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No targeted treatments are currently approved for HER2 exon 20 insertion–mutant lung adenocarcinoma patients. Mobocertinib (TAK-788) is a potent irreversible tyrosine kinase inhibitor (TKI) designed to target human epidermal growth factor receptor 2 (HER2/ERBB2) exon 20 insertion mutations. However, the function of mobocertinib on HER2 exon 20 insertion–mutant lung cancer is still unclear. Here we conducted systematic characterization of preclinical models to understand the activity profile of mobocertinib against HER2 exon 20 insertions. In HER2 exon 20 insertion–mutant cell lines, the IC50 of mobocertinib was higher than poziotinib and comparable with or slightly lower than afatinib, neratinib, and pyrotinib. Mobocertinib had the lowest HER2 exon 20 insertion IC50/wild-type (WT) EGFR IC50 ratio, indicating that mobocertinib displayed the best selectivity profile in these models. Also, mobocertinib showed strong inhibitory activity in HER2 exon 20YVMA allograft and patient-derived xenograft models. In genetically engineered mouse models, HER2 exon 20G776>VC lung tumors exhibited a sustained complete response to mobocertinib, whereas HER2 exon 20YVMA tumors showed only partial and transient response. Combined treatment with a second antibody–drug conjugate (ADC) against HER2, ado-trastuzumab emtansine (T-DM1), synergized with mobocertinib in HER2 exon 20YVMA tumors. In addition to the tumor cell autonomous effect, sustained tumor growth control derived from M1 macrophage infiltration and CD4+ T-cell activation. These findings support the ongoing clinical development of mobocertinib (NCT02716116) and provide a rationale for future clinical evaluation of T-DM1 combinational therapy in HER2 exon 20YVMA insertion–mutant lung adenocarcinoma patients. Significance: This study elucidates the potent inhibitory activity of mobocertinib against HER2 exon 20 insertion–mutant lung cancer and the synergic effect of combined mobocertinib and T-DM1, providing a strong rationale for clinical investigation.

Mobocertinib, an oral epidermal growth factor receptor (EGFR) inhibitor targeting EGFR gene mutations, including exon 20 insertions (EGFRex20ins), in non–small cell lung cancer, was evaluated in a phase I/II dose-escalation/expansion trial (ClinicalTrials.gov NCT02716116). Dose escalation identified 160 mg/d as the recommended phase 2 dose and maximum tolerated dose. Among 136 patients treated with 160 mg/d, the most common any-grade treatment-related adverse events (TRAE; >25%) were diarrhea (83%), nausea (43%), rash (33%), and vomiting (26%), with diarrhea (21%) the only grade ≥3 TRAE >5%. Among 28 EGFRex20ins patients treated at 160 mg/d, the investigator-assessed confirmed response rate was 43% (12/28; 95% confidence interval, 24%–63%) with median duration of response of 14 months (5.0–not reached) and median progression-free survival of 7.3 months (4.4–15.6). Mobocertinib demonstrated antitumor activity in patients with diverse EGFRex20ins variants with a safety profile consistent with other EGFR inhibitors. Significance: No oral EGFR-targeted therapies are currently approved for patients with EGFRex20ins NSCLC. Mobocertinib demonstrated antitumor activity with manageable toxicity in patients with advanced EGFRex20ins NSCLC in this study, supporting additional development of mobocertinib in this patient population. See related commentary by Pacheco, p. 1617. This article is highlighted in the In This Issue feature, p. 1601

Social and healthcare workers are at high risk of experiencing sexual harassment in the workplace. Although sexual harassment is detrimental to people’s well-being, only a few studies have systematically investigated social and healthcare workers’ experiences of different forms of sexually harassing behaviors by patients, clients, and residents in Germany. This study aimed to address this gap by determining the prevalence rates and frequency of nonverbal, verbal, and physical sexual harassment by patients, clients, and residents against social and healthcare workers. In addition, we examined the associations of sexual harassment with workers’ well-being and described employees’ awareness of offers of organizational support for sexual harassment prevention and aftercare. Data were collected from n = 901 employees working in a total of 61 facilities, including inpatient and outpatient care, psychiatric facilities, hospitals, and facilities for persons with disabilities. While the prevalence, frequency, and predominant forms of sexual harassment differed across sectors, the results indicated that nonverbal, verbal and physical sexual harassment were highly prevalent in social and healthcare work, with both men and women being affected. Furthermore, we found that sexual harassment was positively related to impaired well-being (e.g., depressiveness and psychosomatic complaints). In terms of support offers for sexual harassment prevention and aftercare, we found that approximately one-third of social and healthcare workers were not aware of any offers at their facilities. In addition to highlighting the problem of sexual harassment by patients, clients, and residents in social and healthcare settings, this study provides recommendations for the development of interventions and suggests several avenues for future research.

Purpose:This open-label, multicenter, phase IB/II study evaluated sapanisertib, a dual inhibitor of mTOR kinase complexes 1/2, plus exemestane or fulvestrant in postmenopausal women with hormone receptor–positive (HR+)/HER2-negative (HER2−) advanced/metastatic breast cancer.Patients and Methods:Eligible patients had previously progressed on everolimus with exemestane/fulvestrant and received ≤3 (phase IB) or ≤1 (phase II) prior chemotherapy regimens. Patients received sapanisertib 3 to 5 mg every day (phase IB), or 4 mg every day (phase II) with exemestane 25 mg every day or fulvestrant 500 mg monthly in 28-day cycles. Phase II enrolled parallel cohorts based on prior response to everolimus. The primary objective of phase II was to evaluate antitumor activity by clinical benefit rate at 16 weeks (CBR-16).Results:Overall, 118 patients enrolled in phase IB (n = 24) and II (n = 94). Five patients in phase IB experienced dose-limiting toxicities, at sapanisertib doses of 5 mg every day (n = 4) and 4 mg every day (n = 1); sapanisertib 4 mg every day was the MTD in combination with exemestane or fulvestrant. In phase II, in everolimus-sensitive versus everolimus-resistant cohorts, CBR-16 was 45% versus 23%, and overall response rate was 8% versus 2%, respectively. The most common adverse events were nausea (52%), fatigue (47%), diarrhea (37%), and hyperglycemia (33%); rash occurred in 17% of patients. Molecular analysis suggested positive association between AKT1 mutation status and best treatment response (complete + partial response; P = 0.0262).Conclusions:Sapanisertib plus exemestane or fulvestrant was well tolerated and exhibited clinical benefit in postmenopausal women with pretreated everolimus-sensitive or everolimus-resistant breast cancer.

The aim of this study is to obtain a better understanding of the association between the frequency of nurses&rsquo, exposure to workplace aggression from patients and their levels of burnout. In particular, we seek to shed light on the role of the availability of follow-up counseling in organizations after critical incidents in mitigating the adverse relationships between physical and verbal aggression and nurses&rsquo, burnout. A total of 582 nurses reported how frequently they had experienced physical and verbal aggression from patients in the last 12 months and whether they had the opportunity to receive follow-up counseling in their organization. In addition, nurses rated the extent to which they experienced each of the three dimensions of burnout (i.e., emotional exhaustion, depersonalization, and personal accomplishment). The results showed that both physical and verbal aggression were substantially related to the burnout dimensions. Furthermore, we found that the availability of follow-up counseling in organizations attenuated the relationships between physical aggression and all three burnout dimensions. While we found that the availability of follow-up counseling moderated the relationship between verbal aggression depersonalization, the moderating effects were not significant for emotional exhaustion and personal accomplishment. The findings indicate that the availability of follow-up counseling might help minimize the adverse impact of exposure to aggression from patients on nurses&rsquo, mental health.

According to the concept of abusive supervision, abusive supervisors display hostility towards their employees by humiliating and ridiculing them, giving them the silent treatment, and breaking promises. In this study, we argue that abusive supervision may not be limited to mistreatment at the relationship level and that the abuse is likely to extend to employees&rsquo, work tasks. Drawing upon the notion that supervisors play a key role in assigning work tasks to employees, we propose that abusive supervisors may display disrespect and devaluation towards their employees through assigning illegitimate (i.e., unnecessary and unreasonable) tasks. Survey data were obtained from 268 healthcare and social services workers. The results showed that abusive supervision was strongly and positively related to illegitimate tasks. Moreover, we found that the relationship between abusive supervision and unreasonable tasks was stronger for nonsupervisory employees at the lowest hierarchical level than for supervisory employees at higher hierarchical levels. The findings indicate that abusive supervision may go beyond relatively overt forms of hostility at the relationship level. Task-level stressors may be an important additional source of stress for employees with abusive supervisors that should be considered to fully understand the devastating effects of abusive supervision on employee functioning and well-being.

Dialysis nurses face complex and demanding working conditions. Due to demographic changes, the number of dialysis patients has increased, while the number of skilled personnel is expected to decrease, leading to tremendous increases in quantitative demands in the near future. Against the background of increasing workload, focusing on the provision of job resources is considered a promising approach because resources can buffer the negative effects of job demands. The aim of this study is to investigate whether different job resources&mdash, in particular influence at work and feedback&mdash, play a buffering role in the relationship between job demands and employee well-being. The study used a cross-sectional paper&ndash, pencil survey design. Data were collected from 951 dialysis nurses working in dialysis facilities in Germany between October 2010 and March 2012 using validated measures of quantitative job demands, job-related resources (influence at work and feedback), and cognitive stress symptoms. To test the moderating role of resources, we applied hierarchical regression analyses. The findings indicate that feedback buffers the relationship between quantitative demands and well-being, that is, the positive relationship between quantitative demands and cognitive stress symptoms was weaker when feedback was high. However, we found no buffering role of influence at work. The results suggest that feedback is a promising resource that may buffer the negative impact of quantitative demands on well-being of dialysis nurses. The findings offer new approaches for training nurses and implementing a feedback culture.

Importance Metastatic non–small cell lung cancer (mNSCLC) withEGFRexon 20 insertion (EGFRex20ins) mutations is associated with a poor prognosis. Mobocertinib is an oral tyrosine kinase inhibitor designed to selectively targetEGFRex20ins mutations. Objective To evaluate treatment outcomes and safety of mobocertinib in patients with previously treatedEGFRex20ins-positive mNSCLC. Design, Setting, and Participants This 3-part, open-label, phase 1/2 nonrandomized clinical trial with dose-escalation/dose-expansion cohorts (28 sites in the US) and a single-arm extension cohort (EXCLAIM; 40 sites in Asia, Europe, and North America) was conducted between June 2016 and November 2020 (data cutoff date). The primary analysis populations were the platinum-pretreated patients (PPP) cohort and the EXCLAIM cohort. The PPP cohort included 114 patients with platinum-pretreatedEGFRex20ins-positive mNSCLC who received mobocertinib 160 mg once daily from the dose-escalation (n = 6), dose-expansion (n = 22), and EXCLAIM (n = 86) cohorts. The EXCLAIM cohort included 96 patients with previously treatedEGFRex20ins-positive mNSCLC (10 were not platinum pretreated and thus were excluded from the PPP cohort). Interventions Mobocertinib 160 mg once daily. Main Outcomes and Measures The primary end point of the PPP and EXCLAIM cohorts was confirmed objective response rate (ORR) assessed by independent review committee (IRC). Secondary end points included confirmed ORR by investigator, duration of response, progression-free survival, overall survival, and safety. Results Among the PPP (n = 114) and EXCLAIM (n = 96) cohorts, the median (range) age was 60 (27-84) and 59 (27-80) years, respectively; most patients were women (75 [66%] and 62 [65%], respectively) and of Asian race (68 [60%] and 66 [69%], respectively). At data cutoff, median follow-up was 14.2 months in the PPP cohort (median 2 prior anticancer regimens; 40 [35%] had baseline brain metastases), with confirmed ORR of 28% (95% CI, 20%-37%) by IRC assessment and 35% (95% CI, 26%-45%) by investigator assessment; median duration of response by IRC assessment was 17.5 months (95% CI, 7.4-20.3). Median progression-free survival by IRC assessment was 7.3 months (95% CI, 5.5-9.2). Median overall survival was 24.0 months (95% CI, 14.6-28.8). In the EXCLAIM cohort, median follow-up was 13.0 months, with confirmed ORR by IRC assessment of 25% (95% CI, 17%-35%) and by investigator assessment of 32% (95% CI, 23%-43%). The most common treatment-related adverse events were diarrhea and rash. Conclusions and Relevance In this open-label, phase 1/2 nonrandomized clinical trial, mobocertinib was associated with clinically meaningful benefit in patients with previously treatedEGFRex20ins-positive mNSCLC, with a manageable safety profile. Trial Registration ClinicalTrials.gov Identifier:NCT02716116

Purpose Preclinical in vivo nuclear imaging of mice offers an enabling perspective to evaluate drug efficacy at optimal dose and schedule. In this study, we interrogated sufficient estrogen receptor occupancy and degradation for the selective estrogen receptor degrader (SERD) compound SAR439859 using molecular imaging and histological techniques. Material and methods [18F]FluoroEstradiol positron emission tomography (FES-PET), [18F]FluoroDeoxyGlucose (FDG) PET, and [18F]FluoroThymidine (FLT) PET were investigated as early pharmacodynamic, tumor metabolism, and tumor proliferation imaging biomarkers, respectively, in mice bearing subcutaneous MCF7-Y537S mutant ERα+ breast cancer model treated with the SERD agent SAR439859. ER expression and proliferation index Ki-67 were assessed by immunohistochemistry (IHC). The combination of palbociclib CDK 4/6 inhibitor with SAR439859 was tested for its potential synergistic effect on anti-tumor activity. Results After repeated SAR439859 oral administration over 4 days, FES tumoral uptake (SUVmean) decreases compared to baseline by 35, 57, and 55% for the 25 mg/kg qd, 12.5 mg/kg bid and 5 mg/kg bid treatment groups, respectively. FES tumor uptake following SAR439859 treatment at different doses correlates with immunohistochemical scoring for ERα expression. No significant difference in FDG uptake is observed after SAR439859 treatments over 3 days. FLT accumulation in tumor is significantly decreased when palbociclib is combined to SAR439859 (− 64%) but not different from the group dosed with palbociclib alone (− 46%). The impact on proliferation is corroborated by Ki-67 IHC data for both groups of treatment. Conclusions In our preclinical studies, dose-dependent inhibition of FES tumoral uptake confirmed target engagement of SAR439859 to ERα. FES-PET thus appears as a relevant imaging biomarker for measuring non-invasively the impact of SAR439859 on tumor estrogen receptor occupancy. This study further validates the use of FLT-PET to directly visualize the anti-proliferative tumor effect of the palbociclib CDK 4/6 inhibitor alone and in combination with SAR439859.

6087 Background: SAP (TAK-228, MLN0128) is a selective dual inhibitor of mammalian target of rapamycin complexes 1 and 2. In endometrial tumor xenograft models, SAP+PAC exhibited stronger antitumor efficacy than PAC alone. Methods: Female pts with histologic/cytologic diagnosis of endometrial cancer were randomized to receive SAP 4 mg by mouth (days [d] 2–4, 9–11, 16–18, 23–25) plus PAC 80 mg/m2 intravenously (d 1, 8, 15), or PAC alone, in 28-day cycles until unacceptable toxicity or disease progression. Randomization was stratified by histologic subtype, lines of prior chemotherapy (1 vs. 2), and prior taxane therapy. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), overall response rate (ORR), clinical benefit rate (CBR; ORR + stable disease), and safety. Additional treatment arms of SAP alone (weekly dosing) and SAP+TAK-117 were closed after futility analyses. Results: 180 pts were randomized to SAP+PAC (n=90) or PAC (n=90); 86 and 87 pts received SAP+PAC and PAC, respectively; 3 pts from each arm were ongoing on treatment at data cut (30 July 2019). Baseline characteristics were balanced between arms. After a median follow-up of 17.2 vs. 14.4 mos with SAP+PAC vs. PAC, median PFS was 5.6 mos vs. 3.7 mos (hazard ratio [HR] 0.82; 95% CI 0.58–1.15). In pts with endometrioid histology (n=116), median PFS was 5.7 mos with SAP+PAC vs 3.3 mos with PAC (HR 0.66; 95% CI 0.43–1.03). In pts with nonendometrioid histology (n=64), median PFS was 3.6 mos with SAP+PAC vs. 5.4 mos with PAC (HR 1.09; 95% CI 0.62–1.90). Median OS was 13.7 mos with SAP+PAC vs. 14.6 mos with PAC (HR 1.01; 95% CI 0.67–1.53). Confirmed ORR was 24% with SAP+PAC vs. 18% with PAC (endometrioid, 23% vs. 16%; nonendometrioid, 28% vs. 22%); CBR was 80% vs. 58% (endometrioid, 84% vs. 55%; nonendometrioid, 72% vs. 63%). Median number of cycles received was 5 (range 1–23) with SAP+PAC and 4 (range 1–37) with PAC. Rates of grade ≥3 treatment-emergent adverse events (TEAEs) were 90% with SAP+PAC vs. 54% with PAC; the most common included anemia (21% vs.12%), neutropenia (12% vs. 3%), fatigue (12% vs. 5%), hypophosphatemia (12% vs. 1%), and pulmonary embolism (11% vs. 3%). Conclusions: Median PFS was longer with SAP+PAC vs. PAC in pts with endometrial cancer but did not reach statistical significance. PFS was particularly longer in the endometrioid subtype but again was not significant, and further studies are warranted. Incidence of grade ≥3 TEAEs was higher with SAP+PAC vs. PAC, but SAP+PAC toxicity was manageable, with no new safety signals. Clinical trial information: NCT02725268.

Current research confirms the link between leadership behavior and subordinates’ health. However, only a few longitudinal surveys have been carried out. The present longitudinal study examined whether occupational self-efficacy moderates the impact of transformational leadership on perceived negative well-being. The sample consisted of 339 employees working in the health-care sector. The correlations between transformational leadership at the first time of measurement (Time 1) and emotional exhaustion and perceived strain at the second time of measurement (Time 2) were negative and significant, but the correlation with depersonalization was not significant. Regression analyses revealed that the effect of transformational leadership behavior on perceived negative well-being was not moderated by the level of occupational self-efficacy. Implications for future research are discussed.

9007 Background: TAK-788 is an oral investigational EGFR/HER2 inhibitor under evaluation in NSCLC patients (pts) with EGFR exon 20 insertions. We report results of a phase 1/2 open-label, multicenter study (NCT02716116). Methods: Pts with advanced, previously treated NSCLC received daily TAK-788 in dose escalation and expansion cohorts based on tumor genotype. Antitumor activity was determined for pts with EGFR exon 20 insertions who received TAK-788 at the RP2D. Safety is reported for all pts across all doses and at 160 mg. Results: As of 14 Sep 2018, 101 pts (median age, 61 y; female, 70%; ≥2 prior anticancer therapies, 76%; brain metastases, 53%) were treated with TAK-788 at 5–180 mg qd. RP2D was determined to be 160 mg. 28 pts with EGFR exon 20 insertions were treated with 160 mg qd during dose escalation or in expansion cohort 1 (median 3.6 mo on treatment; median 3.8 treatment cycles); 24 pts remain on treatment. Antitumor activity in pts with EGFR exon 20 insertions is shown in Table. At data cutoff, 7/14 responses were confirmed with 6 awaiting confirmation and 1 unconfirmed PR at 160 mg qd; median time to response in these 14 pts was 56 days. 23/24 evaluable pts with EGFR exon 20 insertions treated at 160 mg qd had decreased target lesion measurements (median best percent change, -32.6% [-79.1%, 3.8%]). Rate of treatment discontinuation due to AEs was 10.7% in pts treated at 160 mg. Most common TEAEs (≥20%) in pts treated with 160 mg qd: diarrhea (85%), rash (43%), nausea (41%), vomiting (30%), decreased appetite (28%), and stomatitis (22%); gr ≥3 TEAEs (≥5%) were diarrhea (26%) and hypokalemia, nausea, and stomatitis (7% each). Median dose intensity for pts treated with 160 mg qd was 93%. There is no clear trend that response to TAK-788 is enriched in particular EGFR exon 20 insertion variants. Conclusions: In NSCLC pts with EGFR exon 20 insertions, TAK-788 demonstrated antitumor activity and an AE profile consistent with other EGFR TKIs. Clinical trial information: NCT02716116. [Table: see text]

Der Einfluss des Fuhrungsverhaltens auf die Gesundheit von Mitarbeitern gewinnt in den letzten Jahren sowohl in der Forschung als auch in der betrieblichen Praxis zunehmend an Aufmerksamkeit. Gegenstand der vorliegenden Studie ist die Entwicklung und Validierung eines Instruments zur Messung gesundheits- und entwicklungsforderlichen Fuhrungsverhaltens. Als konzeptionelle Grundlage dient ein integratives Rahmenmodell, das (1) Fuhrung und Wohlbefinden sowie (2) Arbeitsbedingungen und Wohlbefinden miteinander in Beziehung setzt. Dieses Instrument wurde anhand einer Stichprobe von 822 Beschaftigten validiert. Die Skalenstruktur konnte mittels konfirmatorischer Faktorenanalyse bestatigt werden. Die Skalen zeigen gute psychometrische Kennwerte. Zusammenhangsanalysen mit Befindensvariablen weisen auf eine gute Kriteriumsvaliditat hin. Die uberprufung der inkrementellen Validitat bekraftigt die Bedeutsamkeit der neu entwickelten Fuhrungskonstrukte fur das Befinden der Mitarbeiter.

Nearly 70% or more of newly diagnosed cases of breast cancer (BC) are estrogen receptor positive (ER+) where endocrine therapy is a primary treatment. However, substantial evidence describes a continued role of ER signaling in tumor progression, where approximately 40% of patients on endocrine therapy develop resistance that include mutations in the ER that drive a constitutively active receptor. Fulvestrant, an estrogen receptor degrader, is effective at shutting down ER signaling. However, fulvestrant efficacy studies report insufficient blockade of ER signaling in patients that may be a consequence of poor pharmaceutical properties. Here we describe the discovery of SAR439859, a novel, orally bioavailable SERD with potent antagonist and degradative properties against ER both in vitro and in vivo. SAR439859 has robust inhibition of ER signaling activity in multiple ER+ breast cancer cell lines including tamoxifen resistant lines harboring ER mutations. Across a large panel of ER+ cells, SAR439859 demonstrated broad and superior ER degradation activity as compared to other SERDs including improved inhibition of ER signaling and inhibition of cell growth. Similarly, in vivo treatment with SAR439859 demonstrated significant tumor regression in ER+ BC models including MCF7-ESR1 mutant-Y537S model and endocrine therapy resistant patient-derived xenograft tumor transplantation. Collectively, these results showed that SAR439859 is an oral, nonsteroidal, selective estrogen receptor antagonist and degrader that could provide therapeutic benefit to ER+ breast cancer patients. SAR439859 is currently being evaluated in a phase I clinical trial. Citation Format: Maysoun Shomali, Youssef El-Ahmad, Frank Halley, Jane Cheng, Michael Weinstein, Muchun Wang, Fangxian Sun, Natalia Malkova, Mikhail Levit, Malvika Koundinya, Zhuyan Gou, Andrew Hebert, Jessica McManus, Dietmar Hoffman, Hui Cao, Joonil Jung, Jack Pollard, Sylvie Vincent, Timothy Ackerson, Francisco Adrian, Chris Winter, Victoria Richon, Hong Chen, Karl Hsu, Joanne Lager, Albane Courjaud, Rosalia Arrebola, Laurent Besret, Pierre-Yves Abecassis, Laurent Schio, Gary McCort, Michel Tabart, Victor Certal, Fabienne Thompson, Bruno Filoche-Romme, Laurent Debussche, Patrick Cohen, Carlos Garcia-Echeverria, Monsif Bouaboula. Identification of SAR439859, an orally bioavailable selective estrogen receptor degrader (SERD) that has strong anti-tumor activity in wild-type and mutant ER+ breast cancer models [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 5775.

Introduction Breast cancer is the most prevalent cancer in women, with approximately 250,000 diagnoses per year in the US. Non-invasive detection of breast cancer is of critical importance but has proven challenging due to the rate of false-positive diagnoses with current tests. Liquid biopsies including circulating tumor cells (CTCs) or cell-free DNA (cfDNA) have struggled with the detection of early stage disease. For example, a recent multi-analyte (cfDNA+protein) analysis, ‘cancerSEEK', achieved a sensitivity of just 33% in breast cancer, highlighting the challenges facing the development of more sensitive and specific diagnostics for this disease. Exosome-based liquid biopsy is a promising approach for minimally-invasive and highly sensitive diagnostics and it has been demonstrated that combining exosomal RNA and cfDNA greatly enhances mutation detection compared to profiling cfDNA alone. While most liquid biopsies profile mutations, studying RNA abundance in exosomes adds a new dimension to these non-invasive diagnostics. To date, much of the focus on exosomal RNA expression profiling has been on the small-RNA fraction. Here we demonstrate that whole-transcriptome profiling of mRNAs and lincRNAs greatly expands the landscape of potential biomarkers to clinically actionable genes. Results We have developed a novel platform designed to perform long-RNA sequencing on transcripts obtained from exosomes. We used this platform to compare expression profiles of total plasma exosomes versus subpopulations enriched for breast cancer-derived exosomes (CDE) versus depleted of non-cancer exosomes (NCE). The NCE-depleted and CDE-enriched exosomes equally outperformed total plasma exosomes, each detecting significantly more genes exhibiting breast cancer vs. healthy expression differences. We performed NCE-depletion on 1.5 mL of input plasma from 15 stage I & II ER+/Her2- breast cancer patients and 12 healthy women matched for age & menopausal-status. RNA-seq data from these samples detected over 10,000 mRNAs and over 1,000 lincRNAs. Of these, we observed significantly increased abundance in over 100 mRNAs and lincRNAs in these early stage breast cancer patients. These mRNAs are enriched for gene-sets including those previously implicated in ‘breast cancer', ‘chromatin remodeling', and ‘immune response'. We also performed RNA-seq on formalin-fixed paraffin-embedded (FFPE) samples from healthy and matched breast cancer tissue. The >100 genes found to be more abundant in breast cancer plasma exosomes significantly (p Conclusions This preliminary analysis highlights the exciting potential of exosomal long RNA based liquid biopsy for non-invasive early-stage detection of breast cancer. The platform is readily applicable to other disease areas and other biofluids such as urine or CSF. Citation Format: Sudipto K. Chakrabortty, Robert R. Kitchen, Christine M. Coticchia, Vasisht R. Tadigotla, Erez Eitan, Elena Castellanos-Rizaldos, Lisa Bedford, Sunita Badola, Michael D. Valentino, Nicholas Colafemina, Hidefumi Uchiyama, Mario Morken, Miguel Williams, Sylvie Vincent, Hadi Danaee, Seth Yu, Johan Skog. Exosomal liquid biopsy reveals mRNA and lincRNA biomarkers in early stage breast cancer patient plasma [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 LB-226.

Despite resistance to endocrine therapies, estrogen receptor-positive (ER+) breast cancers (BC) still rely on ER. Eliminating ER by inducing its degradation with selective ER downregulators (SERD) should induce complete ablation of ER pathways. The clinical SERD fulvestrant, although it has demonstrated clinical benefits, is hampered by its poor drug properties and undesirable pharmacokinetics, undermining its optimal clinical activity. Therefore there is an unmet need for an improved therapy targeting ER. Here we describe SAR439859, a novel, nonsteroidal, orally bioavailable SERD currently in clinical trials. SAR439859 has a potent ER antagonist and ER degrading activity that translates in a robust inhibition of ER signaling in multiple ER+ breast cancer cell lines, including tamoxifen-resistant lines as well as cell lines harboring ER mutations. SAR439859 displays a broad and superior ER degradation activity across a large panel of ER+ cells. Importantly, based on its mechanism of action SAR439859 shows limited cross-resistance with other clinical SERD molecules. SAR439859 induces strong in vivo antitumor activity against a variety of BC cell lines and patient-derived xenografts, including models that harbor ERα mutations. The transcriptional profile analysis highlighted a crosstalk of ER mutant signaling and other oncogenic pathways. Interestingly, CDK4/6 inhibition by palbociclib induces partial activation of ER pathways as potential mechanism of tumor escape, which is completely abolished by the combination of SAR439859 with palbociclib. Finally, we demonstrate that SAR439859 in combination with palbociclib can lead to higher in vivo efficacy. This study highlights novel mechanism of ER degradation by SAR439859 that leads to profound inhibition of ER signaling as well as modulation of other oncogenic pathways and provides rationale for the ongoing clinical investigation of SAR439859 in ER+ breast cancer patients, both as a single agent and in combination with approved agents, such as CDK4 inhibitor. Citation Format: Monsif Bouaboula, Maysoun Shomali, Jane Cheng, Natalia Malkova, Fangxian Sun, Malvika Koundinya, Zhuyan Guo, Stephane Poirier, Mikhail Levit, Dietmar Hoffman, Hui Cao, Laurent Bestret, Francisco Adrian, Christoph Winter, Youssef El-Ahmad, Sylvie Vincent, Frank Halley, Gary McCort, Laurent Schio, Vicky Richon, Hong Cheng, Karl Hsu, Chris Soria, Patrick Cohen, Joanne Lager, Carlos Garcia-Echeverria, Laurent Debussche. SAR439859, an orally bioavailable selective estrogen receptor degrader (SERD) that demonstrates robust antitumor efficacy and limited cross-resistance in ER+ breast cancer [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 943.

Breast cancer development is a complex pathobiological process involving sequential genetic alterations in normal epithelial cells that results in uncontrolled growth in a permissive microenvironment. Accordingly, physiologically relevant models of human breast cancer that recapitulate these events are needed to study cancer biology and evaluate therapeutic agents. Here, we report the generation and utilization of the human breast cancer in mouse (HIM) model, which is composed of genetically engineered primary human breast epithelial organoids and activated human breast stromal cells. By using this approach, we have defined key genetic events required to drive the development of human preneoplastic lesions as well as invasive adenocarcinomas that are histologically similar to those in patients. Tumor development in the HIM model proceeds through defined histological stages of hyperplasia, DCIS to invasive carcinoma. Moreover, HIM tumors display characteristic responses to targeted therapies, such as HER2 inhibitors, further validating the utility of these models in preclinical compound testing. The HIM model is an experimentally tractable human in vivo system that holds great potential for advancing our basic understanding of cancer biology and for the discovery and testing of targeted therapies.

Purpose: ERBB3 is overexpressed in a broad spectrum of human cancers, and its aberrant activation is associated with tumor pathogenesis and therapeutic resistance to various anticancer agents. Neuregulin 1 (NRG1) is the predominant ligand for ERBB3 and can promote the heterodimerization of ERBB3 with other ERBB family members, resulting in activation of multiple intracellular signaling pathways. AV-203 is a humanized IgG1/κ ERBB3 inhibitory antibody that completed a first-in-human phase I clinical trial in patients with advanced solid tumors. The purpose of this preclinical study was to identify potential biomarker(s) that may predict response to AV-203 treatment in the clinic. Experimental Design: We conducted in vivo efficacy studies using a broad panel of xenograft models representing a wide variety of human cancers. To identify biomarkers that can predict response to AV-203, the relationship between tumor growth inhibition (TGI) by AV-203 and the expression levels of ERBB3 and NRG1 were evaluated in these tumor models. Results: A significant correlation was observed between the levels of NRG1 expression and TGI by AV-203. In contrast, TGI was not correlated with ERBB3 expression. The correlation between the levels of NRG1 expression in tumors and their response to ERBB3 inhibition by AV-203 was further validated using patient-derived tumor explant models. Conclusions: NRG1 is a promising biomarker that can predict response to ERBB3 inhibition by AV-203 in preclinical human cancer models. NRG1 warrants further clinical evaluation and validation as a potential predictive biomarker of response to AV-203. Clin Cancer Res; 21(5); 1106–14. ©2014 AACR.

Purpose . The protein encoded by the Microphthalmia gene (MITF) is a transcription factor essential for the development and survival of melanocytes. It serves as a master regulator in modulating extracellular signals. Because of its central role in melanocytes survival and to assess its potential use as a histopathological marker for melanoma, MITF expression was examined in human choroidal melanomas. Methods . Fifty-seven paraffin-embedded sections of choroidal melanoma specimens and 1 choroidal melanoma cell line were analyzed using immunochemistry and RT-PCR. Normal choroids and normal choroidal melanocyte cells were used as control. Results . Sixty-five percent of the tumoral specimens stained positively for MITF with a predominant nuclear pattern of reactivity. MITF-M and MITF-A isoforms were detected by RT-PCR in all specimens examined. Using a chimeric protein resulting from the fusion of each Mitf protein with the GFP, Mitf-M exhibited an exclusive nuclear staining whereas Mitf-A exhibited a mixed nuclear and cytoplasmic staining. No correlation between MITF-positivity and parameters such as cell type, largest tumor diameter, sclera invasion, mitotic figures was observed. In contrast, a significant negative association was found between MITF staining and the pigmentation (p=0.02) and a positive correlation between MITF staining and the proliferative marker Ki67 was found ( p =0.02). Conclusion . MITF may be implicated in choroidal melanoma pigmentation and proliferation. Further analysis should provide new insights into the mechanisms underlying the molecular and cellular changes of choroidal melanomas.

Background The expression of the Ca(2+)-binding protein calbindin-D(28k) was analyzed in medulloblastomas in relation to clinical features and other biologic markers related to cell proliferation, differentiation, p53, and cerebellar developmental regulated gene expression. Methods Immunohistochemistry was carried out on histologic slides from a first retrospective series of 29 nonmetastatic and 10 metastatic medulloblastoma formalin-fixed, paraffin-embedded tissues, using specific antibodies against calbindin-D(28k), calretinin, alpha-parvalbumin and beta-parvalbumin, and S100 proteins. Informed consent was obtained from the subjects and/or guardians. Other biologic markers for differentiation, cell proliferation, the expression of the p53 tumor suppressor gene protein, and cerebellar developmental regulated genes were similarly investigated. A second series of 16 medulloblastomas from young patients (younger than 15 years) was added in order to validate the results obtained in the first series. Results Of all the markers investigated, only calbindin-D(28k) was significantly associated with prognosis. Survival and remission (i.e. recurrence free) time analysis performed on all the cases (n = 55) confirmed a high risk of death (P = 0.004) and recurrence (P = 0.003) associated with calbindin-positivity. As calbindin-positivity was predominantly observed in tumors from young patients, the authors confirmed its prognostic value in the subgroup of patients younger than 15 years (n = 37). Cox regression analysis showed a significant and independent prognostic value for calbindin expression and, to a lesser extent, the type of surgery (total or subtotal). Three risk groups were thus identified, distinguishing among the cases characterized by a total resection and calbindin-negativity (good prognosis), by a subtotal resection and calbindin-negativity (intermediary), and by calbindin-positivity (bad prognosis). Conclusions The current study suggests that calbindin-positive medulloblastomas represent a subclass of aggressive tumors more frequently seen in younger patients.

Primary papillary tumors of the central nervous system are rare. We have encountered a series of six papillary tumors of the pineal region with distinctive features that appear to represent a clinicopathologic entity. The tumors occurred in four women and two men, ranging in age from 19 to 53 years. Imaging studies showed a large well-circumscribed mass in the pineal region. The tumors were characterized by an epithelial-like growth pattern, in which the vessels were covered by a layer of tumoral cells. In papillary areas, the neoplastic cells were large, columnar or cuboidal, with a clear cytoplasm. Nuclei, round or infolded, were found generally at the basal pole of tumoral cells. Immunohistochemically, the tumor cells showed strong staining for cytokeratin, S-100 protein, neuron-specific enolase, and vimentin but only weak or no staining for epithelial membrane antigen and glial fibrillary acid protein. Ultrastructural examination of two cases revealed abundant rough endoplasmic reticulum with distended cisternae filled with secretory product, microvilli, and perinuclear intermediate filaments. The morphofunctional features of these papillary tumors of the pineal region, remarkably uniform within this series, are similar to those described for ependymal cells of the subcommissural organ, and the papillary tumors of the pineal region may be derived from these specialized ependymocytes.

The presence of the iron-binding protein lactoferrin (Lf) in some specific areas of the central nervous system and particularly in the normal human substantia nigra, where it is found in dopaminergic (DA) neurons and some glial cells, led us to investigate Lf synthesis in this area. Lf mRNA were identified using in situ hybridization and found in small ameboid cells. These cells were identified using immunocytochemistry as activated microglia since they exhibited macrophage markers such as the CD68 and the CR1 antigens. Double immunofluorescent labeling confirmed that the two Lf immunostained cell populations were activated microglia and DA neurons. Since activated microglia contained both Lf and its messenger, these cells are the Lf producing cells. The presence of Lf in DA neurons in which no Lf messengers were visible, might be due to an endocytosis mechanism, DA neurons probably internalizing Lf produced in microglial cells located in their neighborhood. In neuropathological disorders, such as Alzheimer's and Parkinson's diseases, inflammatory process and oxidative stress are events that contribute to neuronal death. Since Lf concentration increases during these pathologies, we studied the level of Lf expression under these different stresses and showed, using RT-PCR, that the immortalized human embryonic microglial CHME cell line produced Lf transcripts under tumor necrosis factor alpha or 1-methyl-4-phenylpyridinium treatment whereas untreated cells did not. These data confirm that Lf is produced only when microglia are activated.

Targeted therapies have changed the treatment paradigm of cancer. Specifically, the use of tyrosine kinase inhibitors (TKIs) has improved therapeutic responses in a number of tumor types. However, initial response to TKIs is often followed by rapid relapse due to the acquisition of molecular features that lead to resistance. ERBB3, a receptor of the epidermal growth factor receptor (EGFR/ERBB1) family, has been linked to the development of resistance to multiple ERBB targeting TKIs. A proposed potential mechanism is the recruitment and activation of ERBB3 as a bypass mechanism to activate PI3K dependent pro-survival pathways. We investigated whether the inhibition of ERBB3 could reverse TKI resistance linked to ERBB3 activation. AV-203 is a humanized IgG1 antibody directed against ERBB3. AV-203 potently inhibits both ligand dependent and ligand independent activation of ERBB3. AV-203 was shown to inhibit the binding of NRG1 to ERBB3 and promote ERBB3 degradation. The tumor growth inhibitory activity of AV-203 was demonstrated in numerous xenograft models representing major human carcinomas (breast, lung, ovarian, kidney and pancreas). Here, we investigated the ability of AV-203 to restore TKI sensitivity in models with activated ERBB3. First, we demonstrated that ligand mediated (NRG1) activation of ERBB3 leads to acquired resistance to the EGFR TKI erlotinib in a lung cancer model bearing EGFR TKI sensitizing mutation, to the ERBB2/HER2 inhibitor lapatinib in a HER2 amplified breast cancer model, and to the EGFR inhibitory antibody cetuximab in head and neck cancer models. AV-203 was able to restore sensitivity to these RTK inhibitors. This data suggest that the combination of AV-203, with EGFR/HER2 targeted therapies could potentially extend the efficacy of these agents by preventing the emergence of ERBB3 mediated resistance. This hypothesis will be tested in future clinical trials. AV-203 is currently in Phase I development for the treatment of solid tumors. Citation Format: Steven M. Tyler, Sylvie Vincent, Christina Fleet, Steve Bottega, Donna McIntosh, Kristan Meetze, Jeno Gyuris. AV-203, a fully humanized ERBB3 inhibitory antibody, reverses ERBB3-induced resistance to targeted therapies. [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 1228. doi:10.1158/1538-7445.AM2013-1228

International audience; This chapter describes the methodology for the characterization and regulation analysis of genes activated by serum or purified growth factors using the small GTPase RhoG as a model. To maximize the finding of growth-induced genes, the most widely used methods work with cells synchronized by serum starvation or density-dependent growth arrest. Conditions for both methods have to be adjusted depending on the cell type. Subconfluent fibroblastic murine NIH 3T3 cells are starved in 0.5% of fetal calf serum (FCS) for 48 hours, whereas hamster CCL39 cells are starved without serum for 24 hours. The biological system from which RNA is extracted must be checked with suitable controls. As far as growth-stimulated genes are concerned, the most commonly used probes are c-fos, whose gene is induced by a wide variety of agents in most cell types, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), or S26 ribosomal protein, which is highly expressed in all tissues or cell types. Although the GAPDH probe is widely used, its level of expression differs from one tissue to another and increases two to threefold in cells stimulated to grow. The assay for growth factor activity is described in the chapter.

ERBB3 is widely expressed in human carcinomas, and its over expression is associated with poor prognosis in patients with various carcinomas, (i.e., breast, ovarian, prostate, colorectal, pancreatic, gastric, and head and neck cancers). The presence of ERBB3 correlates with local to distal metastasis in lung, gastric, and colorectal cancers as well as bone invasion in prostate cancer. Activation of ERBB3 is also implicated in the development of resistance to current cancer treatments. Due to its lack of kinase activity, the activation of the ERBB3 receptor is dependent on heterodimerization with active receptor tyrosine kinases (RTKs). The recruitment of ERBB3 into active, heterodimer complexes is mediated by its ligand Neuregulin-1 (NRG-1) or by amplified, over expressed RTKs in a ligand independent manner. Therefore, ERBB3 can crosstalk with most major receptors involved in cancer development and maintenance such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and c-MET. AV-203 is a potent, humanized anti-ERBB3 antibody that inhibits both ligand-dependent and independent activation of ERBB3 both in vitro and in vivo. Pharmacokinetics and pharmacodynamics of AV-203 were characterized in mice using the A549 non-small cell lung cancer xenograft model. AV-203 administered IV in mice exhibits acceptable pharmacokinetics supporting preclinical efficacy studies. AV-203 administered IV in A549 NSCLC xenograft tumor bearing mice had lower serum AUC than naïve mice, demonstrating that the presence of human ErbB3 may alter the PK parameters of AV-203. In evaluating pharmacodynamics in vivo, AV-203 was able to down regulate total ERBB3 and ERBB3 signaling in A549 tumors in a time-dependent manner. Inhibition of ERBB3 signaling correlated with significant dose-dependent tumor growth inhibition in the A549 xenograft model. Dose scheduling studies with the constant AV-203 dose of 2.5 mg/kg revealed that the most efficacious schedule is the more frequent dosing at Q3D. In comparing the total dose of 10 mg/kg per 14 day cycle, at varying dose per injection and frequency, AV-203 resulted in significant tumor growth inhibition at all dose schedules. These data conclude that the efficacy of AV-203 is driven by total drug exposure and that AV-203 is not dependent on Cmax for its antitumor activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3787. doi:1538-7445.AM2012-3787

Non-small cell lung cancers (NSCLC) driven by ligand-independent activating mutations in epidermal growth factor receptor (EGFR) often respond to treatment with EGFR tyrosine kinase inhibitors (TKIs). About half of acquired resistance to EGFR-TKI therapy results from a secondary point mutation in the EGFR tyrosine kinase domain at amino acid position 790 (T790M). T790M mutants also display reduced sensitivity to Cetuximab treatment. We have investigated the molecular mechanism responsible for the reduced Cetuximab sensitivity and found that T790M mutant receptors primarily exist and signal as monomers. We have exploited this characteristic of the T790M mutant to isolate novel EGFR inhibitory antibodies with activities against all EGFR variants. In addition, as opposed to other EGFR inhibitory antibodies, these novel antibodies have reduced ligand binding inhibitory activity and minimal inhibitory effect on EGF induced human primary keratinocyte proliferation, suggesting a potentially reduced skin toxicity profile. The broad activity profile, combined with potentially reduced skin toxicity, suggests that these antibodies will have great potential for combinability with other therapeutic agents. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 642. doi:10.1158/1538-7445.AM2011-642

We recently reported that triiodothyronine (T3) enhances MyoD gene expression and accelerates terminal differentiation in murine C2 myoblasts. In this paper, we are interested in the effects of other hormones acting through related nuclear receptors. Retinoic acid (RA), but not estradiol or dexamethasone, is also able to enhance MyoD gene expression (about threefold). However, the effects of RA and T3 on myogenesis are quite distinct, with a much more potent RA action. In deed, although T3 and RA positively regulate myogenesis with similar efficiency in poorly mitogenic conditions, in presence of high serum concentrations T3 can no longer trigger terminal differentiation whereas RA still remains efficient. Thus, serum concentration is a crucial parameter in discriminating between the effects of T3 and RA on myogenesis. The differential effects between these two hormone are likely to be related to the ability of RA-activated endogenous retinoic acid receptors (RARs) to induce C2 myoblasts growth-arrest and to extinguish AP1 activity (thought to act as an inhibitor of myogenesis) whereas T3-activated endogenous thyroid hormones receptors (THRs) are relatively inefficient. We propose that the much higher level of RARs in C2 cells versus THRs could to some extent account for the differential ability of T3 and RA to antagonize serum-regulated mitogenic pathways in myogenic cells. This study provides clear evidence for an important role of RA on MyoD gene expression and myogenesis and suggests that T3 and RA could play overlapping, but distinct, roles on muscle development.