Large-scale real-life analysis of survival and usage of therapies in multiple myeloma

Survival in multiple myeloma has improved significantly in recent years, especially in young patients. We reviewed the evolution of the survival of patients with MM in three groups based on age at MM diagnosis over three time periods between 1999 and 2020 at our 12 de Octubre Hospital institution (H12O). Then, to confirm our results, we used data from TriNetx, a global health research platform that includes patients from Europe to US. Finally, we analysed differences in the patterns of treatment between networks across the world. Kaplan‒Meier analysis was used to estimate survival probabilities, and between-group differences were tested using the log-rank test and hazard ratio. For patients from H12O, the median OS was 35.61, 55.59 and 68.67 months for the 1999-2009, 2010-2014 and 2015-2020 cohorts, respectively (p = 0.0001). Among all patients included in the EMEA network, the median OS was 20.32 months versus 34.75 months from 1999-2009 versus 2010-2014. The median OS from the 2010-2014 versus 2015-2020 time cohorts was 34.75 months versus 54.43 months, respectively. In relation to the US cohort, the median OS from before 2010 versus 2010-2014 was not reached in either time cohort and neither when comparing the 2010-2014 versus 2015-2019 time cohorts. Bortezomib is the most commonly used drug in the EMEA cohort, while lenalidomide is the most commonly used drug in the US cohort. This large-scale study based on real-world data confirms the previous finding that MM patients have increased their survival in the last two decades.

Latin American registry of renal involvement in COVID-19 disease. The relevance of assessing proteinuria throughout the clinical course

The Latin American Society of Nephrology and Hypertension conducted a prospective cohort, multinational registry of Latin American patients with kidney impairment associated to COVID-19 infection with the objective to describe the characteristics of acute kidney disease under these circumstances. The study was carried out through open invitation in order to describe the characteristics of the disease in the region. Eight-hundred and seventy patients from 12 countries were included. Median age was 63 years (54-74), most of patients were male (68.4%) and with diverse comorbidities (87.2%). Acute kidney injury (AKI) was hospital-acquired in 64.7% and non-oliguric in 59.9%. Multiorgan dysfunction syndrome (MODS) due to COVID-19 and volume depletion were the main factors contributing to AKI (59.2% and 35.7% respectively). Kidney replacement therapy was started in 46.2%. Non-recovery of renal function was observed in 65.3%. 71.5% of patients were admitted to ICU and 72.2% underwent mechanical ventilation. Proteinuria at admission was present in 62.4% of patients and proteinuria during hospital-stay occurred in 37.5%. Those patients with proteinuria at admission had higher burden of comorbidities, higher baseline sCr, and MODS was severe. On the other hand, patients with de novo proteinuria had lower incidence of comorbidities and near normal sCr at admission, but showed adverse course of disease. COVID-19 MODS was the main cause of AKI in both groups. All-cause mortality of the general population was 57.4%, and it was associated to age, sepsis as cause of AKI, severity of condition at admission, oliguria, mechanical ventilation, non-recovery of renal function, in-hospital complications and hospital stay. In conclusion, our study contributes to a better knowledge of this condition and highlights the relevance of the detection of proteinuria throughout the clinical course.

Impact of COVID-19 in patients with multiple myeloma based on a global data network

The COVID-19 pandemic has represented a major cause of morbidity/mortality worldwide, overstressing health systems. Multiple myeloma (MM) patients show an increased risk for infections and they are expected to be particularly vulnerable to SARS-CoV-2 infection. Here we have obtained a comprehensive picture of the impact of COVID-19 in MM patients on a local and a global scale using a federated data research network (TriNetX) that provided access to Electronic Medical Records (EMR) from Health Care Organizations (HCO) all over the world. Through propensity score matched analyses we found that the number of new diagnoses of MM was reduced in 2020 compared to 2019 (RR 0.86, 95%CI 0.76-0.96) and the survival of newly diagnosed MM cases decreased similarly (HR 0.61, 0.38-0.81). MM patients showed higher risk of SARS-CoV-2 infection (RR 2.09, 1.58-2.76) and a higher excess mortality in 2020 (difference in excess mortality 9%, 4.4-13.2) than non-MM patients. By interrogating large EMR datasets from HCO in Europe and globally, we confirmed that MM patients have been more severely impacted by COVID-19 pandemic than non-MM patients. This study highlights the necessity of extending preventive measures worlwide to protect vulnerable patients from SARS-CoV-2 infection by promoting social distancing and an intensive vaccination strategies.

P905 Value of global longitudinal strain (GLS) in the short term prognosis of geriatric patients with asymptomatic severe aortic stenosis

Funding Acknowledgements

VII Convocatoria del Banco de Santander and Alfonso X el Sabio University.

Background

Detection of symptoms in geriatric population with aortic stenosis (AS) is challenging, especially when they associate other comorbidities or frailty. Left ventricular global longitudinal strain (GLS) occurs before left ventricular ejection fraction impairment and could be useful for risk stratification and management of these patients.

Purpose

We sought to analyze the usefulness of GLS for predicting major cardiovascular adverse events (MACEs) in geriatric patients with asymptomatic severe AS.

Material and Methods:

Prospective study on 54 patients older than 70 years old with severe asymptomatic AS. Patient evaluation included biochemistry tests, electrocardiogram and echocardiography. We use a GLS cut-off point of 18% to dichotomize patients. Outcomes were defined as the composite of MACEs – occurrence of death from any cause, hospitalization for heart failure, appearance of symptoms or change in treatment.

Results

The mean age was 83.2 ± 7.1, with 60.4% of women. 24.5% showed atrial fibrillation. At 6 months of follow-up, 33% of patients reached the endpoint: 5.6% CHF, 11.1% death, 3.7% symptoms without changes in management and 13% were referred to an invasive treatment. The event-free survival rate at 6 months for the global population was 83%. 41.5 % of the subjects had GLS < 18%. Kaplan Meier analysis showed that the probability of freedom from MACEs was not significant in patients with lower GLS (Log Rank p = 0.39). In the multivariate analysis only AVA was an inverse predictor of events (AVA) HR 0.05 (95% CI 0.007- 0.471, p < 0.05).

Conclusions

The value of GLS was not a predictor of short term events in geriatric patients. Only assessment of AVA was an independent marker of MACES and in this kind of subjects.

Charasteristics of the global population Global N = 53 (%) GLS ≥ 18 N = 31 (58.5%) GLS < 18 N = 22 (41.5%) (p) HBP 42 (79.2) 27 (87.1) 19 (82.6) 0.09 Atrial fibrillation 13 (24.5) 6 (19.4) 7 (31.8) 0.29 CVD 6 (11.3) 1 (3.2) 5 (22.7) 0.02 LVEF: Normal >50% 48 (92) 31 (100) 17 (77.2) 0.05 Peak velocity 3.72 ± 0.72 3.81 ± 0.71 3.60 ± 0.74 0.315 Mean gradient 34.01 ± 14.06 35.61 ± 13.54 32.09 ± 15.07 0.29 Integral ratio 0.25 ± 0.08 0.26 ± 0.09 0.25 ± 0.08 0.83 AVA 0.8 ± 0.26 0.78 ± 0.27 0.83 ± 0.26 0.651 Indexed AVA 0.48 ± 0.16 0.48 ± 0.17 0.48 ± 0.16 0.9 AVA Aortic valve area; CVD: cerebro vascular disease; HBP: High blood presure; LVEF: left ventricule ejection fraction.

Abstract P905 Figure. Kapplan-Meier event-free survival curves

P225 Carcinoid heart disease: report of a case in a patients with trombocytopenia absent radius

Background

The carcinoid syndrome is characterized by extensive and several clinical manifestations. The diarrhea, the cutaneous flushing are the most frequents symptoms while cardiac manifestations (carcinoid heart disease) (CHD) occurs in a mean of 40%. Nowadays, the number of cases of CHD is lower than 20%, as a consequence of the widespread use of somatostatin analogues. At present, there is a mean delay in diagnosis of CHD of 1.5 years from the time of carcinoid syndrome detection. Hence, CHD is associated with a poor prognosis for clinical management.

Case report

We present a case of 45-years-old active woman, with Thrombocytopenia absent radius (TAR). This is characterized by a bilateral absence of the radio with the presence of both thumbs and thrombocytopenia. Our patient was attended for dyspnea of medium efforts, history of diarrhea, cutaneous flushing with tachycardia and elevated urinary 5-hydroxyindoleacetic acid (5-HIAA) (89,6 mg/24 (2,0-9,0)). The Transthoracic echocardiography showed morphologic changes that affected the tricuspid valve: diminished curvature of the leaflets, altered dynamic motion of the leaflets during diastole, fused and shortened chordae retraction and reduced excursion of the valve. A moderate to severe tricuspid regurgitation and tricuspid stenosis with gradient media de 5 mmHg was observed. In addition, the right ventricle was dilated, a severe pulmonary hypertension, a right pleural effusion and a minor pericardial effusion circumference were detected. All these findings were consistent with CHD.

Conclusions

This report describes an unusual case of CHD in TAR patient. In fact, the interest of this case is the role played by the echocardiogram in the differential diagnosis for tricuspid valve diseases. Tricuspid stenosis is an infrequent condition and it is usually related with rheumatic disease associated with mitral valve disease. Although the carcinoid syndrome is infrequent, any changes in the anatomical structure of the tricuspid valve (thickening, fibrosis and rigidity associated with stenosis and tricuspid regurgitation) should alert us to the suspicion of CHD

Abstract P225 Figure.

P1439 Familial dilated cardiomyopathy: assessment of left ventricular systolic and diastolic function by echocardiogram in asymptomatic patients

Funding Acknowledgements

Alfonso X El Sabio University

Introduction

Familial dilated cardiomyopathy (fDCM) represents 20% to 30% of idiopathic DCM (iDCM) ethiology. The assessment of cardiac function of these patients is awfully complex. Usually, myocardial fiber damages can not be detected in the early DCM stages. In this sense echocardiogram could be useful to detect incipient changes.

Purpose

The aim of this study was to characterize the systolic function of asymptomatic fDCM, compared within iDCM and control patients.

Material and methods

This study was carried out in 33 fDCM patients. A total of 4 fDCM families with LMNA gene mutation and 3 fDCM families with BLC2-associated athanogene 3 (BAG3) mutation were recruited. Moreover, a total of 30 iDCM and 66 healthy matched controls were enrolled in the study.

Results

58.14% were male. The average age was 45.3 ± 17 years. 72% showed sinus rhythm. Left bundle branch block (LBBB) was observed in 7.8% of patients. The LV ejection fraction (LVEF), sphericity index and mitral annular plane systolic excursion (MAPSE), were significantly improved in the fDCM patients compared to iDCM subjects. However, these parameters were aggravated compared with healthy controls. LVEF was enhanced in fDCM in contrast to iDCM (56% versus 35%; P < 0.001). Nevertheless, LVEF value was deteriorated in fDCM compared to healthy controls (56% versus 65%; P < 0.001). The values of septal and lateral annulus early diastolic velocity measured by DTI, were also diminished. All results are presented in Table 1.

Conclusions

Asymptomatic fDCM shown an intermediate value of LVEF between the iDCM and the control group. This ventricular remodeling process could be the consequence of a slight increase in the end-systolic diameter.

Patients Characteristics Patients Characteristics iDCM 30 patients fDCM 33 patients Control Group 66 Healthy P LVEF 32 (29.78-40) 56.0 (39.7-64.2) 65 (62-69.5) 0.001 EDD 62.5 (59.2-65.7) 53.7 (45.7-57.6) 45.50 (43-48.8) 0.001 ESD 53 (47-58.75) 36 (30.9-54.2) 27.9 (24-31) 0.001 MAPSE 11 (10-12.50) 14 (14-18) 19 (17-20) 0.001 Sphericity index 0.70 (0.66–0.79) 0.69 (0.66-0.79) 0.53 (0.48-58) 0.001 LA volume 61.5 (57-75.1) 32 (23-46.5) 17 (14.2-20) NS Septal annulus Early diastolic Velocity (cm/s) DTI 3.5 (3-4.2) 7.5 (1.6-8.8) 9 (7.9-11) 0.001 Lateral annulus Early diastolic Velocity (cm/s) DT 7.2 (5-8.9) 9.5 (1.8-11.8) 13 (10.37-15) 0.001 Table1. Echocardiografic findings in patients. LVEF: left ventricular ejection fraction; EDD: end-diastolic diameter; ESD: end systolic diameter; MAPSE:mitral annular plane systoluc excursion; LA: left atrium; TDI: Tissue Doppler imagin.

Abstract P1439 Figure. Familial dilated cardiomyopathy

4119Predictors of progression of preclinical left ventricular diastolic dysfunction to clinical heart failure in patients with malignancy

Background

Preclinical diastolic dysfunction PDD is a well-known but poorly understood risk factor for clinical heart failure CHF. Preclinical diastolic dysfunction and predictors of progression of PDD to CHF in patients with malignancy has never been studied.

Purpose

The purpose of our study was to determine the incidence of CHF in cancer patients who have preexisting preclinical diastolic dysfunction, with a particular focus on identifying the risk factors contributing to progression of PDD to CHF.

Study design

We retrospectively sought all the patients who underwent echocardiography from 2003 to 2008 and were found to have preclinical diastolic dysfunction at our institution. PDD was defined as presence of grade I diastolic dysfunction, LVEF ≥50%, and free of clinical diagnosis of heart failure. Of these, only the patients who had a confirmed histopathological diagnosis of malignancy were included in the study. The end point was incidence of clinical heart failure, HFrEF and HFpEF. Multivariable adjusted Cox proportional hazards regression were performed to study the predictors of CHF.

Results

Out of 1086 patients with PDD and a histopathological diagnosis of malignancy, 208 patients were diagnosed with new onset CHF during the 10 years follow-up. Incidence of CHF, HFpEF and HFrEF was found to be 32.1 per 1,000 person-year, 13.9 per 1,000 person-year and 2.93 per 1,000 person-year respectively. Patients who developed clinical heart failure were found to have more hypertension, diabetes, myocardial infarction, peripheral vascular disease, pulmonary disease, renal disease, hematological malignancies and metastatic disease when compared to patients who did not develop heart failure. In multivariable adjusted Cox regression analysis, age at index date (HR 1.02, 95% CI 1.01–1.04, p=0.001), diabetes (HR 1.74, 95% CI 1.28–2.35, p<0.001), myocardial infarction (HR 2.19, 95% CI 1.49–3.20, p<0.001), lung disease (HR 1.53, 95% CI 1.14–2.06, p=0.004) and renal disease (HR 2.03, 95% CI 1.45–2.84, p<0.001) were independent predictors of CHF in patients with PDD and malignancy. Among chemotherapy agents, Vincristine, Ifosfamide, transtuzumab and Bortezomib were found to be associated with CHF.

Conclusion

This is the first study ever to report the incidence of CHF, HFrEF and HFpEF and identify a distinct set of predictors of heart failure in patients with PDD and malignancy. We estimated a much higher incidence of CHF (19%) in our study population, when compared to the general population with malignancy. Our study also depicted a significantly high incidence of HFpEF compared to HFrEF (8.3% vs 1.75%). Our study shows that patients with malignancy are at a significantly higher risk of developing heart failure if they have preexisting diastolic dysfunction. This emphasizes the importance of identifying patients with diastolic dysfunction and a more rigorous cardiovascular surveillance to prevent them from potential heart failure.

Acknowledgement/Funding

None

Abstract P6-17-11: The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer

Background: Pharmacologically targeting the HER2 oncoprotein provides clinical benefit for patients with HER2-amplified cancers. However, a significant number of patients do not respond to the currently approved HER2-targeted therapies, despite carrying the HER2-alteration. Small molecule inhibitors of HER2, that target other receptor tyrosine kinases such as EGFR (i.e. lapatinib), are approved and provide some clinical benefit but are often associated with increased toxicity. Tucatinib (ARRY-380) is an orally available, potent, highly selective small molecule inhibitor of the HER2 kinase. In this study, we assessed the in vitroand in vivoactivity of tucatinib, relative to approved HER2-targeting molecules, in a panel of molecularly characterized breast cancer cell lines.

Materials and Methods:The growth inhibitory activity of tucatinib, trastuzumab and lapatinib were evaluated in a panel of 48 breast cancer cell lines molecularly characterized at baselineby genomic (array-CGH) and proteomic (Reverse Phase Protein Array; RPPA) profiling. IC50values for tucatinib and lapatinibwere determined from direct cell counts using a Cellavista Cell Imaging System. Trastuzumab activity was measured as % inhibition of cell growth at fixed concentrations. In vivoefficacy of tucatinib was assessed in cell line xenograft models of HER2+/ER- and HER2+/ER+ breast cancers as a single agent or in combination with targeted therapies for breast cancer.

Results: A broad range of IC50values (3.2nM to &gt;10μM), was seen for tucatinib with a high degree of selectivity for the HER2-amplfied sub-type. High levels of total and phosphorylated HER2 (pHER2) accompanied by high levels of pEGFR and pHER3 enriched for sensitivity to tucatinib, confirming that HER2-driven cancers may be uniquely sensitive to tucatinib. The response profile for lapatinib was less clean, with responses also observed in HER2-low/EGFR-high cell lines. Sensitivity to tucatinib was also observed in HER2-amplified cell lines that were either de novoor acquired resistant to trastuzumab. Single agent tucatinib induced tumor regressions in a xenograft model of HER2+/ER+ breast cancer. Tumor regressions were further enhanced by combination with trastuzumab. The combination of tucatinib plus trastuzumab was as efficacious and better tolerated than trastuzumab plus docetaxel or trastuzumab plus pertuzumab plus docetaxel. The triple combination of tucatinib plus hormonal blockade (fulvestrant) and CDK4/6 inhibition (abemaciclib) also induced robust tumor regressions, without significant body weight loss.

Discussion: These preclinical data highlight the potential of the HER2-selective small molecule inhibitor, tucatinib, to provide benefit to patients with HER2-amplifed cancers. Furthermore, our biomarker analysis of response to tucatinib has identified a HER2-driven signature within the HER2-amplfied sub-type that selects for sensitivity to tucatinib. Selecting patients based on this profile may further enrich for individuals most likely to benefit from tucatinib-based therapies.

Citation Format: O'Brien NA, Conklin D, McDermott M, Luo T, Ayala R, Issakhanian S, Salgar S, Hurvitz S, Slamon DJ. The small molecule inhibitor of HER2, tucatinib, has potent and highly selective activity in preclinical modes of HER2-driven cancer [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 P6-17-11.

Abstract P4-06-07: Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer

Background: Recent advances in the field of cancer immunotherapy have increased demand for reliable preclinical models to inform patient selection and rational drug combination strategies. The development of the bone marrow-liver-thymus (BLT) mouse may provide the opportunity to study the complex interactions of human tumor and host immune systems in vivo. Other models are limited by the rapid onset of graft versus host disease (GVHD) and a lack of orderly maturation and trafficking of human T and B cells. In BLT mice, implantation of human fetal liver and thymus fragments beneath the kidney capsule of NSG (NOD/SCID/IL-2RΥ-/-) mice followed by engraftment of matched ex vivoexpanded CD34+ cells supports the production of an almost complete human immune system. In this study, we used this model to assess the efficacy of the anti-PD-1 therapeutic antibody, nivolumab, in combination with targeted therapeutics in specific breast cancer sub-types.

Materials and Methods: For triple negative breast cancer (TNBC), the activity of nivolumab was assessed in combination with the PARP1/2 inhibitor, talazoparib, in humanized BLT mice. Xenografts were established by subcutaneous injection of 5.0x106MDA-231 (TNBC) cells. Mice (n=5) were randomized into treatment groups as follows; 1) Vehicle control (PBS), 2) nivolumab (10mg/kg QW), 3) talazoparib (0.33mg/kg Q5/2D) and 4) nivolumab+talazoparib. After 21 days of treatment, tumor tissue, serum and PBMCs were collected for biomarker analysis.

Results: Successful reconstitution of mature human T and B cells was confirmed in BLT mice 12-weeks post engraftment of donor tissue and CD34+ hematopoietic stem cells. MDA-231 cells injected subcutaneously into the flank of these mice formed palpable tumors (150-200mm3) within 9 days of injection. For vehicle control treated mice, tumors grew (2.5-fold) throughout the 21-day study. Single agent nivolumab induced significant tumor growth inhibition (TGI) relative to vehicle control treated mice at Day 21. Single agent talazoparib also induced comparable levels of TGI as did the combination of nivolumab plus talazoparib. Nivolumab treated mice continued to gain weight throughout the study without overt signs of toxicity. Reversible weight loss was observed in the talazoparib and combination treated arms. Overt signs of GVHD were not observed in any of these animals. Preliminary tissue analysis identified high levels of cell surface PD-L1 protein in control treated MDA-231 xenografts. Further analysis of the treated tumors will provide valuable insight into the mechanism of action of this class of molecule. We are establishing xenograft models of hormone receptor (ER+) positive breast cancer to measure the activity of nivolumab+/-CDK4/6-inhibition in humanized BLT mice and these data will also be presented.

Discussion: The data presented here highlight the potential of the PD-1 antibody nivolumab to have activity in TNBC. Furthermore, these findings illustrate the potential of the humanized BLT-mouse to model responses to immune check-point in the preclinical setting. Expanded use of this model may help to identify response biomarkers and inform design of combination therapies using immune oncology molecules and approved targeted therapies.

Citation Format: O'Brien NA, Luo T, Ayala R, Salgar S, Conklin D, McDermott M, Kitchen S, Rezek V, Horak C, Dugan U, Slamon DJ. Activity of nivolumab alone or in combination with targeted therapies in a humanized BLT-mouse model of human breast cancer [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 P4-06-07.

[Lithogenic risk index in urinary lithiasis patients and their evolution after treatment.]

OBJECTIVE

To determine the lithogenic risk index and its evolution after treatment of paraguayan lithiasic patients.

METHODS

This experimental study of temporal series included 28 lithiasic patients of both sexes that attended to the Instituto de Prevision Social in 2012. Basal evaluation included metabolic study and urinary saturation indexes determined by EQUIL software. With this data, a specific treatment was selected for each patient. The follow up included a medical consultation monthly and the metabolic evaluation after 6 month. The study was approved by an ethical committee.

RESULTS

Basal evaluation showed hypocitraturia, hypercalciuria and hyperoxaluria in 50%, 46.4% and 14.3% of patients, whereas 42.9% showed diuresis lower than 2 L/day. Crystallization risk for calcium oxalate, sodium urate, hidroxiapatite and uric acid was observed in 1,3, 12 and 12 patients respectively. After treatment, a decrease in the frequency of hypercalciuria and hypocitraturia was observed, just like the urinary saturation risk for all types of crystals studied. Statistical analysis showed a significant variation of diuresis (p 0,0001) and uric acid urinary saturation (p 0,002) after treatment.

CONCLUSIONS

The lithogenic risk factors more frequently detected were hipocitraturia and hypercalciuria. Therapeutic measures achieved the decrease of saturation risk indexes for all the crystals analyzed, registering significant effects in the increase of diuresis and uric acid saturation decrease. The use of software tools for the calculation of crystallization risk is an important innovation in Paraguay.

Abstract P3-04-15: The PI3K-inhibitor, copanlisib, has selective activity in luminal breast cancer cell lines and shows robust combined activity with hormonal blockade and CDK-4/6 inhibition in ER+ breast cancer cell line xenografts

Background: Genetic and epigenetic alterations in the PI3K/mTOR and cyclin D:CDK-4/6:Rb signaling axes occur frequently in breast cancer and have been attributed to resistance to both ER- and HER2-directed therapeutics. Pharmacologically targeting CDK-4/6 in combination with hormonal blockade provides clinical benefit in patients with advanced ER+ breast cancer. In this study, we evaluated the activity of the pan-class I PI3K inhibitor, copanlisib (BAY-80-6946), with potent alpha and delta activity as a single agent or in combination with CDK-4/6 inhibition and hormonal blockade in a panel of breast cancer cell lines.

Methods: The growth inhibitory activity of copanlisib was evaluated against a large panel of 48 breast cancer cell lines molecularly characterized by genomic, transcriptomic and proteomic profiling. IC50 values were determined from direct cell counts using a Z1-particle counter. The activity of copanlisib in combination with hormone blockade and CDK-4/6 inhibition, by palbociclib, was assessed in two cell line xenograft models of ER+ breast cancer; MCF7(PIK3CA-E545K) and ZR751(PIK3CA WT). For xenograft studies, tumor bearing mice were treated once weekly (BID) by intravenous injection with clinically achievable doses of copanlisib (10 mg/kg) as single agent or in combination with tamoxifen or fulvestrant with or without 75 mg/kg daily palbociclib for 21 days.

Results: A broad range of IC50 values (0.491-895 nM), with a high degree of separation between sensitive and resistant histologically defined subgroups were determined for copanlisib, indicating the potential for a wide therapeutic window. Luminal subtype, the presence of activating mutations in PIK3CA, high levels of ER, HER2, HER3 and EGFR protein enriched for sensitivity to copanlisib. Activating mutations of KRAS and BRAF were associated with resistance to copanlisib. Single agent copanlisib induced significant tumor growth inhibition (TGI) relative to vehicle control in each of the xenograft models. Modest increases in anti-tumor activity were achieved when copanlisib was combined with hormonal blockade by either tamoxifen or fulvestrant. However, robust tumor regressions were observed with the triple combinations of copanlisib-palbociclib-tamoxifen and copanlisib-palbociclib-fulvestrant. Furthermore, these triple combinations achieved a statistically significant improvement in anti-tumor activity over the standard of care combination of palbociclib plus fulvestrant. Each of the single agent and treatment combinations tested were well tolerated in animals.

Discussion: These preclinical data illustrate the potent and selective activity of the pan class I PI3K inhibitor copanlisib in luminal breast cancers and support the clinical investigation of copanlisib in combination with CDK-4/6 inhibition and hormonal blockade in ER+ breast cancer.

Citation Format: O'Brien NA, Conklin D, Luo T, Ayala R, Issakhanian S, Kalous O, Von Euw E, Politz O, Wilhelm S, Childs BH, Hurvitz SA, Slamon DJ. The PI3K-inhibitor, copanlisib, has selective activity in luminal breast cancer cell lines and shows robust combined activity with hormonal blockade and CDK-4/6 inhibition in ER+ breast cancer cell line xenografts [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 P3-04-15.

Abstract PD1-5: Targeting PI3K overcomes in vivo resistance to everolimus in estrogen receptor (ER+) breast cancer

Background: The selective mTORC1 inhibitor everolimus (RAD001/Affinitor®) has recently been approved, in combination with exemestane, for treatment of advanced hormone receptor positive breast cancer after demonstrating significantly improved progression free survival for patients having progressed on a previous non-steroidal aromatase inhibitor. However, despite these improved outcomes many tumors go on to develop resistance to everolimus. Alterations in PI3K/AKT signaling, either through activating mutations in PIK3CA or loss of PTEN, have been shown to influence responses to everolimus treatment in vitro (Weigelt et al., 2011). In this study we used cell line xenograft models of everolimus resistance to assess the potential of a pan-PI3K inhibitor (BKM120) or a p110a-specific inhibitor (BYL719) to reverse resistance either as single agents or in combination with anti-ER therapy (Fulvestrant).

Materials and Methods: Everolimus resistant xenografts were developed from three originally everolimus sensitive ER+ cell lines carrying distinct genetic alterations that confer aberrant PI3K/AKT signaling; ZR75-1 (PTEN null), MCF7 (PIK3CA mutant) and KPL1 (wild-type). Mice were treated by daily oral everolimus (10 mg/kg) until tumors began to progress on treatment (∼ 35 days of daily treatment). Mice that developed everolimus resistant tumors were randomized into six treatment groups (n = 6) as follows: continued on everolimus (10 mg/kg), fulvestrant (5 mg/wk), BKM120 (35 mg/kg), BYL719 (50 mg/kg), fulvestrant + BKM120 or BYL719.

Results: All three cell line xenografts were initially responsive to everolimus. ZR75-1 xenografts were allowed to progress on everolimus until they reached a mean tumor volume greater than that on day zero, at which point mice were randomized into treatment groups. Tumor selected to continue on everolimus gained a mean tumor volume of 550 mm3 over the six-week duration of study, demonstrating resistance to everolimus. These tumors showed a partial response to Fulvestrant (28% TGI), BYL719 alone (40% TGI) and BYL719 combined with fulvestrant (61% TGI). In contrast, over 100% tumor growth inhibition (tumor regression) was observed with both single agent BKM120 or BKM120 plus fulvestrant. This is consistent with our in vitro findings that PTEN null tumor cells might be less sensitive to inhibition by BYL719 yet sensitive to BKM120. Data from the ongoing PIK3CA mutant and wild-type KPL1 models will inform whether these molecular subtypes of ER+ breast cancer are more sensitive to the pan-PI3K inhibitor or the p110α-specific inhibitor. Comprehensive pharmacodynamic analyses of these tumor tissues may identify the additional molecular determinants responsible for resistance to everolimus and help guide the design of future clinical studies.

Discussion: These pre-clinical data indicate that targeting PI3K either alone or in combination with fulvestrant overcomes resistance to everolimus in ER+ breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD1-5.

Epigenomic profiling in polycythaemia vera and essential thrombocythaemia shows low levels of aberrant DNA methylation

AIMS

The purpose of this study was to compare the DNA-methylation signature in classic chronic Philadelphia negative myeloproliferative neoplasms (MPN), polycythaemia vera (PV) and essential thrombocythaemia (ET), in order to obtain a global insight into DNA-methylation changes associated with these malignancies.

METHODS

Thirty-five MPN samples from 11 ET JAK2 V617F, 12 ET JAK2 wild type (WT) and 12 PV JAK2 V617F patients as well as 12 from healthy donors were analysed. DNA samples extracted from whole peripheral blood were hybridised to the 'HumanMethylation27 DNA Analysis BeadChip.'

RESULTS

All groups showed a very homogeneous methylation pattern. Only the ZNF577 gene showed a differential methylation profile between PV JAK2 V617F positive and controls. This aberrant methylation was correlated with a differential gene expression of ZNF577. No aberrant hypermethylation was found in the SOCS-1 and SOCS-3 genes.

CONCLUSIONS

According to our results, an aberrant methylation pattern does not seem to play a crucial role in MPN pathogenesis; nor does it justify phenotypical differences between PV and ET.

Living donor liver transplantation: usefulness of hemostatic and prothrombotic screening in potential donors

Bleeding and thrombosis are serious complications of living donor liver transplantation (LDLT). The aim of this paper was to describe the results of a screening for coagulation disorders, including for thrombophilic factors, in potential living liver graft donors and to evaluate thrombotic and bleeding events in donors and recipients, during and after the procedure. From January 2001 to January 2007, 41 LDLTs were performed at our institution. We performed systematic screening for bleeding or prothrombotic states among 188 potential donors, 38 (20.2%) of whom showed at least one abnormality. We rejected potential donors with factor V Leiden, prothrombin mutation G20210A, and deficiencies in anticoagulant proteins (protein C, protein S, and antithrombin) or coagulation factors. Bleeding and thrombotic events in donors and recipients of the 41 LDLTs were evaluated during 7 days to 70 months follow-up. No major bleeding events were detected in the donors. Neither donor nor recipient experienced venous thrombosis or pulmonary embolism. Among all recipients, six suffered hepatic artery thrombosis including five in the first month probably related to surgery. Deep venous thrombosis and pulmonary embolism are well-known complications of hepatic surgery; Prothrombotic abnormalities in the donor can be transmitted to the recipient, leading to increased risk of serious postoperative events. Although the cost-effectiveness is not definitely established, we recommend systematic screening for hemostatic and prothrombotic disorders to prevent more morbidity of a procedure that already has high risks of bleeding and thrombosis.