Abstract LB-193: Phase I study of safety, tolerability, pharmacokinetics, and pharmacodynamics of AMP-224 (B7-DC Fc fusion protein) in a regimen containing cyclophosphamide (CTX) in patients with advanced solid tumors

Background: AMP-224 is a recombinant Fc fusion protein that binds to the programmed death-1 (PD-1) receptor. This first-in-human study was designed to determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetic (PK) profile, pharmacodynamics (PD), and preliminary anti-tumor activity of AMP-224. Additional translational studies were incorporated to characterize MOA in patients and identify possible prognostic indicators and markers of response.

Methods: Cohorts of 3-6 eligible patients with advanced solid tumors received CTX on Day 0, followed by AMP-224 by intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle in doses ranging from 0.3 to 30mg/kg. Following dose escalation, an expansion cohort is ongoing at 10 mg/kg in predominantly melanoma patients. Fresh pre-treatment biopsies were obtained from patients and evaluated via IHC for B7-H1 (PD-L1), PD-1, CD8 and CD4. PD testing performed throughout the study included serial blood samples to assess lymphocyte subsets, expression of PD-1 on T cells and changes in T cell effector function.

Results: 42 patients (83% melanoma), were treated in cohorts of 0.3mg/kg (n = 6); 1mg/kg (n=4); 3mg/kg (n = 4); 10mg/kg (n = 21); 30mg/kg (n = 6), mean age 56 years. Two dose-limiting toxicities were observed, 1 each at 10 mg/kg (infusion reaction) and 30 mg/kg (flu-like symptoms). Infusion reactions were common (61%) across all doses but manageable with pre-medications. Common treatment-related adverse events (all grades) were chills (54%), fatigue (34%) flushing (34%), nausea (32%), vomiting (29%), fever (27%), and headache (22%). No drug-related inflammatory adverse events were identified. Preliminary PK analysis showed that exposures of AMP-224 were linear, dose-proportional with no evidence of target mediated clearance or accumulation. PD assays confirmed PD-1 receptor targeting with specific reduction of PD-1HI CD4 and PD-1HI CD8 T cells in a dose dependent manner. B7-H1+ tumors were found in fresh pre-treatment tumor biopsies in 31.4% of patients, yet B7-H1 expression within the tumor did not predict AMP-224 clinical activity. The trial is ongoing and the preliminary evaluation of clinical activity suggests individual patients with partial response, stable disease, and mixed response.

Conclusions: AMP-224 was well-tolerated up to its maximally administered dose of 30mg/kg, with manageable infusion reactions in the majority of patients. The trial is ongoing including monitoring for clinical activity.

Citation Format: Patricia M. LoRusso, John Powderly, Howard A. Burris, Muaiad Kittaneh, Jessica Grice, James F. Smothers, Sara Brett, Margaret Fleming, Rena J. May, Shannon Marshall, Martin Devenport, Stanley Pillemer, Drew M. Pardoll, Lieping Chen, Solomon Langermann, Jeffrey Infante. Phase I study of safety, tolerability, pharmacokinetics, and pharmacodynamics of AMP-224 (B7-DC Fc fusion protein) in a regimen containing cyclophosphamide (CTX) in patients with advanced solid tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-193. doi:10.1158/1538-7445.AM2013-LB-193

Observational Skill-based Clinical Assessment tool for Resuscitation (OSCAR): development and validation

Aim

The aim of the study reported here was to address the need to assess and train teamwork and non-technical skills in the context of Resuscitation. Specifically, we sought to develop a tool that is feasible to use and psychometrically sound to assess team behaviours during cardiac arrest resuscitation attempts.

Methods

To ensure validity, reliability, and feasibility, the Observational Skill based Clinical Assessment tool for Resuscitation (OSCAR) was developed in 3 phases. A review of the literature leading to initial tool development was followed by an assessment of face and content validity, and finally a thorough reliability assessment, using Cronbach's α to assess internal consistency and intraclass correlation to assess inter-rater reliability.

Results

OSCAR was developed methodically, and tested for face and content validity. Cronbach's α results ranged from 0.736 to 0.965 demonstrating high internal consistency, and intraclass correlation results ranged from 0.652 to 0.911, all of which are strongly significant and indicate good inter-rater reliability.

Conclusion

On the basis of our results, we conclude that OSCAR is psychometrically robust, scientifically sound, and clinically relevant. We have developed the Observational Skill-based Clinical Assessment tool for Resuscitation (OSCAR) for the assessment of non-technical skills in Resuscitation teams. We propose the use of this tool in simulation and real Cardiac Arrest Resuscitation attempts to assess, guide and train non-technical skills to team members, to improve patient safety and maximise the chances of successful resuscitation.

Induction of homologous rather than heterologous antigen-specific CD4 T cell responses is critical for functional CD8 T cell responses in mice transgenic for a foreign antigen

The development of a successful cancer vaccine requires the ability to break immunological tolerance to self-Ags expressed on tumor cells. The transgenic rat insulin promoter (RIP) OVA(LOW) mouse model has been reported to be hyporesponsive for both OVA-specific CD4 and CD8 T cell responses. The experiments described in the current study show that this hyporesponsiveness can be overcome by inclusion of GM-CSF and the TLR7 agonist imiquimod as adjuvants in a DNA immunization regimen with OVA-encoding plasmids. High frequencies of OVA-specific CD8 and CD4 T cells, including a response to a CD4 T cell epitope seen only in the RIP OVA(LOW) mice, were generated by this regimen. These responses were associated with the development of autoimmunity and increased protection to tumor challenge in the RIP OVA(LOW) mice. Heterologous CD4 T cell help has been shown to improve functional CD8 T cell responses, and we confirmed that inclusion of the CD4 T cell epitope pan HLA-DR-binding epitope improved CD8 T cell responses compared with self-Ag alone. Addition of GM-CSF and imiquimod, however, resulted in dominance of the pan HLA-DR-binding epitope-specific response over the OVA-specific CD4 T cell responses, decreased OVA-specific CD8 T cell numbers and function in tolerant RIP OVA(LOW) mice, and failure to induce diabetes. The results of this study suggest that the use of heterologous help needs to be evaluated carefully in the context of specific immunization regimes and that a preferable approach may be adjuvantization of DNA vaccines.

Report on the donation of supernumerary embryos from fresh IVF and ICSI treatment cycles for human stem cell research

BACKGROUND

Research involving human embryos promises exciting therapeutic advances but raises ethical and moral dilemmas for scientists and potential donors. The aim of this study is to report the proportion of couples donating supernumerary fresh embryos for development of stem cell lines from a single centre and the characteristics of those who donate.

METHODS

Couples undergoing assisted conception treatment in a teaching hospital received research information between January 2005 and July 2006. Counselling and consenting was performed by a dedicated research nurse. Demographic data was collected for couples who enrolled in the study.

MAIN OUTCOME MEASURES

To determine the proportion of couples willing to donate surplus embryos for stem cell derivation and to examine the characteristics of those who consent to donate.

RESULTS

Of 508 couples, 353 (69%) expressed an interest in research on their treatment consent forms. Sixty-six percent of those interested in research and 87% of counselled couples consented to donation. The demographic characteristics of those who agreed to donate were similar to those of all couples attending the unit.

CONCLUSIONS

Approximately half of couples consented to donate under the described system in our centre. Detailed information provision helps the majority of those counselled to proceed to donation.

Programmed death 1 expression during antiviral treatment of chronic hepatitis B: Impact of hepatitis B e-antigen seroconversion

Hyperexpression of the programmed death 1 (PD-1) molecule is a hallmark of exhausted T-cells, having a negative impact on T-cell activation and function. We studied longitudinally 18 hepatitis B e antigen (HBeAg)-positive patients undergoing treatment with direct antivirals (telbivudine or lamivudine) to determine the relationship between treatment-induced viremia reduction and HBeAg seroconversion with respect to PD-1 levels and T-cell reactivity. PD-1 expression was assessed by (1) flow cytometry and (2) quantitative real-time polymerase chain reaction; hepatitis B virus (HBV)-specific CD8+ T-cells were quantitated by pentamer staining; T-cell reactivity to HBV antigens was determined by interferon gamma (IFNgamma) and interleukin 10 (IL-10) enzyme-linked immunosorbent spot (ELISPOT) assays; and central/effector memory phenotypes were defined by phenotypic markers. PD-1 expression correlated closely with viremia levels. On therapy, PD-1 decreased significantly on total CD8+ T-cells, HBV-specific CD8+ T-cells, and CD3+/CD8- T-cells both as the percentage of positive cells (P < 0.01) and as the mean fluorescent intensity (P < 0.05), and this was paralleled by a marked reduction of PD-1 messenger RNA levels (P = 0.001). HBeAg serocoversion (in 6/18 patients) resulted in a further PD-1 decrease with a 50% reduction in the frequency of PD-1+/CD8+ T-cells, which was not observed in patients remaining HBeAg-positive. The decrease in PD-1 expression was associated with increased frequencies of IFNgamma-producing T-cells and decreased frequencies of IL-10 producing T-cells. At baseline, PD-1 expression correlated directly with the frequency of hepatitis B core antigen (HBcAg) central and effector memory phenotypes, whereas an inverse correlation was observed between PD-1 expression and HBcAg-specific effector phenotypes.

CONCLUSION

These results demonstrate that in chronic HBV infection, both viremia levels and HBeAg drive PD-1 expression and resulting T-cell impairment. Treatment-induced suppression of HBV replication reduces PD-1 expression; however, additional immunotherapeutic interventions are needed for restoration of T-cell functions.

Silent myocardial ischaemia and haemoglobin concentration: a randomized controlled trial of transfusion strategy in lower limb arthroplasty

BACKGROUND AND OBJECTIVES

Red cell transfusion is commonly used in orthopaedic surgery. Evidence suggests that a restrictive transfusion strategy may be safe for most patients. However, concern has been raised over the risks of anaemia in those with ischaemic cardiac disease. Perioperative silent myocardial ischaemia (SMI) has a relatively high incidence in the elderly population undergoing elective surgery. This study used Holter monitoring to compare the effect of a restrictive and a liberal red cell transfusion strategy on the incidence of SMI in patients without signs or symptoms of ischaemic heart disease who were undergoing lower limb arthroplasty.

MATERIALS AND METHODS

We performed a multicentre, controlled trial in which 260 patients undergoing elective hip and knee replacement surgery were enrolled and randomized to transfusion triggers that were either restrictive (8 g/dl) or liberal (10 g/dl). Participants were monitored with continuous ambulatory electrocardiogram (ECG) (Holter monitoring), preoperatively for 12 h and postoperatively for 72 h. The tapes were analysed for new ischaemia by technicians blinded to treatment. The total ischaemia time in minutes was divided by the recording time in hours and an ischaemic load in min/h was calculated. Haemoglobin levels were measured preoperatively, postoperatively in the recovery room, and on days one, three and five after surgery.

RESULTS

The mean postoperative haemoglobin concentration was 9.87 g/dl in the restrictive group and 11.09 g/dl in the liberal group. In the restrictive group, 34% were transfused a total of 89 red cell units, and in the liberal group 43% were given a total of 119 red cell units. A postoperative episode of silent ischaemia was experienced by 21/109 (19%) patients in the restrictive group and by 26/109 (24%) patients in the liberal group [mean difference -4.6%; 95% confidence interval (CI): -15.5% to 6%, P = 0.41). There was no significant difference (P = 0.53) between the overall ischaemic load in the restrictive group (median 0 min/h, range 0-4.18) and the liberal group (median 0 min/h, range 0-19.48). In those patients who did experience postoperative SMI, the mean ischaemic load was 0.48 min/h in the restrictive group and 1.51 min/h in the liberal group (ratio 0.32, 95% CI: 0.14-0.76, P = 0.011). The median postoperative length of hospital stay in the restrictive group was 7.3 days [range 5-11; interquartile range (IQR) 6-8] compared with 7.5 days (range 5-13; IQR 7-8) in the liberal group. The numbers were not large enough to conclude equivalence.

CONCLUSIONS

In patients without preoperative evidence of myocardial ischaemia undergoing elective hip and knee replacement surgery, a restrictive transfusion strategy seems unlikely to be associated with an increased incidence of SMI. A proportion of these patients experience moderate SMI, regardless of the transfusion trigger. Use of a restrictive transfusion strategy did not increase length of hospital stay, and use of this strategy would lead to a significant reduction in red cell transfusion in orthopaedic surgery. Our data did not indicate any potential for harm in employing such a strategy in patients with no prior evidence of cardiac ischaemia who were undergoing elective orthopaedic surgery.

Increased incidence of cancer in adult Gaucher disease in Western Europe

The adult form of Gaucher disease (type I GD) is associated with a high prevalence of hypergammaglobulinemia and monoclonal gammopathy of undetermined significance (MGUS). A significantly increased risk of cancer, especially of hematological types, has been found in Ashkenazi-Jewish GD type 1 patients. In this study, incidence and mortality of cancer were assessed in a total of 131 GD patients of mixed ancestry in a population from Western Europe, i.e. 2 Gaucher referral centers in Germany (Düsseldorf) and the Netherlands (Amsterdam). Standardized rate ratios were determined by indirect standardization, using age- and sex-specific incidence and mortality rates of the Dutch population. A total of 14 GD patients of non-Ashkenazi-Jewish descent were identified of whom 5 had a hematologic malignancy. These numbers correspond to an increased risk of cancer of 2.5 (95% CI 1.1-4.7) and an increased risk of hematologic cancer of 12.7 (95% CI 2.6-37.0) among GD patients compared to the general population. In particular, the incidences of multiple myeloma and hepatocellular carcinoma in absence of preexisting cirrhosis were highly elevated, with standardized rate ratios of 51.1 (95% CI 6.2-184) and 141.3 (95% CI 17.1-510.5), respectively. These strongly increased risks on developing cancer suggest that measures for early detection and prevention of hematological and hepatic malignancies in patients with Gaucher type I disease are mandatory.

Induced recruitment of NK cells to lymph nodes provides IFN-gamma for T(H)1 priming

Naive T cells are stimulated by antigen-presenting dendritic cells (DCs) in secondary lymphoid organs, but whether other types of cell participate in T cell priming is unclear. Here we show in mice that natural killer (NK) cells, which are normally excluded from lymph nodes, are rapidly recruited in a CCR7-independent, CXCR3-dependent manner to lymph nodes on stimulation by the injection of mature DCs. Recruitment of NK cells is also induced by some, but not all, adjuvants and correlates with the induction of T helper cell type 1 (T(H)1) responses. NK cell depletion and reconstitution experiments show that NK cells provide an early source of interferon-gamma (IFN-gamma) that is necessary for T(H)1 polarization. Taken together, our results identify an induced pathway of NK cell migration in antigen-stimulated lymph nodes and a mechanism by which some adjuvants may facilitate T(H)1 responses.

The pulmonary physician in critical care * illustrative case 3: pulmonary vasculitis

The case history of a patient admitted to the ICU with severe hypoxic respiratory failure later diagnosed as Wegener's granulomatosis is presented. The diagnosis and management of patients with suspected pulmonary vasculitis is discussed.

White cell count and intensive care unit outcome

A high white cell count on admission to the intensive care unit (ICU) is generally perceived to be associated with severe illness and poor outcome, but the implications of a low white cell count are less well recognised. We retrospectively analysed data on 4,165 patients. The white cell count on admission was split into four categories, leucopenic (< 4.0 x 10(9).l(-1)), normal (4.001-10.0 x 10(9).l(-1)), leucemoid (10.001-25.0 x 10(9).l(-1)) and an exaggerated leucemoid response (> 25.001 x 10(9).l(-1)). The mortality of patients with leucopenia on admission to the intensive care unit was higher than those with normal or moderately raised white cell count (37.5% vs. 18.9% and 23.9%, respectively). A leucopenic response, as well as an exaggerated leucemoid response, is associated with an increased mortality.

Infection of mouse bone marrow-derived dendritic cells with recombinant adenovirus vectors leads to presentation of encoded antigen by both MHC class I and class II molecules-potential benefits in vaccine design

Dendritic cells (DCs) are highly specialised antigen-presenting cells (APCs) that are essential for the initiation and modulation of T cell-mediated immune responses. In order to induce effective CTL responses against most infections and tumours, DCs must prime both CD4(+) and CD8(+) antigen-specific T cells. It is, therefore, important in vaccine design to produce antigen-delivery systems that lead to the simultaneous presentation of multiple histocompatibility complex (MHC) class I- and class II-restricted antigenic peptides by DCs. In this study, the infection of immature mouse bone marrow-derived DCs (BMDCs) with recombinant adenovirus (rAd) vectors led to a marked upregulation of surface costimulatory molecules, IL-12 p40 production and capacity to stimulate both allogeneic and antigen-specific T cells. Furthermore, infection of immature and mature BMDCs with a rAd encoding chicken ovalbumin (OVA) led to presentation of the antigen to TCR-transgenic OVA-specific CD4(+) and CD8(+) T cells. In addition, the activation state of responding CD8(+) T cells was further amplified if they recognised antigen on rAd-transduced BMDCs in the presence of antigen-specific CD4(+) T cells. The results suggest that rAd-encoded OVA protein is secreted by BMDCs, taken up by endocytosis and presented in association with MHC class II molecules for activation of OVA-specific CD4(+) T cells. Consequently, rAd-transduced immature BMDCs become better stimulators of antigen-specific CD4(+) T cells than rAd-infected mature BMDCs. Taken together, these data have important implications for vaccine design, and suggest that infection of immature DCs with rAd encoding MHC class I and class II-restricted T cell epitopes could be an efficient means of inducing effective immune responses.

Perturbation of naive TCR transgenic T cell functional responses and upstream activation events by anti-CD4 monoclonal antibodies

It is well established that non-depleting anti-CD4 monoclonal antibodies (mAb) have potent immunomodulatory properties in vivo and as such can induce a profound state of tolerance. Receptor blockade, CD4 modulation, or the transmission of a negative signal have all been proposed to explain their effects, however their precise mechanism of action, particularly at the level of cellular signaling, remains obscure. Experiments were thus carried out to examine the underlying mechanisms of action of two non-depleting anti-mouse CD4 mAb, YTS177 and KT6, which differ in their ability to modulate CD4 expression. The effects of the mAb were examined on CD4(+) T cells derived from D0.11.10 TCR transgenic mice. Functional studies revealed that both mAb could effectively block antigen-driven proliferation and IL-2 production but had only modest effects at higher peptide doses. Importantly, mAb pre-treatment of T cells stimulated by sub-optimal peptide seemed to induce an anergy-like state making them unresponsive to subsequent re-stimulation. Analysis of intracellular signaling demonstrated that certain key upstream events such as the phosphorylation of Zap-70 and LAT were also blocked by mAb pretreatment which may be due to interference with stable T cell-APC conjugate formation.