Abstract PD1-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Cortes J, Martin M, Pernas S, Gomez Pardo P, Lopez-Tarruella S, Gil-Martin M, Manso L, Ciruelos E, Perez-Fidalgo JA, Hernando C, Ademuyiwa FO, Weilbaecher K, Mayer I, Pluard TJ, Martinez Garcia M, Vahdat L, Wach A, Barker D, Romagnoli B, Kaufman PA. Withdrawn [abstract].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 PD1-02.

Abstract OT3-06-01: SHERBOC: A double-blind, placebo-controlled, phase 2 trial of seribantumab (MM-121) plus fulvestrant in postmenopausal women with hormone receptor-positive, heregulin positive, HER2 negative metastatic breast cancer whose disease progressed after prior systemic therapy

Background: The receptor tyrosine kinase, HER3 and its ligand, heregulin (HRG), have been implicated in the initiation and progression of multiple cancer types including: breast, lung, and head & neck cancers. Seribantumab is a fully human, monoclonal IgG2 antibody that binds to the ligand-binding domain of HER3 and inhibits HRG-mediated signaling. Previously, seribantumab was tested in combination with exemestane in a placebo-controlled, Phase 2 study in post-menopausal women with ER/PR+, HER2 negative metastatic breast cancer (mBC). Although the trial failed to meet its primary efficacy objective of a 50% reduction in hazard ratio in the seribantumab/exemestane treatment vs. the placebo/exemestane control group, a positive trend in PFS and a statistically significant improvement in median OS was observed in patients in the seribantumab/exemestane treatment group. Seribantumab has also been tested in three randomized Phase 2 studies adding to standard of care (SOC) in non-small cell lung, ER/PR+ mBC, and platinum resistant/refractory ovarian cancer. These studies were retrospectively analyzed to determine correlation between HRG mRNA levels in tumor tissue and PFS. In each of these studies, the presence of tumor cell HRG mRNA was prognostic for shortened PFS with SOC treatment. Further, the addition of seribantumab to SOC therapy improved PFS for patients with HRG+ tumors. These data support the hypothesis that HRG expression may define a drug tolerant cancer cell phenotype characterized by poor response to multiple classes of cytotoxic and targeted therapies, including aromatase inhibitors and SERDs. Additionally, blockade of HRG-induced HER3 signaling by seribantumab may counter such protective effects of HRG on cancer cells, with the potential for improved outcomes in HRG+ patients. It is estimated that ˜45% of hormone-receptor positive, HER2 negative advanced breast cancers are HRG+ and that HRG expression may contribute to accelerated clinical progression observed in this subset of patients.

Trial design: In the upcoming randomized, double-blinded, multi-center, Phase 2 study, ER/PR receptor-positive, HER2 negative mBC patients with HRG+ tumors will be prospectively selected using a HRG RNA in situ hybridization assay. Approximately 200 women will be screened to enroll 80 HRG+ subjects. Eligible subjects will be randomized in a 1:1 ratio to receive seribantumab/fulvestrant or placebo/fulvestrant until investigator-assessed disease progression or unacceptable toxicity, whichever comes first. Subjects will have progressed on one or two prior hormonal therapies, one of which must have been a CDKi-containing regimen. The goal of this study is to determine if the combination of seribantumab + fulvestrant is more effective than placebo + fulvestrant based on PFS (primary end point) in HRG positive subjects. Secondary endpoints include OS, objective response rate, and time to progression. Safety will also be assessed. Enrollment is expected to begin in 2017 at approximately 80 sites globally.

Citation Format: Kaufman PA, Pipas M, Finn GJ, Mathews SE, Zhang H, Richards J, Kudla AJ, Bloom T, Zalutskaya AA, Llorin-Sangalang J, Pinto AC, Ettl J. SHERBOC: A double-blind, placebo-controlled, phase 2 trial of seribantumab (MM-121) plus fulvestrant in postmenopausal women with hormone receptor-positive, heregulin positive, HER2 negative metastatic breast cancer whose disease progressed after prior systemic therapy [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 OT3-06-01.

Abstract P5-08-27: Treatment patterns and clinical outcomes in patients with hormone receptor (HR)+ HER2+ metastatic breast cancer and low vs high levels of HR positivity from the SystHERs Registry

Introduction In 2010, the cutoff for HR positivity in breast cancer was established as ≥1% of cells staining HR+, previously having varied from 1% to 10%. The impact of this change on treatment patterns and outcomes is poorly understood. SystHERs is a prospective, observational cohort registry of patients (pts) with HER2+ metastatic breast cancer (MBC) that commenced enrollment in 2012. To our knowledge, SystHERs is the largest registry to collect and analyze data for the HER2+ subgroup. We report baseline characteristics, treatment patterns, and early outcomes by %HR+ (1–9% vs 10–100%).

Methods SystHERs enrolled pts aged ≥18 years and within 6 months of HER2+ MBC diagnosis. For pts with locally-determined HR+ disease, defined as HR+ in primary or metastatic tissue, %HR+ is the highest percentage of ER+ or PR+ tissue in early breast cancer or MBC. The percentage of ER+ or PR+ cells was not reported for pts considered HR– by the investigator. Median overall survival (OS; Kaplan–Meier) and hazard ratios (Cox regression) were estimated.

Results As of Feb 1, 2016, data were available for 872 eligible pts with known HR status, of whom 608 (70%) had HR+ disease. Of the 608 pts, 53 (9%) had 1–9%HR+ and 496 (82%) had 10–100%HR+; %HR+ was not reported for 59 pts. Baseline characteristics were similar between %HR+ subgroups (Table 1).

As shown in Table 2, the 1–9%HR+ subgroup was less likely to receive first-line hormonal therapy (26%) than the 10–100%HR+ subgroup (56%). 87% and 79% of pts received chemotherapy, respectively.

Median time from MBC diagnosis was 16.5 months (range, 0.4–49.4 months). Median OS was not reached at the data cutoff. The number of deaths was 13 (25%) in the 1–9%HR+ subgroup, and 68 (14%) in the 10–100%HR+ subgroup (log-rank P=0.025). The OS hazard ratio (0.514, 95% CI 0.283–0.931) favored the 10–100%HR+ subgroup. OS did not differ significantly between pts with 1–9%HR+ vs HR– disease (log-rank P=0.582, hazard ratio 1.185, 95% CI 0.647–2.169).

Table 1. Baseline characteristics 1-9%HR+ (n=53)10-100%HR+ (n=496)HR– (n=264)Age at MBC diagnosis, median yrs (range)54 (30–86)57 (21–86)55 (28–88)Race, %   White838372Black151320Premenopausal, %282522ECOG performance status, %   04654441463942≥2878MBC diagnosis type, %   De novo404958Recurrent605142Visceral, %*686275*Non-hepatic abdominal, ascites, CNS, liver, lung, or pleural effusion sites of metastasis

Table 2. First-line treatment 1-9%HR+ (n=53)10-100%HR+ (n=496)HR– (n=264)HER2-targeted therapy, %969391Chemotherapy, %877989Hormonal therapy, %26564

Conclusions These preliminary observational data suggest potential differences in treatment patterns and survival outcomes in low vs moderate/high HR+ expressers, with the former being less likely to receive hormonal therapy (26% vs 56%). Furthermore, low HR positivity was associated with poorer OS and was similar to OS observed in pts with HR– disease.

Citation Format: Jahanzeb M, Tripathy D, Rugo H, Swain S, Kaufman PA, Mayer M, Hurvitz S, O'Shaughnessy J, Mason G, Yardley DA, Brufsky A, Chu L, Antao V, Beattie M, Yoo B, Cobleigh M. Treatment patterns and clinical outcomes in patients with hormone receptor (HR)+ HER2+ metastatic breast cancer and low vs high levels of HR positivity from the SystHERs Registry [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-27.

Abstract P3-05-03: Estrogen receptor alpha reactivation for the treatment of anti-estrogen-resistant breast cancer

Adjuvant anti-estrogen therapies that antagonize ER transcriptional activity have improved outcome in many patients, yet resistance to anti-estrogen therapies is common, resulting in disease recurrence in 1/3 of patients within 15 years of follow-up. However, prior to the introduction of tamoxifen, estrogens were used for treatment of breast cancer with response rates similar to those obtained by anti-estrogens in the advanced setting. Similarly, withdrawal of anti-estrogen therapy has shown anti-tumor effects, indicating that reactivation of ER may elicit therapeutic benefit.

MCF-7 cells with long-term (>1 yr) acquired resistance to the selective ER downregulator fulvestrant (fulv; MCF-7/FR) retain ER expression and harbor ESR1 (ER) gene amplification. Upon withdrawal of fulv, these cells re-engage ER as demonstrated by increased luciferase transcriptional reporter activity and re-expression of proteins encoded by ER-inducible genes. Following fulv withdrawal, MCF-7/FR cells show drastically decreased proliferation and increased apoptosis that are temporally correlated with ER reactivation. Protein levels of the anti-senescence protein FoxM1 decline following ∼12 d of fulv withdrawal, paralleled by increased staining for senescence-associated β-galactosidase. Transcriptomic analyses confirmed that fulv withdrawal progressively induces gene expression patterns indicative of stress and senescence. Similar effects were observed in long-term estrogen-deprived (LTED) MCF-7 cells treated with 17b-estradiol. Prospective studies characterizing the development of acquired anti-estrogen resistance have demonstrated the MCF-7 cells at 9 months of fulv resistance do not respond to fulv withdrawal, contrasting the long-term (>1 yr) MCF-7/FR cells. Additionally, withdrawal of fulv from T47D/FR, ZR75-1/FR, or HCC-1428/FR cells did not induce cell death or re-engage ER activity, confirming that ER reactivation is required for anti-cancer effects. Ongoing studies are characterizing the temporal changes in ER transcriptional activity during 1) development of acquired anti-estrogen resistance, and 2) 17b-estradiol treatment of mice bearing WHIM16 patient-derived xenografts (regress in response to 17b-estradiol) to elucidate the mechanism underlying sensitivity of anti-estrogen resistant cells to ER reactivation.

While estrogen therapies have shown clinical efficacy for decades, biomarkers to identify patients with tumors likely to respond to estrogen remain undefined. We are conducting a Phase II clinical trial [Pre-emptive OsciLLation of ER activitY levels through alternation of estradiol/anti-estrogen therapies prior to disease progression in ER+/HER2- metastatic breast cancer (POLLY); NCT02188745] that will use tumor biopsy tissues to identify baseline and pharmacodynamic biomarkers that predict response to 17b-estradiol therapy.

Citation Format: Hosford SR, Kaufman PA, Miller TW. Estrogen receptor alpha reactivation for the treatment of anti-estrogen-resistant breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-05-03.

Abstract P5-08-13: Tumor infiltrating lymphocytes and pathological response are prognostic biomarkers in inflammatory and non-inflammatory breast cancer

Background: Tumor-infiltrating lymphocytes (TILs) have been associated with pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) as well as disease-free (DFS) and overall survival (OS) in certain breast cancer subtypes. pCR has been shown to be predictive of long-term outcome in several neoadjuvant studies and is therefore a potential surrogate marker for patient outcome. The aim of this study was to determine whether TILs and pCR can be used as a prognostic biomarker in inflammatory and non-inflammatory breast cancer.

Materials and Methods: Stromal lymphocytic infiltration (strTILs), defined as the percentage of tumor stroma containing infiltrating lymphocytes (lymphocyte predominant breast cancers (LPBC) cut-off: ≥50%), and pCR, defined as the absence of any residual invasive cancer on the resected breast specimen and all sampled ipsilateral lymph nodes following completion of NACT, were evaluated in 383 (221 Inflammatory (IBC) and 162 non-IBC Locally-advanced (LABC)) breast cancer patients. Tumors were categorised into molecular subtypes and Ki-67 status based on immunohistochemistry. Correlations with clinico-pathological variables, breast cancer-specific (BCSS) and disease-free survival (DFS) were made.

Results: strTILs were present in all patients (median: 15%, IQR: 5% to 30%). There was no difference in the frequency of strTILs between IBC and LABC cases. Thirty three (15%) IBC and 18 (11%) LABC tumors were LPBC. strTILs were significantly more frequent in triple negative (TNBC) (median, 25%) than in HER2+, Ki-67-high (15% for both) and ER/PR+ (10%)(p<0.001; Kruskal-Wallis One Way Analysis of Variance on Ranks). There was a significant association of strTILs with pCR (p<0.001). strTILs median was 27.5%, 15% and 10% for pCR, partial response and no response, respectively (p<0.001). pCR was obtained in 4 (9.1%) of patients with strTILs <10%, in 25 (56.8%) of patients with strTILs between 10 and 40% and in 15 (34.1%) of patients with strTILs >40% (p=1.09E5). strTILs did not predict either DFS or BCSS in the overall breast cancer population. pCR was negatively associated with ER+ (p=0.002), positively with TN (p=0.02) and strongly associated with both DFS & BCSS (p<0.0001, for both). Multivariate analysis showed that, in IBC patients, pCR (p<0.0001) and lymph node rate (p=0.034) were independent predictors for DFS and pCR (p<0.0001), lymph node rate (p=0.034) and LPBC (p=0.024) were independent predictors for BCSS. In LABC, DFS was independently predicted by pCR (p<0.0001) and LPBC (p=0.042) and BCSS by pCR (p<0.0001), LPBC (p=0.005) and ER (p=0.029). LPBC was associated with negative outcome in both IBC and LABC cases.

Conclusion: strTILs showed a strong association with TNBC tumors and with pCR. pCR is a strong prognostic factor for both IBC and LABC. The negative association of LPBC with outcome is unexpected and warrants additional studies.

Citation Format: Kaufman PA, Arias-Pulido H, Colpaert C, Chaher N, Qualls C, Marotti JD, Vermeulen P, Dirix L, van Laere S, Kuppusamy P. Tumor infiltrating lymphocytes and pathological response are prognostic biomarkers in inflammatory and non-inflammatory breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-13.

Abstract P1-12-05: Phase 2 study of dose-dense doxorubicin and cyclophosphamide followed by eribulin mesylate with or without prophylactic growth factor for adjuvant treatment of early-stage breast cancer

Background: Eribulin has demonstrated antitumor activity and significantly improved overall survival (OS) in patients (pts) with heavily pretreated locally advanced/metastatic breast cancer (BC). This trial assessed the feasibility of eribulin as adjuvant therapy following dose-dense doxorubicin and cyclophosphamide (AC) for pts with human epidermal growth factor receptor 2 (HER2)-negative early-stage BC.

Methods: Pts with HER2(-), stage I–III, invasive BC were enrolled. Pts received dose-dense AC (doxorubicin 60 mg/m2 IV and cyclophosphamide 600 mg/m2 IV) on D1 of each 14-day cycle for 4 cycles with pegfilgrastim, followed by 4 cycles of eribulin (1.4 mg/m2 IV) on D1 and D8 every 21 days. Pts were divided into 2 cohorts: Cohort 1 did not receive any prophylactic growth factor (GF); Cohort 2 received a short course of prophylactic GF (filgrastim) on days 3, 4, 10, and 11 of each eribulin cycle. Primary endpoint of feasibility was determined as %pts who completed eribulin portion of the regimen without a dose delay (>2 days) or reduction due to eribulin-related adverse event (AE). Based on similar previous studies, the target for feasibility was 80%. Relative dose intensity of eribulin and toxicities were also summarized by cohort. Exploratory objectives include efficacy endpoints of 3-yr disease-free survival and OS.

Results: We report data from 81 pts (55 Cohort 1; 26 Cohort 2) enrolled in the study, of whom 88% completed study treatment. Pt characteristics include median age 49 yrs (range 26–69), ECOG status 0 (85%), BC stages 1/2/3 (21%/57%/22%). Of 90% (73/81) pts evaluable for feasibility, 27% and 40% of pts in Cohorts 1 and 2, respectively, had dose delay or reduction during eribulin treatment, indicating the primary endpoint was not met. Overall, results were similar between the 2 cohorts (Table). Median duration of treatment with eribulin was 10.14 weeks in both cohorts (vs 10 weeks planned). Most eribulin-related dose delays were due to grade 3 (n=18) or grade 4 (n=7) neutropenia. Non-fatal serious AEs were observed in 11% of pts in Cohort 1 and 15% in Cohort 2. Discontinuations due to AEs occurred in 6% of pts in Cohort 1 and 0 in Cohort 2. Neutropenia (all grades) was reported in 36% of pts in Cohort 1 and 42% in Cohort 2. Most common AEs (all grades) were fatigue (96%), nausea (75%), alopecia (73%), hot flush (63%), and constipation (57%).

 ACEribulin Cohort 1*Cohort 2*Cohort 1 (without GCSF)Cohort 2 (with GCSF)Relative dose intensity, mean99.5%99.0%92.0%90.9%Completed all planned doses98.2%96.2%87.0%84.0%Dose modification†12.7%15.4%35.2%40.0%GCSF, granulocyte-colony simulating factor. *With pegfilgrastim 6 mg given subcutaneously on D2 of each AC cyle; † including dose delays (>2 days)/reduction/interruptions, missing, and permanent discontinuation due to AE.

Conclusions: The primary study endpoint of >80% feasibility of planned dose delivery without any dose delays or reduction was not met. However, adjuvant treatment with dose-dense AC-eribulin was given safely, with two-thirds (67%) of pts achieving full dosing with no dose delay or reduction. Investigation into alternative dosing schedules or GF support is recommended.

Citation Format: Cadoo K, Kaufman PA, Hudis C, Chang C, Berrak E, Song J, Seidman AD, Traina TA. Phase 2 study of dose-dense doxorubicin and cyclophosphamide followed by eribulin mesylate with or without prophylactic growth factor for adjuvant treatment of early-stage breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-12-05.

Abstract P3-13-04: Effect of age on tolerability and efficacy of eribulin and capecitabine in patients with metastatic breast cancer treated in study 301

Background:

The Phase III trial (NCT00337103) compared eribulin (E) with capecitabine (C) in patients (pts) with metastatic breast cancer (MBC) in the 1st-, 2nd-, and 3rd-line setting. Median overall survival (OS) was 15.9 and 14.5 months (HR 0.88; 95% CI 0.77, 1.00; P = 0.056) and median progression-free survival (PFS) was 4.1 and 4.2 months (HR 1.08; 95% CI 0.93, 1.25; P = 0.30) for E and C, respectively. This analysis compares toxicity and efficacy of E and C in relation to age.

Material and methods:

In this post-hoc exploratory analysis, the effect of age on the incidence of adverse events (AEs), OS, PFS, and objective response rate (ORR) with E and C were analyzed for two age groups: ≤65 years (E, n = 468; C, n = 491) and >65 years (E, n = 86; C, n = 57). For OS and PFS, analyses were stratified by HER2 and geographic region.

Results:

With increasing age, the proportion of pts with worse performance status (PS ≥1: 54.5% vs 69.2% for ≤65 and >65 years, respectively), ER+ (47.4% vs 57.3%), and PgR+ MBC (41.3% vs 45.5%) increased, and the proportion with triple-negative MBC decreased (26.6% vs 20.3%). With both treatments, AEs were reported in a higher proportion of pts in the older age group, this becoming more apparent for grade 3+ AEs (E: 64.6% vs 70.2%, and C: 45.0% vs 54.4% for ≤65 and >65 respectively). With E, there was a trend for increased incidence of grade 3/4 neutropenia (45.0% vs 50.0%) and leukopenia (13.7% vs 22.6%) but, in contrast, decreased peripheral sensory neuropathy (3.9% vs 1.2%) with increasing age. For C, there was a trend for increased palmar-plantar erythrodysethesia syndrome (total: 44.4% vs 50.9%; grade 3/4: 14.1% vs 17.5%), and grade 3/4 fatigue (1.8% vs 7.0%) and diarrhea (4.7% vs 10.5%) with increasing age; emesis and nausea were similar for both age groups. Dose adjustments due to AEs with E were slightly higher in the older age group: withdrawals 7.4% vs 10.7%; dose reductions 31.1% vs 36.9%; and dose delays 30.9% vs 36.9%. With C, there was a trend for an increased incidence of withdrawals (9.2% vs 21.1%) and dose delays (34.2% vs 49.1%) due to AEs with increasing age: the incidence of dose reductions was slightly higher in the older age group (31.3% vs 36.8%). In an unadjusted analysis, a trend for improved OS with E vs C was observed in both subgroups (≤65 years: median 15.8 vs 14.5 months; HR 0.90; 95% CI 0.78, 1.04; P = 0.16, and >65 years: median 18.4 vs 14.1 months; HR 0.74; 95% CI 0.50, 1.12; P = 0.16). PFS and ORR for E and C were: median PFS: E, 4.0 and 5.4 months; C, 4.2 and 5.9 months; ORR: E, 10.9% and 11.6%; C, 11.6% and 10.5%, in the ≤65 and >65 groups respectively.

Conclusions:

This exploratory and unadjusted analysis suggests a trend for improved OS with E in both younger and older pts with MBC. With both treatments there was a suggestion that AEs were reported in a higher proportion of pts in the older age group, this becoming more apparent for grade 3+ events. Specifically, these data suggest an increased incidence of grade 3/4 diarrhea, dose delays, and study withdrawal due to AEs in pts treated with C, and potentially suggest that with E there may be less difference between the AE profile in younger vs older pts than with C.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-13-04.

Abstract P2-05-06: Quantitative measurement of HER2 expression in breast cancers: comparison with “real world” HER2 testing in a multi-center Collaborative Biomarker Study (CBS) and correlation with clinicopathological features

Background: Accurate determination of HER2 status is critical in determining appropriate therapy for breast cancer patients. The HERmark® assay is a novel method to quantitatively measure HER2 total protein expression (H2T) in breast cancer. In this study, we compared HERmark H2T with central laboratory HER2 retesting and local (site reported) HER2 testing of formalin-fixed, paraffin-embedded (FFPE) breast cancer tissues. The quantitative total HER2 measurements (H2T) by HERmark and results of local HER2 tests were correlated with tumor pathohistological characteristics and overall survival of breast cancer patients.

Methods: 232 FFPE breast cancer tissues were provided by 11 CBS study sites for HER2 testing by the HERmark assay and central laboratory IHC re-testing performed in blinded fashion. Local HER2 immunohistochemistry and/or fluorescence in situ hybridization (FISH) results and valid HERmark H2T and central HER2 IHC results were obtained in 192 cases for analysis.

Results: H2T showed a significant correlation with central HER2 IHC staining intensity (P < 0.0001). The concordance rates of positive and negative HERmark status (excluding equivocal) with those of local HER2 status determined by the CBS sites, and with those of central HER2 IHC status were 84% (Kappa = 0.68) and 96% (Kappa = 0.91), respectively. Higher H2T levels significantly correlated with higher tumor grade (p = 0.007) and negative ER/PR status (p = 0.002). Twenty-six (14%) cases showed discordant (conversion of negative and positive) results between local HER2 status and HERmark status. Of the discordant cases, HERmark significantly agreed with H-score of central HER2 IHC retesting (p = 0.014), as compared with local HER2 status. The concordant negative group (local HER2 negative/H2T low) demonstrated better overall survival (OS) (HR = 0.198, p = 0.0001), compared to that of concordant positive group (local HER2 positive/H2T high). The concordant negative group also showed better OS than that of discordant local HER2 negative/H2T high group (HR = 0.065, p = 0.0003), but showed no significant difference in OS as compared to that of discordant local HER2 positive/H2T low group (HR = 1.774, p = 0.499).). In 24 cases (13%) considered to be “triple negative” by local HER2, ER and PR testing, HERmark re-classified 4 cases (17%) as HER2 positive.

Conclusions: H2T by HERmark yields a continuum of quantitative HER2 protein measurements that shows an excellent correlation with central HER2 IHC retesting and confirms the known correlations between HER2 expression with tumor grade and ER/PR status. OS results of concordant HER2 positive or negative groups (between local HER2 testing and HERmark H2T) confirmed that HER2 positive patients (excluding adjuvant trastuzumab therapy) have worse OS than patients with HER2 negative disease. However, in the HERmark and local HER2 discordant groups, OS appeared to track better with H2T by HERmark and not with the local HER2 status. Novel quantitative HER2 measurements may identify patients with false (+) and (−) HER2 status by local HER2 testing and may provide added clinical value to routine “real world” HER2 testing.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-06.

PD05-03: Impact of Quantitative Measurement of HER2, HER3, HER4, EGFR, ER and PTEN Protein Expression on Benefit to Adjuvant Trastuzumab in Early-Stage HER2+ Breast Cancer Patients in NCCTG N9831

Background: Prediction of benefit from trastuzumab in patients (pts) with HER2+ breast cancer remains an important goal. We sought to investigate the predictive value of quantitative measurement of HER2, HER3, HER4, EGFR, ER and PTEN protein expression on the benefit of trastuzumab in the phase III HER2+ adjuvant N9831 study for pts randomized to chemotherapy alone (Arm A) or chemotherapy with sequential (Arm B) or concurrent trastuzumab (Arm C).

Methods: For each marker, we evaluated quantitative expression, relationship with demographic data, and association with disease-free survival (DFS) of pts. Freshly cut tissue microarray slides with up to three-fold redundancy per specimen from the N9831 cohort were treated identically using the AQUA (Camp, et al; Nat Med 2002, JCO 2008) method of quantitative immunofluorescence for each marker. HER2 was tested with CB11 (mouse monoclonal, Biocare, Inc.) and preliminary results were available for 698 of nearly 1400 pt specimens to be tested. The minimum value per pt was used in statistical analysis. Specimens were classified with high versus low expression based on a median value cutpoint for each marker. Median follow-up was 7.0 yrs.

Results: Quantitative HER2 was compared with centrally performed HER2 testing by IHC and FISH. Median quantitative HER2 via AQUA was 10,017 units for the HER2 IHC 3+ group (n=607) versus 1058, 831, and 970 for the HER2 IHC 2+ (n=68), 1+ (n=11), and 0 (n=11) groups, respectively. The Spearman correlation between quantitative HER2 and FISH HER2/CEP17 ratio was 0.32 (p<0.001). High quantitative HER2 was associated with lower percentage of hormone receptor positivity (48% vs 59%, chi-sq p=0.003) but not associated with age, race, nodal positivity, tumor histology, grade, or size. High HER2 did not impact DFS in any arm of the study (See Table). Data for additional HER2 testing, HER3, HER4, EGFR, ER and PTEN are in process and will be ready by September, 2011.

Conclusions: Similar to results based on standard HER2 testing by IHC and FISH in N9831, quantitative HER2 did not impact benefit from adjuvant trastuzumab. Results for additional markers will be presented. Our complete quantitative results for a second epitope on HER2, HER3, HER4, ER and EGFR will be the first report of these markers in a large patient cohort in the adjuvant setting.

Disease Free Survival

P1-08-22: Treatment Patterns and Clinical Outcomes in Elderly Patients with HER2−Positive Metastatic Breast Cancer from the registHER Observational Study

Background: Data are lacking regarding treatment patterns and outcomes in elderly patients (pts) with HER2−positive (HER2+) metastatic breast cancer (MBC).

Methods: registHER is a large, observational cohort of pts with HER2+ MBC diagnosed within 6 months of enrollment. Pts (N=1,001) were followed until death, disenrollment, or June 2009 (median follow-up 27 months). In these analyses, pts were stratified into three groups based on age at MBC diagnosis: younger (<65 years), older (65-74 years), elderly (≥75 years). For Progression Free Survival (PFS) and Overall Survival (OS) analyses of 1st-line trastuzumab (T) vs. no T, older and elderly pts were combined due to small number of events in elderly. Hierarchical multivariate analyses were adjusted for baseline characteristics and treatments.

Results: ER/PR status was similar across age groups (Table 1). Elderly pts with HER2+ MBC had higher rates of underlying cardiovascular disease (CVD) than younger or older pts. In pts receiving T-based 1st-line treatment, elderly pts were less likely to receive chemotherapy (C), and more likely to receive T alone or combined with hormone therapy (HT). Central nervous system (CNS) events decreased with increasing age. In T-treated pts, incidence of left ventricular dysfunction (grade ≥3) was higher in elderly pts (3/63 [4.8%]) than in younger (21/746 [2.8%]) or older pts (2/134 [1.5%]). Across age groups, unadjusted median PFS (months) was significantly higher for pts treated with T in 1st-line than those who were not (<65 years T: 11.0; <65 years no T: 3.4; ≥65 years T: 11.7; ≥65 years no T: 4.8). In pts <65 years, unadjusted median OS (months) was significantly higher in T-treated pts; in pts ≥65 years, median OS was similar (<65 years T: 40.4, <65 years no T: 25.9; ≥65 years T: 31.2, ≥65 years no T: 28.5). In multivariate analyses, T in 1st-line was associated with significant improvement in PFS across age (Table 2). In OS, significant improvement was observed for pts <65 years; results were suggestive for pts ≥65 years.

Conclusions: Elderly pts (≥75 years) with HER2+ MBC in registHER had higher rates of underlying CVD than younger counterparts and received less aggressive treatment, including less 1st-line T. These population-based, real-world data suggest improved PFS with T as 1st-line therapy across all age groups.

P2-12-02: Correlation between BMI and Clinical Outcome of Patients with Early Stage HER2+ Breast Cancer from the N9831 Clinical Trial

Background

Obesity, as defined by body mass index (BMI), has been associated with increased recurrence rate, shorter DFS and increased death rates due to breast cancer (BC). Most of the studies to date have examined the relationship of BMI and DFS in patients with hormone receptor positive disease. To our knowledge, BMI and its relationship with outcome in early stage HER2 positive breast cancer has not previously been examined. The N9831 is a large phase III trial testing the role of trastuzumab in the adjuvant setting of high risk patients with early stage HER2+ BC. We hypothesized that the occurrence of overweight and obesity may correlate with outcome.

Methods: This analysis presents BMI and its relation to tumor characteristics and DFS in patients (pts) enrolled in the N9831 clinical trial. Pts were categorized as normal weight, overweight or obese using the WHO BMI classification parameters of < 25%, 25–29% and ≥ 30% respectively. For patient characteristics, patients were grouped into non-obese (BMI< 30) and obese (≥ 30) cohorts. DFS was estimated by the Kaplan-Meier method. Comparisons between arms A (chemotherapy alone), B (chemotherapy plus sequential trastuzumab) and C (chemotherapy plus concurrent trastuzumab) were performed using the Cox proportional hazards model, stratified by BMI.

Results: Analysis was completed on 3,017 eligible pts. Obese pts were more likely to be older and postmenopausal (p<0.0001 for both). There was no significant association between BMI and ER/PR status (p=0.07) or histologic tumor grade (p=0.33). Obese pts were found to have significantly larger tumors ≥ 2 cm (p=0.002) and more positive lymph nodes (p=0.02). There was no significant difference in DFS within each intrinsic arm (A, B and C) between the obese and non-obese pts at 3, 5 or 7 yrs of follow up. However, pts in the non-obese group had significantly improved DFS in arm B and C compared to arm A (p=0.001 and p<0.0001 respectively). Also obese pts in arm C had significantly improved DFS compared to obese pts in arm A (p=0.008). There was a trend of improved DFS in the obese group in arm B compared to arm A, but this was not statistically significant (p=0.09). Pts in the normal weight and overweight groups did significantly better in arm B (p=0.02 for both) and arm C (p=0.01 and p=0.002 respectively) compared to arm A.

Conclusions: This analysis of data from the N9831 study confirms that obese pts with early stage HER2+ tumors have worse clinical outcome than pts with BMI < 30%. Adjuvant trastuzumab improved clinical outcome regardless of BMI. This study supports weight loss intervention for obese women with early stage HER2+ BC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-02.

P1-07-02: Discordance between Central and Local Laboratory HER2 Testing from a Large HER2−Negative Population in VIRGO, a Metastatic Breast Cancer Registry

Background: HER2 overexpression is associated with unfavorable prognosis and is reported in 18–25% of breast cancers (BC). HER2 testing is often performed using immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). Because of the significant benefit of HER2−directed therapies, it is critical to accurately identify women whose tumors are HER2+. Reports have noted discordance between HER2+ test results from local vs. large reference labs in patients with HER2+ BC evaluated for trastuzumab-based clinical studies. There are little published data on central testing of BC found to be negative locally.

Patients and Methods: VIRGO is an observational cohort of N=1,287 women with primarily HER2−negative metastatic BC. An optional tissue collection substudy was conducted, and 776 patient samples were received and centrally retested. Central testing was performed at 2 reference labs and tumors were deemed HER2+ if IHC 3+ and/or FISH positive (HER2:CEP17 ratio ≥2.0). Tumors with unknown/missing local HER2 status (n=68) were excluded from primary analyses. Number of patients potentially affected based on BC incidences from the American Cancer Society (ACS) 2011 estimates and the World Health Organization (WHO) 2008 report were calculated. Testing on the remainder of the HER2−negative cohort is in process.

Results: Central retesting has been performed on tumor samples from n=373 patients to date: HER2−negative locally evaluable tumors (n=301), n=4 HER2−negative locally with no evaluable tumor, and HER2 unknown (n=68). A total of 301 unique patient samples were included in the primary analysis. Of these, 15 (4.98% [95% CI (2.7%, 7.9%)] were found to be HER2+ by central testing (Table). Based on sensitivity analyses assuming all 68 tumors with unknown HER2 status to be negative locally, 4.07%(15 /369) would be centrally HER2+.

Benefit of adjuvant trastuzumab in breast cancer patients with focal HER2 amplified clones: Data from N9831 Intergroup Adjuvant Trial

520

Background: Targeted therapy using trastuzumab (an anti-HER-2 receptor monoclonal antibody) has significantly improved survival in breast carcinoma patients (pts), but determining which pts will respond to this therapy remains a challenge. We previously reported (Miller DV, ASCO 2004 abstract #568) a subset of pts with breast cancers demonstrating focal HER-2 amplified clones (FHAC) amidst otherwise nonamplified tumor cells by fluorescence in-situ hybridization. These accounted for 21% of the HER-2 amplified but immunohistochemistry (IHC) negative cases and 30% of the HER-2 amplified but IHC equivocal cases. The clinical significance of this phenomenon was unclear at that time. We now report the disease-free survival (DFS) data on 91 FHAC pts with a comparison to the diffusely amplified (DA) cases in this trial group. Methods: Breast tumors were evaluated for HER-2 gene amplification using PathVysion™. FHAC cases demonstrated 2–40% of cells with >10 HER-2 signals and HER-2:CEP17 ratio >5.0, regardless of the overall HER-2:CEP17 ratio. Patient and disease characteristics were compared using chi-square tests. Cox regression models compared DFS between pts randomized to arms A (standard chemotherapy) and C (standard chemotherapy with concurrent trastuzumab) within 91 FHAC and 1571 DA cases. Median follow up was 4.0 years. Results: Age, race, menopausal status, surgical procedure, nodal status, histologic type and grade, and tumor size, were not significantly different between pateints with FHAC and DA. Pateints with FHAC had more frequent hormone receptor positivity compared to DA cases (66% vs 50%; p = 0.004). Hazard ratios between pts with FHAC and DA showed that both groups of pts had similar DFS (A: HR = 0.86, p = 0.65; C: HR = 0.72, p = 0.57). Hazard ratios between arms within FHAC and DA groups demonstrated similar benefit from trastuzumab in each group (FHAC: HR = 0.50, p = 0.30; DA: HR = 0.59, p < 0.0001). Results remained consistent when including hormone receptor status in the model. Conclusions: Based on a small number (n = 91) of pts with FHAC, benefit from trastuzumab appears to be similar whether the population of HER-2 amplified cells with breast carcinomas is focal or diffuse.

[Table: see text]

Phase 1b study of motesanib diphosphate (AMG 706) in combination with paclitaxel or docetaxel for the treatment of locally recurrent, unresectable or metastatic breast cancer

Abstract #4117

Background: Motesanib is a novel oral angiogenesis inhibitor designed to selectively target the tyrosine kinase activity of VEGF 1, 2 and 3; PDGF and Kit receptors. Here we report safety, preliminary efficacy and pharmacokinetics (PK) from an ongoing phase 1b dose-finding study of motesanib plus either paclitaxel (P) or docetaxel (D) in patients (pts) with advanced breast cancer.&#x2028; Methods: Eligible pts with ECOG 0 or 1 and ≤1 prior chemotherapy regimen for metastatic breast cancer received (until toxicity or disease progression) escalating doses of motesanib (50 or 125mg) QD orally continuously from day 3 of cycle 1 plus either P (Arm A) at 90mg/m2 on days 1, 8 and 15 of each 28-day cycle; or D (Arm B) at either 100mg/m2 on day 1 of every 21-day cycle or at 75mg/m2 with motesanib maximum tolerated dose (125mg QD). Objective response (OR) per RECIST was assessed every 8 (Arm A) or 6 wks (Arm B).&#x2028; Results: To date, 33 pts have received ≥1 dose of motesanib: Arm A, n=10; Arm B, n=23. Median age is 51 (range, 28-66) years. There were 5 DLTs (all grade 3) in 4 pts: abnormal liver function tests and deep vein thrombosis (Arm A, 125mg QD), fatigue (Arm A, 125mg QD), gallbladder enlargement (Arm B, 125mg QD+75mg/m2 D) and migraine (Arm B, 125mg QD). 28 pts (85%) had motesanib-related AEs; the most common were (worst grade): diarrhea, Arm A/B 60%/61% (grade 3, 0%/13%); fatigue, 30%/26% (grade 3, 10%/4%); hypertension, 20%/22% (grade 3, 10%/4%); and nausea, 10%/26% (no grade 3). Treatment-related AEs of interest in Arm A/B included epistaxis (10%/18%; all worst grade 1) and deep vein thrombosis (10%/0%; all worst grade 3). There were no grade 4 or 5 related AEs. Two deaths on study occurred (Arm B; 50 and 125mg QD n=1 each); both were not considered to be motesanib related. Motesanib PK parameters were generally within the range previously described for single-agent motesanib. PK profiles of P and D showed high interpatient variability, with AUC higher in some pts after motesanib coadministration. In pts with measurable disease at baseline (Arms A&B, n=7&18), best OR at time of last data cut-off was: confirmed PR in Arm A n=2 (29%), in Arm B n=5 (28%); SD in Arm A n=2 (29%), in Arm B n=9 (50%); durable SD ≥24 wks in Arm A n=0, in Arm B n=3 (17%). Median (range) duration of response currently is 169 (58-169) days in Arm A and 198 (96-337+) days in Arm B.&#x2028; Conclusions: Motesanib combined with P or D appears to be tolerable with evidence of antitumor activity in pts with advanced breast cancer. No marked effect on motesanib PK has been noted with coadministration of either P or D. Updated safety and efficacy data, including PFS, will be presented.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4117.

CALGB 150002: Correlation of HER2 and chromosome 17 (ch17) copy number with trastuzumab (T) efficacy in CALGB 9840, paclitaxel (P) with or without T in HER2+ and HER2- metastatic breast cancer (MBC)

1009

Background: Accurate assessment of HER-2 is critical in MBC and predicts benefit from T. We have previously shown low level amplification of HER-2 associated with ch17 polysomy is common in IHC 2+ cases that are FISH(-). However, the clinical relevance of this is unknown. Methods: CALGB 150002, a correlative companion to 9840, was designed to assess the predictive role of HER-2 in MBC pts treated with weekly vs q 3W P ± T. Pts HER-2(-) locally were randomized to ±T. 585 pts were enrolled in 9840; 304 blocks were available for central analysis with DAKO HercepTest (IHC) and Pathvysion (FISH). Logistic regression was used to test HER-2:ch17 ratio and HER-2 copy # as predictor of response rate (RR) to T in HER-2(+) pts. 1-sided Fisher’s Exact Test was used to compare RR of P vs P+T in pts with ch17 polysomy on central testing (>2.2 copies ch17/cell), but defined as HER-2(-) locally and randomized to T. Results: In pts HER-2(+) locally, FISH is a significant predictor of RR to P+T. A higher HER-2:ch17 ratio is associated with a higher RR by logistic regression (p=0.033, n=95). No interaction is seen between HER-2 and P schedule, p=0.71. On central testing of cases IHC(-) locally, 16/140 (11%) were IHC 3+ and 5/133 (4%) HER-2 amplified. In 21 HER-2(-) cases reclassified as HER-2 3+ or FISH (+) centrally, we do not find a difference in RR to P vs P+T. However among 133 cases HER-2(-) locally and central FISH(-) we find 32 with ch17 polysomy (copy # ch17 = 2.2); 12 treated with P alone, and 19 with P+T (see table for RR). Conclusions: These data suggest a higher RR to P+T in HER-2(+) pts with a higher HER-2:ch17 ratio, consistent with a relationship between RR to T and HER-2 copy #. In FISH(-) cases we note an increased RR to P+T vs P in cases with ch17 polysomy, typically reported clinically as HER-2(-). This analysis suggests that T might be effective in a subpopulation of breast cancer conventionally defined as HER-2(-), but in fact displaying low level HER-2 amplification.

[Table: see text]

[Table: see text]

registHER: Patient characteristics, treatment patterns, and preliminary outcomes in patients with HER2-positive (HER2+), hormone receptor-positive (HR+) metastatic breast cancer (MBC)

21007

Background: Approximately 50% of HER2+ breast cancers are HR+, however, the interaction between HER2 and HR is not completely understood. Patients with HR+/HER2+ or HR-/HER2+ tumors treated with trastuzumab + chemotherapy (CT) achieve similar clinical benefit. Retrospective analyses suggest that HER2+ tumors are resistant to hormone therapy (HT), particularly anti-estrogens, possibly due to estrogen receptor /HER2 interactions and quantitatively lower HR expression in HER2+/HR+ tumors. Conducting randomized clinical trials in HER2+/HR+ MBC is challenging given the small patient population. Methods: registHER is a prospective observational study of approximately 1000 patients with newly diagnosed (<6 months) HER2+ MBC treated in community or academic settings. Baseline characteristics and treatment patterns in patients with HR+ vs HR-, HER2+ MBC receiving first-line therapy were studied in this analysis. The influence of adjuvant HT on disease-free intervals (DFI) from time of diagnosis and MBC treatment selection in patients with HR+/HER2+ tumors was examined. Results: Of 976 patients with HER2+ MBC and recorded tumor HR status, those with HR+ MBC (54.9%) tended to be white (81.7% vs 77.0%), were more likely to have bone only metastases (18.1% vs 6.4%), less likely to have CNS metastases (2.8% vs 8.2%), and have fewer metastatic sites at diagnosis (49.1% vs 43.2%) than those with HR- MBC. Of patients with HR+ MBC, who were stage I- III at initial diagnosis, 51.3% received adjuvant HT, of which 73.2% received tamoxifen. Median DFI was 48.8 vs 29.4 mo for patients receiving tamoxifen vs an aromatase inhibitor. First-line MBC treatment regimens included: HT only (13.8%); HT + trastuzumab (8.4%); HT + trastuzumab + CT (6.2%); trastuzumab only (6.0%); CT only (11.0%); trastuzumab + CT (53.5%). Analyses of progression-free survival by HR status and first-line treatments (HT only, trastuzumab ± HT or ± CT), are ongoing and will be described. Conclusions: registHER represents the largest dataset of patients with HER2+/HR+ MBC and provides a unique opportunity to characterize treatment patterns, efficacy and safety, and the natural history of this subset of breast cancer patients.

[Table: see text]

Study participants’ perceptions of the process and impact of receiving results of N9831

518

Background: There has been growing interest in providing clinical trial participants with study results. We sought to evaluate the process of sharing results from a large cooperative group trial in an effort to guide clinicians and clinical investigators. Methods: We mailed surveys to a subset of women who participated in NCCTG 9831, Phase III Trial of Adjuvant Chemotherapy with or without Trastuzumab for Women with HER2+ Breast Cancer, after the preliminary study results were mailed to participants. Surveys were sent to all trial participants enrolled through 9 CALGB/ECOG institutions. Results: Of 228 surveys sent, 160 (70%) have been returned. Average age of respondents was 51 years (range 26–76); 84% were white; 61% were college graduates; 4% reported recurrent disease. Women reported receiving results by mail (84%), from a health care provider in person or by phone (43%), and/or from the media (47%); 2% reported that they were not informed of the results. 29% heard the results first from the media; 27% first heard by mail. 35% of women might have preferred to be offered results, with the option of not receiving them, but only 4% of women indicated that they would have declined results had they been offered first. 89% of women found the results information easy to understand; 69% correctly interpreted the results of the study; 31% either had an incorrect interpretation or were unsure of the findings. 81% of women were satisfied with how results were shared; 63% of women felt that learning results had an impact on their lives, 24% were more anxious after learning the results; 36% were less anxious. Multivariable analyses evaluating factors associated with greater satisfaction and increased anxiety will be presented. Conclusions: Sharing results is met with overwhelmingly favorable responses from patients, although a substantial proportion of patients may not initially understand the findings. Some patients desire to be offered results first, but few would decline them. The potential for increased anxiety should be considered, and psychosocial support may be required by some. A plan to share results should be routinely and prospectively included in the design of clinical trials. (Supported in part by an ASCO Career Development Award (AHP)

No significant financial relationships to disclose.

Breast sentinel lymphadenectomy—Is immediate intra-operative assessment warranted?

10533

Background: Sentinel lymphadenectomy is the standard of care in breast cancer evaluation. Since conventional axillary dissection is only considered for patients (pts) with sentinel lymph node positive (SLN+) disease, there is increasing interest in immediate intra-operative assessment of SLN by frozen section or RT- PCR. Methods: Institutional SLN cases (2003–2004) were retrospectively reviewed. Each SLN (submitted in toto for processing with 21 tissue levels/block, H&E staining, and cytokeratin (CK) immunostudies) was evaluated for tumor deposit size, distribution and extranodal extension. Results: 80% (n = 222) of pts had SLN biopsy: 50% at primary excision, 21% at mastectomy, 9% at re-excision and 20% as a separate procedure. 1–4 SLN were sampled in 41%, 25%, 19%, and 14% respectively with no node identified in 1 case. Of all, 31% (n = 68) had >/=1 (+) node and 72% of those (n = 50) had a completion axillary dissection. 50% of pts required separate surgical procedure. Only 21% (n = 14) of pts with SLN+ had subsequent (+) axillary nodes on completion dissection. Nodal deposits ranged in size from </= 0.02 cm (13%) to >2.0 cm (1%). The majority (26%) were in the micrometastasis range of >0.02<0.2 cm, where CK-immunostaining was useful to confirm detection. 19% were >/=0.2< 0.5 cm, 25% >/= 0.5<1.0 cm, and 15% >/= 1.0<2.0 cm. 3% SLN showed CK(+)-only cells without H&E confirmation. Tumor sites were parenchymal (1%), subcapsular (31%), or both (68%). Only 7% of nodes with subcapsular metastases were associated with subsequent positive axillary nodes. In 91% (n = 62) of SLN+ cases, metastases were identified in the first 3 tissue levels. Extranodal extension was seen in 22%. Conclusions: Overall, 31% were SLN+; 21% of those were node + in subsequent axillary sampling. These findings do not support the labor and expense of immediate intraoperative SLN assessment. 3-level tissue processing with simultaneous RT-PCR could be performed on all SLN. Subsequent tissue leveling and immunostaining could potentially only be performed on PCR+ cases to provide metastasis size and extranodal extension. PCR probes can also facilitate detection of novel prognostic markers. Additionally, identification of only subcapsular deposits may warrant foregoing subsequent axillary sampling in some clinical scenarios.

No significant financial relationships to disclose.

Pharmacokinetic-pharmacodynamic relationships of the bispecific antibody MDX-H210 when administered in combination with interferon gamma: a multiple-dose phase-I study in patients with advanced cancer which overexpresses HER-2/neu

INTRODUCTION

MDX-H210 is a Fab'xFab' bispecific antibody (BsAb) constructed chemically by crosslinking Fab' mAb 520C9 (anti-HER-2/neu) and Fab' mAbH22 (anti-CD64).

STUDY DESIGN AND OBJECTIVES

This was a dose escalation study of intravenous MDX-H210 (1-70 mg/m(2)), preceded 24 h beforehand by subcutaneous IFNgamma (50 microg/m(2) to up-regulate FcgammaRI) administered three times a week for 3 weeks. We investigated the pharmacokinetic-pharmacodynamic relationships between MDX-H210 C(max) and AUC and (i) MDX-H210 binding to peripheral blood monocytes and neutrophils, (ii) the peak plasma G-CSF, IL-6, IL-8 and TNFalpha concentrations, and (iii) the observed clinical toxicity.

RESULTS

23 patients (19F:4M; median age 51.5; range 25-72 y) with advanced HER-2/neu positive cancers (19 breast, three prostate and one lung) were studied. Plasma MDX-H210 concentrations over time, circulating numbers of monocytes and neutrophils, percent saturation of monocyte and neutrophil FcgammaRI, and plasma concentrations over time of G-CSF, IL-6, IL-8 and TNFalpha were measured and clinical toxicity monitored. The E(max) pharmacodynamic model best fitted the relationship of MDX-H210 C(max) and the maximum percent saturation of both monocytes (E(max)=74.6; EC(50)=0.9 microg/ml) and neutrophils (E(max)=66.2; EC(50)=2.3 microg/ml) on the first day of treatment. On the last day of treatment, day 19, these parameters were E(max)=57.0% and EC(50)=0.46 microg/ml for monocytes and E(max)=61.9% and EC(50)=0.26 microg/ml for neutrophils. No positive relationship was defined between the log MDX-H210 C(max) and the log peak plasma IL-6, G-CSF, TNF or IL-8 concentrations on day 1. On day 19 these plasma cytokine concentrations were undetectable post MDX-H210 therapy. There was no consistent relationship between MDX-H210 C(max) and the observed clinical toxicities.

CONCLUSIONS

These data suggest that MDX-H210 C(max) and AUC could be related by the E(max) model to maximum percent FcgammaRI saturation on circulating monocytes and neutrophils in the patients studied. After day 1, the post MDX-H210 therapy cytokine response attenuated over time, consistent with desensitization. We did not find a relationship between log MDX-H210 C(max) and peak plasma cytokine concentrations or clinical toxicities.

Bispecific antibody-targeted phagocytosis of HER-2/neu expressing tumor cells by myeloid cells activated in vivo

Studies from our laboratory and others have established that both mononuclear phagocytes and neutrophils mediate very efficient cytotoxicity when targeted through Fc receptors using a suitable monoclonal or bispecific antibody (BsAb). Cross-linking an Fc receptor for IgG (FcgammaR) triggers multiple anti-tumor activities including superoxide generation, cytokine and enzyme release, phagocytosis and antibody-dependent cellular cytotoxicity (ADCC). In this report, using unfractionated leukocytes and two color flow cytometric analysis, we describe the phagocytic capacity of peripheral blood polymorphonuclear cells (PMN) and monocytes isolated from patients enrolled in a phase I clinical trial of MDX-H210 given in combination with IFNgamma. MDX-H210 is a BsAb targeting the myeloid trigger molecule FcgammaRI and the HER-2/neu proto-oncogene product overexpressed on a variety of adenocarcinomas. In this trial, cohorts of patients received escalating doses of MDX-H210 3 times per week for 3 weeks. Interferon-gamma (IFNgamma) was given 24 h prior to each BsAb infusion. Our results demonstrate that monocytes from these patients were inherently capable of phagocytosing the HER-2/neu positive SK-BR-3 cell line and that addition of MDX-H210 into the assay significantly enhanced the number of targets phagocytosed. Two days after administration of an immunologically active dose of MDX-H210 (10 mg/m2), monocytes from these patients were able to phagocytose greater amounts of target cell material, indicating that these cells remained armed with functionally sufficient BsAb for at least 48 h. PMN from these patients very efficiently mediated phagocytosis through FcgammaRI after being treated with IFNgamma, but not before. We conclude that phagocytosis is not only an efficient mechanism of myeloid cell-mediated cytotoxicity, but may also be a mechanism by which antigens from phagocytosed cells can enter a professional antigen presenting cell for processing and presentation.

Phase I pilot trial of the bispecific antibody MDXH210 (anti-Fc gamma RI X anti-HER-2/neu) in patients whose prostate cancer overexpresses HER-2/neu

The goal of this study was to evaluate, in patients with prostate cancer, the toxicity profile and biologic activity of the bispecific antibody MDXH210, which has specificity for the non-ligand-binding site of the high-affinity immunoglobulin G receptor (Fc gamma RI) and the extracellular domain of the HER-2/neu proto-oncogene product. Patients with prostate cancer that expressed HER-2/neu were entered into a phase I dose-escalation trial of MDXH210. Patients received an intravenous infusion MDXH210 during a period of 2 h three times per week for 2 weeks and were monitored for toxicity. Pharmacokinetic and pharmacodynamic parameters were measured and included the biologic end points of monocyte-bound MDXH210, cytokine production, and clinical response. Seven patients were treated with MDXH210 doses ranging from 1 to 8 mg/m2. In general, MDXH210 was well tolerated, with only mild infusion-related malaise, fever, chills, and myalgias. No dose-limiting toxic effects were observed. Biologic effects included induction of low plasma concentrations of tumor necrosis factor-alpha and interleukin-6 observed immediately after MDXH210 infusion and 70% saturation of circulating monocyte-associated Fc gamma RI with MDXH210 at a dose level of 4 to 8 mg/m2. Five of six patients had stable prostate-specific antigen levels during the course of 40 days or more. Circulating plasma HER-2/neu levels decreased by 80% at days 12 and 29 (p = 0.03 and 0.06, respectively, by the Wilcoxon signed rank test). MDXH210 can be given safely to patients with HER-2/neu-positive prostate cancer in doses of at least 8 mg/m2. At the doses studied, biologic activity was demonstrated and characterized by binding of MDXH210 to circulating monocytes, release of monocyte-derived cytokines, a decrease in circulating HER-2/neu, and short-term stabilization of prostate-specific antigen levels.

Paclitaxel and anthracycline combination chemotherapy for metastatic breast cancer

Numerous clinical trials have demonstrated that the combination of paclitaxel and doxorubicin is extremely active in metastatic breast cancer. Overall response rates of 42% to 94% and complete response rates of 4% to 41% have been reported. However, several trials with the highest response rates were associated with the development of congestive heart failure (CHF) in approximately 20% of patients. These early findings resulted in reducing the maximum permitted cumulative dosages of doxorubicin in subsequent trials, with a corresponding decrease in cardiac toxicity being noted. Several subsequent series suggest that with cumulative dosing of 360 mg/m2 doxorubicin, the rate of CHF can be reduced to approximately 5%. A recently completed Eastern Cooperative Oncology Group phase III randomized trial comparing paclitaxel versus doxorubicin versus combination therapy with paclitaxel and doxorubicin noted an overall response rate of 33% and 34% in each single-agent arm, respectively, and a response rate of 46% with the combination therapy. There was an acceptable incidence of CHF. However, no difference in overall survival was noted with the combination therapy compared with the single-agent treatment. Losoxantrone, an anthrapyrazole in clinical development, has shown promising single-agent activity in metastatic breast cancer. An initial phase III randomized clinical trial comparing treatment with either paclitaxel alone versus losoxantrone and paclitaxel was recently completed. With no maximal cumulative dosage of losoxantrone incorporated into this trial design, an overall incidence of CHF of 4.9% was noted with combination therapy. Other hematologic and nonhematologic toxicities were overall acceptable with this new regimen as well. Additionally, preliminary analyses of clinical efficacy suggest that this new combination is promising therapy for the treatment of patients with metastatic breast cancer.

Phase II trial of tamoxifen, etoposide, mitoxantrone, and cisplatin in patients with metastatic breast carcinoma

BACKGROUND

Based on previous data demonstrating a potentially synergistic interaction between tamoxifen and cisplatin in metastatic melanoma therapy, a Phase II study was performed to assess the activity of tamoxifen, etoposide, mitoxantrone, and cisplatin (TEMP) in patients with metastatic breast carcinoma.

METHODS

Forty-six patients with metastatic breast carcinoma were treated with tamoxifen, 10 mg orally, twice a day for 28 days; etoposide, 100 mg/m2, on Days 1-3; mitoxantrone, 10 mg/m2, on Day 1; and cisplatin, 30 mg/m2, on Days 1 and 2. Forty-four patients (7 with bone only disease) were evaluable for response and toxicity after at least 1 cycle of therapy. All patients had previously received doxorubicin-containing regimens in either the adjuvant or metastatic setting.

RESULTS

The overall objective response rate for the 37 patients with visceral and/ or soft tissue disease was 41% (95% confidence interval, 25-58%). The objective response rate among women previously treated with doxorubicin in the adjuvant setting was 56% (14 of 24). Only 1 of 13 patients with metastatic carcinoma who had failed doxorubicin responded. Five of seven patients with bone-only disease had subjective improvement of bone pain without worsening of bone scans. Approximately 59% of patients had Grade 3 or 4 neutropenia at some time in their therapy and 1 patient died of neuropenic sepsis. Logistic regression analysis (n = 37) revealed that response was not related to estrogen receptor (ER) status or to the presence of visceral metastases.

CONCLUSIONS

TEMP appears to be an active regimen for patients with either ER positive (tamoxifen-resistant) or ER negative metastatic breast carcinoma that progresses after adjuvant doxorubicin therapy. Moreover, among patients who developed metastatic disease either during or < 12 months after adjuvant doxorubicin therapy, TEMP had a higher response rate than would have been predicted from previous studies. Although the mechanism remains to be elucidated, these results suggest a potentially synergistic role for tamoxifen in etoposide/cisplatin-based chemotherapy of breast carcinoma.

Clinical trials of bispecific antibody MDX-210 in women with advanced breast or ovarian cancer that overexpresses HER-2/neu

MDX-210 is a bispecific antibody (BsAb) that recognizes Fc gamma R1 on monocytes and macrophages and the cell surface product of the HER-2/neu oncogene, which is overexpressed on some breast and ovarian cancers. Clinical trials have demonstrated that treatment with MDX-210 is well tolerated and that MDX-210 is both immunologically and clinically active. Optimization of the dose and schedule of MDX-210 and development of combination treatments with cytokines that modulate immune effector cells will greatly enhance the efficacy of this novel BsAb construct for treatment of tumours that overexpress HER-2/neu. We envision that MDX-210 will be effective for treating patients with tumors that overexpress HER-2/neu, especially in the minimal disease setting.

Phase Ia/Ib trial of bispecific antibody MDX-210 in patients with advanced breast or ovarian cancer that overexpresses the proto-oncogene HER-2/neu

PURPOSE

MDX-210 is a bispecific antibody that binds simultaneously to type I Fc receptors for immunoglobulin G (IgG) (Fc gamma RI) and to the HER-2/neu oncogene protein product. MDX-210 effectively directs Fc gamma RI-positive effector cells such as monocytes and macrophages to phagocytose or kill tumor cells that overexpress HER-2/neu. The goals of this phase Ia/Ib trial were to determine the maximum-tolerated dose (MTD) and/or the optimal biologic dose (OBD) of MDX-210.

PATIENTS AND METHODS

Patients with advanced breast or ovarian cancer that overexpressed HER-2/neu were eligible for treatment. Cohorts of three patients received a single intravenous (IV) infusion of MDX-210 at increasing dose levels from 0.35 to 10.0 mg/m2.

RESULTS

Treatment was well tolerated, with most patients experiencing transient grade 1 to 2 fevers, malaise, and hypotension only. Two patients experienced transient grade 3 hypotension at 10.0 mg/m2. Transient monocytopenia and lymphopenia developed at 1 to 2 hours, but no other hematologic changes were observed. Doses of MDX-210 > or = 3.5 mg/m2 saturated > or = 80% of monocyte Fc gamma RI and produced peak plasma concentrations > or = 1 microgram/mL, which is greater than the concentration for optimal monocyte/macrophage activation in vitro. Elevated plasma levels of the monocyte products tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF), and neopterin were observed with maximal levels at doses > or = 7.0 mg/m2. Localization of MDX-210 in tumor tissue was demonstrated in two patients. One partial and one mixed tumor response were observed among 10 assessable patients.

CONCLUSION

MDX-210 is immunologically active at well-tolerated doses. The MTD and OBD is 7 to 10 mg/m2.

The v-rel oncogene: insights into the mechanism of transcriptional activation, repression, and transformation

The v-rel oncogene product from the avian reticuloendotheliosis virus strain T corresponds to a member of the Rel-related family of enhancer-binding proteins that includes both the mammalian 50- and 65-kDa subunits of the NF-kappa B transcription factor complex. However, in contrast to NF-kappa B, v-Rel has been shown to function as a dominant-negative repressor of kappa B-dependent transcription in many mature cell types. We now demonstrate that a highly conserved motif within the Rel homology domain of v-Rel containing a consensus protein kinase A phosphorylation site is required for DNA binding, transcriptional repression, and cellular transformation mediated by this oncoprotein. However, replacement of the serine phosphate acceptor within the protein kinase A site with an alanine did not alter any of these functions of v-Rel, suggesting that phosphorylation at this site is not central to the regulation of this oncogene product. Rather, the inactive mutations appear to identify a functional domain within v-Rel required for these various biological activities. It is notable that these same mutations do not impair the ability of v-Rel to heterodimerize with the 50-kDa subunit of NF-kappa B, suggesting that v-Rel-mediated transcriptional repression likely involves direct nuclear blockade of the kappa B enhancer rather than indirect alterations in the composition of preformed cytoplasmic NF-kappa B complexes. Paradoxically, when introduced into undifferentiated F9 cells, v-Rel functions as a kappa B-specific transcriptional activator rather than as a dominant-negative repressor. These stimulatory effects of v-Rel require both the conserved protein kinase A phosphorylation site and additional unique C-terminal sequences not needed for v-Rel-mediated repression in mature cells. Retinoic acid-induced differentiation of these F9 cells restores the repressor function of v-Rel. These opposing biological actions of v-Rel occurring in cells at distinct stages of differentiation may have important implications for the mechanism of v-Rel-mediated transformation occurring in avian splenocytes.

Nuclear expression of the 50- and 65-kD Rel-related subunits of nuclear factor-kappa B is differentially regulated in human monocytic cells

The nuclear factor (NF)-kappa B transcription factor system is composed of at least four inducible nucleoprotein adducts termed p50, p55 (NF-kappa B p50), p75 (NF-kappa B p65), and p85 (c-Rel). These proteins are expressed in the nuclei of activated T cells in a distinctly biphasic fashion, with p55 and p75 induction occurring within minutes whereas the induction of p50 and p85 occurs after several hours. In contrast, p50 and p55 are constitutively expressed in the nuclei of U937 and THP-1 monocytic cells. However, cellular activation is required for the nuclear expression of p75 in these cells. Additionally, activation of monocytic cells does not result in a significant induction of p85. Tumor necrosis factor alpha induces the nuclear expression of p55 and p75 in these monocytic cells within 20 min, presumably reflecting the liberation of these proteins from I kappa B. In contrast, phorbol myristate acetate (PMA) induces the expression of these proteins with delayed kinetics, raising the possibility that PMA is incapable of mediating the efficient release of p55 and p75 from I kappa B in these cells. These findings highlight important differences in the regulation of these proteins in monocytic cells versus T cells and suggest that the induced expression of NF-kappa B p65 in monocytes may play a central role in the activation of HIV-1 gene expression.

Urea kinetics evaluation of hemodialysis and CAPD patients

Urea kinetics have been used to measure adequacy of hemodialysis. The role of urea kinetics in CAPD has not been clearly established. Using urea kinetics, we studied 71 hemodialysis and 71 CAPD patients. Age was 53 +/- 12 and 45.8 +/- 12 respectively. Urea kinetics in hemodialysis were studied in the standard manner. CAPD patients collected 24 hr, dialysate fluid to measure urea, creatinine, glucose and protein. Urine was collected for 24 hr. to measure urea and creatinine. Protein catabolic rate (pcr) was calculated from the total amount of urea cleared in 24 h. Both groups of patients had similar body weight. Kt/V in CAPD (0.65 +/- 0.1) was at a level considered underdialysis for hemodialysis. In both groups, pcr increased as Kt/V increased. However, CAPD patients had levels of pcr higher than hemodialysis patients at the same level of Kt/V. BUN, serum albumin and serum potassium were significantly lower in CAPD patients. Patients who dialyze more, eat more. Differences in protein intake may be due to a more liberal diet in CAPD, patient selection, removal of middle molecules, or better control of the acidosis.

Autologous bone marrow transplantation and factor XII, factor VII, and protein C deficiencies. Report of a new association and its possible relationship to endothelial cell injury

Four patients who underwent treatment with high-dose chemotherapy (HDC) and autologous bone marrow transplantation (ABMT) and in whom posttreatment deficiencies of Factor XII and protein C subsequently developed are reported. Factor VII or Factor X deficiencies also developed in several of these patients. Three of these patients experienced chemotherapy-related cardiac, hepatic, or pulmonary toxicity. It is believed by many that endothelial cell injury may be the underlying lesion responsible for these various organ system toxicities seen in the setting of ABMT, although direct evidence of this is lacking. It is proposed that the factor deficiencies described in this report may be an additional consequence of endothelial cell injury or dysfunction. These coagulation factor deficiencies may therefore serve as both a marker to follow these organ system toxicities with and as a useful tool to better study and understand the mechanisms underlying these events. Additionally, deficiencies of either Factor VII or Factor X developed in several patients that were of a sufficient magnitude such that factor replacement therapy would be indicated before any invasive procedures or in the event of significant hemorrhage.

Distancing for intimacy in lesbian relationships

The authors present a collaborative treatment model designed to help the closely merged, troubled lesbian relationship. Therapeutic techniques focus on change in territorial, temporal, monetary, cognitive, emotional, and environmental space. A case example illustrates the interventions, which include individual and conjoint work, collaboration between therapists, education, bibliotherapy, referral to gay community resources, and specific suggestions for behavior change. The therapeutic goal is to restore intimacy to the relationship by offering each partner increased distance, personal space, and individual autonomy.

The case against tylectomy for carcinoma of the breast. The factor of multicentricity

Five hundred consecutive cases of breast carcinoma were studied to determine the incidence of multicentric lesions in the resected specimens. When residual tumor in juxtaposition to the primary tumor or biopsy cavity is excluded, 41.6 per cent of specimens exhibited multicentric foci of tumor; 31 per cent of such foci were in sectors or quadrants remote from the primary tumor. In more than half of these cases the lymph nodes were uninvolved and cure rate would have been maximal had these multicentric tumor foci been removed. These findings confirm previous similar studies and we consider tylectomy an inappropriate mode of therapy for breast cancer.