Abstract P4-01-04: ESR1 mutation in cell free DNA (cfDNA) is associated with significantly increased circulating tumor cell (CTC)-clusters and progress in stage III/IV breast cancer after systemic treatments

Introduction: CTCs play a critical role in the process of tumor metastasis, and a portion of CTCs may form clusters that contain two or more CTCs bound together which were reported to have up to 50-fold of potential of forming distant metastasis in breast cancer (MBC) as compared to individual CTCs. However, molecular and genomic characterization of CTCs cluster remain largely unknown. Here we report a highly significant correlation between ESR1 mutation in cfDNA, CTCs count and CTC-cluster, which may help to understand MBC metastasis and predict treatment benefit, especially for metastatic or recurrent disease.

Methods: A total of 80 whole blood samples (7.5ml/each) were collected from 80 patients with stage III/IV BCa after informed consent under IRB-approved trial at the RHLCCC at Northwestern University before and after systemic therapies. Among these 80 patients, 41 patients received chemotherapy and 23 patients received endocrine therapy, among which 20 patients received combo treatments (16 plus Palpociclib, 1 plus Ribociclib, 2 plus Everolimus, and 1 plus trastuzumab). CTC enrichment and enumeration were performed in CELLTRACKS ANALYZERII® System (Menarini) by using CTC Kit Meanwhile, we detected the ESR1 hotspot mutations (Y537S and D538G) in plasma cfDNA from all 80 patients by Droplet digital PCR (ddPCR) assay using the QX200 ddPCR System (Bio-Rad). cfDNA was isolated from 2 mL of plasma using the QIAamp Circulating Nucleic Acid Kit (Qiagen) and the MAF was analyzed using QuantaSoft software (Bio-Rad).Database of CTCs and ESR1 mutation was linked with clinical database. Kruskal-Wallis test was used for statistics.

Results: Of the 80 samples analyzed, there were 57 samples without ESR1 mutations (Group 1), and 23 samples that had ESR1 mutations (8 Y537S mutations and 23 D538G mutations, Group 2). CTC positive (≥5) were detected in 13/57 samples (Group 1) and 15/23 samples, and the average amounts of CTCs were 21.77 CTCs/each sample and 59.86 CTCs/each sample in Group 1 and Group 2 respectively. There was a significant association between ESR1 mutations and high level of CTCs (P=0.000088). More important, CTC-clusters were found in 3 samples in Group 1 (5.26%) and in 5 samples in Group 2 (21.74%) respectively. There was a significant correlation between ESR1 mutations and CTC-clusters (P=0.026). Furthermore, there were 18/57 patients in group 1 and 5/23 in group 2 receiving chemotherapy. Moreover, 26/57 in group 1 and 15/23 in group 2 that received chemotherapy. Our results also confirmed that both endocrine therapy and chemotherapy benefited more patients without ESR1 mutations in compared with patients with ESR1 mutations (P<0.05).

Conclusion:We first elucidated the association between ESR1 mutations in ctDNA and CTC-cluster in MBC patients, and provides new insights on the molecular mechanisms associated with the metastasis process. In addition with the highly significant association between ctDNA ESR1 mutations and endocrine resistance we describe a new association allowing to expand the prognostic and predictive role of both tests enabling monitoring the metastatic prognosis and endocrine resistance for clinical decision-making.

Citation Format: Zhang Q, Gerratana L, Zhang Y, Flaum L, Shah A, Davis A, Behdad A, Gradishar W, Platanias L, Cristofanilli M. ESR1 mutation in cell free DNA (cfDNA) is associated with significantly increased circulating tumor cell (CTC)-clusters and progress in stage III/IV breast cancer after systemic treatments [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-04.

Abstract P5-17-03: How is inflammatory breast cancer (IBC) different? Integration of clinico-pathological features and circulating tumor cells (CTCs)-based biomarkers for disease and prognostic assessment

Background: Since IBC is rare and burdened by a particularly unfavorable prognosis, biomarkers able to enhance diagnosis and risk assessment are of pivotal importance and a current unmet need. The aim of this study is to integrate standard clinico-pathological features with CTCs-based biomarkers for a more objective and detailed characterization of IBC.

Methods: This study analyzed retrospectively 251 Advanced Breast Cancer (BC) patients (pts) longitudinally characterized for CTCs and CTCs-based biomarkers at Thomas Jefferson University (Philadephia, PA) and Northwestern University (Chicago. IL). CTCs were enumerated through the CellSearch system (Menarini Silicon Biosystems), and characterized for HER2 expression using the CellSearch CXC Kit. Pts were defined as stage IV aggressive based on the previously reported ≥5 CTCs cut-off (Davis et al. 2018). Associations between clinical features, CTC-derived biomarkers and IBC were tested through uni and multivariate logistic regression. Survival was tested though log-rank test.

Results: Within the analyzed cases, 46% were diagnosed with IBC and among them, 38% was stage IV aggressive. CTC clusters (CTC_CL) were detectable in 12.5% of pts and HER2 positive CTCs (HER2_CTC) in 29.5%. Notably, IBC patients (pts) had a significantly lower CTC count with respect to non-IBC (median 2.5 vs 0 respectively for non-IBC and IBC; P=0.019). BC subtype (HER2 positive BC: OR 2.97; Triple negative BC: OR 2.13), liver and bone involvement (liver: OR 0.46; bone involvement: OR 0.31) were the only significant clinico-pathological features associated with IBC at univariate logistic regression. Interestingly, a marginal significance was observed for soft tissue involvement (OR 1.65, 95%CI 0.95 - 2.87, P=0.07). Stage IV aggressive and presence of HER2_CTC at baseline were moreover inversely associated with IBC. The multivariate model confirmed the significant association between IBC and HER2 positive BC subtype (OR 2.64, 95%CI 1.08 - 6.48, P=0.034), absence of bone involvement (OR 0.31, 95%CI 0.14 - 0.68, P=0.003) and absence of HER2_CTC (OR 0.38, 95%CI 0.15 - 0.98, P=0.045). The baseline detection of CTC_CL was a strong predictor of prognosis for OS in IBC pts (median OS (mOS) 7.6 months (mts) vs not reached (NR) respectively for detectable vs non-detectable CTC_CL; P<0.0001), while a trend was observed for HER2_CTC (mOS 9.9 mts vs NR respectively for detectable vs non-detectable HER2_CTC; P<0.082). Pts negative for CTC_CL at baseline had higher odds of developing CTC_CL in later time-points if stage IV aggressive (OR 12.27, 95%CI 2.10 - 71.57, P=0.005). Despite no baseline factors were significantly associated with the onset of HER2_CTC in later time-points, a trend (P=0.05) was observed for patients without lymph node involvement (OR: 5) and with bone involvement (OR: 4.3).

Conclusion: HER2_CTC and in particular CTC_CL are promising prognostic predictors in IBC. Stage IV aggressive IBC pts could benefit from a longitudinal CTCs assessment, being more prone to develop CTC_CL and therefore at higher risk of rapid disease progression. Probably due to the tropism for soft tissue, IBC is characterized by a lower number of HER2_CTC.

Citation Format: Gerratana L, Zhang Q, Wang C, Shah A, Davis AA, Ye Z, Zhang Y, Abu-Khalaf M, Flaum L, Strickland K, Rossi G, Behdad A, Gradishar W, Platanias L, Yang H, Cristofanilli M. How is inflammatory breast cancer (IBC) different? Integration of clinico-pathological features and circulating tumor cells (CTCs)-based biomarkers for disease and prognostic assessment [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 P5-17-03.

Abstract P4-01-18: Correlation between circulating tumor DNA (ctDNA) alterations and circulating tumor cells (CTC) uncovers new mechanisms of metastasis for patients with metastatic breast carcinoma (MBC)

Introduction:Novel molecular diagnostics including CTCs and ctDNA have been proved to predict disease metastasis and survival. However, the frequency of detection of actionable mutations using CTCs and ctDNA is variable based upon tumor related factors and diagnostic platform sensitivity. Herein, we evaluated a novel NGS technology in the ability of detecting driver and clonal genomic abnormalities in samples from MBC patients, and compared ctDNA alterations with CTCs and CTC-cluster. This study demonstrated several novel correlation between some specific ctDNA alterations and CTCs or CTCs related biomarkers, which opened new insight on mechanisms of metastasis for MBC.

Methods: This study included 52 samples from 26 patients with stage III/IV BCa treated at NMH (2016-2017) and who received standard systemic treatments based on disease subtypes. Whole blood samples (7.5ml/each) were used for CTC enrichment and enumeration in FDA approved CELLTRACKS ANALYZERII® System (Menarini). ctDNA from clinical plasma samples was analyzed by using PredicinePLUS, a NGS-based assay (Predicine Inc) with a 180-gene panel for genomic alterations mutations. Results of CTCs and ctDNA alterations were linked to clinical database. Matched pairs variations between CTCs and ctDNA alterations was compared by Wilcoxon signed-ranks test and Kruskal-Wallis test.

Results: Genomic Alterations (SNVs, Indels and copy number variations) were detected on 52 genes by PredicinePLUS assay. All samples (100%) demonstrated at least 1 somatic alterations. There were 75 mutations detected within 29 genes, and the variant frequency of mutated genes ranges from 0.11% to 68.56%. Increased CTCs were highly significantly correlated with genomic alterations in the genes (wild type vs alterations) including GATA3 (8vs 37), ESR1 ( 2.5 vs 41.3), CDH1 (3.5 vs 50.5) and CCND1 (4 vs 120) (P<0.01). Decreased CTCs were correlated with alterations of CDKN2A (20.5 vs 0) (P=0.025). CTC-cluster appear associated predominantly with alterations of CDH1 (P=0.0018), CCND1 (P=0.008) and BRCA1 (P=0.04). Furthermore, in HER positive CTCs group, ERBB2 mutations caused increased CTCs in compared with ERBB2 wild type (0 vs 5), when CCND1, CDKN2A, GATA3 and TP53 alterations were associated with increase of HER2 negative CTCs.

Conclusions: By using the novel diagnostic platform with the ability to identify ctDNA mutation and copy number variation, this study demonstrated several novel genes alterations which were highly correlated with CTCs, CTC-cluster and HER2. Some genes (CCND1 and CDH1) got involved into the changes on both CTCs and CTC-cluster, when some genes (CCND1, CDKN2A, ESR1 and GATA3) were related with change of CTCs and HER2 expression. Correlation of CTCs and ctDNA can be reliably and routinely used as non-invasive method for monitoring disease metastasis and predict the prognosis in MBC in clinic.

Citation Format: Davis A, Zhang Q, Gerratana L, Zhang Y, Flaum L, Shad A, Behdad A, Gradishar W, Platanias L, Cristofanilli M. Correlation between circulating tumor DNA (ctDNA) alterations and circulating tumor cells (CTC) uncovers new mechanisms of metastasis for patients with metastatic breast carcinoma (MBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-18.

Abstract P4-01-08: Characterization of circulating tumor free DNA (ctDNA) obtained from patients with metastatic breast carcinoma (MBC) undergoing systemic therapies using comprehensive genomic profiling

Introduction:Therapeutic benefit from individual treatments in patients with MBC is limited to small subsets of patients and of short duration due to tumor heterogeneity. Novel molecular diagnostics including ctDNA has been shown to predict response or resistance and survival. However, the frequency of detection of actionable mutations using ctDNA is variable based upon tumor related factors and diagnostic platform sensitivity (e.g. ddPCR or NGS). We evaluated a novel NGS technology in the ability of detecting driver and clonal genomic abnormalities in samples from MBC patients. Moreover, we wanted to compare the new technology to another state-of-the-art, commercially available diagnostic ctDNA testing with similar sensitivity to demonstrate both are able to detect genomic abnormalities in MBC.

Methods: This study included 30 samples from 15 patients with stage III/IV BCa treated at NMH (2016-2017) and who received standard systemic treatments based on disease subtypes longitudinally characterized for ctDNA before or 3 months after systemic therapies respectively. ctDNA from clinical plasma samples was first analyzed using PredicinePLUS, a NGS-based assay (Predicine Inc) with a 180-gene panel for genomic alterations mutations. The results were then independently analyzed with Guardant360TM (Guardant Health), a 73-gene panel. Matched pairs variations between Guardant360TM and Predicine was compared by Wilcoxon signed-ranks test. The prognostic impact of ctDNA was tested through Cox regression.

Results: Genomic Alterations (SNVs, Indels and copy number variations) were detected on 43 genes by PredicinePLUS assay. All samples (100%) demonstrated at least 1 somatic alterations. There were 75 mutations detected within 29 genes, and the variant frequency of mutated genes ranges from 0.11% to 68.56%. Median variant frequency was around 3.42%. Key cancer related genes including TP53, ESR1, PIK3CA, PTEN and BRCA1, are frequently mutated. Copy number variation were detected on 18 genes, among which 15 genes showed copy number gain, including MYC, PIK3CA, CCND1, and 3 genes (ATM, BRCA1 and CDKN2A) with copy number loss. There were no significant difference of % ctDNA (P=0.3967) and number of variations (P=0.5) between results of Predicine and Guardant360TM, neither to the comparison of main detected alterations (BRCA1, ESR1, MYC, PIK3CA and TP53) with Guardant360TM and Predicine (P=1). Furthermore, results from Predicine indicated that there is correlation with treatment response and benefit. A significant decrease on variations in %ctDNA levels (P=0.028) and variations in the number of genomic variants (P=0.028) after systemic therapies, was associated with longer overall survival.

Conclusions: Our study describes a novel diagnostic platform with the ability to identify ctDNA mutation and copy number variations in patients with MBC receiving systemic therapy. We also confirm that when comparing ctDNA using NGS platforms with similar sensitivity, the results are robust and reproducible which indicates that these technologies can be reliably and routinely used as non-invasive method for monitoring response to systemic therapies and predict the prognosis in MBC.

Citation Format: Zhang Q, Gerratana L, Zhang Y, Flaum L, Gradishar W, Platanias L, Cristofanilli M. Characterization of circulating tumor free DNA (ctDNA) obtained from patients with metastatic breast carcinoma (MBC) undergoing systemic therapies using comprehensive genomic profiling [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-08.

Abstract P3-01-10: Associations between plasma Interleukin 2 (IL-2) and HER2 expression in circulating tumor cell (CTC) and MYC alterations in circulation tumor DNA (ctDNA) open a new insight on immune microenvironment for patients with metastatic breast cancer (MBC)

Introduction: Overexpression of HER2 has been reported to be associated with metastasis and poor prognosis of patients with MBC. We reported in AACR 2018 that HER2 overexpression is associated with CTC-cluster. Preclinical data suggested that MYC and HER2 cooperate to drive stem cell phenotype and poor prognosis in MBC (Nair R). Furthermore, IL-2 upregulates the transcription of MYC (Grigorieva I) and gets involved into its alterations. We reasoned that further understanding of interactions of HER2 in CTC and MYC will be important to elucidate the mechanism of metastasis of MBC. Herein, we report a significant correlation between the plasma IL-2 level and HER2 expression in CTCs, and the IL-2 related MYC ctDNA alterations in MBC.

Methods: This study enrolled 43patients with stage III/IV BCa at the Northwestern Memorial Hospital (2016-2017) that had longitudinally detection of CTCs and ctDNA. Whole blood samples (7.5ml/each) were collected for CTCs enumeration by using CELLTRACKS ANALYZERII® System (Menarini) contains antibodies of anti-EpCAM for capturing CTCs, anti-CK-PE for epithelial cells, DAPI for nucleus, anti-CD45-APC for leukocytes and anti-HER-2/neu-FLU. The CTCs were classified based on phenotype as CK+, EpCAM+, DAPI+ and CD45-.Plasma ctDNA was analyzed using the Guardant360 TM NGS-based assay (Guardant Health), a 73 genes panel. ELISA for IL-2 was performed by using patients' plasma. Database of IL-2, HER2, CTCs and ctDNA was linked with clinical database and analyzed by Kruskal-Wallis test.

Results: CTCs ≥ 5 were found in 20 patients (46%). There were 15 patients that had HER2 negative CTCs (Group 1), and 5 patients had HER2 positive (Group 2) CTCs. The level of IL-2 was much higher in Group 1 (88.17pg) compared to Group 2 (66.81pg), indicating that patients with HER2 positive CTCs have significant lower IL-2 than patients with negative CTCs (P=0.02). Meanwhile, ctDNA MYC alterations were detected in 10 patients (including 1 L114R mutation, 7 CNV and 2 SNV) who have the average IL-2 level as 94.00pg. There were 11 patients without any alterations of MYC had average IL-2 level of 70.17pg, which indicated that patients with alterations in the ctDNA MYC have significant higher level of IL-2 in compared with patients without MYC alterations (P=0.02).

Conclusions: Findings of the correlation between overexpression of HER2 in CTCs and low IL-2 level indicated that low immunity may contribute to more aggressive MBC. And the higher level of IL-2 appear associated predominantly with MYC genomic alterations indicated that overexpression of MYC may also stimulate the immune response by upregulating IL-2 via a reverse feedback pathway. We postulated that increasing IL-2 suppresses the HER2 expression in CTC and breaks cooperation between HER2 and MYC. Although the interactions between them still unknown, our results suggest that IL-2 related immune microenvironment acts as a key player to suppress HER2- and MYC-mediated progress in MBC, including the formation of CTC-cluster. Monitoring and administration of IL-2 may benefit pretreated MBC patients and predict disease metastasis.

Citation Format: Zhang Q, Gerratana L, Zhang Y, Flaum L, Shah A, Davis A, Behdad A, Gradishar W, Platanias L, Cristofanilli M. Associations between plasma Interleukin 2 (IL-2) and HER2 expression in circulating tumor cell (CTC) and MYC alterations in circulation tumor DNA (ctDNA) open a new insight on immune microenvironment for patients with metastatic breast cancer (MBC) [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 P3-01-10.

Abstract P4-01-14: Association between interleukin 2 (IL-2) and circulating tumor DNA (ctDNA) is a novel biomarker for patients with metastatic breast cancer (BCa) after systemic therapies

Introduction: The detection and monitoring of ctDNA in metastatic breast cancer showed ability to predict treatment resistance and outcome. But the mechanisms has been a challenge to clinicians. Immune escape and immune tolerance has also been reported to cause BCa progress. Herein, we report a novel finding of the association between plasma IL-2 and the ctDNA in advanced BCa patients who received the systemic therapies, and it is potential utilization in clinic.

Methods: This study enrolled 43 patients with stage III/IV BCa at the Northwestern Memorial Hospital (2016-2017) that had longitudinally detection of ctDNA and circulating tumor cells (CTCs) before (baseline, BL) or 3 months after (first evaluation, FE) systemic therapies respectively. Duplicate whole blood samples (7.5ml/each) were collected in EDTA tubes from these patients. Plasma ctDNA was analyzed using the Guardant360 NGS-based assay (Guardant Health) and CTC enrichment and enumeration were performed in FDA approved semi-automated fluorescence CELLTRACKS ANALYZERII® System (Menarini Silicon Biosystems) by using CELLSEARCH® CXC Kit (Menarini). ELISA (Fisher) for IL-2 was performed by using patients' plasma. Database of IL-2, ctDNA and CTCs was generated and linked with clinical database. Kruskal-Wallis test was used for statistics. We previously reported cut-off of 5.7 was used to dichotomize the prognostic value of ctDNA percentage (%ctDNA) in 2018 ASCO. Matched pairs variations between IL2 levels at BL and at FE were tested through Wilcoxon signed-ranks test. Associations between %ctDNA and IL2 levels were explored through Kruskal-Wallis test. The prognostic impact of IL2 was tested through Cox regression.

Results: CTCs ≥ 5 were found in 23 patients at BL and 21 patients in FE respectively. There were 12 patients that had increase CTCs, and 31 patients with similar or less CTCs FE after systemic therapies. Decreased in CTCs was associated with increased IL-2 (P=0.004).The FE analysis showed that IL-2 dropped significantly in patients with CTC stably ≥5 (from 95.84pg to 79.46pg) after therapies (P<0.001). Furthermore, baselineIL-2 levels were significantly higher in patients with % ctDNA levels ≥5.7 (97.15pg) compared to patients with %ctDNA levels <5.7 (68.64pg) (P=0.0027). No other associations were highlighted in respect to age or number of ctDNA alterations. There was no significant variations between BL and FE levels of IL2 were observed according to BCa subtypes nor in respect to baseline %ctDNA ≥5.7 or CTCs ≥5. Compared with low level of BL IL-2 (<78.3pg) group, high level of BL IL-2 (≥78.3pg) had a significant negative impact on overall survival (OS) (P=0.037) in univariate analysis.

Conclusions: Our findings indicated that aggressive BCa with high level ctDNA mutation are associated with high level of IL-2 and immune response in patients with advanced disease. In addition we confirm a reverse correlation between change of IL-2 and change of CTCs potentially indication of immune escape. In summary, the study shows a dynamic relation between IL-2 level and tumor burden (ctDNA) and immune escape (CTCs) suggesting another potential biomarker to monitor interaction between tumor and immune environment.

Citation Format: Zhang Q, Gerratana L, Zhang Y, Flaum L, Shah A, Davis A, Behdad A, Gradishar W, Platanias L, Cristofanilli M. Association between interleukin 2 (IL-2) and circulating tumor DNA (ctDNA) is a novel biomarker for patients with metastatic breast cancer (BCa) after systemic therapies [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-14.

Abstract P5-17-02: Dissecting the biology of inflammatory breast cancer (BC) through cell free DNA and a circulating tumor cells (CTC)-derived signature

Background: The biological characteristics conferring Inflammatory BC's (IBC) distinctive and aggressive clinical features are currently not fully clarified. The aim of this study is to dissect IBC's biology through the integration of DNA and CTC-based circulating biomarkers.

Methods: This study retrospectively analyzed 251 Advanced BC (ABC) patients (pts) treated and longitudinally characterized for CTCs and circulating tumor DNA (ctDNA) at Thomas Jefferson University (Philadephia, PA) and Northwestern University (Chicago, IL). CTCs were enumerated through CellSearch (Menarini Silicon Biosystems), and characterized for HER2 expression using the CellSearch CXC Kit, while ctDNA was analyzed using the Guardant360 NGS assay (Guardant Health) and its percentage (%ctDNA) was classified based on the previously reported cut-off of 5.7% (Gerratana et al 2018). A subset of 117 pts was further characterized for circulating cell-free DNA (ccfDNA) through Qubit® dsDNA HS quantitation Assay (Thermo Fisher Scientific) and quantitative real-time PCR assay for ALU DNA repeats on chromosome 1.Associations between clinical characteristics, CTCs-derived biomarkers and IBC were explored through Fisher's exact test; survival was tested though Cox regression and log-rank test.

Results: Of the total 251 pts, 115 were diagnosed with IBC. Among the 117 patients characterized for ccfDNA, 70 had IBC. Median ccfDNA was 1.59 for IBC (IQR 1.02-3.19) and 2.37 for non-IBC (nIBC) (IQR 1.13-3.52), P=0.27. Consistent results were observed for %ctDNA levels (median value: 2 vs 1.6). The impact on OS of ccfDNA after log transformation was significant for the total population (HR 1.73 95%CI: 1.11-2.69) but not in IBC pts (HR 1.40 95%CI: 0.84-2.34). On the other hand, ctDNA high pts had a significantly worse OS (nIBC: HR 5.34 95%CI: 1.70-18.81 P=0.004; IBC: HR 4.05 95%CI: 1.91-8.58 P< 0.001). In the ctDNA high subgroup no differences in total number of CTCs were observed between IBC and nIBC, while significantly lower CTCs were observed in ctDNA low IBC pts (P=0.0097). The ctDNA low IBC subgroup had a higher incidence of HER2 positive BC (P=0.003) and a significantly lower incidence of CTCs clusters (P=0.006), HER2 positive CTCs (P=0.041). Notably, no associations were observed with stage at baseline, number of metastatic sites, liver, lung and visceral involvement. On the other hand, the ctDNA_high IBC subgroup was characterized by a lower incidence in liver, bone and visceral involvement (P=0.017, P=0.014 and P=0.03 respectively) and a marginally high incidence in soft tissue involvement (0.084). Moreover, IBC diagnosis conferred a significantly worse prognosis only in the ctDNA low subgroup (OS at 12 months nIBC: 100% vs IBC: 70%; P=0.049), while no differences were observed in the ctDNA_high subgroup (OS at 12 months nIBC: 29% vs IBC: 26%; P=0.767).

Conclusion: ctDNA is able to stratify BC according to aggressiveness independently from the sites and type of metastases, both in the IBC and nIBC subgroups. IBC has a distinctive CTCs/ctDNA-based signature, in particular ctDNAlow pts have a lower incidence of HER2 positive CTCs and CTC clusters. This signature is probably due to predominant lymphatic metastatic spread and aggressive phenotype.

Citation Format: Gerratana L, Zhang Q, Wang C, Shah A, Davis AA, Ye Z, Zhang Y, Abu-Khalaf M, Flaum L, Strickland K, Rossi G, Behdad A, Gradishar W, Platanias L, Yang H, Cristofanilli M. Dissecting the biology of inflammatory breast cancer (BC) through cell free DNA and a circulating tumor cells (CTC)-derived signature [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 P5-17-02.

Abstract OT1-03-06: Phase IB/II clinical trial to evaluate safety and efficacy of tucatinib in combination with palbociclib and letrozole in patients with hormone receptor positive and HER2-positive metastatic breast cancer

Breast cancers overexpressing HER2-oncogene and hormone receptors (HR) represent therapeutic challenge because of a bi-directional cross-talk between HR and HER2 pathways leading to tumor progression and drug resistance. There is a strong rationale for evaluation of novel targeted drug combinations in this breast cancer subtype.

We designed a phase IB /II clinical trial to test the combination of novel oral HER2 small molecule inhibitor tucatinib with CDK4/6 inhibitor palbociclib and aromatase inhibitor letrozole in patients with HR+/HER2+ metastatic breast cancer (NCT03054363). In addition to the rationale for the synergy of targeting HR, HER2 and CDK4/6 pathways simultaneously in this disease setting and its potential for anti-tumor efficacy, we propose this novel combination of three oral agents, if well tolerated, will be highly patient-centered as an effective non-chemotherapy based regimen for treatment of HR+/HER2+ breast cancer.

This multicenter clinical trial is conducted through the Academic Breast Cancer Consortium (ABRCC), with the University of Colorado Cancer Center as the lead site.

Target enrollment: 40 patients (20 patients in phase IB and 20 patients in phase II part).

Main inclusion criteria:

1. HR+/HER2+ locally advanced unresectable / metastatic breast cancer

2. Measurable or evaluable disease. Bone only disease is allowed.

3. Subjects without brain metastases are eligible; subjects with untreated asymptomatic CNS metastases not needing immediate local therapy, and subjects with stable brain metastases previously treated with radiation therapy or surgery are eligible

4. ECOG 0-1

5. Postmenopausal women, or premenopausal women on ovarian suppression

6. Prior treatments:

- At least two approved HER2-targeted agents (trastuzumab, pertuzumab, or TDM-1) at any time in the course of the disease

- At least 1 line of HER2-targeted therapy in the metastatic setting (with the exception of asymptomatic subjects with oligometastatic or bone / soft tissue only disease who, on investigator opinion, are appropriate for a front line single agent anti-endocrine therapy per NCCN guidelines)

- Up to 2 lines of prior endocrine therapy in the metastatic setting are allowed

7. Adequate organ and marrow function

Main exclusion criteria:

1. Previously treated progressing brain metastases

2. Brain metastases and contraindications to undergo contrast brain MRI

3. Toxicities of prior cancer therapies that have not resolved to grade 1 or less, except peripheral neuropathy, which must have resolved to grade 2 or less, and alopecia

4. Previous treatment with EGFR or HER2 tyrosine kinase inhibitors or CDK4/6 inhibitors

5. Systemic anti-cancer therapy or radiation within 2 weeks of the first dose of study drugs

6. Active bacterial, fungal or viral infections, hepatitis B, C, or HIV

7. Clinically significant cardio-vascular disease

Primary objectives:

- Phase IB: safety and tolerability of combination therapy

- Phase II: efficacy by PFS

Exploratory assessment of biomarkers of resistance and response will be performed in the blood and biopsy samples

Study contact: Elena Shagisultanova, MD, PhD, elena.shagisultanova@ucdenver.edu

Citation Format: Shagisultanova E, Diamond J, Stopeck A, Pusztai L, O'Regan R, Gradishar W, Brown-Glaberman U, Chalasani P, McSpadden T, Borakove M, Shedin T, Kabos P, Borges V. Phase IB/II clinical trial to evaluate safety and efficacy of tucatinib in combination with palbociclib and letrozole in patients with hormone receptor positive and 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 OT1-03-06.

Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Background

Homologous recombination defects in BRCA1/2-mutated tumors result in sensitivity to poly(ADP-ribose) polymerase inhibitors, which interfere with DNA damage repair. Veliparib, a potent poly(ADP-ribose) polymerase inhibitor, enhanced the antitumor activity of platinum agents and temozolomide in early phase clinical trials. This phase II study examined the safety and efficacy of intermittent veliparib with carboplatin/paclitaxel (VCP) or temozolomide (VT) in patients with BRCA1/2-mutated breast cancer.

Patients and methods

Eligible patients ≥18 years with locally recurrent or metastatic breast cancer and a deleterious BRCA1/2 germline mutation were randomized 1 : 1 : 1 to VCP, VT, or placebo plus carboplatin/paclitaxel (PCP). Primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and overall response rate (ORR).

Results

Of 290 randomized patients, 284 were BRCA+, confirmed by central laboratory. For VCP versus PCP, median PFS was 14.1 and 12.3 months, respectively [hazard ratio (HR) 0.789; 95% CI 0.536-1.162; P = 0.227], interim median OS 28.3 and 25.9 months (HR 0.750; 95% CI 0.503-1.117; P = 0.156), and ORR 77.8% and 61.3% (P = 0.027). For VT (versus PCP), median PFS was 7.4 months (HR 1.858; 95% CI 1.278-2.702; P = 0.001), interim median OS 19.1 months (HR 1.483; 95% CI 1.032-2.131; P = 0.032), and ORR 28.6% (P < 0.001). Safety profile was comparable between carboplatin/paclitaxel arms. Adverse events (all grades) of neutropenia, anemia, alopecia, and neuropathy were less frequent with VT versus PCP.

Conclusion

Numerical but not statistically significant increases in both PFS and OS were observed in patients with BRCA1/2-mutated recurrent/metastatic breast cancer receiving VCP compared with PCP. The addition of veliparib to carboplatin/paclitaxel significantly improved ORR. There was no clinically meaningful increase in toxicity with VCP versus PCP. VT was inferior to PCP. An ongoing phase III trial is evaluating VCP versus PCP, with optional continuation single-agent therapy with veliparib/placebo if chemotherapy is discontinued without progression, in this patient population.

Clinical trial information

NCT01506609.

Abstract P5-17-01: Bevacizumab (B) in the adjuvant treatment of breast cancer - first toxicity results from Eastern Cooperative Oncology Group trial E5103

Background: A previous feasibility trial (E2104 – Ann Oncol 23(2):331–7,2012) suggested incorporation of B into anthracycline-containing adjuvant therapy was feasible but ongoing cardiac monitoring was required to define the true impact of B on cardiac function.

Methods: Patients (pts) were assigned 1:2:2 to one of three treatment arms. In addition to doxorubicin and cyclophosphamide followed by weekly paclitaxel, patients received either placebo (Arm A – AC&gt;T) or B during chemotherapy (Arm B - BAC&gt;BT), or B during chemotherapy followed by B monotherapy (15 mg/kg q3wk) for an additional 10 cycles (Arm C – BAC&gt;BT&gt;B). Randomization was stratified and B dose adjusted for choice of AC schedule (classical q3wk − 15 mg/kg; dose dense(dd) q2 wk − 10 mg/kg). When indicated, radiation and hormonal therapy were administered concurrently with B (for Arm C pts). The primary cardiac endpoint was the incidence of clinically apparent cardiac dysfunction (CHF)defined as symptomatic decline in left ventricular ejection fraction (LVEF) to below the lower limit of normal (LLN) or symptomatic diastolic dysfunction as assessed by independent review. Cumulative toxicity data as of Jan 23, 2012 are presented.

Results: From 11.07 to 2.11, 4994 pts were enrolled. Median age was 52; 80% received ddAC. Chemotherapy associated toxicities including myelosuppression (Grade 4 neutropenia 16/20/19%) and neuropathy (Grade ≥ 3 8/8/8%) were similar across all arms. Grade ≥ 3 hypertension/thrombosis/proteinuria/hemorrhage was reported by 7/3/&lt;1/&lt;1% of B-treated pts. 99 pts developed CHF, most commonly reported at the post-AC or post-T evaluation. After a median follow-up of 26 months, the cumulative incidence of clinical CHF at 15 months from randomization in Arm A/B/C was 1.0/1.7/2.9% respectively. Median age of CHF pts was 57; median baseline LVEF of CHF pts was 60.

Abstract OT1-1-04: ALTERNATIVE: safety and efficacy of lapatinib (L), trastuzumab (T), or both in combination with an aromatase inhibitor (AI) for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer

Background: Overexpression of the human epidermal growth factor receptor 2 (HER2) gene in breast cancer is associated with an aggressive phenotype, poor prognosis, and resistance to endocrine therapies. Of HER2+ patients, ∼50% are also hormone receptor-positive (HR+). For patients who are both HER2+ and HR+, combining the AI letrozole with the dual tyrosine kinase inhibitor L has been shown to improve outcomes compared with letrozole alone. The combination of L and T, a humanized monoclonal antibody-targeting HER2, has been shown to improve outcomes compared with L alone.

Trial design: The ALTERNATIVE study is a Phase III, randomized, open-label, multicenter trial, which will examine the efficacy of L/T/AI in combination versus T/AI alone. Patients will be randomized to 1 of 3 treatment arms: L 1000 mg po QD plus T (loading dose of 8 mg/kg followed by maintenance with 6 mg/kg IV q3w plus an AI po QD); T plus an AI; or L 1500 mg po QD plus an AI. Choices of AI include letrozole, anastrozole, or exemestane.

Eligibility criteria: Postmenopausal female patients with HER2+/HR+ metastatic breast cancer (MBC) who have received neo/adjuvant T and endocrine therapy, are treatment naïve for MBC, and are not candidates for chemotherapy.

Specific aims: The primary efficacy endpoint is overall survival (OS), defined as the time from randomization until death due to any cause, for L/T/AI compared with T/AI alone. Secondary efficacy objectives include comparisons of OS between T/AI and L/AI as well as between T/L/AI and L/AI in addition to comparisons of progression-free survival, overall response rate, time to response, and duration of response. The safety objective is to evaluate the safety and tolerability for all 3 treatment groups.

A 4-year recruitment is anticipated. More than 200 centers across 37 countries are planned; approximately 110 centers are currently open for enrollment.

Statistical methods: The study is powered to detect a 42% reduction in risk of death (hazard ratio=0.70) in patients who receive L/T/AI (median 28.5 months) versus T/AI (median 20 months) using a 1-sided test for superiority with α=0.025. The required number of total events to achieve a power of 80% is 249. Secondary comparisons are not powered and will be based on the intent-to-treat population.

Present and target accrual: Twenty-six (26) of 525 patients have been randomized. Patients who have participated in previous neo-/adjuvant trials including a T regimen are eligible, provided they meet all other inclusion criteria.

The study is currently recruiting patients, with an anticipated target accrual of 525 patients by March 2016.

Clinical trial registry number: NCT01160211

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT1-1-04.

The sequential use of endocrine treatment for advanced breast cancer: where are we?

BACKGROUND

Hormone receptor-positive advanced breast cancer is an increasing health burden. Although endocrine therapies are recognised as the most beneficial treatments for patients with hormone receptor-positive advanced breast cancer, the optimal sequence of these agents is currently undetermined.

METHODS

We reviewed the available data on randomised controlled trials (RCTs) of endocrine therapies in this treatment setting with particular focus on RCTs reported over the last 15 years that were designed based on power calculations on primary end points.

RESULTS

In this paper, data are reviewed in postmenopausal patients for the use of tamoxifen, aromatase inhibitors and fulvestrant. We also consider the available data on endocrine crossover studies and endocrine therapy in combination with chemotherapy or growth factor therapies. Treatment options for premenopausal patients and those with estrogen receptor-/human epidermal growth factor receptor 2-positive tumours are also evaluated.

CONCLUSION

We present the level of evidence available for each endocrine agent based on its efficacy in advanced breast cancer and a diagram of possible treatment pathways.

OT1-02-03: EGF114299: Safety and Efficacy of an Aromatase Inhibitor (AI) in Combination with Lapatinib (L), Trastuzumab (T) or Both for the Treatment of Hormone Receptor-Positive (HR+), HER2+ Metastatic Breast Cancer (MBC)

Background: Data from the L plus letrozole (EGF30008) and the Trastuzumab and Anastrozole Directed Against ER-Positive HER2−Positive Mammary Carcinoma (TaNDEM) studies demonstrated that HER2 targeted and endocrine therapy (ET) is a better strategy than ET alone. In EGF30008, progression-free survival (PFS) in the HER2+ population was statistically significantly longer in the letrozole plus L group compared with the letrozole plus placebo group. The HR was 0.71 (95% CI: 0.53−0.96; stratified log rank P=.019). Median PFS was 35.4 weeks in the letrozole plus L group compared with 13.0 weeks in the letrozole plus placebo group.

The present study (EGF114299) is a phase III, open-label, multicenter trial designed to evaluate benefit in overall survival (OS) provided by L/T/AI and L/AI, in pts with HR+/HER2+ MBC who have received neo-/adjuvant T and ET. It will also provide further data on dual HER2 suppression in an attempt to prevent acquired endocrine resistance.

Trial Design: Pts will be randomized to 1 of 3 treatment arms: L 1000 mg po QD plus T (loading dose of 8 mg/kg followed by maintenance with 6 mg/kg IV q3w plus an AI po QD); T plus an AI; or L 1500 mg po QD plus an AI). Choices of AI include letrozole, anastrozole, or exemestane.

Eligibility Criteria: HR+ (ER and/or PgR) and HER2+ Stage IV MBC pts are to be enrolled. Pts must have received neo-/adjuvant T and ET, and are treatment naive for MBC.

Specific Aims: The primary objective is to evaluate OS of L/T/AI as compared with T/AI. The secondary objectives are to assess: OS in T/AI vs L/AI and T/L/AI vs L/AI; PFS; overall response rate; clinical benefit rate; safety and tolerability; and QoL relative to baseline. A 4-year recruitment is anticipated. More than 200 centers across 25 countries are planned; approximately 50 centers are currently open for enrollment.

Statistical Methods: The study is powered to detect a 42% improvement in the risk of death (HR=0.70) in all pts receiving L/T/AI (median 28.5 months) compared with T/AI (median 20 months). The hypothesis will be tested using a 1-sided test for superiority with a=0.025 with a power of 80%.

Present and Target Accrual: One (1) of 525 pts has been randomized. The majority of eligible pts may reside in countries where T is commercially available and reimbursable, particularly North America and Western Europe. Patients who have participated in previous neo-/adjuvant trials including a T regimen are eligible, provided they meet all other inclusion criteria.

The study is currently recruiting pts, with an anticipated target accrual of 525 patients by March 2016.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-02-03.

A Phase I Trial of a Pegylated Liposomal Anthracycline (Doxil TM) and Lapatinib Combination in the Treatment of Metastatic Breast Cancer: Dose-Escalation Results of an Anthracycline and Lapatinib Combination Trial

Background: Liposomal formulations such as pegylated liposomal doxorubicin (PLD) were developed to improve the therapeutic index and overall benefit of the anthracyclines (A). Lapatinib (L) is a selective and highly competitive inhibitor of ErbB1 and ErbB2 tyrosine kinases. The combination of conventional doxorubicin and an ErbB2 targeting agent (trastuzumab) was effective but led to an unacceptable risk of cardiac toxicity. The combination of PLD and L however may be effective with less cardiac risk. Methods: This is an open-label, phase I, dose-escalation trial of PLD at 20, 30, 45 and 60 mg/m2 IV every 4 weeks (maximum of 8 doses) and L, 1500 mg po daily until progression in patients (pts) with metastatic breast cancer (MBC). EGFR and/or ErbB2 positivity was not required. Prior chemotherapy, endocrine therapy and trastuzumab were allowed however prior A use was limited to 240 mg/m2 of doxorubicin or 600 mg/m2 of epirubicin. Initially, prior EGFR targeting therapies were not allowed however the trial was subsequently amended to allow prior lapatinib. Concomitant CYP3A4 inducers/ inhibitors were not allowed. A left ventricular ejection fraction (LVEF) of ≥ 50% was required. The primary objective was to evaluate the safety, tolerability and feasibility of the combination of PLD and L, particularly with respect to cardiac safety. MUGAs were performed at entry and every 8 weeks thereafter. Results: 16 patients (PLD: 20 mg/m2 - 4 pts; 30 mg/m2 - 3 pts; 45 mg/m2 – 6 pts; 60 mg/m2- 3 pts) with a mean age of 53 yrs (range, 33-68) have been treated for a total of 30 treatment cycles. Dose-limiting toxicity (DLT) was not reached. One pt experienced an LVEF drop to &lt; 50% after 4 cycles however this was accompanied by a pericardial effusion felt to be secondary to progressive disease. Adverse events observed include: grade IV- mucus plugging and knee pain in 1 pt each; grade III- fatigue and hand-foot-syndrome (HFS) in 2 pts each and edema, diarrhea, dizziness, headache, stomatitis and skin toxicity in 1 pt each; grade I/II in ≥2 pts- anemia, leucopenia, fatigue, shortness of breath, pain, nausea, stomatitis, anorexia, diarrhea, increased alkaline phosphatase or transaminases, hypoalbuminemia and hyperglycemia. Preliminary response data in 11 evaluable pts reveals 1 PR, 3 SD, and 8 PD. Event-free and overall survival curves are as shown.Conclusions: In the first 16 pts treated, the combination of PLD and L has been well tolerated without treatment-related cardiac toxicity. One pt experienced an LVEF drop to &lt; 50%, however this was felt likely to be disease-related. DLT was not reached however grade 3 HFS occurred in 2 out of 3 pts in the 60 mg/m2 cohort. A pharmacokinetic interaction cohort at the 45 mg/m2 dose is planned.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3096.

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.

Nab-paclitaxel weekly or q3w compared to docetaxel q3w as first-line therapy in patients with metastatic breast cancer: An economic analysis of a prospective randomized trial

6592

Background: In patients with MBC, the current practice is first-line chemotherapy often with a taxane such as docetaxel. However, docetaxel is associated with dose-limiting toxicities. A nanoparticle albumin-bound (nab) formulation of paclitaxel was recently developed to overcome the safety drawbacks of docetaxel and to provide additional efficacy. A randomized phase II trial comparing nab-paclitaxel 100 or 150 mg/m2 weekly 3 out of 4 and nab-paclitaxel 300 mg/m2 q3w to docetaxel 100 mg/m2 q3w reported improved progression-free survival and reduced toxicity with the former regimens (Gradishar, 2008). To measure the economic value of the nab-paclitaxel regimens, an economic analysis from the perspective of the United Kingdom (UK) was conducted. Methods: The current study extracted data captured during the randomized trial. Resource utilization data contained within the database were converted into UK cost estimates. This consisted of costs for chemotherapy, drug delivery, patient monitoring, supportive care drugs, and hospitalization due to toxicity. Multivariate regression analysis was then conducted to compare the total cost of therapy between the four regimens. Results: Growth factor use, hospital days for side effects management, and toxicity-induced protocol discontinuations were higher in the docetaxel group. When all of the cost components were combined for the entire population (n = 300), patients in the nab-paclitaxel 100 mg/m2 weekly and 300 mg/m2 q3w groups had comparable costs to the docetaxel control (£15,396 vs. £15,809 vs. £12,923; p = NS). The nab-paclitaxel 150 mg/m2 weekly arm had significantly higher overall costs of £27,222 but was associated with a significant improvement in progression-free survival relative to docetaxel. As alternatives to docetaxel, the incremental cost per progression-free year gained with nab-paclitaxel 100, 150 mg/m2 weekly and 300 mg/m2 q3w were £5,600, £31,800, and £9,900 respectively. Conclusions: Given its more favorable safety profile, superior efficacy, and reasonable economic impact, nab-paclitaxel (weekly or q3w) can be a preferred option over docetaxel as first-line chemotherapy in MBC.

[Table: see text]

Dasatinib plus capecitabine (Cap) for progressive advanced breast cancer (ABC): Phase I study CA180004

1012

Background: SRC family kinases (SFK) mediate numerous signal-transduction pathways relevant to breast cancer as well as osteoclast function. Dasatinib, a potent oral inhibitor of SFK and other kinases has preclinical activity in breast models and in vitro synergy with Cap in some breast cancer cell lines (KPL-4 and HCC-70). A phase I trial of dasatinib plus Cap was conducted to define dose-limiting toxicities (DLT), maximum tolerated (MTD), and recommended phase II (RP2D) doses. Methods: Sequential cohorts of pts with ABC were treated with Cap twice daily (BID) on days 1–14 and dasatinib daily in 21-day cycles using dose levels (DL) for Cap (mg/m2) and dasatinib (mg): DL1: Cap 825 + dasatinib 50 BID; DL2: Cap 825 + dasatinib 70 BID; DL3: Cap 1000 + dasatinib 70 BID; DL3a: Cap 1000 + dasatinib 100 once daily (QD). All pts had ECOG performance status 0–1, had prior anthracycline and/or taxane, and received ≤2 regimens in advanced setting. MTD was based on DLT in first cycle and RP2D also based on tolerability of additional cycles. Results: 31 pts with ABC, median age 53 years (range 36–78) were treated. Number of pts treated/evaluable for DLT/reported DLT (event) were DL1: 7/6/1 (headache, grade 3); DL2: 9/7/0; DL3: 6/6/1 (diarrhea, grade 3), and DL3a: 9/9/1 (pneumonia, grade 3). Most frequent AEs related to either drug and occurring at any time on study (n pts) were nausea (12), vomiting (7), diarrhea (6), abdominal pain (2), fatigue (8), headache (7), musculoskeletal pain (1), and pleural effusion (4); hand-foot syndrome (5) was as expected for Cap alone. 11 patients experienced a Grade 3–4 non-hematologic AE at some point during the study. Laboratory abnormalities were uncommon. To date, 20 pts have continued treatment for ≥6 weeks and 9 pts for ≥12 weeks. Number of pts who (at any time) reduced dasatinib/reduced Cap/discontinued for toxicity were DL1: 2/2/1; DL2 2/2/3; DL3: 2/1/2; DL3a: 0/1/1. Updated safety and efficacy data will be presented. Conclusions: Dasatinib + Cap was tolerated without unexpected combined-treatment toxicity; few pts required dose reduction in later cycles. The recommended phase II dose, Cap 1000 plus dasatinib 100 QD, is well tolerated and will be studied for efficacy in an expanded patient cohort.

[Table: see text]

Randomized comparison of weekly or every-3-week (q3w) nab-paclitaxel compared to q3w docetaxel as first-line therapy in patients (pts) with metastatic breast cancer (MBC)

1032

Background: 130-nM albumin-bound (nab™) paclitaxel combines paclitaxel with albumin without solvents or altering either component. A cross analysis of 2 clinical trials comparing solvent-based (SB) paclitaxel 175 mg/m2 q3w to nab- paclitaxel (Gradishar et al, JCO, 2005) and SB docetaxel (Jones et al, JCO, 2005) suggested comparable antitumor activity between nab-paclitaxel and SB docetaxel and better tolerability with nab-paclitaxel in pts with MBC. The aim of this study was to compare the toxicity and antitumor activity of 3 regimens of nab-paclitaxel (q3w and 2 weekly) with each other and that of SB docetaxel in MBC. Methods: In this open-label study, first-line pts with MBC were randomly assigned to nab-paclitaxel 300 mg/m2 q3w (A); nab-paclitaxel 100 mg/m2 (B) or 150 mg/m2 (C) days 1, 8, and 15, q28 days (q 3/4 w); or SB docetaxel 100 mg/m2 q3w (D). The primary endpoints were overall response rate (complete response + partial response, evaluated q8w) and toxicity. Progression-free survival (PFS) was also determined. Results: 302 pts (median age, 54 years; 99% Caucasian; 75% postmenopausal; ECOG PS =2 [94% =1]) either had at least 2 response assessments (94%) or had discontinued due to PD (6%). The efficacy results are shown in the Table . Neutropenia (N) was greater with D than with A, B, or C (p < 0.001). Grade 4 N was: A) 4%, B) 3%, C) 7%, and D) 74%. Febrile neutropenia (FN) was: A) 1%, B) 1%, C) 1%, and D) 7%. Gr 3 peripheral neuropathy was: A) 14%, B) 7%, C) 12%, and D) 5%. Conclusions: The response rates of q3w nab-paclitaxel and solvent-based docetaxel were comparable. Q 3/4 W nab-paclitaxel resulted in higher response rates than solvent-based docetaxel. Grade 4 N and FN were less frequent with nab-paclitaxel as compared with solvent-based docetaxel. To date, all 3 nab-paclitaxel regimens have a longer PFS than SB docetaxel although the data are not yet mature (33% of events). Final data for a radiological review of response data, PFS, and toxicity will be presented.

[Table: see text]

No significant financial relationships to disclose.

Safety and efficacy of capecitabine (C) plus bevacizumab (B) as first-line in metastatic breast cancer

1013

Background: C alone has good activity and tolerability in metastatic breast cancer (MBC) and when combined with docetaxel improves response and survival. C combined with B in heavily pretreated MBC improved the response rate but not PFS. In untreated MBC, the addition of B to chemotherapy significantly improves progression-free survival (PFS) which suggests that B, is most effective in early disease. Methods: Primary objective of this single-arm, 2-phase study, is to evaluate PFS in MBC patients receiving first-line treatment with C 1,000 mg/m2 twice daily on days 1–15 (28 doses) and B 15 mg/kg on day 1. Treatment was repeated every 21 days until progression. Eligibility criteria included HER2-negative MBC previously untreated for metastatic disease; ECOG performance status =1; no prior anti-angiogenic or oral fluoropyrimidine therapy. A sample size of 109 patients (including dropouts) was required to give 90% power to test an improvement from 4 months median PFS to 5.6 months with the two-sided test (a 5%) Results: At data cut-off, 103 patients had received study medication. Present results are based on 103 patients (ITT population), except tumor response which is based on 91 patients who had response evaluation. The average # of cycles received in first phase is 6.8. 84 pts.are alive at this time. 38.5% (35/91) pts. have had a response: complete response 5.5%; partial response 33.0%. Stable disease is 42.9% with 81.4% clinical benefit. Planned dose received is 77.7 % for C and 99.0 % for B. The majority of adverse events (AEs) were mild or moderate. The most common grade 3 AEs were hand-foot syndrome (13%) and pain (10%); grade 4 pulmonary embolism occurred in 2% in the first phase of the study. Conclusions: Updated results with longer follow-up including toxicity, TTP and PFS will be presented at the meeting. It appears that in first-line C+B is active for MBC and is well tolerated, with few grade 3/4 toxicities.

[Table: see text]

Increased HER2 expression in women with recurrent ER positive breast cancer

10516

Introduction: Tamoxifen (TAM) remains widely used in the treatment of all stages of breast cancer. Although the majority of hormone receptor (HR) positive tumors respond to TAM, many of these breast cancers will develop resistance resulting in disease recurrence or progression. Over-expression of HER2 appears to play a role in de novo tamoxifen-resistance. We have demonstrated previously that HR-positive breast cancers exposed to selective estrogen receptor modulators (SERMs), such as tamoxifen, in vivo continue to express HR but have an increase in the expression of HER2 (O'Regan Clin Cancer Res 2006). However the above finding has not been confirmed in patient samples. Materials and Methods: We evaluated 30 paired tissue samples from patients with HR positive tumors whose cancers recurred. The first tissue sample is from diagnosis and the paired sample comes from metachronous metastatic disease. Results: The median age of diagnosis was 56 (29–96). Seven patients presented with stage I disease, 11 with stage II and nine with stage III3, and three patients had missing staging information. The median time to recurrence was three years. The expression of ER decreased from diagnosis to recurrence from 79% to 59% (p=0.035). PR also decreased between diagnosis and recurrence from 34% to 22% (p=0.13). HER2 score was 2 or 3 in 27% of samples at diagnosis and in 53% at time of recurrence (p=0.01). These cancers did not have HER2 gene amplification. Conclusions: These results confirm our in vivo findings that over-expression of HER2 plays a significant role in acquired TAM- resistance. We have previously demonstrated that trastuzumab inhibits growth of SERM-resistant breast cancers in vivo despite the fact that these cancers did not have HER2 gene amplification. Taken together, our findings suggest that trastuzumab should be examined clinically in patients with TAM-resistant metastatic breast cancer, as they may be particularly sensitive to inhibition of HER2-driven pathways.

No significant financial relationships to disclose.

Phase II study of gemcitabine (Gem) + docetaxel (D) in combination with trastuzumab (T) in patients (pts) with HER2-overexpressing metastatic breast cancer (MBC)

10730

Background: Addition of T to chemotherapy (chemo) is assoc. with improved overall survival (OS) in pts with HER2+ tumors. Combination chemo has shown improvements in PFS and OS over single agent in recent phase III studies. Pre-clinical models suggest that the combination of G and D appears to be synergistic and that either agent is also synergistic with T. Objectives: This multi-institutional study was designed to determine overall RR (primary endpoint), TTP, OS and the toxicity profile of the combination of G + D + T as first-line therapy for MBC pts. Design: Pts with measurable HER2-overexpressing (FISH+) MBC, no prior chemo in the metastatic setting, adequate end-organ function and PS 0–2, received Gem 1,000 mg/m2 over 30 min on days 1 and 8 + D 75 mg/m2 day 1 and T on day 1 (8 mg/kg over 90 min on cycle 1, then 6 mg/kg over 30 min on subsequent cycles) of a 21-day cycle, until progressive disease or undue toxicity. Results: 8 pts have been enrolled over a period of 16 months. Median age: 53 years (range 40–74); ER status ±: 5/3 pts; ECOG PS 0 = 3 pts, 1 = 4 pts, 2 = 1 pt; Prior adjuvant therapy: Chemo ± Hormonal 3, Hormonal only 3, T 1. Sites of Disease: All pts had visceral involvement (Lung 4, Liver 5) and 5 pts ≥ 2 sites of metastatic disease. Total number of cycles administered was 52; median per pt. 7 (range 4–10). Median delivered dose intensity for G, D and T was 91%, 92% and 100% respectively. Toxicity was generally manageable. One pt discontinued therapy due to adverse events (grade 3 pneumonitis). Grade 3/4 neutropenia occurred in 27% and 10% of cycles; no grade 3/4 anemia or thrombocytopenia were recorded; Non-Heme toxicities of grade 2/3, included with dyspnea (0/2 pts), emesis (2/1), fatigue (4/1), diarrhea (1/1), dehydration (0/1), constipation (1/0). Complete alopecia was observed in 2 pts. No symptomatic cardiac toxicity was recorded. Best Overall RR assessment (N = 8): CR 3, PR 4, SD 1, PD 0, for an ORR of 7 out of 8 pts or 88% (95% CI: 47%–100%). Only 3 pts have progressed, and no pt has died. Progression-free survival at 1 year is 58%. Conclusion: According to this limited experience, the combination of G + D + T in front-line MBC is well tolerated and active. Study was discontinued due to slow accrual as of Feb 2004. Supported by Eli Lilly & Company.

[Table: see text]

Capecitabine-induced multifocal leukoencephalopathy: A report of five cases

Capecitabine is used to treat advanced breast and gastrointestinal malignancies. A single case of encephalopathy and three cases of peripheral neuropathy are the only neurotoxicities reported. The authors report five additional cases of capecitabine-induced multifocal leukoencephalopathy.

A randomized phase II pilot trial of adjuvant marimastat in patients with early-stage breast cancer

BACKGROUND

This pilot trial was performed to evaluate the safety, toxicity and pharmacokinetics of chronic therapy with the matrix metalloproteinase inhibitor marimastat in the adjuvant treatment of breast cancer.

PATIENTS AND METHODS

Patients with high-risk node negative or node positive breast cancer received marimastat either 5 or 10 mg p.o. b.i.d. for 12 months. Marimastat was given either as a single agent following completion of adjuvant chemotherapy or concurrently with tamoxifen.

RESULTS

Sixty-three patients were enrolled from June 1997 to May 1998. All patients have completed 12 months of treatment or have discontinued therapy due to toxicity, relapse or intercurrent illness. Moderate (WHO criteria) arthralgia/arthritis was reported by 34% of patients receiving 5 mg b.i.d. and 45% of patients receiving 10 mg b.i.d.; severe arthralgia/arthritis was reported by 6% and 23% of patients, respectively. Six patients (19%) receiving 5 mg b.i.d. and 11 (35%) receiving 10 mg b.i.d. discontinued marimastat therapy due to toxicity. Trough plasma levels were rarely within the target range for biological activity (40-200 ng/ml) with mean concentration for patients receiving: 5 mg b.i.d. = 7.5; 5 mg b.i.d. plus tamoxifen = 6.9; 10 mg b.i.d. = 11.9; 10 mg b.i.d. plus tamoxifen = 12.8.

CONCLUSIONS

A randomized adjuvant trial with marimastat is not warranted as chronic administration cannot maintain plasma levels with the target range.

Effects of high dose raloxifene in selected patients with advanced breast carcinoma

BACKGROUND

An earlier trial of raloxifene, conducted in women with metastatic breast carcinoma who initially had responded to tamoxifen and subsequently developed disease progression, suggested no antitumor activity for raloxifene in tamoxifen-refractory disease. However, preclinical studies and preliminary clinical data in healthy women suggest that raloxifene antagonizes growth of estrogen-dependent neoplasia.

METHODS

Raloxifene HCl 150 mg twice daily was given to 22 postmenopausal women with metastatic (American Joint Committee on Cancer Stage IV) or locoregionally recurrent, initially estrogen receptor positive breast carcinoma. Prior systemic treatment of metastatic disease was not allowed. Prior adjuvant chemotherapy or hormonal therapy was required to have been completed at least 1 year before study entry. Tumor response was evaluated every other month either radiographically or by physical examination. Evaluable disease was defined as bidimensionally measurable lesions.

RESULTS

Twenty-one patients were eligible for efficacy analysis; 6 had been treated previously with tamoxifen. There were no complete tumor responses. Four patients (19%; 95% confidence interval [95% CI], 2.2%, 36%) had partial tumor responses lasting 6.3, 17.5, 23.9, and 28.1 months, respectively. Prolonged stable disease (i.e., tumor size stable for > or = 6 months) was observed in 3 patients (14%; 95% CI, 0.0%, 29%) and lasted 7.9, 12.2, and 25.1 months, respectively. Combining partial responses and prolonged stable disease yielded an overall clinical benefit rate of 33% (95% CI, 13%, 53%). Adverse events generally were consistent with the disease state; there were no serious adverse events or laboratory changes believed to be therapy-related.

CONCLUSIONS

Raloxifene HCl, 150 mg, administered twice daily was safe, well tolerated, and modestly effective in highly selected postmenopausal women with advanced breast carcinoma. Further study of high dose raloxifene as monotherapy for advanced breast carcinoma most likely is unwarranted.

A hospice/palliative medicine rotation for fellows training in hematology-oncology

A clinical hospice/palliative medicine rotation for physicians enrolled in a three-year hematology/oncology fellowship was established in academic year 1993-1994 as a way to accomplish important training goals in pain management and the palliative care of patients with terminal illness. This study was conducted to obtain initial information about its effectiveness. Ten fellows, one at a time, evaluated new hospice/palliative medicine consultations, supervised the care of patients on an inpatient hospice/palliative care unit, and visited patients at home. For the first 13 months, seven fellows were assigned to this rotation for one month each, and three fellows were assigned to spend two separate months each. A self-report evaluation of the experience was administered at the end of each service month. In five of these 13 evaluations, the fellows reported their skills in managing pain and symptoms to be much improved, and in eight they indicated their skills were improved; none stated that there had been no change. Comfort and skill with discussing death, dying, and advanced directives with patients and families were reported by the fellows to be much improved in nine evaluations, improved in three, and unchanged in one. In nine evaluations, the fellows reported their understanding of hospice/palliative care as a program and approach to patient care was much improved; in two, improved; and in two, unchanged. All of the fellows would recommend this rotation to other fellows. A clinical rotation in palliative medicine and hospice care is a useful addition to the curriculum of fellows training in hematology-oncology.

A phase-ii trial of neoadjuvant chemotherapy and concomitant chemoradiotherapy for the treatment of locally advanced nonsmall cell lung-cancer

Treatment strategies for locally advanced nonsmall cell lung cancer have failed to significantly alter the survival of most patients. Treatment strategies utilizing, neoadjuvant chemotherapy and concurrent chemotherapy/radiation therapy have shown promise in some reports. Twenty-six consecutive patients with stage III, non-small cell lung cancer were treated over a 3 year period according to a strategy involving neoadjuvant chemotherapy (mitomycin, vinblastine, cisplatin [MVP]) followed by reassessment for surgical resection, followed by treatment with concomitant radiation therapy and chemotherapy (hydroxyurea [HU], 5-fluorouracil [5-FU]). Staging revealed stage IIIa disease in 15 patients and stage IIIb disease in 11 patients. Nine of 18 evaluable patients responded to MVP (50%) with 1 CR and 8 PRs. Only one of nine responders underwent surgical resection. Eleven of 19 patients receiving concomitant 5-FU, HU, and radiation therapy were evaluable for response. Two of 11 patients were converted to clinical CRs, and the remaining 9 patients had stable disease. Myelosuppression, mucositis and hand-foot syndrome were observed with 5-FU/HU/RT. Median survival for all patients is 10.5 months. One and 2-year survival is estimated at 36% and 27%, respectively. This clinical trial combining neoadjuvant chemotherapy with concurrent chemotherapy/radiation therapy is feasible. Select patients appeared to have a survival benefit however most patients failed to derive an improvement in clinical endpoints.

Phase II trial of oral etoposide plus cisplatin in extensive stage small cell carcinoma of the lung: an Eastern Cooperative Oncology Group study

Based upon the schedule specificity of etoposide and the in vitro and clinical synergy observed with cisplatin, the Eastern Cooperative Oncology Group conducted a phase II trial of oral etoposide and cisplatin in newly diagnosed, untreated patients with extensive stage small cell carcinoma of the lung. 35 patients received 100 mg/m2 of cisplatin intravenously on day 1 and 50 mg/m2 of etoposide orally for 21 consecutive days. Cycles were repeated every 28 days. The most common toxicity observed was myelosuppression. Sixty-seven per cent of patients had grade 3 or 4 leukopenia and 34% had grade 3 or 4 thrombocytopenia during cycle one. Of 26 evaluable patients, 4 had a complete response (15%) and 17 had a partial response (65%). The median survival for the group as a whole was 8.5 months. We conclude that this regimen was associated with significant myelosuppression, and offered no therapeutic advantage to other commonly administered chemotherapeutic regimens for small cell carcinoma of the lung.

Vascular events in patients receiving high-dose infusional 5-fluorouracil-based chemotherapy: the University of Chicago experience

In a retrospective review, 22 of a total of 244 patients (9%) patients with head and neck or gastrointestinal cancer who were treated with infusional 5-fluorouracil (5-FU)-based chemotherapy regimens experienced thrombotic vascular events. These events occurred concurrently with treatment or several months following the completion of therapy and consisted mainly of cardiac arrhythmias, myocardial infarction, sudden death, and thromboembolism. The temporal relationship of these vascular events to the time of treatment suggests that infusional 5-FU may have been the underlying cause.

Obstructing plasmacytoma of the duodenum: first manifestation of relapsed multiple myeloma

A patient with an obstructing, annular duodenal neoplasm is described. Percutaneous fine needle aspiration biopsy, and biopsy performed through an endoscope, confirmed that the lesion was an extramedullary plasmacytoma. The patient had been in clinical remission from multiple myeloma for the preceeding 13 months. Radiation therapy resulted in cessation of symptoms including gastrointestinal blood loss. After 5 months, recurrent obstructive symptoms and melena led to surgical extirpation of the tumor, with relief of all symptoms.