A GINECO randomized phase II assessing addition of an aromatase inhibitor to oral vinorelbine in pretreated metastatic breast cancer patients

1043

Background: For ER+/HER2- metastatic breast cancer (mBC), efficacy of endocrine therapy + chemotherapy combination remain an open question. We hypothesized that continuing ER targeted therapy after progression in combination with chemotherapy may improve disease control. The objective of the CHEOPS trial was to assess the benefit of adding aromatase inhibitor (AI) to metronomic chemotherapy,oral vinorelbine, 50mg/3 time a week (OV) for AI pre-treated, ER+/HER2- mBC patients. Methods: Eligible patients had to have progressed on endocrine therapy and one or two lines of chemotherapy. They were randomized between vinorelbine (OV) and vinorelbine + AI (OV+AI). Primary end point was progression-free survival (PFS). To show an increase of median PFS (from 3.5 to 5.5 month, HR 0.636), with alpha = 5% and power = 80%, 130 evaluable patients were needed. Results: 121 patients were Included (OV = 61; OV+AI = 60). Median age was 68 (range: 49-87), Median time from metastatic diagnosis was 3.2 years (range 0 - 16.9). 109 patients (90%) had visceral metastases. They all had previously received an AI and had been treated with one line (N = 66, 54.5%), or 2 lines (N = 55, 45.5%) of chemotherapy. Median PFS was increased from 2.3 months with OV to 3.7 months with OV+AI, but this difference was not significant (HR 0.73 [95 % CI 0.50-1.06], log-rank test: P = 0.09) 81 patients (67%) had at least one adverse event (AE) of grade ≥ 3 (40 (66%) for OV vs 41 (68%) for OV+AI). The most common grade ≥ 3 AE were: GT gammas (23%), neutropenia (18%), arterial hypertension and lymphopenia (17%). The occurrence of 3 toxic deaths (OV = 1; OV+AI = 2) secondary to febrile aplasia motivated the early cessation of this clinical trial. 9 patients (5 OV (10%) and 4 OV+AI (8%) presented an objective complete or partial response. Conclusions: The addition of AI to OV over OV alone in AI resistant mBC was associated with a non-significant improvement of PFS, but both PFS are lower than expected. Metronomic OV schedule, at 50 mg three times a week, requires close biological monitoring. The question of hormonal treatment and chemotherapy combination remains open. Clinical trial information: EudraCT Number: 2015-000401-39.

Express study: A trial in progress exploring the association between low level of genomic alteration and exceptional and unexpected response to targeted therapies in patients with solid tumors

TPS3159

Background: Molecular targeted agents (MTA) resulted in breakthroughs in selected niches. It is often assumed that tumor regression is consecutive to an oncogenic de-addiction effect. An emerging hypothesis suggests that genomic instability may be associated with poor response to MTA. Indeed, the accumulation of defects in multiple oncogenes or tumor suppressor genes may result in the activation of multiple oncogenic pathways. These multiple signaling would mechanically result in a limitation of the oncogenic de-addiction process. Another hypothesis, suggests that tumor heterogeneity could also be associated with poor outcome under MTA. Such heterogeneity could also result from the genomic instability, and be appraised by bioinformatic and functional approaches. In this study, we thought to investigate whether molecular profiles reflecting a low level of genomic alterations in genes causally implicated in oncogenesis could be associated with an exceptional response (ER) to MTA. Methods: This is an exploratory, multicenter, multicohort, prospective trial conducted in 264 adult patients, with advanced breast, lung, colorectal, ovarian, kidney cancers and melanoma, having presented an ER to an approved MTA. ER is defined using the definition chosen by the NCI which combines the three criteria: - complete or partial response, - lasting > 6 months, - and not expected in > 10% of the patients in this drug – organ situation. The primary objective is to assess whether ER can be associated with a low level of genomic instability in the tumor. Low genomic instability is defined by the presence of less than the 5th quantile of genomic alterations (mutations, amplifications, deletions) to be expected in the given tumor type as per TCGA database. For each tumor type, the null hypothesis H0: π = 0.05 will be tested, against the one-sided alternative hypothesis π > 0.05. For each of the 6 cohorts, a sample size of 44 patients is necessary to achieve 80% power at π = 15 with a one-sided level 5% test. Patients presenting an ER will be identified retrospectively, in a nationwide manner, then monthly reviewed and validated for inclusion by a panel of pathology experts. As of February 2019, 75 patients have been included. The identification of molecular traits associated with ER might serve the development of predictive classifiers for precision medicine. This study also represents a unique opportunity to better understand cancer biology. Clinical trial information: NCT02701907.

A phase II study of abemaciclib in patients (pts) with brain metastases (BM) secondary to HR+, HER2- metastatic breast cancer (MBC)

1017

Background: Abemaciclib is a selective CDK4 & 6 inhibitor approved to treat HR+, HER2- MBC pts on a continuous dosing schedule as monotherapy or in combination with endocrine therapy (ET). Clinical data demonstrate abemaciclib penetrates the blood brain barrier resulting in comparable concentrations in tissues and plasma. Methods: JPBO is a Simon 2-stage trial evaluating abemaciclib in 6 pt cohorts with BM secondary to HR+ MBC, non-small cell lung cancer, or melanoma. Here, we report on HR+, HER2- MBC pts. Eligible pts had ≥1 new or not previously irradiated measurable BM ≥10mm or a progressive previously irradiated BM. Pts receiving ET at the time of enrollment were permitted to continue the same ET provided that extracranial (EC) disease was stable ≥3 months and the CNS progression occurred on the ET. Abemaciclib was orally administered 200mg BID. Primary endpoint was objective intracranial response rate (OIRR; [CR+PR]) based on Neuro-Oncology BM response assessment criteria (RANO-BM). Secondary endpoints included intracranial clinical benefit rate, PFS, and safety. Results: 58 HR+, HER2- MBC pts were enrolled and 52 pts were evaluable. Pts had a median of 4 prior systemic therapies, 75% of pts had prior chemotherapies (0-6, median of 2), and 71% of pts had prior ET (0-4, median of 1), in the metastatic setting. 50% of pts had prior whole brain radiotherapy, 39% stereotactic radiosurgery, and 8% surgical resection of BM. Median time from radiation to study enrollment was 9.4 months. Out of the 52 evaluable patients, 3 pts had a confirmed intracranial response (6% OIRR), and 38% of pts showed a decrease in the sum of their intracranial target lesions. Intracranial clinical benefit rate (CR+PR+SD persisting for ≥ 6 months) was 25%. Median PFS was 4.4 months (95% CI, 2.6-5.5). Safety and tolerability were similar to previous reports for abemaciclib. Conclusions: Abemaciclib demonstrated intracranial clinical benefit in heavily pretreated HR+, HER2- MBC pts with BM in this study. Further evaluations are ongoing to identify ABC patients with BM who might benefit most from abemaciclib. Clinical trial information: NCT02308020.

mTORC1 activation assessed in metastatic sample to predict outcome in patients with metastatic breast cancer treated with everolimus-exemestan: Results from the SAFIRTOR study

1024

Background: Using samples from TAMRAD study (Treilleux, Ann Oncol, 2015), we previously reported that p4EBP1, a downstream protein of mTOR, was associated with higher benefit to everolimus (eve). SAFIRTOR study was designed to validate clinical utility of this biomarker. Methods: Patients (pts) with ER+, HER2 negative, AI resistant MBC were prospectively included (NCT02444390). All pts had a biopsy of a metastatic site and were then treated with standard eve + exemestane (exe) combination. The primary end point was to validate that p4EBP1 expression is associated with longer PFS in patients treated with eve. 120 evaluable pts were needed for the pre planed statistical analysis. All samples were collected and processed in a standardized procedure in order to allow phophoproteins IHC staining. In addition to p4EBP1, we explored prognostic value of pS6K, pAkt, PTEN and LKB1, together with genomic alterations assessed by NGS and CGH arrays. Results: 150 pts were included, 30 pts had no adequate sample, and further 13 had missing clinical data, 107 were evaluable for primary objective. Median age was 62, they had previously progressed on AI treatment, either in the adjuvant (22 pts) or the metastatic setting (83 pts). 20 were considered as primary hormone resistant, 87 as secondary resistant. The median Allread score for p4EBP1 was 5.5 (range: 0-6.5). Analysis of the primary endpoint showed that p4EBP1 staining above the median is associated with a longer PFS on eve+exe. (median PFS: 9.3 months, 95CI 6.3-13.1 for high p4EBP1 versus 5.8 months, 95CI 3.7-7.8 for low p4EBP1, p = 0.02). Prognostic value of high pEBP1 remained significant when assessed in a multivariate analysis along classical clinico-biological prognostic factors for MBC (HR 0.57, 95%CI 0.38-0.88, p = 0.01). In this AI resistant population, the tumor of 42 (46%), 33 (35%) and 5 (5.3%) pts carried an activating mutation for ESR1, PIK3CA and AKT1, respectively. None of these mutational statuses were correlated to outcome. Conclusions: This prospective study validates p4EBP1 expression analysis to select patients most likely to benefit from everolimus + exemestane. Clinical trial information: NCT02444390.

Prognosis value of a genetic score based on germline genetic variants in a prospective cohort of early triple-negative breast cancer patients

1529

Background: Triple-negative breast cancers (TNBC) are a heterogeneous group of tumors with poor outcome. In this study, the association between germline genetic variants and invasive disease-free survival (iDFS) was analyzed in TNBC patients. Methods: A genome wide-association study (GWAS) aimed to identify variants (single nucleotide polymorphisms – SNPs) associated with prognosis in 1121 patients with TNBC in the SIGNAL prospective cohort. Associations between gene variants and iDFS were assessed in univariate Cox regression models. Variants were combined in a score to identify risk categories. A prognostic model based on breast cancer stage and genetic variants was estimated using a multivariate Cox regression. Interaction between stage and genetic score was tested. Discrimination of the model was assessed by the Harrell’s C statistic and internal validity by bootstrap method. Results: The characteristics of the 1121 patients were representative of a population with early TNBC. Four SNPs on chromosomes 9 and 2 were found significantly associated to iDFS in univariate Cox models. Homozygous status for the most frequent allele was associated with poorer iDFS for two SNPs and this status was present in 50% and 57% of the population. For the two other SNPs, the most frequent allele was associated with more favorable iDFS. Three prognostic categories were derived from the genetic score. The following table presents the results from the multivariate Cox model including genetic score and disease stage. Clinical trial information: RECF1098. Conclusions: In a prospective cohort of 1121 patients with early TNBC, 4 genetic variants (SNPs) were associated with iDFS. A score involving SNPs provided similar prognostic indications as breast cancer stages. A search assessing the function and the role of the involved genes is ongoing.[Table: see text]

First-line ribociclib plus letrozole for postmenopausal women with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC): MONALEESA-2 safety results

1047

Background: In the randomized, phase III MONALEESA-2 study (NCT01958021), first-line therapy with ribociclib (RIB; cyclin-dependent kinase 4/6 inhibitor; 600 mg/day; 3-weeks-on/1-week-off) + letrozole (LET; 2.5 mg/day) in postmenopausal women with HR+, HER2– ABC significantly prolonged progression-free survival vs placebo (PBO) + LET (hazard ratio: 0.556; p = 0.00000329; Hortobagyi GN et al. N Engl J Med 2016;375:1738–48). Here we present further safety analyses from MONALEESA-2. Methods: Adverse events (AEs) were characterized per CTCAE v4.03. Analyses of key AEs included time to first event, duration (time to AE resolution), and the rate of associated dose interruptions or reductions. Results: Safety analysis included 664 patients (pts; RIB + LET: 334; PBO + LET: 330). Neutropenia was the most common all-grade (G) and G3/4 AE in the RIB + LET arm (Table); febrile neutropenia rates were low (RIB + LET arm: 1.5%) with no associated deaths. Median time to first event for G ≥2 neutropenia in the RIB + LET arm (based on neutrophil counts) was 16 days. Other common G3/4 AEs (increased by ≥5% in the RIB + LET vs PBO + LET arm) were leukopenia (21% vs 1%), elevated alanine aminotransferase (ALT; 9% vs 1%), lymphopenia (7% vs 1%), and elevated aspartate aminotransferase (AST; 6% vs 1%). Neutropenia was the most common AE leading to dose interruptions/reductions; G3/4 neutropenia led to dose interruptions in 48% vs < 1% and reductions in 30% vs 0% of pts in the RIB + LET vs PBO + LET arm. 7.5% vs 2.1% of pts (RIB + LET vs PBO + LET) discontinued due to AEs; common AEs leading to discontinuation ( > 1% pts) were elevated ALT (5% vs < 1%), elevated AST (3% vs 1%), and vomiting (2% vs 0%). Conclusions: First-line RIB + LET had a manageable safety profile in postmenopausal women with HR+, HER2– ABC. Neutropenia was the most common AE in the RIB arm, and was transient and reversible with dose modifications. Additional AE analyses will be presented. Clinical trial information: NCT01958021. [Table: see text]

Assessment of multiple endocrine therapies for metastatic breast cancer in a multicenter national observational study

1052

Background: For HR+/HER2– metastatic breast cancer (mBC), International guidelines recommend multiple lines of endocrine therapy (ET) before starting chemotherapy. Few studies have assessed the efficacy of such strategy on large populations. Our objective was to evaluate multiple ET activity according to clinical and biological characteristics and type of ET. Methods: All patients (pts) who initiated treatment for a newly diagnosed mBC between January 2008 and December 2014 in all 18 French Comprehensive Cancer Centers were included in the real life ESME database. ESME collects retrospective data using a clinical trial-like methodology. Database lock was 8 Dec 2016. Primary endpoint of the current study was progression free survival (PFS) on successive ET lines. Only pts with ET alone were assessed (pts receiving ET after chemotherapy as maintenance therapy, or combined with targeted treatment were excluded). Results: 9921 pts out of 16703 in ESME, had HR+/HER2- mBC (median age 62.0 years[range 23-96]). 53.9% of pts had visceral and 80.1% non visceral disease at diagnosis. Median OS of HR+/HER2- pts was 42.15 months (95% CI, 40.93-43.27). As first-line therapy, 4123 pts (41.6%) received ET alone, while 2038 received chemotherapy alone (20.5%) and 3667 received both (37%). Median PFS for first-line ET (N=4123) was 11.3 months (95% CI, 10.6-11.9). Only 668 pts (16%) received subsequent lines of ET alone. Types of ET used are described in the table below. Successive PFS will be reported at the meeting. Conclusions: Those data show that ET is prescribed to less than 50% of patients with HR+/HER2- mBC in first line and only to a small minority in subsequent lines. This is not in line with existing guidelines (NCCN, ABC3). Real-life median PFS for first-line ET is consistent with median PFS reported in clinical trials (Nabholtz, 2000). [Table: see text]

Use of everolimus in advanced hormone receptor–positive metastatic breast cancer in a multicenter national observational study

e12548

Background: The everolimus-exemestane combination has been included in the International guidelines for advanced HR+ breast cancer (mBC) since the results of the Bolero-2 trial. Marketing authorization has been granted in France in July 2012 and reimbursement in Nov. 2014. Very few real life data of everolimus (EVE) use have been reported. Methods: All patients who initiated treatment for a newly diagnosed mBC between Jan. 2008 and Dec. 2015 in all 18 French Comprehensive Cancer Centers have been included in the real life ESME database, which collects retrospective data using a clinical trial-like methodology with quality assessments. Primary endpoint of the current analysis was to evaluate the incidence and indication of EVE use before and after marketing authorization and reimbursement Results: The ESME program included a total of 16,703 patients of which 9,921 had HR+/HER2- mBC. Median age at metastatic diagnosis was 62.0 year (range 23-96). Visceral metastases were present in 60.3% of cases. Only 4123 patients (41.6%) received endocrine therapy alone as first-line therapy, and 60% were deemed endocrine resistant Overall, 1,217 (12.3%) pts have received EVE during therapy as of Dec. 2015 (all lines). EVE was given as first line therapy in 117 pts (10% of all EVE pts and 1.2% of pts receiving a first line therapy). In 99/117 pts (85%) EVE was combined with exemestane. Before 2012, EVE was barely used and mostly within clinical trials. After 2012, use of EVE increased steadily (table). Percentages refer to the total of pts who received any kind of treatment during a given year of observation (e.g., 506/4435 pts took EVE in 2015). Median duration of EVE use was 6.0 months (0-65) as first line treatment and 3.9 months (0-65) in pretreated patients. Main causes of EVE cessation were recorded and will be detailed at the meeting. Conclusions: In this very large French national and representative cohort of HR+ HER2- mBC, EVE use rose quickly as soon as marketed. EVE was mostly used in pretreated mBC albeit in probably too advanced pts. These data underline the need for physician and patient education for oral therapies. [Table: see text]

Evolution of overall survival according to year of diagnosis (2008-2014) and subtypes, among 16703 metastatic breast cancer (MBC) patients included in the real-life "ESME" cohort

1078

Background: Real-life data may help checking that public investments match closely medical needs. During the last decade, several drugs have been released on the market for MBC on the basis of a potential impact on overall survival (OS). Based on the large real-life ESME cohort, we aimed to describe the time evolution of MBC OS according to main phenotypes. Methods: ESME is a unique MBC national cohort including all consecutive patients (pts) who initiated treatment for MBC between 1/01/08 and 31/12/14 in the 18 French comprehensive cancer centres. ESME collects retrospective data using clinical trial-like methodology including quality assessments. Database lock was 8/12/2016. Primary objective was the impact of year of MBC diagnosis on OS. Multivariate Cox regressions were used with adjustment for main prognostic covariates. Results: 15170 out of 16703 pts in ESME had full IHC data allowing their classification as HR+HER2- (N=9922), HER2+ (N=2863), or HR-HER2- (N=2321) cases. Median FU and OS for the whole cohort are 4.05 yrs [95 CI: 3.98-4.12], and 3.1 yrs [95 CI: 3.03-3.18] respectively. In the adjusted multivariate analysis, year of MBC diagnosis, age at MBC, subtype (using HER2+ as reference), disease-free interval (DFI), visceral involvement, and number (nbr) of metastatic sites are significant OS predictors (table) although with low effect for the first item. Age at MBC, DFI, visceral involvement, and nbr of metastatic sites remained significant prognostic variables in subtypes. Year of diagnosis was no longer significant in HR+HER2- nor HR-HER2- cases (HR=0.997, p=0.71 and HR=0.997, p=0.84), while it was highly significant in HER2+ cases (HR=0.91, p<0.0001). Conclusions: Although OS of MBC has slightly improved over the past decade, this remains mostly confined to HER2+ cases, highlighting the need for new strategies for the luminal and triple negative populations. [Table: see text]

Everolimus (EVE) plus endocrine therapy in patients with estrogen receptor–positive (ER+), human epidermal growth factor receptor 2–negative (HER2−) advanced breast cancer (BC): First- and second-line data from the BOLERO-4 study

1010

Background: Initial first-line (1L) data from the phase 2 BOLERO-4 (NCT01698918) study of EVE + letrozole (LET) in postmenopausal patients (pts) with ER+, HER2− metastatic BC (MBC) or locally advanced BC (LABC) have been previously reported. Here, we present updated 1L progression-free survival (PFS) data, plus new data describing second-line (2L) EVE + exemestane (EXE) in pts with disease progression after EVE + LET. Methods: Postmenopausal pts with ER+, HER2− MBC or LABC with no prior therapy for advanced disease received EVE 10 mg/day + LET 2.5 mg/day. After disease progression, pts could receive EVE + EXE 25 mg/day until further disease progression, unacceptable toxicity, or withdrawal of consent. Primary endpoint: 1L PFS. Secondary endpoints: overall response rate (ORR), clinical benefit rate (CBR), 2L PFS, overall survival (OS), and safety (1L and 2L). Results: Among 202 pts (median age, 64 years) with 1L MBC (96%) or LABC (4%), median PFS (95% CI) was 21.7 (18.1–23.9) months, ORR was 43.6%, and CBR was 74.3%. 42 pts (median age, 62 years) with MBC (88%) or LABC (12%) who progressed on 1L EVE + LET received optional 2L EVE + EXE. 2L median PFS (95% CI) was 3.7 (1.8–9.1) months, ORR was 4.8%, and CBR was 21.4%. Common 1L adverse events (all grades, regardless of drug relationship) were stomatitis (69%), weight loss (44%), diarrhea (40%), nausea (37%), and anemia (35%); 2L adverse events included stomatitis (19%) and weight loss (19%). Median duration of follow-up from start of 1L to the data cutoff for these new analyses (17 June 2016) was 23.5 months. OS will be analyzed at a later data cut. Conclusions: EVE + LET is an effective regimen in 1L ER+, HER2− advanced BC. Thesedata support previously reported BOLERO-2 data demonstrating a PFS improvement from addition of EVE to an aromatase inhibitor. 2L data, although limited by the small number of pts, show preliminary evidence of EVE activity when continued beyond disease progression. No new safety signals were seen. Lower rates of stomatitis in 2L were noted. Clinical trial information: NCT01698918.

Triple-NOTE (Triple Negative Outcome in ESME): Large recent real-world prognostic data on triple negative metastatic breast cancers (mTNBC)

e12592

Background: During last decade, therapeutic arsenal has expanded for metastatic breast cancer (mBC), but few data are available about mTNBC, a poor prognosis subtype. In 2014, UNICANCER (composed of 18 French Comprehensive Cancer Centers) launched the Epidemiological Strategy and Medical Economics (ESME) program to centralize real-world data. This base represents a great opportunity to update the outcomes and the treatment practice patterns of this population. Methods: The ESME-mBC database was built from information systems, treatment databases and patients’ electronic files including quality control processes. All pts who initiated treatment for mBC between 01-Jan-2008 and 31-Dec-2014 were selected. The primary objective of this study was to assess overall survival (OS) of mTNBC pts. TNBC status was defined as ER and PR < 10% in both primary and metastatic disease, as well as the absence of overexpression or amplification of HER2. The secondary objectives were to describe the characteristics of this population, clinical management (duration and sequence of treatments) and to evaluate the prognostic value of several clinical factors (age, distant disease free interval, location and number of metastatic sites) Results: Among 16703 pts in the ESME-mBC database, 2368 (14%) had mTNBC. Median OS over this time period was 14.8 months (95% CI 14-15.6). Median age at diagnosis of mBC was 57 years. For the pts who relapsed, median metastasis free interval was 24 months, while 25.5% of the pts were de novo metastatic. 61% of the pts presented visceral metastasis and 12% had cerebral metastasis as first metastatic site. The pattern of metastatic involvement (visceral and cerebral) and a short metastasis free interval ( < 24 months) were the most important prognostic factors in multivariate analysis. The description of treatment sequences (duration, prognostic value) will be presented. Conclusions: In this real-life setting database, mTNBC remain of poor prognosis despite a trend for a better OS than the historical data available (12-13 ms). This TNBC ESME cohort is one of the largest available and offers an updated assessment of the outcomes of this population.

Abstract PD1-06: Comparison of mutational landscapes of primary breast cancer and first metastatic relapse: Results from the ESOPE study

Background

Genomic profile of breast cancer metastases (M) may differ from that of the primary tumor (PT). In a multicenter prospective study (ESOPE, NCT 01956552) including 130 patients with biopsies of the first metastatic deposit, we have shown that luminal breast cancers are the most prone to phenotypical subtype changes (Comte et al, ASCO 2016#550). We report here the first results of a comparative PT/M targeted next generation sequencing (NGS) mutational analysis.

Methods

Of 130 patients, 117 paired PT/M samples obtained before any treatment were available for analysis. Targeted Sequencing was done using Illumina Hiseq2500 technology with a custom made 95 breast cancer associated genes panel. Sequence data were aligned to the human reference genome (hg19) using Bowtie2 algorithm. Median depth was 607X and 87% of targets achieved 100X depth. SNVs and indels were called using GATK UnifiedGenotyper. We retained COSMIC confirmed non synonymous, exonic/splice variants and observed at a frequency lower than 0,1% in population. Further confirmation of detected variants was performed with comparison to public databases (cbioportal, tumorportal), and potential pathogenicity was evaluated with 4 different public algorithms. We present here the results obtained from the first 35 matched PT/M samples (liver mets 68%), focusing analysis on 40 genes including PIK3CA (20 genes), ER (6 genes) and MAPK (11 genes) pathways, RUNX1, CDH1 and TP53 genes.

Results

Patients characteristics are representative of patients with first line metastatic breast cancer (Comte et al, ASCO 2016#550). Among the 40 genes analyzed in the 70 samples, we detected 134 somatic mutations (70 in PT and 64 in M) including 15 indels and 119 SNV. Among these 134 mutations there were 74 different mutations (66SNV and 8 indels) classified pathogenic for 26 and of unknown pathogenicity for 48 of them. We detected at least 1 mutation in 31 PT and in 28 M. Median numbers of mutations were 1 in PT (range 1-9) and 1 in M (range1-22) samples (p=0.295, Wilcoxon rank sum test). Top ten mutated genes in PT included PIK3CA, TP53, NCOR1, NF1, GATA3, CDH1, ERBB3, PTEN, HRAS, INPP4B. In M samples, the 10 top genes were PIK3CA, TP53, ERBB3, AKT3, CDH1, ERBB4, GATA3, INPP4B, MET, MTOR. Only 3 ESR1 mutations were detected, including 1 PT/M pair and 1 M. Beyond highly shared PIK3CA and TP53 mutations, overall crude PT/M discordance rate was 31%. Analysis by histological subtypes showed PT and M specific mutational profiles, suggesting a role in ERB gene family (notably ERBB3) and MAPK driven pathways in early metastatic progression. Specific metastatic site analysis suggested enrichment in MAPK pathway mutations in liver metastases when compared to other sites. Variant allelic fractions were globally not significantly different between PT and M samples.

Conclusion

In this prospective multicenter series of systematic biopsies of first metastases, we report a targeted mutational analysis of matched PT and M samples not modified by previous therapy exposure. Early analyses suggest specific genotypical changes according to tumor subtype and/or metastatic site. Extended and updated results will be reported at the meeting.

Citation Format: Cottu PH, Boulai A, Callens C, Baulande S, Legoix-Ne P, Bernard V, Vincent-Salomon A, Benhamo V, Brain EGC, Chemlali W, Campone M, Bachelot TD, Giacchetti S, Bonneterre J, Bidard F-C, Servois V, Comte A, Belin L, Sigal B, Bièche I. Comparison of mutational landscapes of primary breast cancer and first metastatic relapse: Results from the ESOPE study [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 PD1-06.

Everolimus plus exemestane in patients with advanced invasive lobular carcinoma: Efficacy and safety results from BOLERO-2

152

Background: In BOLERO-2 (NCT00863655), everolimus plus exemestane (EVE + EXE) more than doubled median progression-free survival (PFS) vs placebo (PBO) + EXE (by local assessment: 7.8 vs 3.2 mo; hazard ratio [HR], 0.45; P < 0.0001; by central assessment: 11.0 vs 4.1 mo; HR, 0.38; P < 0.0001) in patients (pts) with hormone-receptor–positive (HR+), human epidermal growth factor receptor 2-negative (HER2–) advanced breast cancer (ABC). This exploratory analysis assessed the efficacy and safety of EVE + EXE in a subset of pts with baseline invasive lobular carcinoma (ILC) (elderly pts with predominantly peritoneal, gastrointestinal, and ovarian metastases [mets]). Methods: Pts with HR+, HER2– ABC recurring or progressing on/after prior nonsteroidal aromatase inhibitor therapy were randomized 2:1 to receive EVE 10 mg/day + EXE 25 mg/day or PBO + EXE. Primary efficacy end point was PFS (by local assessment). Results: Of 724 pts, 77% (n = 556) had ductal carcinoma and 14% (n = 104; EVE + EXE, n = 64; PBO + EXE, n = 40) had ILC. In ILC subset, median age was 63 years, 47.1% had measurable disease, and majority of baseline characteristics were similar to overall study population with exception of main mets sites. In pts with ILC, 36% reported visceral mets (lung, liver, pleural, pleural effusions, peritoneum, and ascites), 10% lung mets, and 23% liver mets when compared with 59% visceral mets, 31% lung mets, and 33% liver mets in overall study population. Median PFS was higher with EVE + EXE vs PBO + EXE (6.9 vs 4.2 mo; HR, 0.59; 95% CI, 0.37-0.95). Objective response rates were 14.1% (EVE + EXE arm) and 0% (PBO + EXE arm) vs 12.6% and 1.7%, respectively, among overall study population. Clinical benefit rates were 45.3% (EVE + EXE arm) and 30.0% (PBO + EXE arm); 51.3% vs 26.4% in overall study population. The safety profile of EVE + EXE in pts with ILC was similar to overall study population. Most common adverse events (all grades) in EVE-treated pts with ILC were stomatitis (50%), diarrhea (41%), nausea (36%), fatigue (34%), and rash (33%). Conclusions: EVE + EXE prolonged PFS in pts with ILC who had different patterns of mets. Other outcomes were similar to those in overall study population. Clinical trial information: NCT00863655.

Characterization of patients who received prior chemotherapy for advanced breast cancer (ABC) in BOLERO-2

557

Background: In patients with hormone-receptor–positive (HR+) breast cancer, endocrine therapy is the standard of care both in the adjuvant setting and as first-line treatment for ABC. For selected HR+ patients with ABC, chemotherapy (CT) may be utilized if disease burden is high and rapid symptom control is required (Barrios CH. GAMO.2010). In the phase 3 BOLERO-2 study (NCT00863655), 1 line of prior CT in the ABC setting was allowed. This subset analysis examined disease characteristics and the efficacy of everolimus (EVE) plus exemestane (EXE) in patients who received CT for ABC prior to BOLERO-2 study entry. Methods: In BOLERO-2, 724 patients with HR+, human epidermal growth factor receptor-2–negative (HER2–) ABC whose disease recurred or progressed during/after a nonsteroidal aromatase inhibitor were randomized 2:1 to EVE (10 mg/d) + EXE (25 mg/d) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local investigator review and confirmed by blinded independent central review. Results: A subset of 186 patients (26%) received prior CT for ABC: 125 in the EVE + EXE group and 61 in PBO + EXE. In this subset, 54% (67 of 186) of patients received prior CT only in the advanced setting and 46% (58 of 186) of patients received prior CT in both the neoadjuvant/adjuvant and advanced settings. Incidences of visceral metastases (67% vs 56%), multiple metastases (79% vs 66%), and ≥ 4 metastatic sites (18.3% vs 15%) were higher in ABC patients with prior CT for ABC at study entry versus those with no prior CT for ABC. Disease recurrence < 6 months from initial diagnosis was recorded in 32.2% (n = 60) of prior CT patients versus 17.3% (n = 93) of patients with no prior CT. Median PFS (by local assessment) in patients who received prior CT for ABC was substantially longer with EVE + EXE versus PBO + EXE (6.1 vs 2.7 mo; HR = 0.38; 95% CI, 0.27-0.53). PFS by central review showed similar results (7.1 vs 2.8 mo, respectively; HR = 0.42; 95% CI, 0.27-0.65). Conclusions: These results demonstrate that patients with HR+, HER2– ABC who received previous CT in the advanced setting had a higher tumor burden and derived clinically significant benefit from combination treatment with EVE + EXE. Clinical trial information: NCT00863655.

Comparative efficacy of everolimus versus fulvestrant for hormone-receptor–positive (HR+) advanced breast cancer (ABC) following progression/recurrence after first-line treatment: A network meta-analysis

e11602

Background: Everolimus (EVE), an oral mammalian target of rapamycin (mTOR) inhibitor, is approved in combination with exemestane (EXE) to treat postmenopausal women (PMW) with HR+, human epidermal growth factor receptor-2–negative (HER2–) ABC that progressed after nonsteroidal aromatase inhibitor therapy. Fulvestrant (FUL), an estrogen receptor antagonist, is another treatment option for PMW previously treated with endocrine therapy. However, the comparative efficacy of EVE + EXE vs FUL is unknown. Methods: Six randomized, controlled trials in HR+, HER2–ABC patients were identified by systematic literature review (Cochrane library, National Horizon Scanning Centre, and NICE Web sites) that formed a network permitting indirect comparisons of EVE + EXE or EVE + tamoxifen (TAM) vs FUL: BOLERO-2, CONFIRM, EFECT, Paridaens (2008), SoFEA, and TAMRAD. All 6 trials had EXE, TAM, or FUL 250 mg as the common comparator to form the network. Relative efficacy of EVE and FUL was obtained using a Bayesian network meta-analysis based on these 6 trials. The primary endpoint was local assessment of progression-free survival (PFS) or time to progression (TTP). The hazard ratio (HR) of EVE + EXE relative to FUL and its 95% credible intervals (CrI) were calculated. Evidence of a difference between treatments is suggested by the 95% CrI not including 1. A HR <1 indicates that the hazard rate is higher in the comparator group and that the treatment is more effective. Results: EVE + EXE was found to be more efficacious for PFS/TTP than FUL 250 mg (HR = 0.47; 95% Crl, 0.38-0.58) and more efficacious than FUL 500 mg (HR = 0.59; 95% Crl, 0.45-0.77). EVE + TAM was found to be numerically better for PFS/TTP than FUL 250 mg (HR = 0.65; 95% Crl, 0.40-1.04) and numerically better than FUL 500 mg (HR = 0.81; 95% Crl, 0.49-1.33). Conclusions: The indirect evidence from this analysis suggests that EVE in combination with EXE is more efficacious than FUL 250 and 500 mg in PMW with HR+, HER2– ABC that progresses after endocrine therapy. These data should be interpreted with caution as there is no randomized trial that directly compares EVE + EXE vs FUL.

Array CGH and DNA sequencing to personalize targeted treatment of metastatic breast cancer (MBC) patients (pts): A prospective multicentric trial (SAFIR01)

511

Background: The aim of the present study was to profile the metastatic lesion of pts using high throughput technologies, and to treat them accordingly. Methods: SAFIR01 trial aimed to include 400 pts with MBC, selected for not presenting a progressive disease at the time of biopsy. A biopsy was done in a metastatic site. DNA was extracted if the tumor contained >50% cancer cells, and sent to one of the 5 genomic centers who performed array CGH (copy number changes) and sanger sequencing on PIK3CA (exon 10/21) and AKT1 (exon 3). A targeted therapy matched to the genomic alteration was expected to be proposed at the time of progressive disease. The primary endpoint was the % of pts who received a targeted therapy according to the genomic alteration. Results: A biopsy of metastatic site was done successfully in 408 out of the 423 included pts. Biopsy was complicated by a serious adverse event in 9 pts. A discrepancy between primary and metastatic lesion was observed in 8% and 19% of pts for Her2 and HR. Array CGH and sequencing were successfully obtained in 277 (68%) and 295 (72%) pts. The main reason for failure of genomic test was the low cellularity (n=93). A targetable genomic alteration was identified in 204 pts. The most frequent genomic alterations were PIK3CA mutations, CCND1, FGF4 and FGFR1 amplifications. 76 pts presented a rare targetable genomic alteration (<5%), including AKT1 mutations, EGFR, FGFR2, PIK3CA, MDM2 amplifications. Early Feb 2013, 4 6 out of 277 pts with genomic analyses (17%) had received a targeted therapy matched to the genomic alteration, covering twelve different targets. Updated results on number of pts treated, together with efficacy data will be presented. Next generation sequencing on metastatic lesions is ongoing and results will be presented. Conclusions: This trial evaluated the concept of personalized medicine for MBC and provided a large scale genomic analysis of metastatic tissue. This study suggests that assessing the biology of metastatic tissue could allow driving pts to targeted therapy. A randomized trial (SAFIR02) testing this approach is expected to start during summer 2013. Clinical trial information: NCT01414933.

BOLERO-4: Multicenter, open-label, phase II study of everolimus plus letrozole as first-line therapy in ER+, HER2- metastatic breast cancer

TPS661

Background: Endocrine therapy (ET) is the standard of care for postmenopausal women with hormone receptor positive (HR+; typically, estrogen receptor [ER] positive) advanced breast cancer (ABC). However, women with HR+ ABC can progress while on ET. Crosstalk between ER signaling and the mammalian target of rapamycin (mTOR) pathway enhances tumor progression. Co-targeting these signaling pathways with the combination of everolimus (EVE), an orally bioavailable mTOR inhibitor, and ET (letrozole [LET] or tamoxifen) has been shown to significantly improve clinical outcomes in the neoadjuvant setting and in patients with HR+ ABC progressing on/after nonsteroidal aromatase inhibitors. In a pivotal phase 3 trial in women with HR+ ABC progressing on ET, EVE + exemestane (EXE) prolonged progression-free survival (PFS; local/central assessment: 7.8/11.0 mo [P < .0001]) compared with EXE alone (3.2/4.1 mo [P < .0001]). This study (BOLERO-4) will extend previous investigations to evaluate the safety and effectiveness of EVE+LET as first-line therapy in ER+ HER2– metastatic BC (mBC), and the potential benefits of continuing EVE+ET beyond initial progression. Methods: In this multicenter, open-label, international, single-arm, phase 2 study, 200 postmenopausal women age ≥18 y with ER+ HER2– mBC or locally ABC without prior therapy for advanced disease will receive EVE (10 mg/d) + LET (2.5 mg/d) until first disease progression. Upon disease progression, patients continuing in the trial will receive EVE+EXE (25 mg/d) until further disease progression. Patients who discontinue therapy in the first-line metastatic setting because of unacceptable toxicity will not be offered second-line therapy. The primary endpoint is PFS with EVE+LET in the first-line setting. Secondary endpoints include PFS in the second-line setting, overall survival, objective response rate, clinical benefit rate, safety, and the efficacy of oral dexamethasone solution to reduce the severity and/or duration of stomatitis using Oral Stomatitis Daily Questionnaire (OSDQ). Accrual across Europe, Asia, and the Americas begins Q1 2013. Estimated study completion is Q4 2015. Clinical trial information: NCT01698918.

Incidence, management, and resolution of noninfectious pneumonitis in BOLERO-2

561

Background: The BOLERO-2 trial showed that adding everolimus (EVE) to exemestane (EXE) more than doubled progression-free survival (PFS) without reducing quality of life versus placebo (PBO) + EXE alone in postmenopausal women with hormone-receptor–positive (HR+), HER2-negative (HER2–) advanced breast cancer (ABC) progressing on/after nonsteroidal aromatase inhibitor (NSAI) therapy. Although generally well tolerated, mTOR inhibitors such as EVE have been associated with noninfectious pneumonitis (NIP). Methods: Patients (pts) were randomized 2:1 to receive EVE+EXE or PBO+EXE. Incidence and severity of NIP, consequent dose interruptions/adjustments, study drug discontinuations, and time to resolution were recorded. Results: Median duration of exposure to EVE was 24 weeks with median dose intensity of 8.6 mg/d. Pulmonary adverse events (AEs) of any grade (NIP, interstitial lung disease, lung infiltration, pneumonia, or pulmonary fibrosis) were recorded in 97 of 482 pts (20%) in the EVE+EXE arm versus 1 of 238 pts (<1%) in the PBO+EXE arm. Of these, 16% of pts (77 of 482) in the EVE+EXE arm versus 0 in the PBO+EXE arm had a diagnosis consistent with NIP. In the EVE+EXE arm, grade 1 (no symptoms), grade 2 and 3 NIP occurred in 7%, 6% and 3% of pts, respectively, and no grade 4 events were reported. Complete resolution of NIP to grade ≤1 was recorded for all but 4 pts for whom NIP was still observed at last follow-up before study discontinuation. Overall, in the EVE+EXE arm, NIP was recorded as the reason for dose interruption and treatment discontinuation in 7.5% and 5.6% of pts, respectively. Conclusions: Data from BOLERO-2 support the combination of EVE and EXE to significantly prolong PFS in postmenopausal women with HR+, HER2– ABC progressing on/after NSAI. The incidence of NIP in this study was generally consistent with reports from other oncology settings, was of mild to moderate severity, and was generally reversible with appropriate interventions and temporary dose modifications. Patient and healthcare provider education for early diagnosis and management of NIP are highly recommended. Clinical trial information: NCT00863655.

UNIRAD: Multicenter, double-blind, phase III study of everolimus plus ongoing adjuvant therapy in ER+, HER2- breast cancer

TPS653

Background: Advances in adjuvant treatment and highly effective endocrine therapies have resulted in better prognosis and survival among patients (pts) with hormone-receptor-positive (HR+; ER+ and/or PgR+) breast cancer (BC). Despite this, high risk pts (>3N+ and/or T3/4) are likely to relapse during/after adjuvant therapy. In a pivotal phase 3 trial (BOLERO-2), everolimus (EVE, an oral mammalian target of rapamycin [mTOR] inhibitor), plus exemestane demonstrated clinical efficacy in postmenopausal pts with HR+, human epidermal growth factor receptor-2–negative (HER2–) advanced BC progressing on non-steroidal aromatase inhibitors. Administering EVE earlier, concurrent with adjuvant endocrine therapy (ET) may lower relapse rates, especially in pts with high and/or persistent nodal involvement after neoadjuvant therapy. This study (UNIRAD) will evaluate the safety and effectiveness of adding EVE to adjuvant ET in pts with ER+, HER2–non-metastatic BC, who are disease-free following 3y of adjuvant ET. Methods: This multi-center, double-blind, phase 3 study will randomize adult (≥18y) women with non-metastatic ER+, HER2- BC, any T, pN+(≥4 if initial therapy and ≥1 after neoadjuvant therapy), who are disease-free following 3y of adjuvant ET to EVE (10mg/d) plus ongoing ET versus placebo (PBO) plus ongoing ET for a total adjuvant therapy duration of 5y. Stratification is by country, ET (tamoxifen or aromatase inhibitors), previous adjuvant versus neoadjuvant therapy, and age (≤70 versus >70y). Follow-up will continue for 5y after treatment. The primary endpoint is disease-free survival (DFS) with EVE versus PBO. Secondary endpoints include overall survival (OS), event-free survival, distant metastasis-free survival, DFS and OS in selected subgroups, safety, incidence of secondary cancers, quality of life, and predictive value of mTOR activation markers on DFS. Results: Accrual to the UNIRAD study will begin in March 2013 (planned N = 1984). Updated information will be presented. Clinical trial information: 2012-003187-44.

Trastuzumab (T) and everolimus (E) pharmacokinetics (PK) in HER2 positive (+) primary breast cancer (BC) patients (pts): Unicancer RADHER trial results

2599

Background: T has greatly modified the prognosis of HER2+ BC, but few studies have analyzed its PK. The RADHER study evaluated the interest of adding E to T as preoperative therapy for primary HER2+ BC. It also aimed at describing the PK of T and studying the impact of E with T in primary BC. Methods: Eligible pts with HER2+ operable primary BC were randomized to receive T alone (loading dose 4 mg/kg, then 2 mg/kg/week (W)) or T + E (10 mg/day (D)) for a 6-W pre-operative treatment. Blood samples were collected to measure T and E concentrations. For T, plasma samples were collected in all pts before each infusion, and at Hour (H) 1, D1, D3, W1, W2, W4, W8 and W12 after the last infusion. E concentrations were determined on whole blood collected at H0, H0.5, H1, H2, H4, H6, H12 and H24 after the first T infusion, and again after the last E intake. T and E PK were described using population compartment analyses. Results: From 82 pts randomized, 79 were evaluable for T and 22 for E PK. Mean estimated PK parameters of T were (interindividual coefficient of variation %): central (Vc) and peripheral (Vp) volumes of distribution = 2 L (24%) and 1.3 L (39%), systemic (CL) and intercompartment (Q) clearances = 0.22 L/day (19%) and 0.36 L/day, respectively. Vc increased with body weight and decreased with age, while CL increased with body weight and with tumor volume. Elimination half-life was 11 days, a value lower than that previously reported in metastatic BC (28 days). E PK was best described by a two-compartment model. Mean estimated PK parameters (RSE%) of E were: CL = 3.96 L/h (22%), Q = 29.1 L/h (7%), Vc = 119 L (11%), Vp = 1530 L (24%). E did not influence T PK. E PK was similar to that previously reported in other indications. Conclusions: This is the first study describing the PK of T and E in primary BC. Notably, T CL increases with tumor volume and the elimination half-life is only 11 days, lower than expected from previous results in metastatic BC. The differences in PK between primary and metastatic BC might lead to take a second look at trastuzumab dose regimen in primary BC. Clinical trial information: NCT00674414.

An open-label randomized, multicenter, phase II study on neoadjuvant treatment with trastuzumab plus docetaxel versus trastuzumab plus docetaxel plus bevacizumab according to positron emission tomography (PET) value modification in patients with early stage HER2-positive breast cancer (AVATAXHER): Design description

TPS646

Background: For patients with early HER2+ breast cancer at diagnosis, addition of trastuzumab (T) to 6 cycles of preoperative docetaxel (D) can reach a pathological complete response (pCR) in ~50% of cases, and a high rate of conservative surgery. pCR can be predicted by changes of Fluorodeoxyglucose (FDG) tumor uptake evaluated by Positon Emission Tomography (PET) after one cycle of therapy. In order to increase this pCR rate, adding an antiangiogenic compound could be considered. Pre-clinical and phase I-II data support that the combination of bevacizumab (B) and T is synergistic and safe when patients are chemotherapy naïve. The neoadjuvant AVATAXHER trial (EUDRACT 2009-013410-26) investigates the potential increase of pCR rate by combining B with T and D for patients with HER2+ breast cancer who are not predicted for pCR by FDG PET. Methods: In this multicenter, open-label, phase II trial, 2 phases are planned after a selection period: phase I: all patients receive two cycles of therapy combining T (8 mg/kg at the first cycle, then 6 mg/kg) and D (100 mg/m2). FDG PET is also performed within 7 days before cycle 1 (baseline) and less than 3 days before cycle 2 in order to calculate changes of the tumor FDG uptake between baseline and after cycle 1 (ΔSUV). Phase 2: if ΔSUV≥70%, patients will continue to receive T and D for (cycles 3 to 6: D 100 mg/m2 + T 6 mg/kg); if ΔSUV<70%, patients are randomized 2:1 to arm A (cycles 3 to 6 D 100 mg/m2 + T 6 mg/kg + B 15 mg/kg) or arm B ( cycles 3 to 6: D 100 mg/m2 + T 6 mg/kg). The primary endpoint is pCR rate evaluated post-surgery 4 to 6 weeks after the last treatment of cycle 6. Enrolment began in May 2010 and 125 patients were to be recruited in 26 sites. According to the hypothesis that 60% of patients will have a ΔSUV<70%, it is presumed that 72 patients will be randomized. There are currently 107 patients included (as of 06 January 2012 ), 95 of them reached the phase 1; 52 of them (55%) showed a ΔSUV<70% and after randomization 34 were included in arm A and 18 in arm B.