Daratumumab: monoclonal antibody therapy to treat multiple myeloma

Daratumumab (Darzalex[TM]) is a human monoclonal antibody (MAb) that targets CD38; a surface protein highly expressed across multiple myeloma (MM) cells. Preclinical studies have shown daratumumab induces MM cell death through several mechanisms, including complement-dependent cytotoxicity (CDC) antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), apoptosis upon secondary crosslinking and immunomodulatory effects via a decrease in immune suppressive cells. Daratumumab has a favorable toxicity profile and encouraging clinical activity as a single agent and in combination with lenalidomide in heavily pretreated, relapsed patients in whom other novel agents (such as bortezomib, thalidomide and lenalidomide) and stem cell transplant have already failed. Given the encouraging efficacy and acceptable safety profile, daratumumab has emerged as a novel treatment option for MM both as a monotherapy and in combination with conventional and novel anti-MM agents. This review will focus on preclinical pharmacology, pharmacokinetics, safety and clinical development of daratumumab in MM.

Abstract P3-10-04: Disparities in human epidermal growth factor receptor 2 testing completion: A population-based retrospective cohort study, 2010-2013

Introduction: Human epidermal growth factor receptor 2 (HER2) is an established biomarker predictive for response to HER2-targeted therapies. Testing breast cancer specimens for HER2 protein overexpression or gene amplification is the standard of care. Earlier work showed inconsistent delivery of HER2 testing to some patient groups. We sought to understand current imbalances in HER2 testing.

Methods: Our retrospective cohort analysis of Surveillance, Epidemiology and End Results Program data included women diagnosed with microscopically confirmed, first primary malignant breast cancer from 2010-2013. Women were categorized by race, stage, age, and whether they received HER2 testing. Those with unknown information in any of these variables were excluded. Descriptive analyses and multivariate logistic regression assessed the effect of these factors on the likelihood of not receiving HER2 testing.

Results: The full cohort included 182,032 women, of which 3,551 (2.0%) did not undergo testing for HER2 (Table 1). The portion of HER2 untested tumors was higher for African American women (2.3%) and other non-white women (2.2%), women over age 70 (2.3%) and women with Stage I (2.3%) or Stage IV disease (5.0%). Within the African American cohort similar patterns were seen: age >70 (2.8%), Stage I (2.8%) and Stage IV (5.4%). The portion of women with untested tumors decreased from 2010 to 2013: 2.6% to 1.6% (p<0.001) for the full cohort, and 2.9% to 1.9% (p<0.001) for African Americans. On multivariate analysis, odds of not undergoing testing were highest for African American women (OR=1.27, p<0.001), women of age >70 (OR=1.26, p<0.001), and women with Stage IV disease (OR=4.07, p<0.001) (Table 2). Odds of not undergoing HER2 testing decreased over time (OR=0.60 for 2013 vs 2010, p<0.001).

Conclusion: Persistent, and significant, disparities in completion of HER2 testing suggest that reasons for not testing extend beyond technical issues. While proportionally small, given the prevalence of breast cancer, addressing these disparities in HER2 testing may offer an opportunity to deliver life-prolonging, often well tolerated, therapy to significant numbers of patients. The improvements in delivery of HER2 testing seen over time are reassuring.

Table 1. Portion of women not having HER2 testing.  Full Cohort African Americans   N%p-valueN%p-valueN3,5512.0 4702.3 Race       White2,7081.9<0.001    African American4702.3 4702.3  Other3732.2    Age at diagnosis       <507081.7<0.0011051.90.024 50-598921.9 1302.3  60-698941.9 1202.4  70+1,0572.3 1152.8 Stage       I2,0692.3<0.0012232.8<0.001 II7621.3 1111.4  III2211.0 441.4  IV4495.0 925.4 Year of diagnosis       20101,0662.6<0.0011322.9<0.001 20119432.1 1442.8  20128011.7 931.7  20137411.6 1011.9 

Table 2. Multivariate logistic regression for odds of not having HER2 testing.  OR*p-valueRace   Whiteref  African American1.27<0.001 Other1.24<0.001Age at diagnosis   <50ref  50-591.080.128 60-691.010.795 70+1.26<0.001Stage   Iref  II1.87<0.001 III0.81<0.001 IV4.07<0.001Year of diagnosis   2010ref  20110.80<0.001 20120.66<0.001 20130.60<0.001* Odds of group not being tested vs being tested, compared to the reference group and controlling for all other factors.

Citation Format: Schroeder MC, Neuner JM, Xia C, Thomas A. Disparities in human epidermal growth factor receptor 2 testing completion: A population-based retrospective cohort study, 2010-2013 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-10-04.

Reduction Levels and the Effects of High-Molecular-Weight Adiponectin via AMPK/eNOS in Chinese Type 2 Diabetes

Aim: This study was to investigate the change of high-molecula-weight (HMW) adiponectin (APN) isoform, the association between type 2 diabetes mellitus (T2DM) and HMW APN isoform, the variation of Disulfide-bond A oxidoreductase-like protein (DsbA-L), the effect of HMW APN isoform on AMP-dependent protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS) in Chinese T2DM. Method: 169 patients aged at (48.7±9.4) years and 107 healthy control subjects aged at (42.6±7.8) years took part in this study. Anthropometric measures of the characters were assayed and different APN isoforms, DsbA-L, AMPK and eNOS levels were determined. Results: Ln(sRAGE) and Ln(Adiponectin) were significantly lower and significantly higher for the other characteristics in T2DM. Ln(Adiponectin) was negatively and significantly correlated with WHR, Ln(triglycerides), fasting plasma glucose, HbA1c (%) in control subjects and T2DM patients. Plasma and adipose tissue total APN and HMW APN were significantly reduced in newly diagnosed T2DM patients. DsbA-L was markedly down-regulated in diabetic adipose tissue. HMW APN caused significant decreases in AMPK and eNOS phosphorylation levels of human umbilical vein endothelial cells (HUVECs). Conclusions: Our results demonstrated that total APN levels was closely related to the risk of T2DM and HMW APN reduction was involved in the diabetic vascular AMPK/eNOS signal pathway. The findings will provide insight into novel therapeutic approaches for reducing the elevated cardiovascular risk associated with T2DM.

[Study on IGF-1 and IGFBP-3 gene expression in liver of young rats with intermittent hypoxia]

Objective:Using the model of young rats with intermittent hypoxia, to study the expression of insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) in liver, and to provide objective evidence for the possible existence of growth retardation in children with OSAHS. Method:Divided 24 rats randomly into three groups, as control group and the mild and severe hypoxia group. Normally fed control group, without treatment, the other two groups were kept in the cabin has been simulated mild and severe intermittent hypoxia conditions of OSAHS in children. 8-hour day cycle of intermittent hypoxia, a total of 35 days. To the last day, animals were sacrificed and fresh liver tissues were fixed in liquid nitrogen, stored in the -80°C refrigerator, then took the molecular biology experiment of IGF-1 and IGFBP-3 in the liver. Result:The expression of IGF-1 mRNA in liver, semi-quantitative analysis showed that the difference of mRNA expression of IGF-1 among the three groups was statistically significant (P<0.05), pairwise comparison, mild hypoxia group was higher than control and severe group, there were significant differences (P<0.05), the control group and severe hypoxia had no significant difference (P>0.05). The expression of IGFBP-3 mRNA in liver showed that, differences between the three groups was not significant (P>0.05). IGF-1 expression in liver tissue analysis showed that, differences between the three groups was statistically significant (P<0.05), pairwise comparisons, its expression in the control group was lower than mild hypoxia group and severe group, there were significant differences (P<0.05), mild hypoxia and severe hypoxia group had no significant difference (P>0.05). IGFBP-3 expression in liver tissue analysis showed that, differences between the three groups was statistically significant (P<0.05), pairwise comparisons, the control group was higher than mild and severe hypoxic group, there were significant differences (P<0.05), mild hypoxia and severe hypoxia group had no significant difference (P>0.05). Conclusion:IGF-1 and IGFBP-3 in the liver of mild hypoxia group, severe hypoxic group and control group showed that their transcription levels and the severity of hypoxia had no significant correlation.

Inflammation and activity augment brain-derived neurotrophic factor peripheral release

Brain-derived neurotrophic factor (BDNF) release to nerve terminals in the central nervous system is crucial in synaptic transmission and neuronal plasticity. However, BDNF release peripherally from primary afferent neurons has not been investigated. In the present study, we show that BDNF is synthesized by primary afferent neurons located in the dorsal root ganglia (DRG) in rat, and releases to spinal nerve terminals in response to depolarization or visceral inflammation. In two-compartmented culture that separates DRG neuronal cell bodies and spinal nerve terminals, application of 50mM K(+) to either the nerve terminal or the cell body evokes BDNF release to the terminal compartment. Inflammatory stimulation of the visceral organ (e.g. the urinary bladder) also facilitates an increase in spontaneous BDNF release from the primary afferent neurons to the axonal terminals. In the inflamed viscera, we show that BDNF immunoreactivity is increased in nerve fibers that are immuno-positive to the neuronal marker PGP9.5. Both BDNF and pro-BDNF levels are increased, however, pro-BDNF immunoreactivity is not expressed in PGP9.5-positive nerve-fiber-like structures. Determination of receptor profiles in the inflamed bladder demonstrates that BDNF high affinity receptor TrkB and general receptor p75 expression levels are elevated, with an increased level of TrkB tyrosine phosphorylation/activity. These results suggest a possibility of pro-proliferative effect in the inflamed bladder. Consistently we show that the proliferation marker Ki67 expression levels are enhanced in the inflamed organ. Our results imply that in vivo BDNF release to the peripheral organ is an important event in neurogenic inflammatory state.

Protein expression in dairy cows with and without subclinical hypocalcaemia

AIM

To determine differences in plasma proteomic profiles between healthy cows and those with subclinical hypocalcaemia within 12 hours after calving, and thereby explore the underlying biological mechanism of subclinical hypocalcaemia in dairy cows.

METHODS

Plasma samples were collected within 6 hours of calving from Holstein cows on a farm in Heilongjiang, China; 32 with subclinical hypocalcaemia (plasma calcium concentration 1.38-2.00 mmol/L and no clinical signs) and 59 control cows (plasma calcium concentration 2.10-2.8 mmol/L). Plasma samples were applied to weak cationic exchange protein chips for protein profiling by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS), and the data were analysed using the PBS-IIC system. The amplitude of peaks for the two groups were compared using the Wilcoxon sum-rank test, and the mass-to-charge ratio of the peaks that differed was used to identify peptide fragments using the Swiss-Prot protein database.

RESULTS

Seven peaks were identified in the subclinical hypocalcaemia group that differed from those of the control group (p<0.001), that represented six unique proteins. Expression of serum albumin, fibrinogen alpha chain, amyloid beta A4 proteins and neurosecretory protein VGF were increased, and expression of apolipoprotein A-II and serum amyloid A proteins were decreased in the subclinical hypocalcaemic cows compared with control cows.

CONCLUSION

Use of SELDI-TOF-MS technology can effectively identify differences in plasma protein expression patterns in cows with subclinical hypocalcaemia. Neurosecretory protein VGF and amyloid beta A4 protein might represent useful biomarkers for diagnosis of subclinical hypocalcaemia.

Territory tenure increases with repertoire size in brownish-flanked bush warbler

Song repertoire size is often cited as a classic example of a secondary sexual trait in birds. Models of sexual selection and empirical tests of their predictions have often related secondary sexual traits to longevity. However, the relationship between repertoire size and longevity is unclear. Using capture-mark-recapture studies in two populations of the brownish-flanked bush warbler Cettia fortipes, we found that males with a repertoire size of three maintained territory tenure for a longer duration than did males with a repertoire size of two. These results provide evidence that even a minimal difference in repertoire size can serve as a potential signal of territory tenure capability.

Abstract P2-02-07: Preoperative breast MRI and follow-up recommendations for the contralateral breast influence the rate of contralateral prophylactic mastectomy

Background: Women with breast cancer increasingly choose to undergo contralateral prophylactic mastectomy (CPM) even as the benefit of this procedure for woman at average risk for breast cancer remains uncertain. Many women with newly diagnosed breast cancer undergo pre-operative MRI for a variety of indications. Growing evidence suggests that obtaining a pre-operative MRI increases the likelihood that a patient will choose CPM. This study evaluates the relationship between a pre-operative MRI and the decision to pursue CPM, as well as the rate of contralateral MRI findings for which follow-up is recommended and the choice to undergo CPM. The pathology found in contralateral breasts in this series is also reported.

Methods: Newly diagnosed breast cancer patients were prospectively enrolled in Breast Molecular Epidemiology Resource (B-MER) observational study at the University of Iowa from April 2010 through March 2013. Prophylactic mastectomy is defined as removal of the contralateral breast within 12 months of definitive mastectomy. Univariate logistic regression was used to identify factors predictive of undergoing CPM. Recommended follow-up of the contralateral breast MRI is defined as any imaging or procedure other than immediate ultrasound evaluation.

Results: Among 134 patients (mean age 53) who underwent mastectomy, 53 (40%) underwent CPM. Univariate analysis revealed that patients undergoing CPM were more likely to have had a preoperative bilateral MRI (52%% vs. 28%, p = 0.006) and were more likely to have been given a recommendation for a follow-up test (79% vs, 40%, p = 0.007).

Univariate Analysis of Odds of Electing to Undergo CPMVariableLevelOdds ratioP-valueAge5 year0.62&lt;.001Breast MRIYes vs No2.740.006MRI follow-up recommendationYes or No5.530.007Nodal statusPositive vs Negative0.820.581History of benign breast biopsiesNo vs Yes1.850.209Family history of breast cancerYes vs No1.160.711ER/PR statusNegative vs Positive1.830.134Triple NegativeNo vs Yes1.910.196HER2 statusPositive vs Negative2.470.066BRCA testing doneYes vs No6.04&lt;.001BRCA results*Positive vs Negative3.120.315Tobacco everYes or No1.390.354Alcohol everYes or No1.250.544* Indeterminate and not done levels were excluded from the analysis

Univariate analysis also revealed associations between choice of CPM and younger age (p&lt;0.001) and BRCA testing (p&lt;0.001). In this series, CPM was not associated with nodal status, ER/PR status, history of benign breast biopsies, family history of breast cancer, BRCA result and tobacco or alcohol use, although there was a trend for association with HER2 status. Of the 53 patients who underwent CPM, one had proliferative disease with atypia, 34 had proliferative disease without atypia. A single patient had DCIS found in the contralateral breast which had not been identified on MRI.

Conclusions: The use of preoperative breast MRI and abnormal imaging findings in the contralateral breast, for which follow-up was recommended, led to a higher CPM rate. Contralateral prophylactic mastectomy rarely uncovered occult malignancy.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-02-07.

Are different song types used in different contexts in brownish-flanked bush warblers?

The repertoires of most songbirds consist of two or more different song types. Studies on a growing number of species have indicated that song types are used selectively in different contexts. For example, two bush warblers (Cettia diphone and C. cettia) use song types selectively in spontaneous singing and playback-evoked singing. Most male brownish-flanked bush warblers (C. fortipes) have two distinct song types. In this study, we tested whether these two song types are used selectively in different contexts. Most frequency and temporal variables are significantly different between these two song types, but neither song type is used more frequently during or after playback compared to spontaneous singing. Additionally, males did not respond differently to the two song types during playback experiments. In conclusion, these two song types differ significantly in both frequency and temporal variables, but we did not find any evidence that they are used selectively in different contexts. Comparing two related bush warblers (C. diphone and C. cettia) that selectively use different song types in different contexts, our study offers further evidence that avian vocalization is a plastic characteristic and can vary considerably, even among closely related species.

Acoustic identification of individuals within large avian populations: a case study of the Brownish-flanked Bush Warbler, South-Central China

Acoustic identification is increasingly being used as a non-invasive method for identifying individuals within avian populations. However, most previous studies have utilized small samples of individuals (<30). The feasibility of using acoustic identification of individuals in larger avian populations has never been seriously tested. In this paper, we assess the feasibility of using distinct acoustic signals to identify individuals in a large avian population (139 colour-banded individuals) of Brownish-flanked Bush Warbler (Cettia fortipes) in the Dongzhai National Nature Reserve, south-central China. Most spectro-temporal variables we measured show greater variation among individuals than within individual. Although there was slight decline in the correct rate of individual identification with increasing sample sizes, the total mean correct rate yielded by discriminant function analysis was satisfactory, with more than 98% of songs correctly recognized to the corresponding individuals. We also found that using a part of randomly selected measured variables was sufficient to obtain a high correct rate of individual identification. We believe that our work will increase confidence in the use of using acoustic recognition techniques for avian population monitoring programs.

Development and validation of a quality of life instrument for Kashin-Beck disease: an endemic osteoarthritis in China

OBJECTIVES

To develop and validate a disease-specific Quality of Life (QOL) measure for a specialized osteoarthritis (OA)-Kashin-Beck disease (KBD).

METHODS

The standard methodology used for developing QOL instruments was employed. In phase 1, initially a group of health care professionals (HCPs) and KBD patient defined the overall concept of KBDQOL. It was followed by generation of an item pool through literature review, in-depth interview of 20 KBD patients and eight KBD HCPs and four focus group discussions. In phase 2, 368 KBD patients were interviewed and the reinterview of 95 participants, 10-14 days later assessed the reproducibility of the KBDQOL instrument.

RESULTS

A 37 items draft instrument was devised during phase 1. Principal Component Analysis (PCA) revealed six domains: physical function, activity limitation, social support, economics, mental health, and general health. Cronbach's alphas of six domains ranged from 0.77 to 0.90. The test-retest reliability (intraclass co-relation coefficient) of six domains was satisfactory, and ranged from 0.73 to 0.90. The smallest detectable change ranged from 13.2 to 30.2 points at the individual level and from 1.4 to 3.1 points at the group level for different domains. The construct validity was adequate when co-related with the EQ-5D (spearman co-relation coefficients: 0.49-0.61) and WHOQOL-BREF (spearman co-relation coefficients: 0.53-0.68). This resulted into the final version of KBDQOL instrument having 28 items and six domains.

CONCLUSIONS

The KBDQOL is a simple and easy to use 28-item six dimensional questionnaire. The measure has been developed as a true patient-based questionnaire and demonstrates good measurement properties.

TLRs antiviral effect on hepatitis B virus in HepG2 cells

AIMS

A hepatoma cell line, HepG2, was used as a model system to detect Toll-like receptor (TLR) expression in hepatocytes and examine the antiviral effect on hepatitis B virus (HBV).

METHODS AND RESULTS

Toll-like receptor expression was detected in HepG2 cells by RT-PCR. The TLRs, which were strongly expressed in HepG2 cells, were stimulated with specific ligands. Interferon (IFN) response was evaluated poststimulation with Western blotting for signal transduction and activators of transcription-1. Furthermore, HepG2 cells were transiently transfected with wild-type HBV 1.3-fold over-length plasmid and treated with specific ligands at indicated times. Replication of HBV DNA, transcription of HBV RNA intermediate and expression of HBV antigens were respectively detected by Southern blotting, real time PCR, ELISA and Western blotting. Activation of different TLRs induced antiviral effects on HBV to varying degrees.

CONCLUSIONS

The TLRs, which were strongly expressed in HepG2 cells, could be stimulated with specific ligands. Activation of TLRs induced apparent production of antiviral cytokines such as IFN-alpha/beta and inhibited HBV lifecycle in the hepatocyte cell model.

SIGNIFICANCE AND IMPACT OF THE STUDY

Expression of TLRs in hepatocytes may be related to local immunity of liver and participate in the outcome of viral hepatitis.