, has potential as a promising therapeutic for the treatment of a variety of 5T4-expressing solid tumors.

Effects of interfacial micromotions on vitality and differentiation of human osteoblasts

Objectives

Enhanced micromotions between the implant and surrounding bone can impair osseointegration, resulting in fibrous encapsulation and aseptic loosening of the implant. Since the effect of micromotions on human bone cells is sparsely investigated, an in vitro system, which allows application of micromotions on bone cells and subsequent investigation of bone cell activity, was developed.

Methods

Micromotions ranging from 25 µm to 100 µm were applied as sine or triangle signal with 1 Hz frequency to human osteoblasts seeded on collagen scaffolds. Micromotions were applied for six hours per day over three days. During the micromotions, a static pressure of 527 Pa was exerted on the cells by Ti6Al4V cylinders. Osteoblasts loaded with Ti6Al4V cylinders and unloaded osteoblasts without micromotions served as controls. Subsequently, cell viability, expression of the osteogenic markers collagen type I, alkaline phosphatase, and osteocalcin, as well as gene expression of osteoprotegerin, receptor activator of NF-κB ligand, matrix metalloproteinase-1, and tissue inhibitor of metalloproteinase-1, were investigated.

Results

Live and dead cell numbers were higher after 25 µm sine and 50 µm triangle micromotions compared with loaded controls. Collagen type I synthesis was downregulated in respective samples. The metabolic activity and osteocalcin expression level were higher in samples treated with 25 µm micromotions compared with the loaded controls. Furthermore, static loading and micromotions decreased the osteoprotegerin/receptor activator of NF-κB ligand ratio.

Conclusion

Our system enables investigation of the behaviour of bone cells at the bone-implant interface under shear stress induced by micromotions. We could demonstrate that micromotions applied under static pressure conditions have a significant impact on the activity of osteoblasts seeded on collagen scaffolds. In future studies, higher mechanical stress will be applied and different implant surface structures will be considered.

Cite this article: J. Ziebart, S. Fan, C. Schulze, P. W. Kämmerer, R. Bader, A. Jonitz-Heincke. Effects of interfacial micromotions on vitality and differentiation of human osteoblasts. Bone Joint Res 2018;7:187–195. DOI: 10.1302/2046-3758.72.BJR-2017-0228.R1.

Abstract B111: Characterization of APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR™ molecule for redirected T-cell cytotoxicity, in preclinical models of AML and nonhuman primates

Introduction: CD123 has emerged as a promising target for T-cell directed immunotherapy in acute myeloid leukemia due to its high level of expression on leukemic blasts and stem cells and low frequency of expression on normal cell types. CD123 is expressed by rare normal leukocyte populations, including basophils and plasmacytoid dendritic cells in circulation and hematopoietic progenitor cells in the bone marrow. We have developed APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR molecule for redirecting T-cell cytotoxicity to CD123-expressing tumor cells. Results are presented that examine the in vitro and in vivo activity of APVO436 in preclinical models of AML, as well as pharmacokinetics and tolerability in nonhuman primates. Methods: CHO-produced APVO436 protein was used for in vitro functional studies with CD123+ AML tumor cell lines and primary human T-cell populations. Cytotoxic activity was determined using chromium release assays. On-cell binding, T-cell activation and proliferation were assessed using multicolor flow cytometry. Cytokine levels were measured using multiplex assay kits. In vivo studies to examine tumor growth inhibition activity were performed using NSG mice with established AML tumors followed by treatment with APVO436 coadministered with T cells. Tumor growth was assessed by bioluminescent imaging. In vivo studies to determine pharmacokinetics of APVO436 following single intravenous injections were performed in healthy BALB/c mice and cynomolgus monkeys. Results: APVO436 bound to CD123 and CD3 expressing cells with high affinity. APVO436 induced concentration-dependent lysis of CD123+ AML cell lines with primary human T cells at low effector-to-target ratios, accompanied by T-cell activation and proliferation. These activities were dependent on the expression of CD123 by the tumor target cells. Treatment of established disseminated tumors in mice with APVO436 resulted in a significant reduction in tumor burden. A single 10 mg/kg IV injection of APVO436 in normal BALB/c mice demonstrated an extended elimination serum half-life of approximately 300 hours. Single IV injections of APVO436 ranging from 0.25 mg/kg to 1 mg/kg were well tolerated in cynomolgus monkeys. The observed elimination half-life in cynomolgus serum was up to 84 hours with normal clearance and volume distribution. Conclusions: These data demonstrate APVO436 has potent in vitro activity against a number of CD123-expressing tumor cell lines and in vivo significantly reduces established tumor burden in xenograft models. APVO436 demonstrates an extended serum half-life in normal mice and cynomolgus monkeys. These data are supportive of further investigation of APVO436 as a potential treatment option for AML and other hematologic malignancies.

Citation Format: Michael R. Comeau, Robert E. Miller, Jeannette Bannink, Starrla Johnson, Robert Bader, Rebecca Gottschalk, Lynda Misher, Danielle Mitchell, Lara Parr, Melissa DeFrancesco, David Bienvenue, Catherine J. McMahan, Gabriela H. Hoyos, Jane A. Gross. Characterization of APVO436, a bispecific anti-CD123 x anti-CD3 ADAPTIR™ molecule for redirected T-cell cytotoxicity, in preclinical models of AML and nonhuman primates [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B111.

Cellular fluid shear stress on implant surfaces-establishment of a novel experimental set up

Background

Mechanostimuli of different cells can affect a wide array of cellular and inter-cellular biological processes responsible for dental implant healing. The purpose of this in vitro study was to establish a new test model to create a reproducible flow-induced fluid shear stress (FSS) of osteoblast cells on implant surfaces.

Methods

As FSS effects on osteoblasts are detectable at 10 dyn/cm², a custom-made flow chamber was created. Computer-aided verification of circulation processes was performed. In order to verify FSS effects, cells were analysed via light and fluorescence microscopy.

Results

Utilising computer-aided simulations, the underside of the upper plate was considered to have optimal conditions for cell culturing. At this site, a flow-induced orientation of osteoblast cell clusters and an altered cell morphology with cellular elongation and alteration of actin fibres in the fluid flow direction was detected.

Conclusions

FSS simulation using this novel flow chamber might mimic the peri-implant situation in the phase of loaded implant healing. With this FSS flow chamber, osteoblast cells’ sensitivity to FSS was verified in the form of morphological changes and cell re-clustering towards the direction of the flow. Different shear forces can be created simultaneously in a single experiment.

Devitalisation of human cartilage by high hydrostatic pressure treatment: Subsequent cultivation of chondrocytes and mesenchymal stem cells on the devitalised tissue

The regeneration of cartilage lesions still represents a major challenge. Cartilage has a tissue-specific architecture, complicating recreation by synthetic biomaterials. A novel approach for reconstruction is the use of devitalised cartilage. Treatment with high hydrostatic pressure (HHP) achieves devitalisation while biomechanical properties are remained. Therefore, in the present study, cartilage was devitalised using HHP treatment and the potential for revitalisation with chondrocytes and mesenchymal stem cells (MSCs) was investigated. The devitalisation of cartilage was performed by application of 480 MPa over 10 minutes. Effective cellular inactivation was demonstrated by the trypan blue exclusion test and DNA quantification. Histology and electron microscopy examinations showed undamaged cartilage structure after HHP treatment. For revitalisation chondrocytes and MSCs were cultured on devitalised cartilage without supplementation of chondrogenic growth factors. Both chondrocytes and MSCs significantly increased expression of cartilage-specific genes. ECM stainings showed neocartilage-like structure with positive AZAN staining as well as collagen type II and aggrecan deposition after three weeks of cultivation. Our results showed that HHP treatment caused devitalisation of cartilage tissue. ECM proteins were not influenced, thus, providing a scaffold for chondrogenic differentiation of MSCs and chondrocytes. Therefore, using HHP-treated tissue might be a promising approach for cartilage repair.

A web-based modern ultrasound diagnostic scanner simulation (SimulUS) for undergraduate medical e-learning education

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Genome wide array-CGH and qPCR analysis for the identification of genome defects in Williams' syndrome patients in Saudi Arabia

Background

Williams-Beuren Syndrome (WBS) is a rare neurodevelopmental disorder characterized by dysmorphic features, cardiovascular defects, cognitive deficits and developmental delay. WBS is caused by a segmental aneuploidy of chromosome 7 due to heterozygous deletion of contiguous genes at the long arm of chromosome 7q11.23. We aimed to apply array-CGH technique for the detection of copy number variants in suspected WBS patients and to determine the size of the deleted segment at chromosome 7q11.23 in correlation with the phenotype. The study included 24 patients referred to the CEGMR with the provisional diagnosis of WBS and 8 parents. The patients were subjected to conventional Cytogenetic (G-banding) analysis, Molecular Cytogenetic (Fluorescent In-Situ Hybridization), array-based Comparative Genomic Hybridization (array-CGH) and quantitative Real time PCR (qPCR) Techniques.

Results

No deletions were detected by Karyotyping, however, one patient showed unbalanced translocation between chromosome 18 and 19, the karyotype was 45,XX, der(19) t(18;19)(q11.1;p13.3)-18. FISH technique could detect microdeletion in chromosome 7q11.23 in 10/24 patients. Array-CGH and qPCR confirmed the deletion in all samples, and could detect duplication of 7q11.23 in three patients and two parents. Furthermore, the size of the deletion could be detected accurately by both array-CGH and qPCR techniques. Three patients not showing the 7q11.23 deletion were diagnosed by array-CGH to have deletion in chr9p13.1-p11.2, chr18p11.32-p11.21 and chr1p36.13.

Conclusion

Both FISH and array-CGH are reliable methods for the diagnosis of WBS; however, array-CGH has the advantage of detection of genome deletions/ duplications that cannot otherwise be detected by conventional cytogenetic techniques. Array-CGH and qPCR are useful for detection of deletion sizes and prediction of the interrupted genes and their impact on the disease phenotype. Further investigations are needed for studying the impact of deletion sizes and function of the deleted genes on chromosome 7q11.23.

Trial registration

ISRCTN ISRCTN73824458. MOCY-D-16-00041R1. Registered 28 September 2014. Retrospectively registered.

Abstract 4995: anti-ROR1 x anti-CD3 ADAPTIR™ molecule, ES425, redirects T-cell cytotoxicity and inhibits tumor growth in preclinical models of triple-negative breast cancer

Background: Effective treatment of metastatic, triple-negative breast cancer (TNBC) remains a highly unmet medical need. We have developed ES425, a bispecific ADAPTIR™ (modular protein technology) molecule that redirects T-cell cytotoxicity to tumor cells expressing ROR1 (receptor tyrosine kinase-like orphan receptor 1), an oncofetal antigen expressed on TNBC and other malignancies. Results are presented for studies run to examine in vitro and in vivo activity of ES425 in preclinical models of TNBC.

Materials and Methods: Target-dependent cytotoxic activity was examined in vitro by treating ROR1(+) cell lines and ROR1(−) cell lines with ES425 in the presence of purified human T cells or human peripheral blood mononuclear cells (PBMCs). Cytotoxic activity was determined using chromium release assays. T cells were assessed for activation and proliferation using multi-color flow cytometry. Pharmacokinetics of ES425 in NOD/SCID gamma (NSG) mice was determined using single intravenous dose of approximately 10 mg/kg. Serum concentrations at time points ranging from 15 minutes to 504 hours were used to calculate the terminal elimination half-life of ES425. To assess activity in vivo, NOD/SCID mice were implanted subcutaneously with the ROR1(+) TNBC tumor cell line MDA-MB-231 and purified human T cells and treated with ES425. This model was run twice with T cells from different human donors. Tumor growth was assessed by measuring tumor volume.

Results: ES425 efficiently redirected T cell cytotoxicity against ROR1(+) cell lines at low picomolar concentrations in vitro. Cytotoxic activity was dependent on expression of ROR1 by the target cells. T cells were activated and proliferated in response to ES425 in the presence of ROR1(+) target cells; proliferation was not observed in response to ROR1(−) cells. In vivo, pharmacokinetic analysis showed a serum half-life of approximately 7 days in NSG mice, and ES425 inhibited growth of MDA-MB-231 tumors in mouse xenografts. Repeat experiments showed similar inhibition of tumor growth and an improvement in overall survival.

Conclusions: These studies show that ES425 may be an efficient agent for redirecting T cell cytotoxicity in preclinical TNBC models and merits investigation as a potential therapeutic in TNBC and other malignancies.

Citation Format: John W. Blankenship, Lynda Misher, Danielle Mitchell, Nicole Zhang, Philip Tan, Gabriela H. Hoyos, Padma Ravikumar, Robert Bader, Catherine J. McMahan, Robert E. Miller, Jeannette Bannink, Hang Fang, Lara Parr, Maria Dasovich, David Bienvenue, Megan Aguilar, Carina Xu, Mollie Daugherty, Brian Woodruff, Jane A. Gross. anti-ROR1 x anti-CD3 ADAPTIR™ molecule, ES425, redirects T-cell cytotoxicity and inhibits tumor growth in preclinical models of triple-negative breast cancer. [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 4995.

MOR209/ES414, a Novel Bispecific Antibody Targeting PSMA for the Treatment of Metastatic Castration-Resistant Prostate Cancer

Treatment of metastatic, castration-resistant prostate cancer (mCRPC) remains a highly unmet medical need and current therapies ultimately result in disease progression. Immunotherapy is a rapidly growing approach for treatment of cancer but has shown limited success to date in the treatment of mCRPC. We have developed a novel humanized bispecific antibody, MOR209/ES414, built on the ADAPTIR (modular protein technology) platform, to redirect T-cell cytotoxicity toward prostate cancer cells by specifically targeting T cells through CD3ε to prostate cancer cells expressing PSMA (prostate-specific membrane antigen). In vitro cross-linking of T cells with PSMA-expressing tumor cells by MOR209/ES414 triggered potent target-dependent tumor lysis and induction of target-dependent T-cell activation and proliferation. This activity occurred at low picomolar concentrations of MOR209/ES414 and was effective at low T-effector to tumor target cell ratios. In addition, cytotoxic activity was equivalent over a wide range of PSMA expression on target cells, suggesting that as few as 3,700 PSMA receptors per cell are sufficient for tumor lysis. In addition to high sensitivity and in vitro activity, MOR209/ES414 induced limited production of cytokines compared with other bispecific antibody formats. Pharmacokinetic analysis of MOR209/ES414 demonstrated a serum elimination half-life in NOD/SCID γ (NSG) mice of 4 days. Administration of MOR209/ES414 in murine xenograft models of human prostate cancer significantly inhibited tumor growth, prolonged survival, and decreased serum prostate-specific antigen levels only in the presence of adoptively transferred human T cells. On the basis of these preclinical findings, MOR209/ES414 warrants further investigation as a potential therapeutic for the treatment of CRPC. Mol Cancer Ther; 15(9); 2155-65. ©2016 AACR.

Potential infection control risks associated with roaming healthcare industry representatives

BACKGROUND

Healthcare industry representatives (HCIR) visit multiple hospitals every day. Most enter hygiene sensitive areas and work in close proximity to caregivers and patients.

OBJECTIVE

The objective of the present study was to evaluate the HCIRs' current status in hygiene training and vaccination.

METHODS

An anonymous walking intercept study was used based on questionnaires to evaluate industry representatives in comparison to physicians and nurses (n = 311 participants, participation rate 30.2%) after their visit to the MEDICA Congress. The valid participants consisted of HCIR (n = 208), hospital nurses (n = 49) and physicians (n = 41). A total of 82.2% (n = 171) HCIR worked in varying hospitals.

RESULTS

They frequently request access to hygiene and data-privacy sensitive areas: Among them 51.9% (n = 108) accessed the outpatient clinic, 41.8% (n = 87) the operating room (OR), 33.7% (n = 70) the central supply and sterilisation department (CSSD), and 32.7% (n = 68) the intensive care unit. HCIR requesting access to hygiene sensitive areas showed the lowest scores in hygiene training and a significantly lower Hepatitis B vaccination status, i.e. 37.5% compared to 70.7% for physicians and 53.1% for nurses.

DISCUSSION

Status of HCIR hygiene training was inadequate - as was vaccination and contamination control. Therefore, HCIR are exposed to increased infection risk and may unknowingly act as infection vector between different hospitals.

Investigation of the inverse piezoelectric effect of trabecular bone on a micrometer length scale using synchrotron radiation

In the present paper we have investigated the impact of electro stimulation on microstructural parameters of the major constituents of bone, hydroxyapatite and collagen. Therapeutic approaches exhibit an improved healing rate under electric fields. However, the underlying mechanism is not fully understood so far. In this context one possible effect which could be responsible is the inverse piezo electric effect at bone structures. Therefore, we have carried out scanning X-ray microdiffraction experiments, i.e. we recorded X-ray diffraction data with micrometer resolution using synchrotron radiation from trabecular bone samples in order to investigate how the bone matrix reacts to an applied electric field. Different samples were investigated, where the orientation of the collagen matrix differed with respect to the applied electric field. Our experiments aimed to determine whether the inverse piezo electric effect could have a significant impact on the improved bone regeneration owing to electrostimulative therapy. Our data suggest that strain is in fact induced in bone by the collagen matrix via the inverse piezo electric effect which occurs in the presence of an adequately oriented electric field. The magnitude of the underlying strain is in a range where bone cells are able to detect it.

STATEMENT OF SIGNIFICANCE

In our study we report on the piezoelectric effect in bone which was already discovered and explored on a macro scale in the 1950. Clinical approaches utilize successfully electro stimulation to enhance bone healing but the exact mechanisms taking place are still a matter of debate. We have measured the stress distribution with micron resolution in trabecular bone to determine the piezo electric induced stress. Our results show that the magnitude of the induced stress is big enough to be sensed by cells and therefore, could be a trigger for bone remodeling and growth.

[Quality of Outcome after Primary Total Hip Replacement at a Maximum Care Hospital in Relation to Preoperative Influencing Factors]

BACKGROUND

As the need for joint replacements will continue to rise, the outcome of primary total hip replacement (THR) must be improved and stabilised at a high level. In this study, we investigated whether pre-operative risk factors, such as gender, age and body weight at the time of the surgery or a restricted physical status (ASA-Status > 2 or Kellgren and Lawrence grade > 2) have a negative influence on the post-operative results or on patient satisfaction.

MATERIAL AND METHODS

Retrospective data collection and a prospective interview were performed with 486 patients who underwent primary total hip replacement between January 2007 and December 2010 in our hospital. The patients' satisfaction and quality of life were surveyed with the WOMAC-Score, SF-36 and EuroQol-5. Differences between more than two independent spot tests were tested with the non-parametric Kruskal-Wallis test. Differences between two independent spot tests were tested with the non-parametric Mann-Whitney U test. The frequencies were reported and odds ratios calculated. The confidence interval was set at 95 %. The level of significance was p < 0.05.

RESULTS

The average WOMAC-Score was 77.1 and the total score of the SF-36 was 66.9 points. The patients declared an average EuroQol Index of 0.81. Our data show that the patients' gender did not influence the duration of surgery or the scores. However, female patients tended to exhibit more postoperative complications. However, increased patient age at the time of surgery was associated with an increased OR for duration of surgery, length of stay and risk of complications. Patients who had a normal body weight at time of the surgery showed better peri- and post-operative results. We showed that the preoperative estimated Kellgren and Lawrence grade had a significant influence on the duration of surgery. The ASA classification influenced the duration of surgery as well the length of stay and the rate of complications.

CONCLUSION

The quality of results after primary THR depends on preoperative factors. Existing comorbidities have a significant influence on the duration of surgery and therefore on the perioperative rate of complications and the postoperative outcome. Despite improvements in the functional and subjective outcome after primary THR, an adverse preoperative symptomatic status is associated with less favourable postoperative results.

Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone

Bone specimens obtained for biomechanical experiments are fresh-frozen for storage to slow down tissue degradation and autolysis in long-term storage. Alternatively, due to infectious risks related to the fresh tissues, fixative agents are commonly used. However, fixatives will likely change the mechanical properties of bone. Existing studies on this issue gave controversial results that are hardly comparable due to a variety of measurement approaches. For this reason, the influence of ethanol and a formalin-based fixative agent was evaluated on the mechanical properties of human cortical bone specimens by means of four-point-bending tests. 127 prismatic specimens with rectangular cross sections (2.5 x 2.5 x 20 mm3) were obtained from different regions of two fresh human femora (medial, lateral, dorsal, ventral). Specimens were either fixed in ethanol or in a mixed formalin solution or frozen following a given scheme. After two weeks of storage the samples were re-hydrated in isotonic saline and subsequently tested mechanically. The elastic bending modulus and ultimate bending strength were computed considering the actual dimensions of each specific specimen. For statistical analysis a one-way-ANOVA and an LSD post-hoc-test were performed. For ultimate bending strength no significant differences due to formalin or ethanol fixation, as compared to unfixed-fresh bone specimens could be found. And only for few cases significant differences in elastic bending modulus were observed when the two bones were evaluated separately. Since more differences of significant level due to the anatomical region of the samples were determined, the original location seems to have more influence on the evaluated mechanical properties than the method of (chemical) fixation. Consequently, ethanol and the mixed formalin solution can be recommended as a fixation agent for samples in biomechanical testing, if these samples are rinsed in isotonic saline prior to static mechanical testing.

The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts

Inflammatory reactions associated with osteolysis and implant loosening can be the result of generated CoCr particles and the simultaneous release of ions, which are the consequence of wear at the articulating surfaces of metallic implants. By now, there is little knowledge about the influence of CoCr ions on the viability of human osteoblasts (hOB).

Therefore, metallic ions were generated from solid CoCr28Mo6 alloys using electric potentials against hydrogen bridge electrodes. For the cell experiments, hOBs (n ≥ 4) in the third passage were used. Cells were cultured for 24 h before incubated with the generated ion solution in two different concentrations (100 µg/l and 500 µg/l in DMEM with 10 % FCS). Cells incubated without ions served as controls. After 48 h and 96 h cell viability was determined (WST-1 assay, live-dead-stainings). Additionally, gene expression levels of osteogenic markers and cytokines were analysed.

A significant increase of metabolic activity and vital cells could be shown for both ion concentrations. Gene expression of alkaline phosphatase and Col1 was highly induced after 96 h for 100 µg/l whereas Col1 protein was significantly reduced on both time points (48 h: p=0.008 (100 µg/l, 500 µg/l); 96 h: p=0,029 (500 µg/l)) compared to the control. Additionally, MMP1 expression was decreased after 48 h and 96 h. IL6 mRNA was concentration-dependent increased after 48 h whereas a significant decrease could be shown for the highest ion concentration (p=0.029). Compared to the lower ion concentration, IL8, MCP1 (p=0.029) and TNF mRNA were clearly reduced for the higher ion solution after 96 h. Our results suggest that ions from CoCr28Mo6 alloys have only marginal effects on osteoblast viability whereas Col1 expression is reduced and cytokine release is induced. In further studies, the effects of metallic ions and particles from CoCr28Mo6 on other cells will be examined.

Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model

The medial patellofemoral ligament (MPFL) is a key structure in the treatment of habitual and traumatic patellofemoral instability. However, there exists little knowledge about its behaviour during deep knee flexion after femoral refixation. Since improper femoral attachment sites may lead to unnatural length change patterns in the ligament and consequently to osteoarthritis due to pathological femoro-patellar contact pressure, the understanding of the patella kinematics and MPFL behaviour is crucial.

The purpose of this numerical study was to compute the six-degree-of-freedom motion pattern of the human patella during deep knee flexion for systematic analysis of varying landmarks for the femoral attachment in medial patellofemoral ligament reconstruction surgery by means of multibody simulation.

Therefore, based on a previously presented musculoskeletal model [1] the dynamic pathways of the patella were computed. Then, the spatial motion was approximated by rheonomic polynomials and exploited for systematic evaluation of the MPFL length change patterns. Hence, 16 femoral attachment points at a radius of 5 mm and 10 mm around the radiographic centre point [2] were defined and the absolute length changes were recorded during deep knee flexion to 120 degree.

This approach allows for a systematic evaluation of numerous MPFL attachment sites while exploiting the physiological patella kinematics. The patella kinematics including shift, flexion, tilt and rotation as well as the MPFL length change patterns were consistent to in vitro and in vivo data in the literature [3–7] and therefore indicate validity of the numerical approach. The parameter study on the femoral attachment site should enable to determine the most isometric point and non-isometric variations corresponding to patellofemoral instability, arthritis or high graft load.

[Influence of surgeon experience in total hip arthroplasty. Dependence on operating time and complication risk]

BACKGROUND

As a consequence of limited personnel and financial resources, the increase in total hip arthroplasties places higher demands on orthopedic surgeons.

OBJECTIVES

In order to maintain high quality treatment, the correlation between surgical experience, duration of surgery and risk of complications was examined.

MATERIAL AND METHODS

The surgery time and, if applicable, complications (until discharge from hospital) of 1129 total hip arthroplasties over a period of 4 years were evaluated retrospectively.

RESULTS

The group of most experienced surgeons needed an average time of 53.2 ± 17.6 min for each implantation, followed by moderately experienced surgeons (74.5 ± 25.5 min) and less experienced surgeons (80.8 ± 21.9 min). Of all included cases, a total of 41 complications until discharge from hospital occurred. The number of complications increased with duration of surgery, whereby the risk of complications was significantly lower for shorter surgery times conducted by the most experienced surgeons as well as moderately experienced surgeons. The complication risk of less experienced surgeons remained constant independent of surgery duration.

CONCLUSION

These results underline the recommendations of the German Endocert system, which determine a minimum number of total joint arthroplasties as a quality indicator not only for hospitals but also for individual surgeons.

[Reimbursement in psychiatry and psychosomatics: proof of concept for a system based on daily costs]

BACKGROUND

In Germany a new reimbursement system for psychiatry and psychosomatics is under development. Based on total costs of each case from selected hospitals and day clinics, in 2013 the Institute for the Hospital Remuneration System (InEK) proposed to reimburse the hospital costs daily with step-wise decreasing remuneration, mainly depending on the ICD-10 diagnosis, duration of stay and some complicating factors (PEPP grouper). It is controversial whether this degressive system will result in an inadequate remuneration of patients with longer duration of severe symptoms, such as suicidality in depression or autoaggressive behavior in borderline personality disorder and will eventually lead to advantages for acutely ill patients with short duration of stay compared to chronically ill patients.

OBJECTIVES

This study formulated and tested an alternative remuneration system (proof of concept) mainly based on an analysis of daily cost data instead of the total costs of each case.

MATERIAL AND METHODS

The study is based on 147,749 treatment days from 4,633 cases of patients with psychotic disorders (PEPP-PA03) in 6 hospitals. As possible cost separating factors the study analyzed days with and without intensive psychiatric care, 1 to 1 care, psychological diagnostics, magnetic resonance imaging (MRI), acute crisis intervention, age at admission, the first days of treatment and day of discharge.

RESULTS AND DISCUSSION

Nearly all factors tested were shown to be statistically significant in separating daily hospital costs. Based on these findings an alternative calculation algorithm (TEPPconcret), which grouped the cases with respect to age, intensive care, 1 to 1 care, treatment days 1-4 and day of discharge, was formulated and tested. For psychotic disorders TEPPconcret with a basic rate complemented by daily add-on payments depending on the effort involved, is a serious alternative to the PEPP system and awaits further evaluation.

[Failure analysis as basis for quality assurance strategies in implant technology]

BACKGROUND

Implant safety is a topic gaining more and more public interest. Implants are safety relevant medical devices which in the case of failure can lead to life-threatening situations.

OBJECTIVES

A well-founded failure analysis requires expert knowledge not only of materials and implant design but also a qualified explantation procedure and storage conditions.

METHODS

A selective literature search was carried out putting the main emphasis on implant failure analysis supplemented with own investigations.

RESULTS

The reasons for implant breakdown are mostly failures of materials and in the manufacturing process. In some cases false material combinations can lead to tribocorrosion effects under cyclic loading.

CONCLUSION

The increased level of knowledge gained from complex analyses of failed implants produces valuable evidence for better quality management.

The IGFBP7 homolog Imp-L2 promotes insulin signaling in distinct neurons of the Drosophila brain

In Drosophila, Insulin-like peptide 2 (Dilp-2) is expressed by insulin-producing cells in the brain, and is secreted into the hemolymph to activate insulin signaling systemically. Within the brain, however, a more local activation of insulin signaling may be required to couple behavioral and physiological traits to nutritional inputs. We show that a small subset of neurons in the larval brain has high Dilp-2-mediated insulin signaling activity. This local insulin signaling activation is accompanied by selective Dilp-2 uptake and depends on the expression of the Imaginal morphogenesis protein-late 2 (Imp-L2) in the target neurons. We suggest that Imp-L2 acts as a licensing factor for neuronal IIS activation through Dilp-2 to further increase the precision of insulin activity in the brain.

[Principles of tribological analysis of endoprostheses]

For the tribological characterization of artificial joints, various experimental methods are currently available. However, the in vitro test conditions applied are only comparable in a limited way and transferability to the in vivo situation is also restricted. This is due to the different wear simulation concepts used and partly insufficient simulation of clinical worst case situations. In the present paper current scientific methods and procedures for tribological testing of artificial joints are presented. In addition, the biological effects of wear products are described enabling clinicians to challenge tribological studies and to facilitate specific interpretation of scientific results taking the clinical situation into account.