Abstract P4-12-12: Phase 2, multicenter, single-arm study of eribulin mesylate + trastuzumab as first-line therapy for locally recurrent or metastatic HER2-positive breast cancer

Background: Eribulin mesylate, a non-taxane microtubule dynamics inhibitor, has been approved for patients with metastatic breast cancer (MBC) who have previously received ≥2 chemotherapeutic regimens for MBC. We present final data from a phase 2 study that evaluated efficacy and safety of eribulin + trastuzumab as first-line therapy for locally recurrent or metastatic human epidermal growth factor receptor 2 positive (HER2+) BC.

Methods: Patients received eribulin mesylate at 1.4 mg/m2 IV on days 1 and 8 of each 21-day cycle and an initial trastuzumab dose of 8 mg/kg IV on day 1, followed by 6 mg/kg on day 1 of each subsequent cycle. Endpoints include objective response rate (ORR), safety, progression-free survival (PFS), time to response (TTR), and duration of response (DOR). Tumor assessments were conducted every 6 weeks for the first 6 cycles and every 6-12 weeks thereafter per RECIST 1.1.

Results: Fifty-two patients with a median age of 60 years (range 31- 81) were treated; 96% had stage IV disease, 73% had visceral disease, and 48% had liver metastases. Thirty one patients had prior neo/adjuvant chemotherapy (11 had prior anthracycline, and 22 had prior taxane). Patients received a median of 10(0, 33) cycles of eribulin and 11(1, 31) cycles of trastuzumab. ORR was 67% with median TTR of 1.3 months and PFS of 11.5 months (Table). The most common (>5%) Grade 3/4 treatment related treatment emergent (TRTE) AEs were neutropenia (n = 20; 38.5%), peripheral neuropathy (n = 14; 26.9%) and febrile neutropenia (n = 4; 7.7%). Serious TRTE AEs occurred in 14 patients and included neutropenia (n = 9; 17.3%), febrile neutropenia (n = 4; 7.7%), and peripheral neuropathy (n = 3; 5.8%). Reasons for discontinuation were AEs (n = 7) and PD (n = 22).

Table. Summary of Efficacy EndpointsEfficacy EndpointsEribulin/Trastuzumab N = 52Objective Response Rate, n (%)35 (67)- Complete Response (CR)2 (4)- Partial Response (PR)33 (64)Stable Disease (SD)15 (29)Progressive Disease (PD)1 (2)Not Evaluable1 (2)Overall Clinical Benefit Rate, n (%)42 (81)Time to First Objective Response, median months (95% CI)1.3 (1.2, 1.4)Duration of Objective Response, median months (95% CI)a11.1 (6.5, 17.8)Progression-Free Survival, median months (95% CI)11.5 (7.3, 13.5)Duration of Stable Disease, median months (95% CI)7.1 (5.2, 13.5)Clinical Benefit Rate = ORR+ ≥6 mo SD; an = 35

Conclusions: This study suggests that the combination of eribulin + trastuzumab first-line therapy for locally recurrent or metastatic HER2+ BC has an acceptable safety profile and results in considerable tumor response with a long DOR. Additional larger studies with this combination are warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-12.

Tetrathiomolybdate-associated copper depletion decreases circulating endothelial progenitor cells in women with breast cancer at high risk of relapse

BACKGROUND

Bone marrow-derived endothelial progenitor cells (EPCs) are critical for metastatic progression. This study explores the effect of tetrathiomolybdate (TM), an anti-angiogenic copper chelator, on EPCs in patients at high risk for breast cancer recurrence.

PATIENTS AND METHODS

This phase 2 study enrolled breast cancer patients with stage 3 and stage 4 without evidence of disease (NED), and stage 2 if triple-negative. TM 100 mg orally was administered to maintain ceruloplasmin <17 mg/dl for 2 years or until relapse. The primary end point was change in EPCs.

RESULTS

Forty patients (28 stage 2/3, 12 stage 4 NED) were enrolled. Seventy-five percent patients achieved the copper depletion target by 1 month. Ninety-one percent of triple-negative patients copper-depleted compared with 41% luminal subtypes. In copper-depleted patients only, there was a significant reduction in EPCs/ml by 27 (P = 0.04). Six patients relapsed while on study, of which only one patient had EPCs maintained below baseline. The 10-month relapse-free survival was 85.0% (95% CI 74.6%-96.8%). Only grade 3/4 toxicity was hematologic: neutropenia (3.1% of cycles), febrile neutropenia (0.2%), and anemia (0.2%).

CONCLUSIONS

TM is safe and appears to maintain EPCs below baseline in copper-depleted patients. TM may promote tumor dormancy and ultimately prevent relapse.

Abstract P1-15-07: Ixabepilone-associated peripheral neuropathy in metastatic breast cancer patients and its effects on the ultrastructure of neurons

Background: Peripheral neuropathy is a dose-limiting toxicity of most microtubule-stabilizing chemotherapeutic agents. Ixabepilone, a semisynthetic analog of the natural epothilone B, has activity in a wide range of tumors including taxane-resistant disease. In this study, we sought to understand the effect of ixabepilone on the development of peripheral neuropathy both clinically and its effect at the ultrastructural level of the peripheral nerves and circulating factors over time. Parallel studies in animal models of neuropathy were performed at the same time (Proc AACR 2010 Abstract 4184).

Methods: This open-label, non-randomized phase II study enrolled 14 patients with metastatic breast cancer. Ixabepilone was administered by 2 schedules: the FDA approved dose of 40 mg/m2 every 3 weeks (q3w) and 16 mg/m2 on day 1, 8, and 15 of a 28-day cycle (weekly). Five controls, 2 with residual taxane-associated peripheral neuropathy and 3 with no prior chemotherapy or peripheral neuropathy, were also accrued. The primary objectives were to characterize the natural history of ixabepilone-associated peripheral neuropathy using the Total Neuropathy Score Clinical (TNSc) assessment tool prior to each cycle and to correlate changes in the ultrastructure of dermal myelinated nerve fibers via a 3 mm punch biopsy of an area 10 cm above the lateral malleolus every 2 cycles with electron microscopy (EM), as well as circulating factors (both inflammatory and neurotrophic) considered to be important in the pathogenesis of chemotherapy-induced peripheral neuropathy. Secondary objectives included progression-free survival (PFS) and non-neurologic toxicity.

Results: 14 patients were enrolled and were equally divided between the 2 schedules of ixabepilone chemotherapy. There were no differences in baseline characteristics between the two groups. Mean age was 54 years (range 32–71). Mean number of previous chemotherapy regimens was 3.5 (range 0–8). 57% of patients had received a taxane in the adjuvant setting and 64% in the metastatic setting. The mean neuropathy score (TNSc) at baseline was 4.6 (range 1–11). At a mean cumulative dose of 185 mg/m2, the TNSc with ixabepilone q3w schedule was 3.7 points higher/worse (95% CI: 2.2–5.3, p = 0.03) than the mean score observed in patients on the weekly schedule. The sensory component was most significantly affected, predominantly numbness. In 3 patients, the chemotherapy schedule was changed from every 3 weeks to weekly due to &gt; grade 2 toxicity at a mean cumulative dose of 107 mg/m2, and TNSc decreased/improved by 2.7 points. PFS in patients on q3w ixabepilone was 133 days (range 28–280) and in patients on weekly ixabepilone was 179 days (range 66–336), nonsignificant. Evaluation of EM and circulating factors is ongoing.

Conclusions: Weekly ixabepilone appears to have a more favorable neurotoxicity profile compared to the standard q3w schedule. Integration of the EM data and the circulating factor data are underway and will be presented. Ixabepilone-associated peripheral neuropathy may improve in patients switched to weekly ixabepilone without compromising efficacy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-15-07.

Abstract P1-12-02: Results of a phase 2, multicenter, single-arm study of eribulin mesylate as first-line therapy for locally recurrent or metastatic HER2-negative breast cancer

Background: Eribulin mesylate is a novel nontaxane microtubule dynamics inhibitor that is approved in patients (pts) with metastatic breast cancer (MBC) who have previously received at least two chemotherapeutic regimens for MBC. We are reporting a preliminary planned analysis (first 6 cycles of treatment) of a phase 2 study that evaluates efficacy and safety of eribulin as first-line therapy for HER2-negative MBC.

Methods: Pts with measureable HER2-negative locally recurrent or MBC with at least 12 months since prior neoadjuvant or adjuvant chemotherapy received eribulin mesylate at 1.4 mg/m2 IV on days 1 and 8 of each 3-week cycle. Endpoints include objective response rate (ORR) (primary), safety, progression free survival (PFS), time to response (TTR), and duration of response (DOR). Tumor assessments were evaluated every 6 weeks for the first 6 cycles and every 6–12 weeks thereafter per RECIST 1.1.

Results: 54 of 56 enrolled pts had at least 1 post-baseline assessment. The median number of cycles delivered was 7 (range 1,21). Pt characteristics: median age, 56 yrs (range 31–85); ECOG of 0, 32 (57%); 29% had de novo stage IV; 38/56 (68%) had prior neo/adjuvant (45% had anthracycline and 45% taxane, the majority of which were given together). Seventy percent have visceral disease (45% liver, 38% lung); 41 (73%) have estrogen receptor-positive (ER) disease and 12 (21%) have triple negative (TN) (ER−/PR−/HER2−) disease. Objective response data are found in Table 1.

Abstract P5-20-04: Eribulin mesylate + trastuzumab as first-line therapy for locally recurrent or metastatic HER2-positive breast cancer: results from a phase 2, multicenter, single-arm study

Background: Eribulin mesylate, a novel non-taxane microtubule dynamics inhibitor, has been approved for patients with metastatic breast cancer (MBC) who have previously received at least two chemotherapeutic regimens for MBC. This study evaluates efficacy and safety of eribulin + trastuzumab (TRAZ) as first-line therapy for human epidermal growth factor receptor 2 positive (HER2+) locally recurrent or MBC.

Methods: Patients received eribulin mesylate at 1.4 mg/m2 IV on days 1, 8 and TRAZ initial dose of 8 mg/kg IV on day 1 every 21 days, followed by 6 mg/kg on day 1 of each subsequent cycle. For study inclusion, patients could have been previously treated with TRAZ, but at least 12 months should have passed since any prior neoadjuvant or adjuvant chemotherapy was used. Endpoints include objective response rate (ORR) (primary), safety, progression free survival (PFS), time to response (TTR), and duration of response (DOR). Tumor assessments are evaluated every 6 weeks for the first 6 cycles and every 6–12 weeks thereafter per RECIST 1.1.

Results: Updated results presented here as of June 1, 2012; 37 of 52 planned patients have been treated. Patient characteristics are as follows: median age: 58 years (range, 31–81), 70% have luminal subtype, 95% are stage IV disease, and 73% have visceral disease, 46% had prior neo/adjuvant, 22% had prior anthracycline and 32% had prior taxane, 35% had original diagnosis of MBC. Patients received median of 7 (1,20) cycles for eribulin and 9 (1,23) cycles for TRAZ. The most common treatment related AEs are reported in Table 1.

Abstract P6-11-04: Targeting the tumor microenvironment: tetrathiomolybdate decreases circulating endothelial progenitor cells in women with breast cancer at high risk of relapse

Background: Bone marrow-derived endothelial progenitor cells (EPCs) constitute an important part of the tumor microenvironment and are critical for metastatic progression in preclinical models and breast cancer patients (Jain et al, Breast Cancer Res Treat, 2012). Tetrathiomolybdate (TM), a copper-depleting compound inhibits angiogenesis, tumor growth, and metastasis. This study explores the effect of TM on EPCs in patients at high risk for breast cancer recurrence.

Methods: This phase II study enrolled stage 3, 4 without evidence of disease (NED), and any node-positive triple negative breast cancer patient. Only concomitant hormone therapy was allowed. Patients received induction TM 180 mg daily at baseline followed by an equal or lower daily dose (median 100 mg, range 0–140) to maintain ceruloplasmin (Cp) level &lt; 17 mg/dl (target for copper depletion). We monitored EPCs (CD45dim/CD133+/VEGFR2+), Cp, CEA, and CA15-3 at baseline and monthly. Wilcoxon signed-rank was used to compare Cp and EPC levels between baseline and subsequent time points. All p-values were two-sided with statistical significance evaluated at the 0.05 alpha level.

Results: 50 patients (33 adjuvant, 17 Stage 4 NED, and 22 triple negative) were enrolled. In the first 40 patients enrolled who had received at least 24 months of TM, EPC and Cp data were available for analysis. Of these 40 patients, 1 patient did not take TM due to patient preference, and 736 cycles of TM (average 18.9 per patient) were administered. Median age was 50 years (range 29–66). Median number of tumor size and positive lymph nodes among adjuvant patients were 3.5 cm (range 1.2–7) and 9 (range 0–42), respectively. Of the patients receiving hormone therapy, 11 patients were on tamoxifen and 16 patients were on an aromatase inhibitor. Median baseline Cp level was 30 mg/dL (range 20–47). 71% patients adequately copper depleted at month 1 to a mean Cp of 14.8 mg/dL. A larger proportion of triple negative patients copper depleted (82%) compared to hormone receptor positive subtypes (47%) and HER2/neu positive subtypes (67%). Median EPCs/ml decreased from baseline to last dose by 16 in patients that achieved the copper depletion target, p = 0.014. Conversely, in patients that did not copper deplete, median EPCs/ml increased by 136, p = 0.005. Of the 50 patients on study, 7 patients relapsed in which a significant increase in EPCs preceded an objective clinical relapse and a tumor marker rise by a median of 1 month. Only grade 3/4 toxicity was hematologic, occurred in 49 cycles (6.7%), and resolved in 5–13 days with TM held and resumed at a lower dose.

Conclusions: TM is a well-tolerated oral copper chelator that may contribute to maintaining EPCs below baseline in copper-depleted patients. Molecular subtype may impact on the ability to copper deplete. EPCs may have potential as a surrogate marker for early relapse and as a therapeutic target for interrupting the metastatic progression.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-11-04.

Abstract P6-11-14: Post-hoc safety and tolerability assessment in patients receiving palliative radiation during treatment with eribulin mesylate for metastatic breast cancer

Background: Management of advanced breast cancer frequently includes palliative radiation therapy (RT) and many chemotherapy agents are radiation-sensitizers. We assessed whether the safety profile of eribulin differed between metastatic breast cancer (MBC) patients receiving eribulin alone and those who also received palliative RT.

Methods: Two previous phase 2 and 3 eribulin trials (Studies 211 and 305, respectively) enrolled a total of 794 patients with locally recurrent or MBC who had received 2–5 prior chemotherapy regimens. In both trials eribulin mesylate (1.4 mg/m2) was given on Days 1 and 8 of a 21-day cycle and intercurrent palliative RT was permitted. In this post-hoc analysis, patient-level data were pooled for a descriptive comparison of adverse events (AEs) between the patients who received RT during their study treatment and those who did not. RT delivered within 3 weeks of initiation of eribulin or RT encompassing &gt;30% of marrow was excluded. If palliative RT was utilized on study, the protocol requirements were as follows: indications included bone pain, bronchial obstruction, ulcerating skin lesions; the total field for palliative RT was not to involve &gt;10% of total bone marrow; and the irradiated lesion was not to be used for tumor response assessment. During palliative RT, eribulin treatment was to be delayed and then resumed when the patient had recovered from any RT-associated toxicities.

Results: Of the 794 patients (291 patients in Study 211 and 503 in Study 305) who received eribulin, 44 (5.5%) received palliative RT.

Employment after a breast cancer diagnosis: a qualitative study of ethnically diverse urban women

Employment status is related to treatment recovery and quality of life in breast cancer survivors, yet little is known about return to work in immigrant and minority survivors. We conducted an exploratory qualitative study using ethnically cohesive focus groups of urban breast cancer survivors who were African-American, African-Caribbean, Chinese, Filipina, Latina, or non-Latina white. We audio- and video-recorded, transcribed, and thematically coded the focus group discussions and we analyzed the coded transcripts within and across ethnic groups. Seven major themes emerged related to the participants' work experiences after diagnosis: normalcy, acceptance, identity, appearance, privacy, lack of flexibility at work, and employer support. Maintaining a sense of normalcy was cited as a benefit of working by survivors in each group. Acceptance of the cancer diagnosis was most common in the Chinese group and in participants who had a family history of breast cancer; those who described this attitude were likely to continue working throughout the treatment period. Appearance was important among all but the Chinese group and was related to privacy, which many thought was necessary to derive the benefit of normalcy at work. Employer support included schedule flexibility, medical confidentiality, and help maintaining a normal work environment, which was particularly important to our study sample. Overall, we found few differences between the different ethnic groups in our study. These results have important implications for the provision of support services to and clinical management of employed women with breast cancer, as well as for further large-scale research in disparities and employment outcomes.

OT3-01-17: Randomized, Double-Blind, Placebo-Controlled Phase II Trial of Low-Dose Metronomic Cyclophosphamide Alone or in Combination with Veliparib (ABT-888) in Chemotherapy-Resistant ER and/or PR-Positive, HER2/neu-Negative Metastatic Breast Cancer: New York Cancer Consortium Trial P8853

Background: Veliparib is an orally available, small molecule inhibitor of poly(ADP-ribose) polymerase (PARP). PARP is an essential nuclear enzyme that plays a role in recognition of DNA damage and facilitation of DNA repair. PARP inhibitors potentiate the cytotoxicity of DNA-damaging agents, including cyclophosphamide (C). The rationale for the proposed trial is as follows: (1) low-dose, continuous metronomic C (50 mp PO daily) has activity in refractory metastatic breast cancer (MBC), (2) PARP is induced by DNA damaging agents, (3) PARP expression is comparable in ER-positive and ER-negative disease, (4) some ER-positive breast cancers exhibit defective homologous recombination pathway repair genes (eg, RAD51 and XRCC3), (5) the PARP inhibitor iniparib appears to be more effective when used in chemotherapy resistant disease. Taken together, these findings suggest that veliparib-C combination may be more effective than metronomic C alone in chemotherapy resistant MBC. Trial design: A randomized Phase II trial design 1:1. S. Blocked randomization will be performed at all participating sites. Patients are randomized to oral C (50mg PO daily) plus either veliparib (60mg PO daily) or matching placebo.

Eligibility criteria:(1) ER- and or PR-positive, HER2−negative MBC, (2) ECOG PS 0–1, (3) at least 2 prior chemotherapy regimens for MBC, including a taxane and capecitabine. 4) at least 1 line of endocrine therapy for metastatic disease (includes relapse while receiving endocrine therapy).

Specific aims: Primary: To determine if the addition of veliparib to metronomic dose C improves median progression free survival (PFS) compared with C alone in patients with ER and/or PR-positive, Her2-negative MBC who progressed on at least two lines of prior chemotherapy and one line of prior endocrine therapy.

Secondary: 1)To determine if the addition veliparib to C chemotherapy improves a) response rate b) clinical benefit rate (defined as objective response plus stable disease for at least 24 weeks from day +1) 2) Survival in patients treated with C alone and C plus veliparib. 3) Adverse event profile in patients treated with C alone and C plus veliparib.

Translational: Exploratory analyses will evaluate whether the macroH2A1.1 and PARP1 expression status in archival paraffin, or veliparib-induced PAR downregulation in peripheral blood mononuclear cells, is predictive of benefit from veliparib.

Statistical methods: The primary endpoint is PFS, and the trial is powered to detect an increase in median PFS from 3 to 6 months (alpha=0.10, beta=0.10), which will require enrollment of 62 eligible patients over 12 months.

Enrollment: The study is active and open to enrollment.

Clinical trials.gov NCT01351909

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-01-17.

P1-03-02: The Norton-Simon Hypothesis and Cancer Stem Cells: How Cancer Stem Cells May Explain the Effectiveness of Dose-Dense Chemotherapy

Background: Systemic therapies are effective initially in controlling and reversing tumor growth; however, residual cancers will invariably re-grow despite this initial response. We have published data from paired human breast cancer samples that standard therapy every three weeks kills dividing daughter cells but not tumor-initiating cells (TICs), so that samples obtained after therapy are enriched for CD44+/CD24−/low putative “tumor-initiating” or “cancer stem” cells, indicating that standard treatment regimens are missing the critical targets, TICs. Interestingly, we have recent data in human breast tumors that indicate that TICs may in fact be chemosensitive initially, with a decrease in TICs observed within two days of chemotherapy, but shortly thereafter, TICS are actually induced by chemotherapy.

Materials and Methods: To evaluate TICs response to chemotherapy, mice with human breast tumor xenograft lines BCM-2665a and BCM-2147 were treated with vehicle, 10-, or 33-mg/kg docetaxel, and then tumors were collected for TIC assays and molecular analysis at both 48 and 72h after treatment. Using Affymetrix gene expression microarrays and reverse phase protein array (RPPA) analysis with 119 different validated antibodies, we identified pathways involved in regulation of TICs. Results: According to flow cytometric analysis for TIC markers and mammosphere (MS) formation efficiency, BCM-2665 TICs were reduced by docetaxel treatment compared to vehicle-treated at 48h post 10 mg/kg docetaxel (4-fold decrease) and 48 and 72h post 33 mg/kg docetaxel compared to control (14- and 2-fold decrease, respectively). Although the BCM-2147 TICs did not significantly decrease at any time points or doses tested, they were clearly induced at 72h post-treatment compared to control. Additionally, BCM-2665 TICs were increased within 72h post 10 mg/kg docetaxel, indicating that these time points are ideal for defining the mechanisms responsible for induction of TICs. Ingenuity Pathway Analysis of Affymetrix microarray data for both BCM-2665 and BCM-2147 revealed induction of inflammatory pathways, suggesting leukocyte infiltration associated with induction of TICs. Furthermore, RPPA analysis confirmed gene expression changes from the microarray data, and implicated apoptosis and inflammatory pathways. Sixteen of 28 proteins significantly changed with activation of CSC are involved in development of leukocytes. Discussion: These findings are consistent with the Norton-Simon Hypothesis in that chemotherapy regimens given more frequently may in fact eliminate TICs, thereby explaining the proven increased effectiveness of dose-dense chemotherapy. Based on when TICs became chemoresistant, we are comparing dose-dense treatment (4 mg/kg docetaxel every 3 days) to a traditional single dose of 32 mg/kg, in an effort to eliminate the tumor cells that cause tumor recurrence. Furthermore, our analysis of gene expression at both the RNA and protein level implicated the immune cells as TICs inducers. Since our immunocompromised mice lack T- and B- cells but have active macrophages, macrophages are indicated as inducers of TICs. We are focusing our current efforts at identifying how immune cells activate TICs and thus enhance tumorigenesis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-03-02.

Abstract P3-15-06: No Correlation between Endocrine Symptoms and Musculoskeletal Symptoms in Women Receiving Adjuvant Aromatase Inhibitor Therapy

Background:

The etiology of Aromatase Inhibitor (AI) associated musculoskeletal symptoms remains unclear. It has been proposed that musculoskeletal side effects are related to the estrogen depletion achieved on AI therapy. Estrogen depletion with AI therapy is known to result in endocrine side effects. The 18-item Functional Assessment of Cancer Therapy Breast Cancer-Endocrine Subscale (FACTB-ES) is a reliable and well validated quality of life questionnaire shown to be sensitive to changes in endocrine symptoms in breast cancer patients. The objective of this study was to determine whether among women with breast cancer treated with adjuvant AI therapy, self reported musculoskeletal side effects correlate with increased hormonal side effects as measured by the FACTB-ES. Methods:

In this 6 month, single center, prospective cohort study, post-menopausal women with hormone-sensitive, non-metastatic breast cancer prescribed AIs by their treating oncologist were evaluated by a rheumatologist at baseline (before starting the AI) and at 6 months. Women who reported new or worsening musculoskeletal symptoms since starting the AI were classified as symptomatic. The FACTB-ES was administered at each visit.

Changes in scores between baseline and 6 months were compared between

the symptomatic and asymptomatic groups

Results:

Thirty-five subjects completed the 6 month follow up period. Nineteen (54%) were symptomatic and n=2 (5.7%) discontinued the AI due to these musculoskeletal symptoms. Mean time to onset of symptoms was 6 weeks (range 2 to 18 weeks). Baseline characteristics including age, ethnicity and body mass index did not differ between the groups. There was no significant difference in hormonal symptoms between groups. Both groups had equivalent worsening of their endocrine symptoms as seen by the reduction in their FACTB-score. The mean change in FACTB-ES score was -2.52 (range: -31.00, 23.00) in the symptomatic women versus -2.06 (range: -19.00, 22.21) in the asymptomatic women (Wilcoxon rank sum p=0.95). Conclusions:

These data suggest that endocrine symptoms as measured by the FACTB-ES do not correlate with the development of musculoskeletal pain in women treated with adjuvant AI therapy for breast cancer. Though larger studies are necessary to confirm these results, the musculoskeletal symptoms associated with AI use may not be estrogen-dependent.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-15-06.

Treatment of metastatic breast cancer: second line and beyond

Increasing use of standard chemotherapy, especially anthracycline- and taxane-based therapies, in early-stage breast cancer has led to a corresponding increase in heavily pretreated and/or treatment-resistant cases of metastatic breast cancer (MBC). Thus, second and later lines of MBC therapy frequently involve the clinically challenging picture of progressive disease and limited treatment options. While several prognostic factors have been identified to aid treatment selection in MBC patients, treatment is palliative and aimed at prolonging survival, controlling symptoms, and maximizing patients' quality of life. No globally accepted standard exists for meeting these goals, and treatment patterns vary according to region. The list of available agents for the treatment of MBC is increasing with newer chemotherapeutic agents and molecular-targeted therapies. Within recent years, several single-agent and combination chemotherapy regimens have been shown to improve progression-free survival and reduce symptoms of disease in clinical studies in patients with resistant and/or heavily pretreated MBC. However, at present, the demonstrated benefits of these medical interventions have usually not included extension of overall survival times. It is hoped that in the near future, ongoing refinements to treatment approaches used in second-line settings and beyond will allow meaningful improvements in symptom control and survival in MBC.

Phase I trial of ixabepilone plus pegylated liposomal doxorubicin in patients with adenocarcinoma of breast or ovary

BACKGROUND

Ixabepilone is a semisynthetic epothilone B analogue that is active in taxane-resistant cell lines and has shown activity in patients with refractory breast and ovarian cancer. We carried out a phase I trial of ixabepilone plus pegylated liposomal doxorubicin (PLD) in patients with advanced taxane-pretreated ovarian and breast cancer.

METHODS

Patients with recurrent ovarian or breast carcinoma received PLD every 3 or 4 weeks plus five different dose schemas of ixabepilone in cohorts of three to six patients.

RESULTS

Thirty patients received a total of 142 treatment cycles of the PLD-ixabepilone combination. The recommended phase II dose and schedule of ixabepilone was 16 mg/m(2) on days 1, 8, and 15 plus PLD 30 mg/m(2) given on day 1, repeated every 4 weeks. Hand-foot syndrome and mucositis were dose limiting when both ixabepilone and PLD were given every 3 or 4 weeks. Objective responses were observed in 3 of 13 patients (23%) with breast cancer and 5 of 17 patients (29%) with ovarian cancer.

CONCLUSION

Ixabepilone may be safely combined with PLD, but tolerability is highly dependent upon the scheduling of both agents. This combination demonstrated efficacy in patients with breast and ovarian cancer and merits further evaluation in these settings.

A Phase II Trial Tetrathiomolybdate (TM), a Copper Depleting Compound, and Its Effect on Circulating Endothelial Progenitor Cells (EPCs) in Patients with Breast Cancer (BC) at High Risk of Recurrence

Background: EPCs are critical to tumor angiogenesis, are increased in BC patients (pts) and are probably an early marker for paclitaxel response. Copper is required for angiogenesis, and pre-clinical data suggest that TM, a copper-depleting compound, inhibits angiogenesis and maintains tumor dormancy. We sought to measure the effect of TM on circulating endothelial progenitor cells (EPCs) in pts at high risk of BC recurrence and to evaluate the effect of copper depletion on EPCs. Methods: This analysis is part of an ongoing phase II study of TM in BC pts at high risk of recurrence defined as any node positive triple negative (TN) BC, Stage III or IV with no evidence of disease (NED). All therapy other than hormonal was completed at least 6 weeks prior to study. Treatment: TM 180 mg daily to achieve a target ceruloplasmin (Cp) level of 5-15 mg/dL (copper depletion), and then 100 mg daily. We monitored levels of EPCs (CD45dim, CD133+, VEGFR2+), CEA, CA15-3, and Cp at baseline and monthly. Imaging studies are done every 6 months (mos). Results: 28 pts are enrolled and 304 cycles of TM have been administered. Adjuvant: 20 pts, Stage 4 NED: 8 pts, Triple negative: 8 pts (5 stage IV NED, 3 Adjuvant) The median age is 51 years (range: 29-64), median number of positive lymph nodes among Stage III patients is 7 (4-42). The median baseline Cp level was 28 mg/dL (21-43). Among 21 patients who have reached target Cp, the median time to target is 6 weeks (2-16 weeks). Two pts discontinued treatment before reaching target. The median baseline EPCs is 17.38 cells/ml (0.0-286.1) Although there was a trend toward increased EPCs at month 1, this was not statistically significant (p=0.8964) and the majority of pts EPCs were maintained below baseline over time when Cp levels were below target (ie. copper depleted). Toxicity: Grade 3/4 neutropenia occurred in 3 patients (0.02%) with 1 pt with febrile neutropenia. All resolved 5-13 days later with TM held and resumed at a lower dose in 2 patients. No other grade 3/4 toxicity was observed. Three patients were diagnosed with recurrent breast cancer at 1, 9 and 10 mos. An EPC rise preceded an abnormal marker or overt relapse by 3-5 months in 2 of 3 pts. Conclusions: TM is well tolerated in breast cancer patients. TM might contribute to maintaining EPCs below baseline in pts who are copper depleted. We postulate that the increased EPCs noted in both patients with recurrent disease 2-4 months prior to overt relapse could represent the turning on of an angiogenic switch, resulting in an outpouring of CEPCs to the new site of metastasis. Other studies geared toward understanding the mechanism for metastases are underway. The trial continues to accrue.Supported by the Susan B Komen for the Cure, NY Community Trust, Breast Cancer Alliance of Greenwich and the Madeline and Stephen Anbinder Foundation.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6090.

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.

Differences in Breast Cancer Subtypes among Asian-American Women with Invasive Breast Cancer in New York City

Background: Specific breast cancer (BC) subtypes conferring distinct phenotypic and prognostic outcomes have been defined by molecular gene expression arrays. A recent study suggested that differences in BC subtypes exist among ethnic subgroups of Asian women in California. It has also been reported that there are differences in clinical outcomes among Asians with BC in the US, with Filipinos having a worse prognosis compared with other Asians. We sought to determine whether differences in BC subtypes exist among Asians in New York.Methods: Using outpatient registration records from Weill Cornell Breast Center and St. Vincent's Medical Center in New York City, we identified patients who were diagnosed with stage I, II, or III invasive BC between 1997 and 2007 who were of Chinese, Filipino, Japanese or Korean ethnicity. We reviewed pathology records according to an IRB approved protocol and recorded patient data for age, stage, grade, estrogen receptor (ER), progesterone receptor (PR) status, and HER-2/neu at diagnosis. Immunohistochemical surrogates for the four molecularly defined breast cancer subtypes were used according to accepted definitions (Luminal A: ER+Her2-; Luminal B: ER+ Her2+; Her2/neu: Her2+ ER-; Basal-like: ER-PR-, Her2-) Using chi-square analysis, we explored the relationship between ethnicity and BC subtypes.Results: 346 Asian women were identified with invasive breast cancer. Among the Chinese subgroup, 67% were of the Luminal A subtype, 15.3% were Luminal B, 10% were the Her2/neu subtype and 8.5% were Basal-like. Filipinos had a higher proportion of Luminal B cancers compared to the other ethnic groups. Filipinos and Koreans had a higher proportion of the Her2+/ER- subtype compared to Chinese and Japanese (P=0.004 by chi-square test). When considering all Her2/neu positive cancers, Filipinos had a significantly higher proportion of HER-2/neu positivity (46%) compared to Chinese (25%), Japanese (14%) and Korean (29%) groups (P=0.002). Filipinos and Koreans had a higher proportion of ER negative cancers and Grade III cancers compared to Chinese and Japanese (P=0.001 for ER status and P=0.01 for grade). In our series, Korean subjects were significantly younger than the other three ethnic groups (P&lt;0.0001 by AVOVA test).Conclusions: Differences in BC subtypes exist among Asian women with invasive breast cancer in New York. Filipino women are significantly more likely to have HER-2/neu positive BC compared with Chinese, Japanese, and Korean women. Our results are supportive of results from a study in which differences in distribution of Her2/neu positive cancers among Asians in California were seen. Furthermore, these findings provide one explanation for the worse clinical outcome for Filipinos compared with other Asians that has been previously reported.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3067.

A phase I/II study of CR011-vcMMAE, an antibody-drug conjugate, in patients (pts) with locally advanced or metastatic breast cancer (MBC)

1067

Background: Glycoprotein NMB (GPNMB), also known as osteoactivin, has been shown to regulate metastasis of breast cancer in vivo. CR011-vcMMAE, a fully-human monoclonal anti-GPNMB antibody conjugated to the tubulin inhibitor monomethylauristatin E, is safe and active in pts with advanced melanoma. This is the first study of CR011-vcMMAE in breast cancer. Methods: Eligible pts with MBC had ≥ 2 prior chemotherapy regimens, including a taxane, an anthracycline, and capecitabine; and ECOG PS ≤ 2. Doses were escalated to 1.88 mg/kg IV q3w (the maximum tolerated dose [MTD] in melanoma) using a standard 3+3 design. Immunohistochemistry (IHC) with goat polyclonal antibody to GPNMB was performed on pt biopsy specimens and on tissue microarrays containing normal breast, DCIS, breast tumor and lymph node metastases. Results: 10 pts with MBC (median age 57, range 36 - 69) had a median of 7 prior regimens and were treated with CR011-vcMMAE for a median of 2 cycles (range 1–4). In the first 2 pts at 1.34 mg/kg, dose limiting toxicity of worsening peripheral sensory neuropathy was observed. Pts with baseline neuropathy worse than grade 1 were subsequently excluded. Pts were treated at 1.0 mg/kg (n = 3), 1.34 mg/kg (n = 5), and 1.88 mg/kg (n = 2); enrollment at 1.88 mg/kg is continuing. Other adverse events (AEs) were grade 1/2 anorexia and pain in 4 pts; diarrhea, rash, fatigue, and neuropathy in 3 pts; and grade 3 rash in 1 pt. Evidence of antitumor activity has been observed. A response of 37% tumor shrinkage was seen in a pt after only 2 cycles and is ongoing. A second pt had a 51% reduction after 2 cycles, but had PD after 12 weeks. Breast tumor samples were more likely to stain positive for GPNMB than normal breast tissues. Conclusions: CR011-vcMMAE 1.34 mg/kg IV q3w is well-tolerated in heavily pretreated pts with MBC. The 1.88 mg/kg q3w dose is being assessed and phase II expansion is planned at the MTD. IHC of pt tumor specimens is being evaluated.

[Table: see text]

Phase II trial of the farnesyltransferase inhibitor tipifarnib plus fulvestrant in hormone receptor-positive metastatic breast cancer: New York Cancer Consortium Trial P6205

BACKGROUND

Fulvestrant produces a clinical benefit rate (CBR) of approximately 45% in tamoxifen-resistant, hormone receptor (HR)-positive metastatic breast cancer (MBC) and 32% in aromatase inhibitor (AI)-resistant disease. The farnesyltransferase inhibitor tipifarnib inhibits Ras signaling and has preclinical and clinical activity in endocrine therapy-resistant disease. The objective of this study was to determine the efficacy and safety of tipifarnib-fulvestrant combination in HR-positive MBC.

PATIENTS AND METHODS

Postmenopausal women with no prior chemotherapy for metastatic disease received i.m. fulvestrant 250 mg on day 1 plus oral tipifarnib 300 mg twice daily on days 1-21 every 28 days. The primary end point was CBR.

RESULTS

The CBR was 51.6% [95% confidence interval (CI) 34.0% to 69.2%] in 31 eligible patients and 47.6% (95% CI 26.3% to 69.0%) in 21 patients with AI-resistant disease. A futility analysis indicated that it was unlikely to achieve the prespecified 70% CBR. Tipifarnib dose modification was required in 8 of 33 treated patients (24%).

CONCLUSIONS

The target CBR of 70% for the tipifarnib-fulvestrant combination in HR-positive MBC was set too high and was not achieved. The 48% CBR in AI-resistant disease compares favorably with the 32% CBR observed with fulvestrant alone in prior studies and merit further clinical and translational evaluation.

The effect of tetrathiomolybdate on circulating endothelial progenitor cells in patients with breast cancer at high risk of recurrence

Abstract #1036

Background: Endothelial progenitor cells are critical to tumor angiogenesis and are increased in breast cancer patients. Copper is required for angiogenesis, and pre-clinical data suggest that tetrathiomolybdate (TM), a copper-depleting compound, inhibits angiogenesis and maintains tumor dormancy. We sought to measure circulating endothelial progenitor cells (CEPCs) in patients at high risk of breast cancer recurrence and to evaluate the effect of copper depletion on CEPCs.&#x2028; Methods: This analysis is part of an ongoing phase II study of TM in breast cancer patients at high risk of recurrence defined as Stage III or IV with no evidence of disease. All therapy other than hormonal was completed at least 6 weeks prior to study. Treatment: TM 180 mg daily to achieve a target ceruloplasmin (Cp) level of 5-15 mg/dL (copper depletion), and then 100 mg daily. We monitored levels of CEPCs (CD45dim, CD133+, VEGFR2+), CEA, CA15-3, and Cp at baseline and monthly. CEPCs were also measured in 6 healthy controls.&#x2028; Results: To date we have enrolled 16 patients with a median age of 51 years (range: 29-64). 14 had a history of Stage III disease, while 2 were considered to be Stage IV with no evidence of disease. The median number of positive lymph nodes among Stage III patients was 7 (1-42), with 2 patients having received neoadjuvant therapy. The median baseline Cp level was 28 mg/dL (21-41). Among 12 patients who have reached target Cp, the median time to target was 1 month (1-3 months). The median follow-up of the 4 patients who have not yet achieved target is 2.5 months. 1 of these discontinued treatment before reaching target. The median baseline CEPCs was lower in patients than healthy controls: 0.022 cells/μL (0.000-0.286) vs. 0.123 cells/μL (0.058-0.418); p=0.03. There was no statistically significant change in CEPCs from baseline over time.&#x2028; One patient was diagnosed with recurrent breast cancer at month 10. A rise in her CEPCs preceded a rise in a CEA and overt relapse by 1 and 5 months, respectively.&#x2028; Toxicity: Grade 3/4 neutropenia occurred in 3 patients. TM was held, and this resolved 5-13 days later, after which TM was resumed. No other grade 3/4 toxicity was observed. One patient discontinued TM due to diarrhea attributed to the lactose used in the compounding of TM.&#x2028; Conclusions: TM is well tolerated in breast cancer patients. We postulate that the increased CEPCs noted in one patient at month 4, 6 months prior to overt relapse, could represent the “turning on” of an angiogenic switch, resulting in an outpouring of CEPCs to the new site of metastasis. The trial is ongoing, and with additional follow-up other trends might emerge.&#x2028; Supported by Komen for the Cure Foundation, Anbinder Foundation, NY Community Trust and Breast Cancer Alliance of Greenwich.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1036.

Kinetics of amoxicillin and clavulanate degradation alone and in combination in aqueous solution under frozen conditions

Kinetics of the reactions of amoxicillin sodium and potassium clavulanate alone and in combination were investigated in the frozen state at selected pH values of 2.0, 4.6 and 7.0. Extrapolation of the rate constant values to the frozen state from the liquid state data indicated marked acceleration of the rates of amoxicillin and clavulanate degradation for the pH values investigated. The highest acceleration in rate recorded was 15.0-fold for clavulanate and the lowest value was 4.6-fold for amoxicillin at -7.3 degrees C in the hydrochloric acid system. The rate constant values obtained were interpreted in terms of the concentration model [Pincock, R.E., Kiovsky, T.E., 1966. Kinetics of reactions in frozen solution. J. Chem. Educ. 43, 358-360], phase-temperature relationship of the solutes, buffer catalysis, pH change and polymerization reactions. A kinetic model was deduced for the hydrochloric acid system providing adequate explanation of the experimental results. A large stabilizing effect of sodium chloride used for maintaining constant ionic strength (micro=0.5) was evident in this system. The shelf-life of amoxicillin was increased from 2.2 to 58.7h at -7.3 degrees C when sodium chloride was included in the hydrochloric acid system.

Phase II study of eribulin mesylate (E7389) halichondrin b analog in patients with refractory breast cancer

1034

Background: Eribulin is a structurally simplified analog of halichondrin B, which inhibits microtubule dynamics via a novel mechanism characterized by suppression of microtubule growth, lack of effect on microtubule depolymerization, and sequestration of tubulin into nonfunctional aggregates. This study was designed to assess the activity and tolerance of eribulin in chemotherapy refractory patients with advanced breast cancer. Methods: Eribulin was evaluated in a single-arm Phase II trial in female patients with refractory breast cancer, ECOG performance status of 0–1, measurable disease, and neuropathy ≤ Grade 2. Patients received ≥ 1 prior chemotherapy regimen, including an anthracycline and a taxane. Eribulin was administered as a 2–5 min IV bolus of 1.4 mg/m2 on Days 1, 8, and 15 of a 28-Day cycle (Group 1). The schedule was modified to Days 1 and 8 of a 21-Day cycle (Group 2), because of dose delays. The primary efficacy endpoint was ORR according to RECIST criteria based upon independent review (IR) of tumor assessment. Results: Of 104 patients enrolled, 103 received eribulin treatment: 70 in Group 1, 33 in Group 2. Median age was 55 yrs (range 32–84). Patients had received a median of 4 prior chemotherapy regimens (range 1–11). Sixty-one percent of tumors were ER+, 14% Her2/neu 3+, and 29% were triple (ER, PR, Her-2) negative. The incidence of dose interruption, delay, or omission during Cycle 1 was 63% (Group 1) and 18% (Group 2). The most common drug related toxicities were neutropenia (75%, Grades 3: 31%, Grade 4: 30%, febrile neutropenia: 3.9%), fatigue (52%, Grade 3: 2.9%, no Grade 4), alopecia (Grade 1/2: 41%), nausea (37%, Grade 3: 1%, no Grade 4), and anemia (36%, Grade 3: 1%, no Grade 4). Peripheral neuropathy occurred in 34% of patients (Grade 3: 3.9%, no Grade 4). Best overall response rate (all PR) by IR was 14.5% and 15.2% in Groups 1 and 2, respectively; the combined ORR was 14.7% (95 % CI: 9–23%). Median PFS was 85 days, and the 6 mo PFS rate was 31%. Conclusions: Eribulin given as a 2–5 min IV infusion on Days 1, 8 of a 21-Day cycle or Days 1, 8, 15 of a 28-Day cycle exhibited a 15% PR rate by IR and a low incidence of Grade 3 neuropathy in this heavily chemotherapy pretreated population. The most common toxicity was neutropenia. The 21-Day schedule had an acceptable toxicity profile.

No significant financial relationships to disclose.

Phase I clinical trial of ixabepilone and pegylated liposomal doxorubicin in patients with advanced breast or ovarian cancers: New York Cancer Consortium Trial P7229

2570

Background: Ixabepilone (IX) is a semisynthetic epothilone B analog with activity in patients (pts) with taxane refractory cancer. Two phase III clinical trials in breast cancer (BC) and a phase II study in ovarian cancer (OC) have recently been completed. Pegylated liposomal doxorubicin (PLD) is used for the treatment of platinum refractory OC and has activity in patients with metastatic BC. Methods: We have completed enrollment of a phase I study of PLD IV and ixabepilone IV over 3 hours. 18 pts with metastatic cancer (10 BC and 8 OC) with median age 51 were enrolled from 1/13/06 to 12/22/06. A total of 60 cycles has been administered to date. 3 OC patients enrolled at dose level 3 have not yet completed 2 cycles of treatment and are not yet evaluable. Results: Dose limiting toxicities (DLT) based on toxicities experienced during the first 2 cycles is provided in the table below. Adverse events (AE) occurring in any cycle were: Grade 4 AE: neutropenia < 7 days (1 pt). Grade 3 AE: palmar plantar erythrodysesthesia (PPE) (4), mucositis (3), infection (2), fatigue (2), neutropenia (2), thrombocytopenia (2), anemia (1), neuropathy (1), bilirubin (1). Non-hematological grade 2 AEs included: mucositis (4), PPE (3), infection (2), neuropathy (2), rash (3), pain (3), fever (1), myalgias (1), and anorexia (1). Responses so far for 10 BC pts are PR (1) SD (3) PD (6) and for 5 OC pts are PR (1) SD (2) PD (2). Updated results will be presented. Conclusions: Although the recommended phase II dose when given every 3 weeks is 30 mg/m2 for PLD and 32 mg/m2 for IX by our criteria, PPE and mucositis became problematic when treatment was continued beyond 2 cycles. We are therefore exploring a 4 week PLD schedule, evaluating IX given either every 4 weeks (as shown) or weekly (on days 1, 8, and 15). A phase II trial of the combination in platinum refractory OC will be initiated upon completion of the phase I. Supported by N01-CM-62204

[Table: see text]

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Randomized trial of low-dose interleukin-2 vs cyclosporine A and interferon-γ after high-dose chemotherapy with peripheral blood progenitor support in women with high-risk primary breast cancer

High-risk primary breast cancer patients treated with high-dose chemotherapy (HDC) and stem cell support (SCS) have shown prolonged disease-free survival (DFS) in many studies; however, only one trial has demonstrated an overall survival benefit (OS). We hypothesize that the period following myeloablative therapy is ideal for immunologic manipulation and studied the effects of two different methods of immunotherapy following HDC with SCS aimed at the window of immune reconstitution. Seventy-two women with high-risk stage II or III breast cancer were randomized following HDC to receive either interleukin 2 (IL-2) at 1 million units/m(2) SQ daily for 28 days or combined cyclosporine A (CsA) at 1.25 mg/kg intravenously daily from day 0 to +28 and interferon gamma (IFN-gamma) 0.025 mg/m(2) SQ every 2 days from day +7 to +28. At a median follow-up of 67 months, no significant difference was observed in DFS or OS between the two treatment groups. The IL-2 arm had a 59% DFS (95% CI (0.45, 0.78)) and a 72% OS (95% CI (0.58, 0.88)) at 5 years. The CsA/INF-gamma arm had a similar outcome with a 55% DFS (95% CI (0.40, 0.76)) and a 78% OS (95% CI (0.65, 0.94)) at 5 years. Treatment was well tolerated, without increased toxicity.

Circulating endothelial progenitor cells correlate to stage in patients with invasive breast cancer

616

Background: Tumor growth and metastasis is dependent on neo-angiogenesis. Both pre-existing and circulating vascular cells have been shown to contribute to the assembly of tumor neo-vessels in specific tumors. Mobilization of endothelial progenitor cells (EPCs) from the bone marrow constitutes a crucial step in the formation of de novo blood vessels, and levels of peripheral blood EPCs have been shown to be increased in certain malignant states. However, the role of circulating EPCs in breast cancer is largely unknown. Methods: We recruited twenty-five patients with biopsy-proven invasive breast cancer (BC) at Weill Cornell Breast Center to participate in a pilot study investigating the correlation of circulating EPCs to extent of disease and initiation of chemotherapy. For each patient, a baseline sample was drawn before systemic treatment, and for seventeen of those patients, a second sample was taken after the first round of chemotherapy. Levels of peripheral blood EPCs, as defined by co-expression of CD133 and VEGFR2, were quantified by flow cytometry. Results: BC patients with stage III & IV disease had statistically higher levels of circulating EPCs than did patients with stage I & II disease (median=165,000 EPCs/5×106MNCs vs. median=6,920 EPCs/5x106MNCs, respectively, p < 0.0001 by Wilcoxon rank-sum test). In addition, in late-stage patients, levels of EPCs demonstrated a statistically significant drop after initiation of chemotherapy (median=162,500 EPCs/5x106MNCs [pre] vs. median=117,500 EPCs/5x106MNCs [post], p = 0.01 by Wilcoxon signed-rank test). Conclusion: These results suggest that circulating EPCs may serve as a potential tumor biomarker in breast cancer and that EPCs may represent a plausible target for future therapeutic intervention. Supported in part by the Mentored Medical Student in Clinical Research Program (General Clinical Research Center/National Institutes of Health Grant M01RR00047), Madeline & Stephen Anbinder Clinical Scholar Award, and Anne Moore Breast Cancer Research Fund

No significant financial relationships to disclose.