Angel Guerrero

Phase III Trial Evaluating the Addition of Bevacizumab to Endocrine Therapy As First-Line Treatment for Advanced Breast Cancer: The Letrozole/Fulvestrant and Avastin (LEA) Study

PURPOSE To test whether combining bevacizumab, an anti-vascular endothelial growth factor treatment, with endocrine therapy (ET) could potentially delay the emergence of resistance to ET. PATIENTS AND METHODS A multicenter, randomized, open-label, phase III, binational (Spain and Germany) study added bevacizumab (15 mg/kg every 3 weeks) to ET (ET-B; letrozole or fulvestrant) as first-line therapy in postmenopausal patients with human epidermal growth factor receptor 2 (HER2) -negative and hormone receptor-positive advanced breast cancer. We compared progression-free survival (PFS), overall survival (OS), overall response rate (ORR), response duration (RD), time to treatment failure (TTF), clinical benefit rate (CBR), and safety. RESULTS From 380 patients recruited (2007 to 2011), 374 were analyzed by intent to-treat (184 patients on ET and 190 patients on ET-B). Median age was 65 years, 270 patients (72%) had Eastern Cooperative Oncology Group performance status of 0, 178 patients (48%) had visceral metastases, and 171 patients (46%) and 195 patients (52%) had received prior chemotherapy or ET, respectively. Median PFS was 14.4 months in the ET arm and 19.3 months in the ET-B arm (hazard ratio, 0.83; 95% CI, 0.65 to 1.06; P = .126). ORR, CBR, and RD with ET versus ET-B were 22% versus 41% (P < .001), 67% versus 77% (P = .041), and 13.3 months versus 17.6 months (P = .434), respectively. TTF and OS were comparable in both arms. Grade 3 to 4 hypertension, aminotransferase elevation, and proteinuria were significantly higher in the ET-B arm. Eight patients (4.2%) receiving ET-B died during study or within 30 days of end of treatment. CONCLUSION The addition of bevacizumab to ET in first-line treatment failed to produce a statistically significant increase in PFS or OS in women with HER2-negative/hormone receptor-positive advanced breast cancer.

Abstract S1-7: Phase III trial evaluating the addition of bevacizumab to endocrine therapy as first-line treatment for advanced breast cancer – First efficacy results from the LEA study.

Background: Preclinical data (de la Haba J, AACR 2011) and retrospective clinical data (Mander P, Cancer 2003; Linderhol B, JCO 2000) suggest that high vascular endothelial growth factor (VEGF) levels in breast tumors are associated with a decreased response to endocrine therapy. We designed the randomized phase III LEA study of first-line bevacizumab in combination with hormone therapy in endocrine responsive advanced breast cancer patients to address the hypothesis that anti-VEGF treatment can prevent resistance to hormone therapy in these patients. Methods: A multicenter, bi-national, randomized, open label, phase III study investigated the addition of Bevacizumab (B) 15mg/kg every 3 weeks to an endocrine therapy (ET) with letrozole (2.5 mg/day) or fulvestrant (250mg/4 weeks) as first-line therapy in advanced breast cancer. Postmenopausal patients with HER2-negative and hormone-receptor-positive breast cancer were eligible and randomized in a 1:1 ratio after being stratified for prior adjuvant therapy with an aromatase inhibitor (AI); number of involved sites (one/multiple); measurable lesions (yes/no) and participating country (Spain/Germany). The primary objective was to compare progression-free survival (PFS) between treatment arms. Secondary objectives were overall survival, time to treatment failure, overall response rate, response duration, clinical benefit rate, and safety. In total, 344 patients (172 in each treatment arm) were needed to detect a hazard ratio of 0.69 (corresponding to a median PFS of 9 months in the ET arm and 13 months in the ET+B arm) with α=0.05 and β=0.2. With an expected drop-out rate of 10%, 378 patients were to be included. The efficacy analysis is pre-planned after 270 events. Results: From 11/2007 to 8/2011, 380 patients were randomized in Spain and Germany to ET (n = 189) or ET+B (n = 191), 342 patients received letrozole and 38 fulvestrant. Baseline characteristics were well balanced. Median age was 65 years (38–86) and 72% of patients had ECOG PS 0. Twelve patients (4%) entered the trial with locally advanced disease, 65% had measurable lesions, 63% had bone and 45% visceral metastasis. 76% of patients had both hormone receptor positive. 44% had adjuvant chemotherapy and 51% adjuvant endocrine therapy from which 36% of patients received adjuvant AI. Full safety data will be presented at ESMO this year. The main side effects (any grade, per patient, ET+B vs ET) were anemia 76% vs 44%, p Conclusions: LEA is the first phase III study to explore the use of an anti-angiogenic drug in combination with endocrine therapy. The efficacy results will be presented at the meeting. First and second authors have contributed equally to this study Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S1-7.

A phase I study of the SRC kinase inhibitor dasatinib with trastuzumab and paclitaxel as first line therapy for patients with HER2-overexpressing advanced breast cancer. GEICAM/2010-04 study

The anti-HER2 antibody trastuzumab have shown clinical activity in combination with chemotherapy in different breast cancer settings. However, most of patients treated with this antibody progress after a period of treatment. Activation of the kinase SRC has been linked with resistance to trastuzumab in several preclinical studies. We designed a phase I clinical study to explore the activity of weekly trastuzumab (2 mg/kg) plus paclitaxel (80 mg/m2) in combination with the anti-SRC kinase inhibitor Dasatinib in the first line treatment of HER2 metastatic breast cancer. The primary objective was to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D); secondary objectives included efficacy, objective response rate (ORR), pharmacokinetics and pharmacodynamics. A “3+3” design guided dose escalation with two oral dose levels of dasatinib: 100mg (DL1) and 140 mg (DL2). 10 patients were included in the phase I part. Dasatinib 100 mg q.d. was established as the recommended RP2D. The median number of administered cycles was 12 (range, 1 to 18). Grade 3 treatment-related AEs at DL1 were diarrhea (n = 2), hyponatremia (n = 1), fatigue (n = 1), and AST/ALT elevation (n = 1). A significant reduction in p-SRC expression on epidermal keratinocytes on sequential skin biopsies was observed. In conclusion, we describe the feasibility of the combination of dasatinib, trastuzumab and paclitaxel, and its effect on proteins involved in trastuzumab resistance. The phase II part of this study is currently evaluating efficacy.

Neoadjuvant Therapy with Weekly Nanoparticle Albumin‐Bound Paclitaxel for Luminal Early Breast Cancer Patients: Results from the NABRAX Study (GEICAM/2011‐02), a Multicenter, Non‐Randomized, Phase II Trial, with a Companion Biomarker Analysis

BACKGROUND Nanoparticle albumin-bound paclitaxel (nab-Paclitaxel) is an alternative to standard taxanes for breast cancer (BC) treatment. We evaluated nab-Paclitaxel efficacy as neoadjuvant treatment for early estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) disease. MATERIALS AND METHODS Women with ER+, HER2-, stage II-III BC were treated preoperatively with four cycles of weekly nab-Paclitaxel (150 mg/m2), 3 weeks on and 1 week off. We hypothesized that poor pathological response rate (residual cancer burden [RCB] III; Symmans criteria) would be ≤16%. RESULTS Eighty-one patients with a median age of 47 years were treated; 64.2% were premenopausal, and 69% of tumors were stage II. Residual cancer burden III rate was 28.4% (95% confidence interval [CI]: 18.6%-38.2%), RCB 0+I (good response) rate was 24.7% (95% CI: 15.3%-34.1%) and RCB 0 (complete response) rate was 7.4% (95% CI: 1.7%-13.1%). Objective response rate by magnetic resonance imaging was 76.5% and rate of conversion to breast conserving surgery was 40.0%. The most frequent grade 3 and 4 toxicity was neutropenia (12.3% and 3.7% of patients, respectively), without any febrile neutropenia. Sensory neuropathy grade 2 and 3 were seen in 25.9% and 2.5% of patients, respectively. Tumor secreted protein, acidic, cysteine-rich (SPARC) overexpression was significantly associated with RCB 0 (odds ratio: 0.079; 95% CI: 0.009-0.689; p = .0216). CONCLUSION Despite failing to confirm an RCB III rate ≤16% in nab-Paclitaxel-treated patients, the RCB 0+I rate indicates a significant drug antitumor activity with low rates of grade 3-4 toxicity. Our exploratory biomarker analysis suggests a potential predictive role of complete response for SPARC. Confirmatory analyses are warranted, adapting dose and schedule to decrease peripheral neurotoxicity. (Trial registration: European Clinical Trials Database study number: 2011-004476-10; ClinicalTrials.gov: NCT01565499). IMPLICATIONS FOR PRACTICE The pathological response rate (residual cancer burden [RCB]; Symmans criteria) of nanoparticle albumin-bound paclitaxel administered as neoadjuvant treatment for early estrogen receptor-positive, human epidermal growth factor receptor 2-negative disease was evaluated. Whereas poor response (RCB III) was 24.7%, similar to that for docetaxel, good response (RCB 0+I) reached 23.0%, far superior to the 13% for docetaxel, while keeping toxicity low. Exploratory biomarker analysis suggests secreted protein, acidic, cysteine-rich overexpression in tumor cells as a potential predictor of complete response (RCB 0). Findings point to an encouraging single-agent neoadjuvant treatment with low toxicity, which warrants future research and development.

Abstract 3890: Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance

Cytotoxic chemotherapy is the standard of care for patients with triple negative breast cancer (TNBC). Most patients with advanced TNBC progress after chemotherapy and die from metastatic disease. MCL1 is an anti-apoptotic Bcl-2 family member known to sequester and inactivate pro-apoptotic Bcl-2 family proteins and, thus, contribute to chemotherapy resistance. We previously reported that ~45% of residual TNBCs that remain in the breast after neoadjuvant chemotherapy harbor MCL1 amplification, suggesting a causal role for MCL1 in drug resistance. A recent report (Goodwin et al. 2015) suggested that siRNA-mediated ablation of MCL1 does not induce apoptosis in claudin-low TNBC cells with a cancer stem cell (CSC) gene expression signature. CSCs comprise a rare population of cells with tumor-initiating properties and refractoriness to chemotherapy. In this study, we showed that MCL1 expression is elevated in claudin-low TNBC SUM159PT and MDA436 CSCs as measured by ALDH + by flow cytometry and ability to form mammospheres. RNA interference of MCL1 in SUM159PT cells reduced CSCs and attenuated tumor formation in vivo. Mitochondrial oxidative phosphorylation (mtOXPHOS) plays a crucial role in maintenance of CSCs. MCL1 has been shown to localize in the mitochondrial matrix and contribute to mitochondrial respiration. Thus, we hypothesized that MCL1 contributes to enrichment of TNBC CSCs and chemotherapy resistance via mitochondrial regulation. Stable transfection and overexpression of MCL1 in MDA468 cells increased oxygen consumption ratio, mitochondrial membrane potential, and production of reactive oxygen species (ROS), all features of activated mtOXPHOS. Conversely, RNAi-mediated ablation of MCL1 in SUM159PT and MDA436 cells repressed these markers of activated mtOXPHOS. A mutant of MCL1 lacking its mitochondrial target sequences (MTS) was unable to localize in mitochondria and, when transfected into MDA468 cells, reduced the CD44 high /CD24 low fraction and mammosphere formation. We next tested VU0659158, a BH3 mimetic in development at Vanderbilt that disrupts MCL1 interactions with BH3 domain-containing proteins, such as BID, BIM, NOXA and PUMA. Treatment of SUM159PT cells with VU0659158 increased caspase activity but did not attenuate mammosphere formation. Analysis of mRNA expression in TCGA revealed that genes induced by mtOXPHOS involved in the hypoxia pathway are significantly up-regulated in MCL1 amplified breast cancers. Finally, pharmacological inhibition of HIF-1α, a key regulator of hypoxia, with digoxin decreased CSCs and attenuated tumor formation in vivo. These data suggest that 1) MCL1 confers resistance to chemotherapy by expanding CSCs via mtOXPHOS independent of its BH3 domain-mediated, anti-apoptotic function, and 2) targeting mitochondrial respiration and the hypoxia pathway may delay or reverse chemotherapy resistance in MCL1 amplified TNBC. Citation Format: Kyung-min Lee, Jennifer Giltnane, Justin Balko, Luis Schwarz, Angel Guerrero, Katie Hutchinson, Mellissa Hicks, Violeta Sanchez, Melinda Sanders, Taekyu Lee, Edward Olejniczak, Stephen Fesik, Carlos Arteaga. Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3890. doi:10.1158/1538-7445.AM2017-3890

Abstract P3-07-42: Predicting outcome and benefit to first-line bevacizumab in advanced/metastatic hormone receptor (HR)+/HER2-negative breast cancer (BC) treated with endocrine therapy: A correlative science study from the LEA phase III clinical trial (GEICAM/2006-11_GBG 051)

Introduction: The role of bevacizumab in combination with chemotherapy in metastatic BC is controversial, and no biomarker exists as of today that predicts benefit to this agent. In the LEA clinical trial, a numerical, statistically non-significant benefit from the addition of bevacizumab to endocrine therapy (ET) was observed in the first-line metastatic setting (18.4 vs. 13.8 months of Progression-Free Survival (PFS), p=0.14). Here, we explored various gene expression-based predictors of outcome and benefit to bevacizumab. Methods and materials: LEA trial randomized 380 patients with HR+/HER2- advanced disease to bevacizumab in combination with ET (ET+B) vs. ET alone. Primary endpoint was PFS. Expression of BC selected genes was evaluated in formalin-fixed paraffin-embedded (FFPE) primary tumors using the nCounter platform from patients randomized in Spain that consent for biomarker analyses. The following variables were evaluated: 1) research-based PAM50 intrinsic subtypes (categorical variable; Luminal A, Luminal B, HER2-enriched, Basal-like and Normal-like); 2) research-based PAM50 signatures (continuous variable; scores showing the distant of the gene expression values of an individual sample compared to the centroid gene values for each PAM50 intrinsic subtype); 3) risk of recurrence (ROR) groups (low, medium and high); 4) the 13-gene hypoxia/VEGF signature (continuous); and 5) Ki67 by immunohistochemistry (continuous). Uni- and multivariable Cox models for PFS were used to test the prognostic significance of each variable. To determine whether each variable is predictive of bevacizumab benefit, we tested the interaction term of each variable by treatment arm in a Cox model. Results: Tumor samples from 103 patients were analyzed: 55 (53%) in ET+B arm and 49 (47%) in ET arm. Subtype distribution was as follows: 57 (55.3%) Luminal A, 32 (31.1%) Luminal B, 5 (4.9%) HER2-enriched, 1 (1.0%) Basal-like, and 8 (7.8%) normal-like. In a univariate analysis, Luminal B tumors had a poorer outcome using Luminal A as reference (13.8 vs. 21.3 months, respectively; (hazard ratio, HR=1.80, 95% CI 1.10-2.95, p=0.019). Concordant with this finding, Luminal A signature was associated with a better outcome. Similarly, ROR-P high group showed a poorer outcome than ROR-P low group (8.5 vs. 19.4 months; HR=2.88, 95% CI 1.30-6.35, p=0.009). Neither VEGF-13 signature nor Ki67 were found to be associated with PFS. Similar findings were obtained after adjustment for treatment, age, previous ET, ECOG, visceral disease and number of metastatic sites. In terms of treatment benefit, the HER2-enriched signature was the only variable found predictive of bevacizumab PFS benefit in univariate (p=0.010) and multivariate (p=0.015) analyses. Conclusions: In advanced HR+/HER2- disease, intrinsic subtype (i.e. Luminal A vs. B) independently predicts PFS following first-line ET. In addition, HR+/HER2-negative tumors with high expression of the HER2-enriched signature, a biomarker of estrogen-independence, benefit the most from bevacizumab. Further validation of these prognostic and predictive biomarkers is warranted. Citation Format: Prat A, de la Haba-Rodriguez J, Guerrero A, Garcia-Saenz JA, Morales S, Anton A, Munoz M, Ramos M, Martinez-Janez N, Margeli M, Servitja S, Rojo F, Galvan P, Gonzalez S, Cruz J, Sanchez-Rovira P, Perello A, Rodriguez-Martin C, Casas M, Carrasco E, Caballero R, Martin M. Predicting outcome and benefit to first-line bevacizumab in advanced/metastatic hormone receptor (HR)+/HER2-negative breast cancer (BC) treated with endocrine therapy: A correlative science study from the LEA phase III clinical trial (GEICAM/2006-11_GBG 051). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-42.

Abstract P6-05-02: Intrinsic subtype and gene expression changes between primary and metastatic breast cancer

Background: A better understanding of the biological changes occurring during metastatic progression of breast cancer is needed to identify new biomarkers, targets and novel treatment strategies. Here, we compared the intrinsic subtype and the expression of a gene panel across a large dataset of paired primary and metastatic tissues. Methods: Expression profiling of 105 breast cancer-related genes was performed on 254 (127 pairs) formalin-fixed paraffin-embedded tumor tissues using the nCounter platform. Tumor samples were obtained from 3 independent sources (ConvertHER trial [BCRT 2014] and two in-house datasets). Tumors were classified into each intrinsic subtype using the research-based PAM50 classifier (Parker et al. J Clin Oncol 2009). Chi-square tests were performed to determine the differences in the distribution of variables. Paired two-class Significance of Microarrays (SAM) was performed to determine the genes differentially expressed between paired primary and metastatic tissues. In vitro stable transfection of FGFR4-GFP was performed on Luminal B MCF7 cell line. RNA was purified on control vs. transfected cell lines. 7-AAD cell viability was performed following estrogen deprivation for 6 days. Results: Subtype distribution in primary vs. metastatic disease was 39.0% vs. 26.8% for Luminal A (p=0.012), 26.0% vs. 35.0% for Luminal B (p=0.322), 11.4% vs. 20.3% for HER2-enriched (p=0.115) and 10.6% vs. 13.0% for Basal-like tumors (p=0.843). The rate of subtype conversion was 7.7% in Basal-like, 23.1% in HER2-enriched, 30.0% in Luminal B and 54.3% in Luminal A disease. The majority of subtype conversions in Luminal A disease were to Luminal B (72.0%) and HER2-enriched (24.0%). Overall, 13.2% of primary Luminal A/B tumors progressed to a HER2-E subtype despite 70% of them being clinically HER2-negative. In a paired analysis using all samples, 10- and 12- genes were found up- and down- regulated in metastatic tissues (False Discovery Rate [FDR] Conclusions: Metastatic tissues are relatively more proliferative and less luminal compared to primary tumors. This is especially relevant in primary Luminal A disease. In contrast, metastatic tissues from Basal-like primary disease remain largely unchanged. In luminal disease, a significant increase in the HER2-enriched profile is observed in metastatic disease despite most tumors being clinically HER2-negative. A potential driver of the HER2-enriched profile and estrogen independence in clinically HER2-negative metastatic tissues might be FGFR4. Citation Format: Prat A, Martinez de Duenas E, Galvan P, Garcia S, Burgues O, Pare L, Antolin S, Martinello R, Blancas I, Adamo B, Guerrero A, Munoz M, Nuciforo P, Vidal M, Perez RM, Chacon JI, Caballero R, Gascon P, Carrasco E, Rojo F, Perou CM, Cortes J, Adamo V, Albanell J, Lluch A. Intrinsic subtype and gene expression changes between primary and metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-05-02.

Abstract P2-13-17: Impact on survival of primary tumor resection in women with de novo metastatic breast cancer. The GEICAM Alamo I-III breast cancer registry (1990-2001)

Introduction: Retrospective data from institutional series and population-based databases have suggested a potential benefit of the primary tumor (PT) surgery in de novo metastatic breast cancer (MBC) patients (pts). Recently reported prospective data from 2 randomized trials and a multicenter registry questioned the real role of the local approach in the modern individualized systemic treatment era. Methods: The ALAMO (A) is a retrospective analysis of pts diagnosed with BC between 1990 and 2001 across 56 GEICAM hospitals in Spain. Patterns of BC presentation (tumor and host characteristics), treatment and survival were recorded in 3 cohorts, AI (1990-93, 4529 pts, closed by 2000), AII (1994-97, 10453 pts, closed by 2003) and AIII (1998-2001, 10675 pts, closed by 2007). MBC pts at first diagnosis excluding those without complete information about their PT surgery were included. Descriptive, Kaplan-Meier and Cox regression analyses were carried out. Results: 5.5% (N=1415) of the ALAMO database pts were initially diagnosed with MBC, 1331 fulfilled the present analysis criteria (327 from AI, 619 from AII and 385 from AIII). Median age was 63.1 years (range: 21.6-96.0), 51.8% had single-organ metastasis, and their distribution according to the predominant site of disease was skin/soft tissue (16.2%), bone (33.7%), and visceral (48.4%). Surgery of the PT was done in 44.5% (N=592) of pts (512 with radical procedures, 46 with palliative procedures and 34 unknown); besides, 427 pts underwent axillary dissection. Initial local treatment was the choice for 380 pts (358 surgery and 22 radiotherapy), 722 received initial systemic therapy (480 chemotherapy, 214 endocrine treatment and 28 both), 29 received best supportive care and for 200 pts the treatment sequence could not be established. Pts in the surgery (S) group were younger (19.5% vs 11.8% were Citation Format: Sara Lopez-Tarruella, Maria Jose Escudero, Miguel Martin, Carlos Jara, Angel Guerrero, Ana Lluch, Ana Santaballa, Purificacion Martinez del Prado, Juan Lao, Emilio Alba, Antonio Fernandez, Raquel Andres, Antonio Llombart, Norberto Batista, Ignacio Porras, Jose Manuel Lopez-Vega, Encarna Adrover, Lourdes Calvo, Marina Pollan, Eva Carrasco. Impact on survival of primary tumor resection in women with de novo metastatic breast cancer. The GEICAM Alamo I-III breast cancer registry (1990-2001) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-13-17.