Phase I Study of Bortezomib, Fludarabine, and Melphalan, with or without Total Marrow Irradiation as Conditioning for Allogeneic Hematopoietic Stem Cell Transplantation in Patients with High-Risk or Relapsed/Refractory Multiple Myeloma

PURPOSE/OBJECTIVE(S)

Though outcomes of patients with multiple myeloma (MM) have improved, cure remains elusive. Allogeneic hematopoietic stem cell transplantation (allo-sCT) is associated with a lower relapse rate, but its role is hindered due to toxicities. We hypothesized that targeted total body irradiation in the form of total marrow irradiation (TMI) could safely facilitate allo-SCT via an improved toxicity profile. Therefore, we conducted a phase I study to investigate the safety and feasibility of a bortezomib (BTZ), fludarabine (FLU), and melphalan (MEL), with or without TMI, prior to allo-SCT for patients with high-risk (HR) or relapsed/refractory (R/R) MM.

MATERIALS/METHODS

Between 2012 and 2018 this study enrolled patients with HR or R/R MM on one of two strata, each comprising BTZ dose-escalation cohorts. Patients aged 18-60 with no prior radiation (RT) received TMI at 900 cGy (in 6 fractions delivered twice-daily), FLU, and MEL conditioning, with BTZ added in the second cohort (stratum I). Patients aged 18-70 with prior RT received FLU, MEL, and BTZ, without TMI (stratum II). The primary endpoint was feasibility of escalating doses of BTZ, with or without TMI, defined using a 3+3 design. Dose-limiting toxicity (DLT) was defined as any Grade 3+ Bearman toxicity or prolonged CTCAE v4.0 Grade 4+ neutropenia. Secondary endpoints included treatment response, time to neutrophil and platelet engraftment, incidence of acute (a) and chronic (c) graft-versus-host disease (GVHD), progression-free-survival (PFS), and overall survival (OS).

RESULTS

Eight patients were enrolled on stratum I. One of three patients in the first cohort of stratum I experienced DLT, which led to expansion to three more patients with no DLT. Cohort 2 enrolled only 2 patients due to low accrual, with BTZ added at 0.5 mg/m2; neither experienced DLT. Nine patients were enrolled on stratum II. Three patients were enrolled on cohort 1 (BTZ 0.5 mg/m2) and none experienced DLT. Three were enrolled on cohort 2 (bortezomib 0.7 mg/m2), and one experienced DLT. Therefore, the cohort expanded to three more patients. One more patient experienced DLT and 0.5 mg/m2 was considered the maximum tolerated dose. There were no primary or secondary graft failures. Complete response was achieved in 7 and 4 patients in strata I and II, respectively. Median follow-up for all patients was 30.7 months (mos) and was 99.8 mos for surviving patients. Median overall survival (OS) on strata I and II were 44.5 mos and 21.6 mos, respectively. Median PFS on strata I and II were 18.1 mos and 8.9 mos, respectively. In strata I, 5 patients developed Grade 2+ aGVHD and 8 developed extensive cGVHD. In strata II, 4 patients developed Grade 2+ aGVHD and 6 developed extensive cGVHD.

CONCLUSION

The TMI 900 cGy, FLU, and MEL conditioning regimen is considered safe as conditioning for allo-SCT and may warrant further investigation due to favorable response rates and survival; the conditioning regimen of FLU, MEL, and BTZ (0.7 mg/m2) is associated with unacceptable toxicities.

Abstract P6-21-08: Synergistic anti-cancer activity of cyclin-dependent kinase 4/6 inhibitor palbociclib and dual mTOR kinase inhibitor MLN0128 in pRb-expressing triple negative breast cancer

Background

No targeted therapies have been approved for triple negative breast cancer (TNBC) thus far. Retinoblastoma protein (pRb), a major substrate of cyclin-dependent kinase (CDK) 4/6, might be a potential target especially in chemoresistant TNBC. Palbociclib is a first approved oral CDK4/6 inhibitor for treatment of patients with estrogen receptor (ER) -positive and human epidermal growth factor receptor 2 (HER2) -negative breast cancers. Nevertheless, the usefulness of CDK4/6 inhibitors has not been established in patients with TNBC although, pRb is expressed in approximately 60% of this subtype of breast cancer. In addition, pRb expression has been shown to be associated with poor prognosis after chemotherapy. This pre-clinical study investigated the combination effects of palbociclib with oral dual mTOR kinase inhibitor MLN0128 in TNBC in vitro and in vivo.

Methods

Four TNBC cell lines (MB231, MB453, MB468, and CAL148) were tested with the combination of two drugs in vitro. The combination effects on cell proliferation were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay. Cell cycle analysis and level changes of molecules related to G1/S transition and mTOR pathway were examined. Importantly, a pRb-expressing TNBC patient-derived xenograft (PDX) model was used for confirming the combination effect in vivo.

Results

Palbociclib suppressed cell proliferation in pRb-expressing cell lines (MB231 and MB453), not pRb-deficient lines (MB468 and CAL148). The combination of palbociclib with MLN0128 showed synergistic inhibition of proliferation of MB231 and MB453 cells. Western blot analysis revealed that CDK4/6-pRb and mTOR-p70S6K pathways were inhibited by palbociclib or MLN0128 alone, but considerably more effective by the combination treatment. Cell cycle analysis showed that this combination induced G1 cell cycle arrest. The combined effect of palbociclib and MLN0128 were investigated further in vivo. In pRb-expressing TNBC PDX, the combination treatment drastically inhibited pRb phosphorylation and tumor growth compared to control or single treatment. In addition, effective reduction of PDX tumors was also demonstrated by major suppression of Ki67-positive cells by the combination treatment compared to control or single treatment.

Conclusions

In this pre-clinical study, we discovered that the combination treatment of CDK4/6 inhibitor palbociclib and dual mTOR kinase inhibitor MLN0128 had synergistic anti-cancer activity in pRb+ TNBC cell lines and a PDX model. Our results prove that such combination therapy is earnest to be further investigated in a clinical setting.

Citation Format: Yamamoto T, Kanaya N, Somlo G, Chen S. Synergistic anti-cancer activity of cyclin-dependent kinase 4/6 inhibitor palbociclib and dual mTOR kinase inhibitor MLN0128 in pRb-expressing triple negative 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 P6-21-08.

Abstract P6-16-04: A self-administered geriatric assessment tool for Spanish-speaking older women with breast cancer

Background: Almost a quarter of older adults in the United States will identify themselves as Hispanic/Latino by 2060. Our group has previously developed and validated a self-administered geriatric assessment tool which can be used to identify functional, psychological, social and cognitive impairments among older patients with various types of cancer. Among English-speaking older adults, completing this tool using paper/pencil or a tablet takes a median of 15-21 minutes (min), with < 10% needing assistance to answer it (Hurria, JOP 2016). However, the utilization of this tool among Spanish-speaking older adults has not been tested. We assessed the feasibility of administering a translated and validated Spanish version of our geriatric assessment tool for older Hispanic women with breast cancer, and identified their preferred format (tablet or paper/pencil).

Methods: Spanish-speaking women aged ≥ 65 years with a diagnosis of breast cancer completed the geriatric assessment twice on the same day. Patients were randomized into 3 groups: paper/pencil twice; tablet and paper/pencil in random order; and tablet twice. We assessed the proportion of patients requiring assistance to complete the geriatric assessment, the time needed to complete it, and the proportion of patients who thought the geriatric assessment was difficult/very difficult.

Results: 140 older women with breast cancer completed the geriatric assessment twice and were evaluable. Mean age was 71.6 years (SD 5.8), 53% had ≤ 8th grade education, 43% were married, 45% were retired, 32% were homemakers, and 6% were employed. The participants came from 13 different Spanish-speaking countries, although 70% were born in Mexico. For 90%, Spanish was their primary language, and 75% spoke only in Spanish at home. Regarding computer skills, 64% of the patients said they had none. 39% (n = 54) were unable to complete the geriatric assessment on their own; mean time to complete the geriatric assessment was 29 min (range 8-90); and 28% (n = 39) thought the geriatric assessment was difficult/very difficult. The most common reasons for needing assistance were difficulty understanding questions (39%) and visual problems (31%). Patients with ≤ 8th grade education took longer to complete the geriatric assessment (mean 37.2 vs 29.4 min, p < 0.01), and more often needed help completing the assessment (51% vs 19%, p < 0.01) than those with ≥9th grade education. 53% of the participants preferred using a tablet to answer the geriatric assessment, while 47% preferred paper/pencil.

Conclusions: A substantial proportion of Spanish-speaking older women with breast cancer required assistance to complete our self-administered geriatric assessment tool. This may be a consequence of the low educational level we found among this patient population. Tailoring assessments for diverse populations with particular attention to educational level is needed in multicultural settings.

Citation Format: Soto-Perez-de-Celis E, Vazquez J, Kim H, Sun C-L, Somlo G, Yuan Y, Waisman JR, Mortimer JE, Kruper L, Taylor L, Patel NH, Moreno J, Charles K, Roberts E, Uranga C, Levi A, Katheria V, Paredero-Perez I, Mitani D, Hurria A. A self-administered geriatric assessment tool for Spanish-speaking older women with 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 P6-16-04.

Abstract P6-18-18: Phase I trial of eribulin and everolimus in patients with metastatic triple negative breast cancer

Background: Alteration of PI3K/Akt/mTOR pathway is the most common genomic abnormality detected in triple negative breast cancer (TNBC). Everolimus acts synergistically with eribulin in inducing apoptosis in TNBC cell lines and xenografts in our preclinical study. This phase I trial was designed to test the safety and tolerability of combining eribulin and everolimus in patients (pts) with metastatic TNBC.

Methods: The overall objective of this study was to describe the safety and toxicities of the combination. The secondary objective was to assess activity based on response rate (RR) and progression free survival (PFS). Eligibility criteria included pts with metastatic TNBC, ECOG 0-2, 0-3 lines of prior chemotherapy in metastatic setting, and prior treatment with anthracycline and/or taxane therapy. The study utilized the toxicity equivalence range (TEQR) design with a target equivalence range for dose-limiting toxicities (DLTs) of 0.20-0.35. The recommended phase 2 dose (RP2D) will be the dose closest to the target of 0.25 below 0.51 based on isotonic regression.Three dosing levels of the combinations were tested: level A1 (everolimus 5mg daily; eribulin 1.4 mg/m2 days 1, 8 every 3 weeks), level A2 (everolimus 7.5mg daily; eribulin 1.4 mg/m2, days 1, 8 every 3 weeks), level B1(everolimus 5mg daily; eribulin 1.1 mg/m2 days 1, 8 every 3 weeks). Nanostring RNA analysis and genomic mutation analysis were conducted in 16 pts with available tumor tissue.

Results: A total of 27 pts were enrolled. Median age was 55 years (range 36-76). Two pts were ineligible due to HER2+ on repeat biopsy and were only included in the toxicity analysis. Dose level B1 (everolimus 5mg daily and eribulin 1.1 mg/m2 days 1, 8 every 3 weeks) was determined to be the RP2D doses. The DLTs were neutropenia, stomatitis and hyperglycemia. Across all cycles, 59% (16/27) had a ≥ Gr3 toxicity attributed to treatment at the possible or above level. 44% (12/27) had Gr3 heme-toxicities. The most common toxicities were ≥ Gr3 neutropenia (10 pts), Gr3 lymphopenia (6 pts) and ≥ Gr3 leukopenia (7 pts). 33% (9/27) had Gr3 non-heme toxicities. The most common were Gr3 stomatitis (3 pts), Gr3 hyperglycemia (3 pts) and Gr3 fatigue (5 pts). The median number of cycles completed was 4 (0-8). 68% (17/25) had a dose modification or hold, 14 of 25 (56%) were for eribulin and 15 of 25 (60%) were for everolimus. Of 25 eligible pts, 8 (32%) achieved a best response as partial response, 11 (44%) had stable disease and 6 (24%) had progression. 80% (20/25) experienced progression by RECIST or showed clinical progression, and the median time to progression was 2.7 mo (95% CI (2.2, 4.6)). At the time of this analysis, 16 participants had died, median OS was 6.3 mo (95% CI (5.3, undefined)). Two pts are still being followed on treatment. PI3K-Akt-mTOR pathway genes and mutations profiles were studied.

Conclusion: Eribulin 1.1 mg/m2 days 1, 8 and everolimus 5mg daily was defined as the RP2D. Genomic analysis is currently underway to understand the molecular mechanisms of resistance.

Citation Format: Yuan Y, Yost S, Blanchard S, Yin H, Li M, Robinson K, Tang A, Martinez N, Leong L, Somlo G, Tank Patel N, Waisman J, Portnow J, Hurria A, Luu T-H, Mortimer J. Phase I trial of eribulin and everolimus in patients with metastatic triple negative 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 P6-18-18.

Abstract P3-06-09: BRCA mutations and not type 1 tandem duplicator phenotypes are associated with pathological complete response in patients with triple negative breast cancer undergoing neoadjuvant carboplatin/nab-paclitaxel

Background. We recently described six distinct genomic configurations characterized by large numbers of distributed somatic tandem duplications (TDs) known as Tandem Duplicator Phenotypes (TDPs). Different TDPs feature TDs of different span sizes, and are enriched in TNBC, ovarian, and uterine cancers. Type 1 TDPs (i.e. groups 1, 1/2mix and 1/3mix) feature short span TDs (˜11Kb in size), invariably show abrogation of BRCA1 (via mutation or methylation) and of TP53, and affect ˜40% of TNBCs. We had observed, in limited in vitro and preclinical PDX models, that TDP status correlates with platinum sensitivity (1). Here, we assess TDP status across a cohort of 42 TNBC patients (pts) undergoing neoadjuvant carboplatin and NAB-paclitaxel to test the hypothesis that type 1 TDP status may be predictive of optimal response to platinum-based therapy.

Methods. 42 pts with TNBC were enrolled in a phase II study of neoadjuvant carboplatin/nab-paclitaxel at the City of Hope National Medical Center (NCT01525966).Pathological complete response (pCR) was achieved in 50% of pts (21/42). WGS was performed using standard Illumina protocols. Structural variants were called using Crest, Delly and BreakDancer, and high confidence breakpoints were selected when called by at least two tools and by requiring split-read support. TDP status was ascertained as recently described (2). BRCA1 methylation was determined by methylation-specific PCR.

Results. 45% of the tumors classified as TDP (19/42). Consistent with our previous observation, the vast majority were type 1 TDPs with short span TDs (n=17) and were strongly associated with BRCA1 mutation or methylation (16/17, P= 1.4E-8). However, there was no correlation between TDP status and pCR (OR=1.1, NS). In a more detailed analysis, we found that BRCA1 mutation correlated with pCR rate (6/7 pCR, P=0.01), whereas promoter methylation did not (4/11 pCR, NS). Moreover, both pts with mutant BRCA2 achieved pCR. Thus, as a group, pts with BRCA1/2 mutations (but not BRCA1 methylation) were more likely to achieve pCR than those with wild type BRCA1/2 (OR=11.9, P=1.7E-2). Results were unchanged when using RCB 0 and 1 vs. RCB 2 and 3 as the response criteria.

Conclusions. This study confirmed that reduction of BRCA1 activity via either mutation or methylation robustly associates with type 1 TDPs in TNBC. However, TDP status did not predict good response, suggesting the separation of BRCA effects on genomic instability and platinum sensitivity. This indicates that genomic signature assessments, such as TDP and HRD, may not be sufficient in predicting pCR in TNBC. Importantly, we found that BRCA1/2 mutated TNBC pts were more likely to experience pCR (8/9) compared with pts with either BRCA1 methylation (4/11) or wild type BRCA1/2 (8/21). The exact genetic underpinnings of response in non-BRCA pts are currently under investigation.

References.

1) Menghi et al, The Tandem Duplicator Phenotype is a Prevalent Genome-Wide Cancer Configuration Driven by Distinct Gene Mutations, Cancer Cell (2018).

2) Menghi et al, The tandem duplicator phenotype as a distinct genomic configuration in cancer, Proc Natl Acad Sci (2016).

Citation Format: Menghi F, Yuan Y, Somlo G, Liu ET. BRCA mutations and not type 1 tandem duplicator phenotypes are associated with pathological complete response in patients with triple negative breast cancer undergoing neoadjuvant carboplatin/nab-paclitaxel [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 P3-06-09.

Abstract P6-17-18: Pathologic complete response (pCR) in locally advanced HER2+ (HER2+) breast cancer (BC) treated with anthracycline-free neoadjuvant therapy

Background: Response to neoadjuvant therapy is a predictor of progression-free and overall survival in HER2+. To decrease treatment associated toxicities in patients with HER2+ breast cancers we utilized a non-anthracycline regimen with pertuzumab (pert), trastuzumab (trast), and nab-paclitaxel (nab). Pre- neoadjuvant therapy biopsies were procured to evaluated possible biological predictors of pathologic complete response (pCR).

Methods: Women with locally advanced HER2 positive breast cancers were recruited from our breast cancer clinics. After obtaining informed consent for this IRB-approved trial, patients were treated with 6 cycles of pertuzumab (day 1 every 21 days [d]), and weekly trastuzumab 2 mg/kg with and nab-paclitaxel 100 mg/m2. Formalin fixed paraffin embedded (FFPE) or frozen biopsies pre-NT and post-NT were collected, along with blood samples at pre-treatment, and at the end of study for correlative analysis.

Results: Accrual is complete, with 42 of the 45 HER2+ patients assessed for pCR rate (3 too early to evaluate). The median age was 54 yrs (range 31-77 years). 12 patients were stage 3, 26 stage 2, and 1 stage 1 patient. The pCR rate was 64.2% (27/42), with 73.7% (14/19) in ER/PR negative patients and 56.5% (13/23) in ER/PR positive patients. The initial primary tumor size was similar for in those who achieved pCR and non-pCR patients (mean 4.1 cm vs 3.2 cm, respectively). Most patients required dose modifications. Grade 3 AEs reported included 6 patients with hypertension, 3 patients with hematological AEs, 3 patients with elevated LFTs, and 2 patients with diarrhea.

Conclusions: This anthracycline-free regimen in HER2+ BC can achieve promising pCR response rates, with toxicities well-managed with dose modifications. Results of correlative analysis will be presented.

Citation Format: Somlo G, Waisman J, Yuan Y, Kruper L, Frankel P, Jones V, Lusi T, Schmolze D, Yim J, Hurria A, Mortimer J. Pathologic complete response (pCR) in locally advanced HER2+ (HER2+) breast cancer (BC) treated with anthracycline-free neoadjuvant therapy [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 P6-17-18.

Abstract P1-15-07: Phase II trial of neoadjuvant carboplatin and nab-paclitaxel in patients with locally advanced triple negative breast cancer

Background: Response to neoadjuvant therapy (NT) predicts progression-free and overall survival in triple negative breast cancer (TNBC). Carboplatin has shown efficacy in patients with TNBC. The current phase II prospective neoadjuvant trial was designed to decrease toxicities and improve efficacy.

Methods: Patients with TNBC received carboplatin (carb) and nab-paclitaxel (nab). Pre-NT biopsies were procured to evaluate for biological predictors of pathological complete response (pCR). Newly diagnosed stage II-III patients with TNBC were treated with 4 cycles of carb (AUC 6, day 1 of 28 day cycle) and weekly nab 100 mg/m2 x 16. Targeted accrual goal is 70. RNA extracted from formalin fixed paraffin embedded (FFPE) biopsies pre-NT was tested for MammaPrint/BluePrint and custom Agilent full genome microarrays for gene expression (GE, by Agendia Inc). The raw gMeanSignal was log2 transformed and normalized to the 75thpercentile for GE analysis. Association between MammaPrint/ BluePrint results and pCR was tested by Fisher exact test. The linear model from R limma package was applied. Ingenuity Pathway Analysis (IPA) was applied to assess functional pathways associated with pCR. Cellular distribution by CIBERSORT analysis was carried out to estimate the abundance of 22 different cell types in each patient sample, and test whether the distribution of cell types is different between pCR and non-responders.

Results: A total of 64 patients were enrolled. Two patients were deemed ineligible (Her2+), and three were too early, resulting in 59 patients evaluable for pathological response. The pCR rate was 47% (RCB0, 28/59). Eight patients had RCB I. RCB0 plus RCBI reached 61%. Sufficient quality RNA and DNA were available from the first 43 of 55 pts with TNBC. 44/59 (75%) required dose modifications (mostly hematologic), 5 patients had grade 3 peripheral neuropathy (PN), 3 had grade 2 PN, and 3 patients had grade 2 LFTs. In the 53 pts with GE assessment, pCR was inversely associated with luminal BluePrint type (p=0.04). With fold change >1.5 and p-value < 0.05, 36 genes were differentially expressed (DE) in TNBC. CIBERSORT analysis suggested that T-cell regulatory cells (TREGS) were associated with pCR in TNBC, and 5 cell types (plasma cells, TREGS, macrophage, dendritic cells and neutrophils) presented differently between all pCR and non-pCRs with P-value <0.05. TDP analysis to assess correlation with pCR is ongoing.

Conclusions: The combination of carboplatin and nab-paclitaxel given in the neoadjuvant setting reached a promising pCR rate of 47%. The MammaPrint non-luminal BluePrint subtype was predictive of pCR in TNBC. Preliminary analysis suggested that a 36-gene signature for TNBC was associated with pCR. CIBERSORT analysis revealed 5 cell types with different abundance between the pCR and non-responders, suggesting the need to target the tumor microenvironment.

Citation Format: Yuan Y, Frankel P, Li M, Kruper L, Jones V, Treece T, Waisman J, Yim J, Tumyan L, Schmolze D, Hurria A, Yeon C, Mortimer J, Somlo G. Phase II trial of neoadjuvant carboplatin and nab-paclitaxel in patients with locally advanced triple negative 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 P1-15-07.

Abstract P6-15-07: Not presented

This abstract was not presented at the symposium.

Abstract OT1-05-02: A phase II clinical trial of the combination of pembrolizumab and selective androgen receptor modulator GTx-024 in patients with advanced androgen receptor positive triple negative breast cancer

Background: Androgen receptor (AR) targeted therapy and immunotherapy represent one of the most promising strategies for metastatic triple negative breast cancer (mTNBC), which accounts for 15-20% of all breast cancers. As a nonsteroidal selective androgen receptor modulator (SARM), GTx-024 demonstrated preclinical activity in AR+ TNBC PDX model. Pembrolizumab is a highly selective humanized monoclonal antibody of the programmed cell death 1 receptor (PD-1). The complementary modes of action and low potential for overlapping toxicity make the combination promising in patients with AR+ mTNBC.

Trial Design: This is an open-label Phase 2 study for AR+ mTNBC. Eligible participants receive pembrolizumab 200mg IV every 3 weeks in combination with GTx-024 18mg po daily.

Eligibility Criteria: Eligible patients must have AR+ (>10%, 1+ by IHC) TNBC; failed up to 2 lines of therapy in metastatic setting; and have measurable disease per RECIST1.1. Patients are excluded if they have had prior checkpoint inhibitors or AR targeted agents. Patients with current or prior use of testosterone, testosterone-like agents, androgenic compounds, or anti-androgens (including systemic steroids and immunosuppressive medications)are excluded, as well as current or prior history of noninfectious pneumonitis requiring systemic steroid therapy.

Specific Aims: The primary objective is to evaluate the safety/tolerability of GTx-024 and pembrolizumab and determine the response rate (CR or PR via RECIST 1.1) in patients with advanced AR+ TNBC. We will use clinical benefit rate (CBR), duration of response (DOR), PFS, and OS to test the efficacy of this novel drug combination.

Statistical Design: A Simon's MiniMax two-stage Phase 2 design will be utilized. Based on the previously reported response rate associated with single agent pembrolizumab (19%), we consider a response rate of 19% for the combination as discouraging, and a 39% response rate as encouraging. As a result, we will initially accrue 15 patients (including 6 patients from safety lead-in treated at the tolerable dose). If 2 or fewer patients respond, we will stop accrual for futility. Otherwise, the study will accrue an additional 14 patients for a total of 29 patients. With 29 patients, if only 8 or fewer respond (≤27.6%), the study will be considered discouraging unless secondary evidence of clinical benefit is substantial. With more than 8 patients responding out of the 29 patients, the combination would be considered promising. This design has 85% power to declare a true response rate of 39% as promising (power), and a 10% probability of declaring a true 19% response rate as encouraging (type I error). The probability of early termination if the true response rate is 19% is 44%.

Target Accrual: 29

Study Contact: Yuan Yuan MD PhD, City of Hope Comprehensive Cancer Center; Duarte, CA 91030; Email: yuyuan@coh.org

Citation Format: Yuan Y, Frankel P, Synold T, Lee P, Yost S, Martinez N, Tang A, Mendez B, Schmolze D, Apple S, Hurria A, Waisman J, Somlo G, Tank N, Sedrak M, Mortimer J. A phase II clinical trial of the combination of pembrolizumab and selective androgen receptor modulator GTx-024 in patients with advanced androgen receptor positive triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-05-02.

Abstract P4-02-06: Intratumoral and peritumoral MRI signatures of HER2-enriched subtype also predict pathological response to neoadjuvant chemotherapy in HER2+ breast cancers

Background: Applying the PAM50 classifier to targeted RNA-Sequencing data allows HER2+ tumors to be sub-categorized into intrinsic breast cancer subtypes. HER2+ breast cancers belonging to the HER2-enriched [HER2-E] subtype exhibit the highest rate of response to neoadjuvant therapy with combination of HER2-blockade and chemotherapy, as well as dual-HER2 blockade alone. A non-invasive predictor of PAM50 subtype from clinical dynamic contrast-enhanced MRI [DCE-MRI] could provide valuable clinical guidance in the treatment of HER2+ breast cancer. In this work, we identify a set of computer-extracted heterogeneity features computed within the lesion and its surrounding peritumoral region capable of distinguishing HER2-E from other HER2+ breast cancers [Non-HER2-E]. We then demonstrate that this imaging signature of HER2-E is also predictive of pathological complete response [pCR] in an independent HER2+ testing set, consistent with the HER2-E subtype's elevated response to HER2-targeted therapy.

Methods: The training set consisted of 42 HER2+ patients with both 1.5 or 3 T DCE-MRI and targeted RNA sequencing collected prior to neoadjuvant treatment from a multicenter trial [BrUOG 211B, n=35] and The Cancer Genome Atlas-Breast Cancer project [TCGA-BRCA, n=7]. Intrinsic subtypes were assigned by unsupervised hierarchical clustering of the PAM50 gene set. 19 patients were determined to belong to the HER2-E subtype, while the remaining 23 represented non-HER2-E subtypes [19 HER2-Luminal, 4 HER2-basal]. Lesion boundaries were annotated by an expertly trained radiologist and expanded to 5 annular peritumoral regions in 3 mm increments out to a maximum radius of 15 mm. Computer-extracted heterogeneity features were computed voxelwise within intratumoral and peritumoral regions by first order statistics. A top HER2-E-associated feature from each region was identified by Wilcoxon feature selection and used to train a diagonal linear discriminant analysis [DLDA] classifier to predict HER2-E in a 3-fold cross-validation setting. This classifier was then applied to pCR prediction from DCE-MRI in a testing set of 28 HER2+ patients with available post neoadjuvant chemotherapy surgical specimens at one institution. 16 patients achieved pCR (ypT0/is), while the remainder had partial or no response (non-pCR).

Results: A combination of heterogeneity features within the intratumoral region and annular peritumoral regions out to 12 mm from the tumor yielded optimal results within the training set, with an average HER2-E prediction AUC of .77 +/- .03. When applied to response prediction in an independent testing set, this HER2-E classifier was predictive of pCR (AUC = .72).

Conclusions: Computer-extracted heterogeneity features calculated within the tumor and the surrounding peritumoral environment on DCE-MRI were able to distinguish the HER2-E PAM50 intrinsic subtype from other HER2+ breast cancers. HER2-E was characterized by elevated expression of intratumoral and peritumoral heterogeneity features, indicating a more disordered imaging phenotype within and around the tumor. Additional independent validation of these findings is needed.

Citation Format: Braman N, Prasanna P, Singh S, Beig N, Gilmore H, Etesami M, Bates D, Gallagher K, Bloch BN, Somlo G, Sikov W, Harris L, Plecha D, Varadan V, Madabhushi A. Intratumoral and peritumoral MRI signatures of HER2-enriched subtype also predict pathological response to neoadjuvant chemotherapy in HER2+ breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-06.

Abstract P5-21-08: Tolerability of the combination of lapatinib and trastuzumab in older patients with HER2 positive metastatic breast cancer

Background: Older adults are less likely to be included in clinical trials leading to the approval of novel cancer treatments. The Institute of Medicine and ASCO have identified therapeutic phase II trials as a key research priority to increase the evidence base for older adults with cancer. While targeted therapies may represent a less toxic option for older patients, few trials have studied their tolerability and efficacy in older adults. Here, we present a phase II study (NCT01273610) of the combination of trastuzumab and lapatinib in older patients with HER2+ metastatic breast cancer (MBC), incorporating geriatric oncology principles in the study design.

Methods: Patients age ≥ 60 years with MBC and any number of prior chemotherapy (CT) lines received trastuzumab (either 4mg/kg loading dose followed by 2mg/kg weekly or 8mg/kg followed by 6mg/kg q/3 weeks) plus lapatinib 1000 mg/m2 daily in 21-day cycles. Patients completed a pre-treatment geriatric assessment including measures of function, comorbidity, cognition, nutrition, and psychosocial status. A toxicity risk score developed for older adults receiving cytotoxic CT was calculated for each patient (Hurria et al. JCO 2011 & 2016). Relationships between tolerability (dose reductions and grade (G) ≥ 3 toxicity attributed to treatment) and risk score analyzed using a log2 transformation were assessed using generalized linear models, Student's t tests, and Fisher's exact test. Response rate (RR) and progression free survival (PFS) were evaluated.

Results: 40 patients (mean age 72 [60-92]) were accrued from 04/11 to 05/15. 25% (n = 10) were ≥ 75 years of age. 65% of patients (n = 26) had HR+ tumors and 35% (n = 14) were receiving ≥ 3rd line treatment. Median number of cycles was 4 (0-28). RR was 23% (n = 9, 95% CI 11-38%; 1 complete, 8 partial). 23% (n = 9) achieved stable disease. PFS was 2.7 months (95% CI 2.5-12). Based on the toxicity risk score, 21% (n = 8), 54% (n = 21), and 26% (n = 10) were at low, intermediate, and high risk. 70% (n = 28) of patients had G ≥ 2 toxicities and 20% (n = 8) G ≥ 3 toxicities. G 2 and 3 diarrhea occurred in 28% (n = 11) and 5% (n = 2) respectively. 5% (n = 2) were hospitalized due to treatment-related toxicity. No G ≥ 3 cardiac toxicities were observed. 23% of patients (n = 9) had treatment delays, and 43% (n = 17) required a lapatinib dose reduction. The mean toxicity risk score was higher in patients who required dose reductions (Student's t: p = 0.02). No statistically significant relationship was found between toxicity risk scores and the presence of G ≥ 3 treatment toxicity (logistic regression: OR = 3.08, 95% CI [0.54, 21.2], p = 0.22).

Conclusions: Among older patients with MBC (79% at intermediate or high risk of G ≥ 3 cytotoxic CT toxicity), trastuzumab and lapatinib were well tolerated, with only 20% experiencing G3 toxicities. The toxicity risk score was not found to be significantly related with treatment toxicity, which may be explained by the very low incidence of G3 events. Patients with a low toxicity risk score were not likely to require a lapatinib dose reduction.

Citation Format: O'Connor T, Soto-Perez-de-Celis E, Blanchard S, Chapman A, Kimmick G, Muss H, Luu T, Waisman JR, Li D, Mortimer J, Yuan Y, Somlo G, Stewart D, Katheria V, Levi A, Hurria A. Tolerability of the combination of lapatinib and trastuzumab in older patients with HER2 positive metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-08.

Abstract P1-08-04: Not presented

This abstract was not presented at the symposium.

Abstract P2-05-06: Not presented

This abstract was not presented at the symposium.

Abstract OT2-01-03: Phase II Trial of the addition of pembrolizumab to letrozole and palbociclib in patients with metastatic estrogen receptor positive breast cancer who have stable disease on letrozole and palbociclib

Background: The combination of palbociclib and letrozole has become the standard of care for patients with newly diagnosed estrogen receptor positive (ER+) metastatic breast cancer (MBC), with promising prolongation of progression free survival (PFS). However, nearly half of all patients achieved stable disease only after the first 6 months of therapy. Check-point inhibitor pembrolizumab was effective in ER+ MBC with a response rate of 13-17%, this study will evaluate the efficacy of adding pembrolizumab for patients with ER+ MBC who have achieved stable disease (SD) on letrozole and palbociclib.

Trial Design:This is an open-label single institutional study. Patient will receive letrozole (2.5 mg) once a day and palbociclib (125 mg, 100 mg, or 75 mg as established tolerated dose) once a day for 3 weeks on and 1 week off. Pembrolizumab will be given at 200 mg IV every 3 weeks.

Eligibility Criteria: Eligible patients must be postmenopausal women with ER+ MBC with measurable disease by RECIST1.1, ECOG performance status 0-1; must have received letrozole and palbociclib for at least 6 months, and have documented SD per RECIST 1.1. Up to3 lines of previous systemic therapy including endocrine therapy and/or chemotherapy are allowed. Patients are excluded if they had prior treatment with anti--PD1 or anti-PD-L1therapy, immunodeficiency; currently using systemic steroids active tuberculosis infection; major surgery within 28 days; active or untreated CNS metastases; history of interstitial lung disease; active infection requiring systemic therapy; or active cardiac disease.

Specific Aims: The primary objective is to evaluate the objective response rate(ORR). The secondary objective is to determine the safety and tolerability of pembrolizumab plus the letrozole/palbociclib combination. We will use clinical benefit rate (CBR), duration of response (DOR), PFS, and OS to test the efficacy of this novel drug combination.

Statistical Design: We will employ a three-at-risk design (modified rolling design) for the initial cohort of this Phase II study to insure the triplet is well-tolerated. This design permits only 3 patients to be a risk for DLT at any one time during the “safety lead-in” .When the first 6 patients have completed the observation period and treatment with ≤1 DLT, the safety lead-in for the triplet will be considered successful, and accrual will proceed to a total of 18 patients. Response (CR or PR by RECIST version 1.1) in patients who have demonstrated only SD on letrozole and palbociclib can be reasonably attributed to the addition of pembrolizumab. As a result, we set the probability of a response occurring without the addition of pembrolizumab as 3% or less. With 18 patients, a true response rate of 20% would result in at least 2 responders with 90% power and a type I error of 10%. With 18 patients, the response can be estimated with a 95% CI half-width of 23%.

Target Accrual: 18.

Citation Format: Yuan Y, Frankel P, Synold T, Yost S, Lee P, Waisman J, Somlo G, Hurria A, Mortimer J. Phase II Trial of the addition of pembrolizumab to letrozole and palbociclib in patients with metastatic estrogen receptor positive breast cancer who have stable disease on letrozole and palbociclib [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 OT2-01-03.

Abstract OT1-02-05: Phase II clinical trial of neratinib in patients 60 and older with HER2 over-expressed or mutated breast cancer: Trial design considerations for older adults

Background: This study addresses a key knowledge gap identified by the Institute of Medicine report on quality cancer care. Although there has been a growth in the number of targeted agents approved for the treatment of breast cancer, there are limited data regarding the efficacy, toxicity, and management of side effects in older adults. Neratinib is a potent oral small molecule tyrosine kinase inhibitor. Early clinical data have demonstrated the activity of neratinib in patients who have already progressed through HER2 targeted therapies. This study is designed to evaluate the tolerability and toxicity profile of neratinib in older adults with metastatic breast cancer (MBC) incorporating geriatric oncology design considerations.

Trial Design: This is an open label, single arm, phase II study of single agent neratinib in patients with HER2 positive MBC. Neratinib is given at 240mg orally in 28 day cycles. Unique factors of this geriatric oncology trial design include: 1) pre-treatment and on-treatment geriatric assessment; 2) additional nurse toxicity visits; 3) an algorithm for aggressive management of diarrhea; 4) measurements of the pharmacokinetics (PK) of neratinib; 5) inclusion of biomarkers of aging; 6) measurement of patient adherence; and 7) evaluation of quality of life.

Eligibility Criteria: Patients must be age≥60 with histologically-proven HER2 positive MBC or MBC with HER2 receptor activating mutations. There is no limitation on the number of previous lines of therapy, but patients must have adequate organ and bone marrow functions, and a baseline LVEF ≥ 50%. Exclusion Criteria include: prior treatment with neratinib; major surgery within 28 days; uncontrolled cardiac disease; concurrent use of digoxin; or chronic diarrhea.

Specific Aims: The primary objective of this study is to identify the rate of grade 2 or higher toxicities attributed to neratinib in adult age ≥60 with HER2 over-expressing breast cancer. The secondary objectives are to describe the full toxicity profile (including all grades of gastrointestinal toxicities); to estimate the rate of dose reduction, holds and hospitalizations; to describe the PK parameters; to estimate the adherence rate to neratinib; and to estimate the overall response, clinical benefit rate, progression-free and overall survival. Furthermore, we will explore the role of a cancer-specific geriatric assessment and serum biomarkers of aging (IL-6, CRP, and D-dimer) in predicting treatment toxicities and PK parameters.

Statistical Design: We plan to enroll 40 patients age ≥60 (at least 5 patients age 75 years or older, and no more than 15 patients 60-70) in order to assure that our sample is representative of the entire age range of older adults. Given a sample size of 40 subjects, the widest half-width of the 95% confidence limits for the rate of grade 2 or higher toxicities will be less than or equal to 0.16. An interim analysis will be performed after 20 subjects have been on study for at least one cycle.

Accrual goal: 40

Contact information: Yuan Yuan MD PhD, Email: yuyuan@coh.org.

Citation Format: Yuan Y, Blanchard S, Li D, Mortimer J, Waisman J, Somlo G, Yost S, Katheria V, Hurria A. Phase II clinical trial of neratinib in patients 60 and older with HER2 over-expressed or mutated breast cancer: Trial design considerations for older adults [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 OT1-02-05.

Abstract P4-21-35: Phase II trial of pertuzumab, trastuzumab, and nab-paclitaxel in patients (pts) with HER2 overexpressing (HER2+) locally advanced or inflammatory breast cancer (LABC) or untreated stage IV metastatic breast cancer (MBC)

Background: Pathologic complete response (pCR) to HER2-targeting neoadjuvant therapy (NT) predicts for improved survival (Cortazar et al, Lancet, 2014). The addition of pertuzumab to trastuzumab and docetaxel increased pCR rates, and, as first line treatment for MBC led to longer overall survival ([OS] Swain et al, NEJM 2015). Avoidance of anthracyclines in the adjuvant setting for HER2+ BC reduced the risk of secondary hematologic malignancies without a detriment to OS (Slamon et al, NEJM, 20111). Finally, nab-paclitaxel (nab) might provide an advantage over other taxanes via decreased use of steroids and may lead to increased response rates (RR). We designed a study of pertuzumab (pert), trastuzumab (trast), and nab, testing the feasibility and efficacy of this regimen in the LABC and metastatic breast cancer settings.

Materials and Methods: Pts with Stages II-III LABC received six cycles of NT with pert (day 1 q 21 days), trast, and nab 100 mg/m2 (both given IV, weekly). Pts with untreated MBC received the same regimen until progression, toxicities, or patient or physician preference led to stopping therapy. Primary endpoints included pCR (LABC) and RR and progression-free survival (PFS) in MBC. Forty pts with LABC and 25 pts with MBC were to be accrued. The study was designed to test whether the pCR rate of Neosphere (Gianni et al, Lancet Oncol, 2012, > 45.8%) and the PFS rate of CLEOPATRA (median of > 18.5 months) can be matched or exceeded. Procurement of serial samples for assessment of tumor gene expression, circulating tumor cells, miRNA, and serum DNA profiling for exploratory biomarker analysis was carried out.

Results:Twenty-two of 28 already enrolled pts with LABC (clinical stage II:15, stage III: 7) completed NT. The median age was 53 (34-77). The pCR rate was 86% (6/7) for hormone receptor negative (HR-) and 40% (6/15) for HR+ pts, with an overall pCR of 55%. Three pts without pCR following NT had residual BC with a HER2 negative phenotype. Eighteen of 22 pts required nab dose modifications. The most frequent toxicities following NT included elevated liver function tests:27%, peripheral neuropathy:23%, hematological toxicities:17%, diarrhea:18%, infusion reactions:18%. In the MBC cohort there were 13 of 16 enrolled pts with > 2 months of follow-up. The median age was 47 (31-65), 62% had HR+ disease. A CR rate of 4/13 (31%) and confirmed RR of 77% were observed. The median number of cycles with pert, trast, nab was 9 (3+ to 41); 11 of 13 pts required dose modifications or delays (3 of the delays were due to primary breast surgery performed upon response to treatment). At a median follow-up of 19 months, PFS and OS estimates are 63% (95% CI 0.09-0.93), and 89% (95% CI 0.61-1.0).

Conclusion: The non-anthracycline-containing regimen of pertuzumab, trastuzumab, and nab-paclitaxel induced a high pCR rate in HER2+ BC. PFS is encouraging in MBC. Outcome of the fully accrued cohorts inclusive of residual cancer burden scores in the LABC cohort, and correlative data with exploratory biomarker analysis will be presented.

Citation Format: Somlo G, Frankel P, Yeon C, Yuan Y, Yim J, Kruper L, Taylor L, Mortimer J, Waisman J, Jones V, Vito C, Paz B, Huria A, Li D, Gaal C, Tong T, Tumyan L. Phase II trial of pertuzumab, trastuzumab, and nab-paclitaxel in patients (pts) with HER2 overexpressing (HER2+) locally advanced or inflammatory breast cancer (LABC) or untreated stage IV metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-35.

Abstract P1-05-09: Association of co-amplicons with immune infiltration in subtypes of HER2-Positive breast cancer

Background: HER2+ breast cancers are heterogeneous at both clinical and molecular levels. We and others have determined that the HER2-Enriched subtype exhibits the highest rate of pathologic complete response (pCR) to neoadjuvant chemotherapy and trastuzumab (T), while the HER2-Basal subtype is resistant to anti-HER2 therapy (Carey et al, JCO 2015;Varadan et al, CCR 2016). Additionally, we reported that signatures of immune cell infiltration and immune cell subsets evaluated after one dose of T can predict pCR to preoperative T and chemotherapy (Varadan et al, CCR 2016). Given recent evidence for improved immune response with increasing mutational load, we chose to characterize the association of somatic mutations and copy-number alterations with subtypes of HER2+ breast cancer and immune modulation after one dose of T.

Methods: Fresh tumor core biopsies were taken at baseline and 2 weeks after one dose of either T or nab-paclitaxel (N) from 60 patients with stage II-III HER2+ cancers enrolled on a multicenter trial (BrUOG 211B). All patients then received 18 weeks of T+N+carboplatin. PAM50 subtyping was performed using gene expression data from patient tumor biopsies and tumors were classified into HER2-Enriched, HER2-Luminal and HER2-Basal subtypes. Whole-exome sequencing (WES) was performed on a total of 86 samples (49 baseline, 37 brief-exposure), sequenced at an average depth of 90X. Somatic mutations were detected by applying multiple mutation-detection algorithms on the WES data, followed by stringent quality control using public and in-house variant databases, and mutation data curated from 11,000 tumors sequenced by the TCGA. Somatic copy-number alterations were estimated using a published algorithm, ENVE (Varadan et al, Genome Med 2015) that robustly detects somatic copy-number alterations in WES tumor profiles. We employed previously defined gene-expression signatures (Varadan et al, CCR 2016) of total immune infiltration and immune cell subsets, to assess for association with genomic aberrations.

Results: HER2-Basal tumors exhibited lower average copy number for HER2 and were less likely to have high-level amplifications of co-amplicons (e.g. 11q13, 20q13) with the exception of the MYC amplicon (8q24). They also exhibited a non-significant (P=0.33) trend towards higher mutational burden (Avg=85) compared to HER2-Luminals (Avg=79). A majority of somatic mutations (62%, 2282/3666) persisted after a single-dose of either T or N, while 17% (624/3666) were not detectable after brief-exposure. There was no association between immune infiltration and mutational burden in any HER2 subtype. Tumors harboring FGFR1 (8p11) amplifications exhibited higher gene-signature levels for macrophages (P=0.0073) and T-cells (P=0.0493) but not B-cells (P=0.213).

Conclusions: The HER2-Basal subtype is less likely to respond to trastuzumab-based neoadjuvant therapy and exhibits lower numbers of common amplicons. The disappearance of mutations after brief-exposure to therapy may be due to either tumor heterogeneity/sampling or clonal selection. The association of 8p11 amplifications with increased T-cell infiltration suggests that this amplicon may play an immunogenic role in HER2+ breast cancer. These results warrant further investigation in larger cohorts.

Citation Format: Singh S, Gilmore H, Somlo G, Abu-Khalaf M, Sikov W, Harris L, Varadan V. Association of co-amplicons with immune infiltration in subtypes of HER2-Positive breast cancer [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 P1-05-09.

Abstract P1-14-10: Phase II trial of neoadjuvant chemotherapy with carboplatin and nab-paclitaxel in patients with triple negative locally advanced and inflammatory breast cancer

Background: Pathologic complete response (pCR) and residual cancer burden (RCB scores of 0 [pCR] or 1[near CR]) after neoadjuvant chemotherapy (NCT) may predict for improved survival (Symmans et al. J Clin Oncol 25:4414-22, 2007). We set out to test the pCR rate with an anthracycline-free regimen of carboplatin (carb) and nab-paclitaxel (nab) in patients (pts) with triple negative breast cancer (TNBC).

Materials and Methods: Forty-nine pts with stages II-III BC were to receive carb (AUC 6) on day 1 of a 28 day cycle, and nab 80 mg/m2 weekly, for a total of 4 cycles. Core biopsies were performed prior to NCT. Blood procurement for circulating tumor cell (CTC) analysis using the CellSearch platform was carried out pre-treatment, mid-treatment, and at surgery. We set out to assess the predictive value of Mammaprint (poor vs. good), BluePrint (basal, vs. luminal, vs. HER2) molecular subtype as well as microarray RNA and miRNA profiling, for pCR. Responses were also dichotomized as complete or near complete response (Symmans RCB scores of 0-1) vs. suboptimal response (RCB score > 1).

Results: The median age was 53 (28-75). Pts presented with clinical stages II (63%) and III (37%). So far, 38 of the 49 pts accrued between 2/2012 and 6/2015, have undergone surgery, 68% of whom underwent modified radical mastectomy. The pCR rate (breast and lymph nodes in CR) was 53%, and RCB 0 and 1 were seen in 68% of pts. Toxicites included grade ¾ anemia (45%), thrombocytopenia (13%) and neutropenia (53%,1 pt with neutropenic fever). Dose adjustments were needed in over 80% of pts. Grades 2 or 3 peripheral neuropathy were seen in 8% each, and grades 3-4 fatigue (13%), hypokalemia (3%), and hyponatremia (3%) were observed. The median number of CTCs (pre-NCT) observed in 7 CTC positive pts of the first 27 pts who completed surgery was 1 (0-7), and 2 of the 7 pts continued to have CTCs at the time of surgery (1 CTC each), while 2 pts without CTCs pre-NCT had CTCs (1 each) detected at surgery. The final pt enrolled is expected to complete surgery by 10/2015. Results of sequential CTC assessments, MammaPrint/Blueprint and RNA/miRNA analysis of pre- and post-treatment specimens and their correlation with pCR will be presented.

Conclusion: The non-anthracycline-containing regimen of carb and nab-paclitaxel induced a high pCR rate in TNBC, in preliminary analysis. Ongoing profiling may allow for future subset-specific modification of this regimen to increase pCR across all molecular subtypes of TNBC.

Citation Format: Somlo G, Chung S, Frankel P, Hurria A, Koehler S, Kruper L, Mortimer JE, Paz B, Robinson K, Taylor L, Vito C, Waisman J, Yeon C, Yim J, Yuan Y, Tong T. Phase II trial of neoadjuvant chemotherapy with carboplatin and nab-paclitaxel in patients with triple negative locally advanced and inflammatory 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 P1-14-10.

Abstract P3-03-02: Identification of molecular pathways to define the intake rate of patient-derived hormone receptor positive (HR+) breast cancer xenografts (PDXs) in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice

Background and Purpose: Despite recent progress in our endocrine therapy of hormone receptor positive (HR+) breast cancers, a significant number of patients with primary breast cancer continue to relapse, and those with stage IV disease face a median overall survival of ∼ 3.5 years. Primary or acquired resistance to anti-estrogen-based therapies is an overarching challenge. To guide our treatment selection, there is an essential need to improve our understanding of the biology of HR+ breast tumors responsive to and those resist to anti-estrogens or aromatase inhibitors (AIs). The application of patient-derived xenografts (PDXs) in preclinical studies has begun to open the door to mimicking human disease on the research bench. However, HR+ breast cancer PDXs are difficult to establish. Although preclinical data from DeRose et al [Nat. Med. 2011: 17:1514-1520] indicate that the rate of engraftment serves as an independent predictor for poor outcome, the question which has not yet been adequately addressed is: "why some tumors can grow in mice, and some don't, even when their clinical, pathological stage and subtype (i.e. ER positivity) are same?" Here, we hypothesize that the molecular characteristics of patient HR+ tumors are key determinants to the tumor intake rate in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice. Hence, reverse phase protein array (RPPA) analysis has be performed using human patient tumors to identify driver-pathways that impact tumor intake in NSG mice.

Results and Discussion: We compared the protein expression profile of six HR+ patient tumors (four HR+ and two HR+ HER2+), which were successfully engrafted into NSG mice and established as PDX models, with the patient tumors which we were unable to establish as PDX. Of 90 patient HR+ tumors which failed to transplant, 21 tumors were picked to match the tumor type (all of them were invasive ductal carcinoma or its metastases), clinical stage and pathological grade of engrafted tumors [Table 1]. In addition to patient tumors, six established HR+ PDXs were also submitted for analysis. Quantified expressions of 272 cancer-related proteins and phospho-proteins by RPPA have been performed on these specimens. Pathways identified as predictors of intake rate of PDXs in NSG mice, and tissues from paired PDX from mice with different passages, will be evaluated for the protein expression changes to elucidate the passage effects and generate therapeutic models based on protein expression and tumor growth.

Table 1. Characteristics of the patient tumors which were successfully established as PDX modelsERPgRHER2AgePatient ethnicityClinical stageNottingham histologic scoreSource++-63Hispanic3IIIBreast tumor+--71Hispanic2IIIBreast tumor+--52African-american4N/ABrain mets+--63Caucasian4N/AChest wall mets+-+34Caucasian2IIBreast tumor+++72Caucasian4IIIChest wall metsmets: metastases

Citation Format: Kanaya N, Somlo G, Wu J, Frankel P, Wu SV, Nguyen D, Kai M, Chan N, Meng-Yin H, Kirschenbaum M, Kruper L, Vito C, Yuan Y, Hurria A, Mortimer J, Chen S. Identification of molecular pathways to define the intake rate of patient-derived hormone receptor positive (HR+) breast cancer xenografts (PDXs) in NOD/SCID/interleukin-2 receptor gamma chain null (NSG) mice. [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 P3-03-02.

Abstract P2-16-05: Efficacy of ABT-888 (veliparib) in patients with BRCA-associated breast cancer

Background: The potential for exploiting BRCA deficiencies with DNA repair inhibitors has both pre-clinical and clinical support. ABT-888 (veliparib), a DNA repair inhibitor initially thought to target Poly(ADP-Ribose) Polymerases (PARP), has demonstrated in vitro inhibition of BRCA1 and BRCA2 deficient mouse embryonic stell cells, with a larger effect on BRCA1 cells. We report on the pre-planned interim analysis of the efficacy of single agent veliparib in patients with either BRCA1 or BRCA2-associated stage IV breast cancer. Methods: BRCA 1 or 2 carrier patients with stage IV breast cancer, with measurable disease, without prior exposure to a PARP inhibitor or a platinum compound in the metastatic setting, were eligible. Velapirib was administered orally, at doses of 400 mg twice daily. Dose adjustments based on toxicity were permitted. Patients progressing on velapirib alone received carboplatin at an AUC of 5, IV, given Q 21 days, and velapirib 150 mg twice daily (the maximum tolerated dose [MTD] of the combination from our completed Phase I study: J Clin Oncol 30, 2012 [suppl; abstr 1024]). Patients were to be accrued from 7 NCI NO1- supported consortia. Initially 10 patients were to be accrued to each stratum (BRCA1 and BRCA2) to provide evidence of single agent activity. If there was sufficient activity to warrant consideration of velapirib as single agent therapy (defined as 2 or more confirmed partial [PR] or better responses out of 10 per stratum), an additional 12 patients would be accrued per stratum. Results: 20 evaluable patients (11 BRCA1 and 9 BRCA2 [1 in screening]) have been accrued, the majority with lung or liver as visceral metastatic sites of disease. Median age (range) is 46 (29-68) years. Tumors from 9 patients were hormone receptor positive. BRCA1 cohort: 4 of 11 patients are off treatment at a median of 2 months (1-4); 1 patient stopped velapirib due to toxicity (grade 2 rash/pruritus, grade 2 vomiting), 3 stopped for progressive disease (one with an unconfirmed PR). Seven patients are still on single agent veliparib with 1 unconfirmed PR, and 1 patient with two evaluations showing stable disease. BRCA2 cohort: 2 patients are off treatment at 2 months for progressive disease, 7 are still on treatment with 1 confirmed PR, and 3 unconfirmed PRs. Data on patients receiving combination of velapirib and carboplatin after progression is too early. Treatment-related toxicity is being updated and has so far been reported from 14 patients: 1 patient had grade 3 fatigue, 1 patient with liver metastasis had both grade 3 alanine aminotransferase elevation and grade 3 abdominal pain. Grade 2 toxicities occurring in more than 1 patient included nausea/vomiting (6 patients), chills (2 patients), and fatigue (2 patients). Conclusion: Velapirib has single agent activity in both BRCA1 and BRCA2-associated stage IV breast cancer patients, and is well-tolerated. Mature response, treatment, and toxicity data will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-05.

Long-term survival after high-dose chemotherapy followed by peripheral stem cell rescue for high-risk, locally advanced/inflammatory, and metastatic breast cancer

Patients with high-risk locally advanced/inflammatory and oligometastatic (≤3 sites) breast cancer frequently relapse or experience early progression. High-dose chemotherapy combined with peripheral stem cell rescue may prolong progression-free survival/relapse-free survival (PFS/RFS) and overall survival (OS). In this study, patients initiated high-dose chemotherapy with STAMP-V (carboplatin, thiotepa, and cyclophosphamide), ACT (doxorubicin, paclitaxel, and cyclophosphamide), or tandem melphalan and STAMP-V. Eighty-six patients were diagnosed with locally advanced/inflammatory (17 inflammatory) breast cancer, and 12 were diagnosed with oligometastatic breast cancer. Median follow-up was 84 months (range, 6-136 months) for patients with locally advanced cancer and 40 months (range, 24-62 months) for those with metastatic cancer. In the patients with locally advanced cancer, 5-year RFS and OS were 53% (95% CI, 41%-63%) and 71% (95% CI, 60%-80%), respectively, hormone receptors were positive in 74%, and HER2 overexpression was seen in 23%. In multivariate analysis, hormone receptor-positive disease and lower stage were associated with better 5-year RFS (60% for ER [estrogen receptor]/PR [progesterone receptor]-positive versus 30% for ER/PR-negative; P < .01) and OS (83% for ER/PR-positive versus 38% for ER/PR-negative; P < .001). In the patients with metastatic cancer, 3-year PFS and OS were 49% (95% CI, 19%-73%) and 73% (95% CI, 38%-91%), respectively. The favorable long-term RFS/PFS and OS for high-dose chemotherapy with peripheral stem cell rescue in this selected patient population reflect the relative safety of the procedure and warrant validation in defined subgroups through prospective, randomized, multi-institutional trials.

P5-19-05: Age-Related Changes in the Pharmacokinetics (pK), Response, and Toxicity of Weekly nab-Paclitaxel in Patients with Metastatic Breast Cancer (MBC)

Background: Although cancer is a disease of aging, few studies have evaluated the association between patient age and the pK or pharmacodynamics (pD) of cancer therapeutics. The goals of this study were 1) to evaluate the age-related changes in the pK and pD of weekly nab-paclitaxel in patients with MBC; 2) to determine response rate; and 3) to explore the relationship of age with pK and pD parameters (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). Patients and Methods: Forty patients with MBC, receiving 1st or 2nd line chemotherapy, entered an IRB approved protocol to evaluate the age-related changes in the pK of weekly nab-paclitaxel administered at 100 mg/m2 IV for 3 weeks followed by a 1-week break. Patients were accrued from 4 age strata &lt;50, 50–60, 60–70, and &gt;70 years of age. Blood samples were collected for pK analysis with the first dose of nab-paclitaxel. Response was assessed every 2 cycles. Toxicity was graded using the NCI Common Toxicity Criteria for Adverse Events (v 3.0) and was adjudicated as attributable to nab-paclitaxel if it was possibly, probably, or definitely related. Linear regression analysis was used to examine the strength of the relationship between patient age and natural logarithm of 24 hour area under the curve (AUC). Two-sided two-sample t-tests were used to assess if there was a difference in mean age based on the presence of pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). The significance level was set to 0.05.

Results: Of the 40 patients who entered the study, 39 (98%) were evaluable with a mean age of 60 (SD=13.4; min=30; max=81). Patients were accrued in the following age cohorts: &lt;50 (n= 10; 26%), 50–60 (n= 5; 13%), 60–70 (n= 15; 38%), and &gt;70 (n= 9; 23%) years of age. The median number of courses completed was 4 (min=1, max=21). The response rate was: 0% (n=0) CR, 31% (n=12) PR, 38% (n=15) SD. Grade 3 toxicity was experienced by 26% (n=10). We observed 8% (n=3) grade 3 hematological toxicities [neutrophils (n=1; 3%), leukocytes (n=2; 5%)] and 18% (n=7) grade 3 non-hematological toxicities [nausea and hypophosphatemia (n=1; 3%), diarrhea and infection without neutropenia (n=1; 3%), fatigue (n=2; 5%), hyponatremia (n=1; 3%), and infections without neutropenia (n=2; 5%)]. There were no cases of grade 4 or 5 toxicity. Grade 2 sensory neuropathy was experienced by 8% (n=3; no cases in the 70+ age cohort). Dose reductions or course delays were experienced by 62% (n=24) and 21% (n=8), respectively. There was a borderline significant positive association between age and natural logarithm of total nab-paclitaxel 24 hour AUC (coef=.01; se=.006; p=0.055; n=36). There were no differences in the mean ages based on the presence of grade 3 or higher toxicity (p =0.75), need for dose reductions (p=0.48), or need for dose delays (p=0.61).

Discussion: There is a borderline statistically significant relationship between age and 24 hour AUC but no differences in mean age based on pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities) were identified. The treatment is well-tolerated across all age groups.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-05.

P4-07-12: Identification of p53 Mutation in Whole Genome DNA from Single Circulating Tumor Cells (CTCs) and Primary Breast Cancers (BC) from Patients (pts) with Metastatic Breast Cancer (MBC)

Background: CTCs represent the source of distant metastases, and are also implied in the growth/re-growth of primary BC. Molecular/gene-level characterization of similarities and discordances between CTCs and BCs in pts with MBC may provide useful information for individualized treatment. Since somatic p53 mutations are frequently observed in primary BCs, we set out to assess the feasibility of identifying such mutations in CTCs from pts with MBCs, and compare the findings with those of the primary BCs from the same pts. Material and Method: Fiber-optic Array Scanning Technology (FAST) was used for identification and location of CTCs on large glass substrates. CTCs were identified after blood samples (10 ml) from MBC pts were stained to detect CTCs via automated digital microscopy by morphology, based on immunofuorescence staining for cytokeratin and nucleus, and the absence of CD45. Single CTCs from 10 pts with MBC were identified and removed from the glass substrates. DNA was extracted, and the whole genome of isolated CTCs was amplified by using whole genome amplification method (Sigma). P53 mutations in exon 5, exon 6, exon 7 and exon 8 were assessed. As comparison, genomic DNA from formalin-fixed and paraffin-embedded (FFPE) from primary BCs of the same pts, was amplified using the same method.

Results: p53 mutations were found in 8 out of 10 CTCs, and in 4 out of 10 in primary BC samples. Of 8 mutations detected in CTCs, one silent mutation and 7 missense mutations were seen. One particular point mutation, R181L, previously assessed as functional mutation, was observed in 4 out of 8 CTCs. None of the 4 mutations (a silent mutation, one missense mutation and two different deletions) detected in tumor samples were found in CTCs. We validated that the mutations detected in CTCs were not artifacts occurring during genome amplification, by comparing p53 mutations between unamplified tumor genomic DNA vs. amplified samples.

Conclusion: Whole genome amplification based on extracting DNA from single CTCs using FAST, and identification of mutations such as those in p53, is feasible. The quantitative and qualitative discordance in detecting p53 mutations between CTCs and primary BCs may be due to CTCs acquiring new -possibly epithelial-mesenchymal transition-like-characteristics with metastatic potential as they evolve from the primary tumors or metastatic sites, or, technical issues (analyzing FFPE-preserved vs. CTCs, tumor heterogeneity) may contribute to our findings. Further assessment of the functionality of high frequent functional mutations such as R181L is warranted.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-12.

A phase I/II prospective, single arm trial of gefitinib, trastuzumab, and docetaxel in patients with stage IV HER-2 positive metastatic breast cancer

Inhibition of the HER-2 pathway via the monoclonal antibody trastuzumab has had a major impact in treatment of HER-2 positive breast cancer, but de novo or acquired resistance may reduce its effectiveness. The known interplay between the epidermal growth factor receptor (EGFR) and HER-2 receptors and pathways creates a rationale for combined anti-EGFR and anti-HER-2 therapy in HER-2 positive metastatic breast cancer (MBC), and toxicities associated with the use of multiple chemotherapeutic agents together with biological therapies may also be reduced. We conducted a prospective, single arm, phase I/II trial to determine the efficacy and toxicity of the combination of trastuzumab with the EGFR inhibitor gefitinib and docetaxel, in patients with HER-2 positive MBC. The maximum tolerated dose (MTD) was determined in the phase I portion. The primary end point of the phase II portion was progression-free survival (PFS). Immunohistochemical analysis of biomarker expression of the PKA-related proteins cAMP response element-binding protein (CREB), phospho-CREB and DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa) plus t-DARPP (the truncated isoform of DARPP-32); PTEN; p-p70 S6K; and EGFR was conducted on tissue from metastatic sites. Nine patients were treated in the phase I portion of the study and 22 in the phase II portion. The MTD was gefitinib 250 mg on days 2-14, trastuzumab 6 mg/kg, and docetaxel 60 mg/m(2) every 21 days. For the 29 patients treated at the MTD, median PFS was 12.7 months, with complete and partial response rates of 18 and 46%, and a stable disease rate of 29%. No statistically significant correlation was found between response and expression of any biomarkers. We conclude that the combination of gefitinib, trastuzumab, and docetaxel is feasible and effective. Expression of the biomarkers examined did not predict outcome in this sample of HER-2 overexpressing metastatic breast cancer.

Phase I study of continuous and intermittent schedules of lapatinib in combination with vinorelbine in solid tumors

BACKGROUND

Chemotherapy in combination with small-molecule epidermal growth factor receptor inhibitors has yielded inconsistent results. Based on preclinical models, we conducted a phase I trial of two schedules of lapatinib and vinorelbine.

PATIENT AND METHODS

Patients had advanced solid tumors and up to two prior chemotherapeutic regimens. Patients were enrolled on two dose-escalating schedules of lapatinib, continuous (arm A) or intermittent (arm B), with vinorelbine on days 1, 8, and 15 of a 28-day cycle. Tumors from a subset of patients were evaluated for gene mutations and expression of targets of interest.

RESULTS

Fifty-one patients were treated. The most common grade 3/4 toxic effects included leukopenia, neutropenia, and fatigue. Dose-limiting toxic effects were grade 3 infection, febrile neutropenia, and diarrhea (arm A) and bone pain and fatigue (arm B). The maximum tolerated dose was vinorelbine 20 mg/m(2) weekly and lapatinib 1500 mg daily (arm A) and vinorelbine 25 mg/m(2) weekly and lapatinib 1500 mg intermittently (arm B). One patient on each arm had a complete response; both had human epidermal growth factor receptor 2-positive breast cancer. In a subset of patients, lack of tumor PTEN expression correlated with a shorter time to progression.

CONCLUSION

In an unselected population, two schedules of lapatinib and vinorelbine were feasible and well tolerated.

FZD7 has a critical role in cell proliferation in triple negative breast cancer

Breast cancer is genetically and clinically heterogeneous. Triple negative breast cancer (TNBC) is a subtype of breast cancer that is usually associated with poor outcome and lack of benefit from targeted therapy. We used microarray analysis to perform a pathway analysis of TNBC compared with non-triple negative breast cancer (non-TNBC). Overexpression of several Wnt pathway genes, such as frizzled homolog 7 (FZD7), low density lipoprotein receptor-related protein 6 and transcription factor 7 (TCF7) was observed in TNBC, and we directed our focus to the Wnt pathway receptor, FZD7. To validate the function of FZD7, FZD7shRNA was used to knock down FZD7 expression. Notably, reduced cell proliferation and suppressed invasiveness and colony formation were observed in TNBC MDA-MB-231 and BT-20 cells. Study of the possible mechanism indicated that these effects occurred through silencing of the canonical Wnt signaling pathway, as evidenced by loss of nuclear accumulation of β-catenin and decreased transcriptional activity of TCF7. In vivo studies revealed that FZD7shRNA significantly suppressed tumor formation, through reduced cell proliferation, in mice bearing xenografts without FZD7 expression. Our findings suggest that FZD7-involved canonical Wnt signaling pathway is essential for tumorigenesis of TNBC, and thus, FZD7 shows promise as a biomarker and a potential therapeutic target for TNBC.

Abstract P2-09-17: Limited Gene Expression Profiling as Predictor of Response to Neoadjuvant Chemotherapy (NCT) with Docetaxel, Doxorubicin, Cyclophosphamide (TAC), or AC and Nab-Paclitaxel and Carboplatin +/− Trastuzumab in Patients (pts) with Locally Advanced (LABC) Stage II-III and Inflammatory Breast Cancer (IBC)

Background: Pathologic complete response (pCR) following neoadjuvant therapy (NCT) may predict for improved survival. Hence, more effective and individualized/targeted NCT regimens in conjunction with molecular markers that predict for both response and/or resistance are needed. Materials and Methods: 119 evaluable pts (121 enrolled) with stages II/III LABC/IBC were prospectively randomized to receive 6 cycles of docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2 with filgrastim support (TAC, arm A) versus a novel regimen of A 60 mg/m2 and C 600 mg/m2 given every 2 weeks x 4, followed by 3 weekly doses of carboplatin (AUC 2) and nab-paclitaxel 100 mg/m2 repeated as 28 day cycles x 3 (arm B). Pts with HER2 overexpressing (HER2+) BC received NCT similar to arm B, but with the addition of 12 weekly doses of trastuzumab given together with carboplatin and nab-paclitaxel (arm C). Core biopsies were performed prior to NCT and samples from 10 micron thick slides of formalin-fixed and paraffin-embedded (FFPE) breast cancer tissue were microdissected, and RNA was extracted for assessment of gene expression by RT-PCR for a panel of genes involved in cell proliferation, tumor suppression, DNA repair, and apoptosis. The following genes were evaluated: HER2/neu, IGF-1R, JAK2, STAT3, EGFR, BRCA1 and 2, PARP1, ERCC1, Topoisomerase 2-alpha, BBC3 (PUMA), p21, p27, IRF1, Beta-catenin, and SPARC, with actin as control. Responses were separated as complete or other response, and the Wilcoxon test was applied. Results: Neoadjuvant response assessment and sufficient amount of RNA following microdissection of primary tumor slides were available in 66/121 pts (55%). These 66 pts had similar characteristics to the entire cohort of enrolled pts. The median age was 51 yrs (range 30-69), and pts were treated for stage II/III BC (N=32, N=34, respectively, with 10 IBC cases). 37 pts were treated on Arms A and B (HER2- cohorts), and 29 on arm C (HER2+ cohort). pCR rates were 5/37 (14%) in groups A and B (of this set) combined, and 14/29 (48%) in group C (HER2+). For all arms/pts combined, overexpression of HER2, EGFR, and BRCA2, and low expression of p27, and IGFR1 were observed in pts with pCR, in comparison to pts not achieving pCR (P&lt;0.05). When the analysis was restricted to HER2 negative cases (Arms A and B), BRCA2, JAK2 overexpression, and low expression of IGF1R were associated with pCR (P&lt;0.05). Conclusion: Limited gene array analysis from microdissected FFPE specimens procured prior to NCT is feasible, and there is sufficient evidence in this limited data set to suggest that the specifc gene expression levels tested may play an important role in determining response to NCT both in HER2+ and HER2-, locally advanced, and inflammatory breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-17.

Abstract P3-13-01: Delayed Chemotherapy-Induced Nausea and Vomiting in Asian Women with Breast Cancer

Background: Chemotherapy-induced nausea and vomiting (CINV) remain among the most frequently reported distressing side effects associated with a doxorubicin-based chemotherapy regimen, and it can significantly affect patients’ quality of life and compliance with therapy. Despite the significant advances in antiemetic management in preventing and controlling CINV, as many as 50% of patients still experience some degree of nausea and vomiting. The main risk factor for the degree of CINV is the emetogenic potential of the chemotherapeutic agents. However, several patient-related risk factors have been identified, including individuals’ genetic makeup. Although several studies have noted that ethnicity influences nausea and vomiting related to motion sickness, fluorescein dye, and pregnancy, no studies have evaluated the relationship between ethnicity and CINV; specifically, if there is a higher incidence of severe CINV in patients of Asian descent.

Methods: A retrospective, comparative, correlational chart review was performed to abstract all relevant variables. The association between CINV and ethnicity was examined through chi square analysis.

Results: Data from a convenience sample of 300 women with breast cancer who received chemotherapy that includes doxorubicin between 2004 and 2008 at City of Hope in Duarte, CA, were evaluated. The sample consisted of Caucasians (46.3%), African Americans (3.7%), Asians (24.0%), and Hispanics (26.0%). The results of this study indicate that Asian women with breast cancer undergoing treatment with chemotherapy that includes doxorubicin experienced statistically significantly more severe CINV (grade ≥ 2) than their non-Asian counterparts (X2 = 10.601, p = .001). Conclusion: This study provides strong but preliminary evidence that Asian ethnicity plays a role in the development of severe CINV. When managing chemotherapy toxicities in women with breast cancer, healthcare providers are advised to optimize their patients’ outcomes by ensuring that therapy is tailored according to each patient's individual risk profile. Consideration of the antiemetic therapy should accommodate patient characteristics, specifically being of Asian descent. In this way, effective prevention of CINV can be maximized during a patient's initial treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-13-01.

Abstract PD04-09: Multiple Biomarker Expression in Circulating Tumor Cells from Metastatic Breast Cancer Patients

Background: Numeration of circulating tumor cells, CTCs, from metastatic breast cancer (MBC) patients (pts) is predictive of outcome. Biomarker characterization of CTCs may be a useful adjunctive guide for personalized targeted and systemic treatment (Rx) selection.

Method: A multimarker assay was used to simultaneously quantify expression of HER2, ER and ERCC1. A fast laser scanning instrument was used for sensitive location of CTCs on large glass substrates. CTCs are identified using automated digital microscopy by morphology, the presence of cytokeratin and a nucleus, and the absence of CD45. At the COHCC pts with newly diagnosed/progressing MBC were accrued. Blood samples (10 ml) were procured prior to initiating systemic Rx and at subsequent 3 month intervals and sent to PARC for analysis. Cell lines with expression of each marker were used for normalization of the cell intensities. Sample scores were derived from the percentage of CTCs expressing the marker and the average expression level.

Results: The multiple-marker assay was done on CTCs at repeat time points and results were compared to findings from the original primary BCs (P) and biopsied metastases (M) in 30 and 20 MBC pts respectively. While P and M tissue scores were concordant for HER2, the CTC score was discordant in 58% of the samples; HER2 expression changed during Rx in 19% of pts. While the status for ERCC1 was discordant between P and M tissue in 13% of the pts, CTCs scores were discordant with P and M tumors in 63% and 67% of the patients respectively, and CTC expression status changed during Rx in 15% and 7% of pts respectively. While the status for ER was discordant between P and M tissue in 15% of the pts, CTC scores were discordant from the P and M tumors in 42% and 71% of pts respectively, and CTC ER status changed in 7% and 17% respectively of pts during Rx.

Conclusions: Significant discordances in expression level of ER, HER2 andERCC 1 was observed between CTCs, and both primary and metastatic BC tissue. Changes in CTC expression patterns were also observed during the course of Rx for all three markers. Correlation of CTC biomarker expression patterns and changes with response to Rx therapy is ongoing to validate medical significance. Multimarker testing may ultimately lead to improvements in personalized Rx for pts with MBC.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD04-09.

Abstract 605: Intermittent treatment of hormone-dependent breast cancer using exemestane: Translational research from lab bench to bedside

Although aromatase inhibitors (AIs) are useful in the treatment of hormone-responsive breast cancer, unfortunately, resistance to such therapy still develops. Based on our published preclinical results that ER, AREG and EGFR play important roles in the acquired resistance mechanism of exemestane (EXE), a steroidal AI, intermittent use of EXE was thought to delay the development of acquired resistance by preventing up-regulation of AREG and activation of EGFR-mediated pathways. This hypothesis was verified by preclinical cell culture and animal studies. Microarray analysis was performed using RNA isolated from week-14 (EXE-resistant) MCF7aro cells that were continuously treated with EXE, week-14 (EXE-responsive) cells that were intermittently treated with EXE (2 weeks on and 1 week off), and cells without EXE treatment. A selective number of estrogen-regulated genes, including AREG and SGK3 (serum/glucocorticoid regulated kinase family member 3), were differentially transcribed between the continuously treated samples and intermittently treated samples. Treatment of EXE resistant cells with siRNAs against AREG and SGK3 suppressed cell growth, supporting the roles of these two proteins in the development of resistance to EXE. Additional results from ChIP and gene expression analyses confirm that the expression of SGK3 can be up-regulated by E2 as well as EXE, and over-expression of SGK3 suppresses apoptosis and increases cell survival. Our animal experiments revealed that intermittent treatment of EXE (250 µg/day, 2 weeks on and 1 week off) was effective at suppressing androgen-induced MCF7aro tumor growth in nude mice, and that after 21 weeks of treatment, resistance resulted in continuous EXE treatment group, while the tumor volumes in the positive control group (androgen treated only) reached 10 cm3 at week 18. qPCR analysis indicated that SGK3 expression in tumors from continous EXE mice was two times that in tumors from the positive control mice, with lowest expression in tumors from the intermittent EXE group (30% of that of the positive control). An analysis on 11 pairs of malignant and adjacent normal tissue has revealed that SGK3 expression is significantly greater in breast tumor specimens than adjacent non-cancer specimens (P=0.006). Since results from these translational research studies provide an important mechanistic basis for intermittent EXE therapy, a clinical trial to evaluate the intermittent use of EXE on postmenopausal women with ER-positive metastatic breast cancer has been recently approved and initiated at the City of Hope NCI-designated Comprehensive Cancer Center.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 605.

Dasatinib Plus Capecitabine for Advanced Breast Cancer: Safety and Efficacy Data from Phase 1 Study CA180-004

Background: SRC is a potential therapeutic target in breast cancer and has a central role in hormone therapy resistance and in osteoclast activity. Dasatinib is a potent SRC inhibitor that inhibits breast cancer cell proliferation and migration in vitro, including synergy with 5FU in some cell lines, and inhibits osteoclast activity in clinical trials. CA180-004 is a phase 1 study designed to identify dose-limiting toxicities (DLT) and recommended phase 2 doses of dasatinib plus capecitabine in women with advanced breast cancer (ABC). Safety and efficacy data are now reported with additional follow-up.Methods: Cohorts of pts with ABC were treated at four dose levels (DL) with capecitabine (mg/m2 twice daily [BID] on D1-14 of 21-day cycles) and dasatinib (mg daily): DL1: capecitabine 825 + dasatinib 50 BID; DL2: capecitabine 825 + dasatinib 70 BID; DL3: capecitabine 1000 + dasatinib 70 BID; DL3a: capecitabine 1000 + dasatinib 100 once daily (QD). All pts had performance status 0-1, prior taxane and/or anthracycline and ≤2 prior chemotherapy-containing regimens for advanced disease. Disease assessments were performed every 6 weeks. DL3a was expanded for further safety and efficacy estimate using best objective response and progression-free survival (PFS) rates.Results: To date, 47 pts with ABC have been treated, 31 in escalation phase plus 16 in expansion (5 too early). Median age was 52 years (range 35-77). Tumor subtypes: 14% were Her2-amplified, 57% ER+ or PR+, 29% triple-negative. Safety was previously reported (ASCO 2009) for escalation phase; no MTD was defined based on DLTs. Of 20 evaluable pts in DL3a, 2 DLTs have been observed: 1 pneumonia, pain and pleural effusion plus 1 diarrhea, neutropenia, vomiting, mucositis and anemia. The most common drug-related adverse events (AEs, any grade) were headache, fatigue/asthenia, nausea/vomiting, diarrhea, hand-foot syndrome (HFS) and pleural effusion. The most common grade 3/4 AEs were fatigue/asthenia, HFS, vomiting and diarrhea. To date, 19 have remained on treatment ≥4 months, including 3 for &gt;1 year. Median duration of treatment (n=42) was 13 weeks; 23 pts have discontinued for progression and 7 for toxicity. Of 38 pts with on-study assessment, 6 had confirmed partial response (treatment durations 17+, 23, 25, 36+, 71, 73 wks), 6 had unconfirmed partial or clinical response (5, 11, 13, 18, 23+, 24 wks), and 9 had prolonged stable disease (16+, 17, 23+, 24+, 25+, 29, 39+, 48+, 63+ wks). Updated efficacy data, including PFS by hormone receptor status, will be presented.Conclusions: Dasatinib and capecitabine combination treatment was well tolerated and encouraging efficacy was observed. Further assessment of this combination is warranted.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3092.

Basal-, Luminal-, and HER2- Molecular Subtype, and the MammaPrint 70-Gene Signature as Predictors of Response to Neoadjuvant Chemotherapy (NCT) with Docetaxel, Doxorubicin, Cyclophosphamide (TAC), or AC and Nab-Paclitaxel and Carboplatin +/- Trastuzumab in Patients (Pts) with Stage II-III and Inflammatory Breast Cancer (BC)

Background: Pathologic complete response (pCR) and minimal residual cancer burden (RCB scores of 0 [pCR]-1[near CR]) after NCT may predict for improved survival (Symmans et al. J Clin Oncol 25:4414-22, 2007). Hence, improved NCT regimens in conjunction with molecular markers that predict for both response and/or resistance are needed. Materials and Methods: 115 pts with stages II-III BC were to be prospectively randomized to receive 6 cycles of docetaxel 75 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2 with filgrastim support (TAC, arm A) versus a novel regimen of A 60 mg/m2 and C 600 mg/m2 given every 2 weeks x 4, followed by 3 weekly doses of carboplatin (AUC 2) and nab-paclitaxel 100 mg/m2 repeated as 28 day cycles x 3 (arm B). Pts with HER2 + BC received NCT similar to arm B, but with the addition of 12 weekly doses of trastuzumab given together with carboplatin and nab-paclitaxel (arm C). Core biopsies were performed prior to NCT and were preserved fresh frozen. 70-gene (MammaPrint™) profiling and 80-gene profiling (van de Vijver et al. NEJM 347:1999-2009, 2002) to categorize all tumors for basal-, HER2-, and luminal subtypes were carried out. We set out to assess the predictive value of Mammaprint scores (poor vs. good), as well as basal, vs. luminal, vs. HER2 molecular subtype profiling, for response to treatment on arms A vs. B vs. C. Responses were dichotomized as complete or near complete response (Symmans RCB scores of 0-1) vs. suboptimal response (RCB score &gt; 1). Results: Sufficient amount of BC tissue and good quality RNA for gene array assessment were procured in 64% of the first 90 patients who have undergone pre-treatment core biopsies, and then proceeded to NCT, followed by definitive surgery. Here we report on the first 50 pts with complete set of data analyzed. The median age was 50 years (range:31-69). Pts were treated for stage II (49%) and III locally advanced (41%), and inflammatory BC (10%). By gene profiling, 28% of the tumors were HER2-type (vs. 38% by IHC 3+, or FISH, representing all pts treated on arm C), 26% basal-type, 42% luminal-type, and 4% borderline luminal-type. Poor-prognosis signature by the 70-gene (MammaPrint) assay was observed in 74% of pts: 92% of HER2-type, 100% of basal-type, and 52% of luminal-type tumors were characterized as poor-risk by the 70-gene assay. Following NCT, Symmans RCB scores of 0-1 were observed in 71% of pts with HER2-type, in 38% with basal-type, and 28% of pts with luminal-type molecular subtype characteristics. Conclusion: BC with HER2- and basal-molecular subtypes are more likely to respond to NCT and is frequently associated with poor-risk characteristics as determined by the 70-gene assay. The complete analysis of correlations among response to specific sets of NCT, molecular subtype, and 70-gene assay results in the entire pt population will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2026.

Multiple Biomarker Expression in Circulating Tumor Cells (CTCs) from Metastatic Breast Cancer (MBC) Patients (Pts)

Background: Numeration of CTCs from MBC pts is predictive of outcome. Quantitative changes in CTC-s are currently tested for their potential to monitor therapy (Rx). Biomarker characterization of CTCs may be a useful adjunctive guide for Rx selection. Method: At the COHCC between 5/1/2008 and 4/31/09, consecutively treated pts with newly diagnosed/or progressing MBC were accrued. Blood samples (10-40 ml) were procured prior to or during systemic Rx, and were sent to PARC for analysis. A novel high-speed scanning instrument located CTCs from cytokeratin (CK) labeling enabling high resolution images to be selectively acquired using digital microscopy. From these images, CTCs were identified by CK, DAPI (nuclear marker) and CD45, and protein expression levels were determined for HER2, ER, ERCC1 and EGFR. Cell lines with expression of each marker were used for normalization of the cell intensities, and a scoring system was used to account for relative number and expression levels of markers on the CTCs. Results: Of 21pts tested 81% were found to have detectable CTCs. CTCs were further analyzed from 13 such pts, some of whom had multiple specimens. Expression of EGFR and ERCC1 were detected in 77% and 92% of specimens tested. Expression of HER2 was detected in 47% and ER in 91% in samples tested. Discordance rates for the expression of the above 4 markers on the primary tumors vs. CTC were measured either before, during systemic treatment, or at progression on therapy. We observed significant discordance rates for all markers tested:ER 36%; ERCC1:20%; EGFR:60%; and HER2: 50%, respectively. Conclusions: Multiplex tumor marker testing of CTCs from pts with MBC is feasible. Following additional validation of expression patterns and the high discordance rates observed between CTCs and primary or metastatic tumor sites, prospective trials incorporating CTC expression into personalized treatment strategies may be justified.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3007.

Barriers to Treatment in Patients with Locally Advanced and Inflammatory Breast Cancer

Background: Breast cancer in the United States will affect approximately one in eight women. Despite a decrease in breast cancer mortality due to increased awareness and more effective screening, many patients still present for treatment after extended delays in diagnosis, resulting in large tumor size, locally advanced disease, inflammatory features, and greater likelihood of regional and distant metastasis. The purpose of this study was to identify reasons why patients may encounter delays in obtaining a diagnosis, seeking medical care, and initiating treatment once symptoms appear.Methods: From 12/2006 through 5/2009, a questionnaire was administered to thirty-four consecutive patients who presented to our institution with histologically-verified stage III breast cancer who had experienced a 3-month or greater delay in diagnosis and initiation of treatment from time of onset of symptoms. The 39-item Likert-scale questionnaire was developed to explore perceived barriers. Responses were rated on a scale of "Strongly Agree" through "Strongly Disagree," relative to the barriers presented.Results: The median age of patients who completed the questionnaire was 52 years (range, 30 to 78 years). Of these, there were 29.4% White/Non-Hispanic, 52.9% White/Hispanic, 11.8% Black and 5.9% Asians. For 73.5% of patients, the diagnosis of breast cancer was made at an outside institution. Most of the participants were diagnosed with locally advanced infiltrating ductal carcinoma (82.4%) and 8.8% were diagnosed with inflammatory breast cancer. Barriers to treatment were divided into the following categories:Patient barriers: The most commonly reported barrier among respondants was "waiting for the scheduled visit to get results." (47.1% with a response of Agree or Strongly Agree) However, 35.2% of patients did not seek treatment because they were concerned about losing their breast. More than a third of patients delayed care because of perception that their breast symptoms were due to infection, muscle strain, or related to their menstrual cycle (35.3%). For 27.6% of respondants, no care was sought because of perception that their breast symptoms would resolve with time. Other barriers, such as access to transportation,, inconvenient physician office hours, child care problems and inability to take time off from work, continued to be present but were not as frequently reported (less than 20%).Physician barriers: Approximately one fourth of women reported that their physician of initial contact, did not believe that their breast lump/symptom was related to cancer (23.5%).System barriers: Among systems barriers, "delay in scheduling diagnostic tests" remained the most prevalent barrier to breast cancer treatment (38.2%).Conclusion: We observed substantial delays between symptom presentation and diagnosis in patients who came to seek therapy at a tertiary comprehensive cancer center (City Of Hope National Medical Center) in Southern California. Patients and physicians need to be educated on the importance of timely diagnostic tests and follow-up visits. In addition, studies are needed to better identify predictive factors for women at risk for encountering barriers to healthcare so that for these subpopulations, interventions can be implemented to reduce breast cancer morbidity and mortality.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3084.