Abstract P4-07-08: Budesonide and loperamide do not impact the cytotoxicity of neratinib or HER2-directed monoclonal antibodies in HER2+ breast cancer cell lines

Background: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor with demonstrated clinical activity in HER2+ and HER2-mutated breast cancers. The main toxicity of neratinib is diarrhea, which is common in the absence of prophylaxis. Preclinical models suggest that neratinib-associated diarrhea may involve inflammatory, bile acid malabsorption and secretory factors. The phase II CONTROL study is currently investigating the prophylactic efficacy of the opioid receptor antagonist loperamide in combination with budesonide (a corticosteroid used for inflammatory gastrointestinal conditions) or colestipol (bile acid sequestrant) on neratinib-associated diarrhea in early-stage HER2+ breast cancer (NCT02400476). This in vitro study examines the impact of loperamide and budesonide on the anti-proliferative activity of neratinib or trastuzumab and pertuzumab in HER2+ or HER2-low breast cancer cell lines.

Methods: HER2+ breast cancer cell lines SKBR3 (estrogen receptor [ER]–), BT474 (ER+), HCC1569 (ER–) and HER2-low, pertuzumab-sensitive MDA-MB-175-VII (ER+) breast cancer cells were investigated using a 5-day acid phosphatase-based proliferation assay to determine the concentrations required to inhibit growth by 50% (IC50). Fixed ratios of drugs were utilised in combination assays to generate Combination Index (CI) values (Calcusyn®) where available. Clinically relevant levels of neratinib, trastuzumab and pertuzumab were utilised in all experiments. Physiologically relevant levels of budesonide (˜4.2 nM) and loperamide (˜2.5 nM) were exceeded to provide IC50 values for these compounds.

Results: All cell lines tested had neratinib IC50 values in the nM range (Table). Trastuzumab and the trastuzumab/pertuzumab combination did not exceed 50% inhibition in the HER2+ cell lines. In the HER2+ breast cancer cell lines tested, loperamide had no impact on neratinib activity in BT474, enhanced neratinib activity in SKBR3, and the combination of loperamide and neratinib proved synergistic in HCC1569 (CI = 0.77 +/– 0.2). Budesonide produced strong synergism in combination with neratinib in SKBR3 (CI = 0.27 +/– 0.03), had no impact on neratinib activity in BT474 and improved response to neratinib in HCC1569. Loperamide and budesonide improved the activity of trastuzumab and pertuzumab in all three HER2+ models tested, and had no impact on pertuzumab activity in MDA-MB-175-VII. Interestingly, neratinib proved synergistic in combination with pertuzumab in MDA-MB-175-VII (CI = 0.75 +/– 0.5 nM).

Table.Anti-proliferative effects of agents testedBreast cancer cell lineNeratinib IC50, nMLoperamide IC50, nMBudesonide IC50, nMPertuzumab IC50, nMTrastuzumab (% inhibition, 2.5μg/ml)Trastuzumab/Pertuzumab (% inhibition, 2.5μg/ml)SKBR32.8 +/– 0.47.7 +/– 0.52.7 +/– 0.2NA26.3 +/– 1.3NABT4741.4 +/– 0.12.6 +/– 0.27 +/– 0.6NA40.1 +/– 4.3NAHCC156917.3 +/– 0.79.3 +/– 1.728.7 +/– 0.5No effectNo effect26.1 +/– 2.8MDA-MB-175-VII3 +/– 0.3> 20> 201.2 +/– 0.2NANANA = not acquired.

Conclusions: Our preclinical results suggest that budesonide and loperamide do not antagonise the anti-proliferative activity of neratinib or HER2-directed monoclonal antibodies in HER2+ breast cancer cell lines.

Citation Format: Collins DM, Gaynor N, Conlon N, Gullo G, Eustace AJ, Crown J. Budesonide and loperamide do not impact the cytotoxicity of neratinib or HER2-directed monoclonal antibodies in HER2+ breast cancer cell lines [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-07-08.

Abstract P4-06-19: The effect of relieving adenosine-mediated immunosuppression on trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity (T-ADCC) against HER2+ breast cancer cell lines

Introduction: Trastuzumab (T) is a monoclonal antibody therapy used in the treatment of HER2+ breast cancer. T inhibits HER2 intracellular signalling and is capable of engaging the immune system through ADCC. Adenosine is an important negative regulator of the immune response through its interaction with the A2A receptor (A2AR, ADORA2A). Relieving adenosine-mediated immunosuppression by inhibiting A2AR may improve NK cell-mediated T-ADCC against HER2+ breast cancer cells. In addition, we have previously shown that SKBR3 cells resistant to the EGFR/HER2 tyrosine kinase inhibitor (TKI) lapatinib are less sensitive to T-ADCC and showed increased A2AR protein levels. This study examines the effects of inhibiting A2AR signalling on NK cell-mediated T-ADCC against treatment naïve HER2+ breast cancer cell lines HCC1954 and SKBR3 and lapatinib and afatinib (irreversible pan-HER-family TKI)-resistant sublines of HCC1954 and SKBR3.

Methods: HER2+ breast cancer cell lines SKBR3 and HCC1954 were exposed to afatinib (150nM) or lapatinib (1μM) for 6 months to generate TKI-resistant SKBR3-A and HCC1954-L cell lines. Acid-phosphatase-based proliferation assays were used to confirm resistance to TKI treatment. Western blotting was used to examine A2AR and HER2 protein levels in cell lines. NK cells were isolated from healthy volunteer whole blood by MACSxpress isolation kits. Immune cell-mediated cytotoxicity was determined at a 1:1 (NK cell: TC) ratio over 12 hours using a flow cytometry-based method. Direct cytotoxicity and T-ADCC were determined +/- A2AR agonist CGS21680 (1 μM) and/or A2AR antagonist preladenant (100 nM) for all cell lines. Experiments were carried out three times with three separate volunteer samples with representative results presented.

Results: HCC1954-L cells were 5.3-fold resistance to lapatinib (IC50 1.65 μM +/- 0.22 μM) vs. HCC1954 (IC50 0.31 μM +/- 0.15 μM). SKBR3-A cells were 33-fold resistant to afatinib (IC50 0.28 μM +/- 0.006 nM) vs. the parental SKBR3 cell line (IC50 0.009 μM +/- 0.006 μM). SKBR3 and HCC1954 expressed detectable protein levels of A2AR. A2AR and HER2 levels were not significantly changed between parental and resistant cell lines. Levels of direct cytotoxicity and T-ADCC elicited by NK cells were higher against SKBR3-A (p=0.002) and HCC1954-L cells (p=0.0004) than parental cell lines. The A2AR agonist CGS21680 alone had inconsistent effects on direct cytotoxicity and T-ADCC in all cell lines tested. The addition of A2AR antagonist preladenant to CGS21680, but not preladenant alone, increased T-ADCC against the parental HCC1954 cells by 12.7 +/- 3.4% and parental SKBR3 cells by 9.5 +/- 3.6%. T-ADCC levels in the targeted therapy-resistant HCC1954-L and SKBR3-A cell lines were not impacted by the CGS21680/preladenant combination.

Conclusions: A HER2-targeted therapy resistance phenotype is associated with increased T-ADCC in the models tested. Inhibition of activated A2AR can increase T-ADCC elicited by NK cells against treatment naïve HER2+ breast cancer cell lines but not TKI-resistant sublines. Further work is warranted to examine the impact of targeting A2AR in HER2+ breast cancer.

Citation Format: Gaynor N, Noone J, Monedero J, Murphy EE, O'Gorman DJ, Crown J, Collins DM. The effect of relieving adenosine-mediated immunosuppression on trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity (T-ADCC) against HER2+ breast cancer cell lines [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-19.

Abstract P4-21-27: Plasma chemokine profile of HER2+ breast cancer (BC) patients treated with docetaxel (D) and carboplatin (C) in combination with trastuzumab (T) and/or lapatinib (L) in the neo-adjuvant setting

Background: Chemokines (chemotactic cytokines) are key regulators of the immune response, attracting immune cells to sites of inflammation, activating adhesion molecules, promoting extravasation and influencing T-cell subset polarization. Recent clinical data has shown a strong correlation between tumor infiltrating lymphocytes (TILs) and response to T therapy in HER2+ BC while the combination of chemotherapy, T and L has proven superior to chemotherapy and T alone in the neo-adjuvant setting (NeoALTTO). This preliminary study examines the levels of 40 circulating chemokines in 32 HER2+ BC patient plasma samples from ICORG 10-05 (neo-adjuvant DCT, DCL or DCTL) to investigate differences in chemokine profiles between treatment arms and patient's response to treatment.

Methods: Pre-treatment blood samples were collected before commencement of chemotherapy; post-treatment samples were collected two weeks prior to surgery. All patients received G-CSF concurrent with treatment. A panel of 40 chemokines and chemokine-associated cytokines were assessed by Luminex xMAP multiplex assay. Matched patient samples were run in single replicates and analysed together (n=32) or by comparing DCT (n=12) and DCTL (n=14) treatment arms (using a paired Mann-Whitney test and adjusting for multiple testing using Bonferroni correction). DCL (n=6) was omitted from the arm comparison due to low numbers. In addition, principle components analysis (PCA) was used to explore any trends within the data based on patient response (pathological complete response (pCR, n=15), partial response (PR, n=12), and non-response (NR, n=4)). 12 non-age matched healthy volunteer controls were also included in the PCA.

Results: PCA shows a clear separation between pre- and post-treatment samples. 30 of the 40 chemokines examined were significantly differentially expressed (adjusted p-value of <0.05) post-treatment across all treatment arms. When comparing DCT and DCTL, nine chemokines were significantly altered post-therapy in both arms with two chemokines, CCL24 (p=0.039) and IL-16 (p=0.039), increased in DCT only and ten chemokines, CCL11 (p=0.009), CX3CL1 (p=0.004), CXCL1 (p=0.009), CCL1 (p=0.024), IL-2 (p=0.043), IL-6 (p=0.034), IL-8 (p=0.004), CXCL11 (p=0.004), CXCL16 (p=0.004) and TNF-alpha (p=0.004) altered in DCTL only. PCA identified no trend between pre- and post-treatment chemokine levels and response.

Conclusions: DCT and DCTL produce statistically different alterations in the plasma chemokine profiles of HER2+ BC patients. Pre- or post-treatment levels of the chemokines examined are not collectively predictive of patient response to treatment. Further work is required to elucidate the relevance of DCT- and DCTL-specific chemokine alterations to response.

Citation Format: Collins DM, Madden SF, Gaynor N, Gallagher WM, O'Donovan N, Crown J. Plasma chemokine profile of HER2+ breast cancer (BC) patients treated with docetaxel (D) and carboplatin (C) in combination with trastuzumab (T) and/or lapatinib (L) in the neo-adjuvant setting [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 P4-21-27.

Are psychiatric Crisis Assessment and Treatment team clinicians on the psychotherapy front line?

OBJECTIVE

There is limited data on the psychological interventions used by Crisis Assessment and Treatment (CAT) team clinicians, even though practice guidelines stipulate part of their role to be the provision of counselling. This study aimed to catalogue and categorise the range of psychotherapeutic interventions utilised by clinicians of a CAT team operating within a metropolitan area.

METHODS

Self-report, episode of care data was collected regarding clinicians' views of the type of psychotherapeutic intervention they employed and details of what they discussed with patients, and location and duration of interventions.

RESULTS

Thirty-two care episodes were catalogued. On average, clinicians spent 74% of their total contact time with patients engaged in psychological interventions. A wide range of strategies, drawn from a broad theoretical base, was used. Aside from general approaches aiding engagement, interventions could be classified into the following categories: meta-strategy ('treatment about the treatment'), 'critical', 'practical', specific psychotherapeutic (cognitive-behavioural therapy (CBT) and others), and supportive.

CONCLUSIONS

Clinicians saw themselves as spending the majority of patient contact time engaged in psychological interventions drawn from a broad theoretical base. Observational studies of what clinicians actually do and empirical investigation of the efficacy thereof may have implications for clinician training and supervision.

Mental health nursing in emergency departments: the case for a nurse practitioner role

AIMS AND OBJECTIVES

This paper aims to explore the effectiveness of the mental health nurse practitioner role in the emergency department in the context of the growing use of special units or segregated areas to manage particular kinds of mental health presentations, often complicated by substance use.

BACKGROUND

In recent years, there has been a significant increase in mental health presentations to emergency departments, often complicated by substance abuse. Emergency departments have introduced a variety of mechanisms to address this growing problem. With the introduction of mental health nurse practitioners, opportunities arise to reconsider these mechanisms.

DESIGN

Discursive paper.

METHODS

In this discursive paper, contemporary practices are described in relation to 'special care areas', 'psychiatric emergency centres' and 'short-stay units'. The mental health nurse practitioner role in training and capacity building is also explored and the notion of 'locational processes' described. Rather than being presented as an alternative to short-stay units, the mental health nurse practitioner role is explored in its potential to enhance mental health nursing practice in a sometimes difficult clinical environment.

RESULTS

The paper provides evidence from literature and practice that the clinical outcome for consumers is enhanced through the mental health nurse practitioner role.

CONCLUSIONS

It is argued that the introduction of the mental health nurse practitioner role in the emergency department leads to increased staff competence and confidence in interacting with those presenting with mental health issues. The mental health nurse practitioner role also addresses the serious problem of stigma associated with those with a mental health issue.

RELEVANCE TO CLINICAL PRACTICE

It is expected that those presenting with mental health issues to the emergency department will benefit through the increased assessment and management skills of staff.

The characteristics, management and outcomes of people identified with mental health issues in an emergency department, Melbourne, Australia

Although the number of mental health presentations to emergency departments is increasing as a result of the integration of psychiatric services with general services, few studies have explored the characteristics of mental health patients presenting to emergency departments in Australia. This study investigated the characteristics of, and outcomes in relation to, people presenting with a mental health problem to one large metropolitan emergency department. Data were collected from the emergency department's electronic records system for adult patients aged 18-65 years old with an emergency department discharge diagnosis of a mental health disorder, including substance abuse and psychosocial crisis, for two months. Mental health patients totalled 5.3% (n= 290) of adult presentations to the emergency department. Over half were male; mean age 37.4 years; 49% were allocated triage category 3/urgent; 45% arrived by ambulance; 39% were overdosed/intoxicated and 55% received one or more diagnostic investigations. Patients who were intoxicated, those who arrived after hours, or patients admitted to a mental health ward were more likely to wait longer than 8h. Findings are broadly in line with that reported for other Australian studies, although the present findings suggest that patients had significantly more routine investigations and there were higher rates of presentations for 'intoxication'.