High-risk Node-negative Breast Research Articles

Abstract PD12-01: Evaluation of sleep problems and their association with febrile neutropenia, leucopenia and infections in women receiving adjuvant chemotherapy for breast cancer in the Canadian Cancer Trials Group MA.21 trial

Abstract BackgroundInsomnia is a frequent complaint in patients with cancer. Sleep problems can affect immune functioning in healthy individuals. Our aim was to evaluate the association between sleep disturbance and the risk of febrile neutropenia, leukopenia and infections in patients treated with chemotherapy in an adjuvant setting for breast cancer.MethodologyThis is a retrospective study using the Canadian Cancer Trial Group data collected for the MA.21 trial, in which three adjuvant chemotherapy regimens (CEF, EC-T dose dense or AC-T) were compared in 2104 patients with node positive or high-risk node negative breast cancer. A total of 1731 patients had completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) and 1727 patients had completed the Breast Cancer Chemotherapy Questionnaire (BCQ) quality of life questionnaires, which both include a question about sleep difficulties. The primary definition for patients with insomnia was a score of three (quite a bit) or greater at Question 11 (Have you had trouble sleeping? with answers ranging from one (not at all) to four (very much)) on the EORTC QLQ-C30 questionnaire. We compared patients classified as having “clinical insomnia” based on their response to this question with patients considered “good sleepers”. The primary endpoint was the risk of febrile neutropenia. Secondary endpoints were the risks of grade one or more leukopenia, neutropenia and infection. ResultsFebrile neutropenia was more frequent in patients with sleep problems compared with those without, with 16.3% and 12.2% of patients having at least one episode in each group respectively (p value = 0.01 in the univariate analysis (table 1)). However, after adjustment for potential confounders in the multi-variate analysis, it was not statistically significant with an odds ratio of 1.07, a 95% confidence interval of 0.76-1.50 and a p value of 0.71. Similarly, no statistically significant difference in the risk of leukopenia could be demonstrated in the multi-variate analysis for patients with sleep problems with an odds ratio of 0.92 a 95% confidence interval of 0.69-1.24 and a p value of 0.59. No significant association could be found between sleep problems and neutropenia and infections. In an unplanned exploratory analysis, chemotherapy dose reductions were significantly more frequent in patients with sleep problems with 30.6% in this group compared to 21.8% in good sleepers, with a p value <0.0001. ConclusionWhile our univariate analysis suggested an increased risk of febrile neutropenia and leucopenia in patients with sleep problems, after adjustment for confounders, we could not show a statistically significant association in women undergoing adjuvant chemotherapy for high-risk locoregional breast cancer. Table 1: Univariate analysis of primary and secondary outcomes in patients with sleep problems and good sleepersCharacteristicsSleep problem= yesSleep problem = noFebrile neutropeniaNo781 (83.7%)701 (87.8%)Yes152 (16.3%)97 (12.2%)P-value0.01White blood cell count (WBC)Grade 0157 (16.8%)141 (17.7%)Grade 1135 (14.5%)138 (17.3%)Grade 2184 (19.7%)186 (23.3%)Grade 3214 (22.9%)173 (21.7%)Grade 4243 (26.1%)160 (20.1%)P-value0.02NeutropeniaGrade 0778 (83.4%)700 (87.7%)Grade 10 (0%)1 (0.1%)Grade 22 (0.2%)0 (0%)Grade 3152 (16.3%)96 (12.0%)Grade 41 (0.1%)1 (0.1%)P-value0.014InfectionGrade 0619 (66.4%)564 (70.7%)Grade 168 (7.3%)62 (7.8%)Grade 2158 (16.9%)110 (13.8%)Grade 387 (9.3%)61 (7.6%)Grade 41 (0.1%)1 (0.1%)P-value0.24Chemotherapy delayNo1 (0.1%)12 (1.5%)Yes932 (99.9%)786 (98.5%)P-value0.0008Chemotherapy dose reductionNo648 (69.4%)624 (78.2%)Yes285 (30.6%)174 (21.8%)P-value< 0.0001 Citation Format: Audreylie Lemelin, Josée Savard, Michelle Chen, Margot Burnell, Mark N Levine, Lois Shepherd, Bingshu E Chen, Julie Lemieux. Evaluation of sleep problems and their association with febrile neutropenia, leucopenia and infections in women receiving adjuvant chemotherapy for breast cancer in the Canadian Cancer Trials Group MA.21 trial [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD12-01.

Prospective, randomized, single-blinded, multi-center phase II trial of two HER2 peptide vaccines, GP2 and AE37, in breast cancer patients to prevent recurrence

PurposeAE37 and GP2 are HER2 derived peptide vaccines. AE37 primarily elicits a CD4+ response while GP2 elicits a CD8+ response against the HER2 antigen. These peptides were tested in a large randomized trial to assess their ability to prevent recurrence in HER2 expressing breast cancer patients. The primary analyses found no difference in 5-year overall disease-free survival (DFS) but possible benefit in subgroups. Here, we present the final landmark analysis.MethodsIn this 4-arm, prospective, randomized, single-blinded, multi-center phase II trial, disease-free node positive and high-risk node negative breast cancer patients enrolled after standard of care therapy. Six monthly inoculations of vaccine (VG) vs. control (CG) were given as the primary vaccine series with 4 boosters at 6-month intervals. Demographic, safety, immunologic, and DFS data were evaluated.Results456 patients were enrolled; 154 patients in the VG and 147 in CG for AE37, 89 patients in the VG and 91 in CG for GP2. The AE37 arm had no difference in DFS as compared to CG, but pre-specified exploratory subgroup analyses showed a trend towards benefit in advanced stage (p = 0.132, HR 0.573 CI 0.275–1.193), HER2 under-expression (p = 0.181, HR 0.756 CI 0.499–1.145), and triple-negative breast cancer (p = 0.266, HR 0.443 CI 0.114–1.717). In patients with both HER2 under-expression and advanced stage, there was significant benefit in the VG (p = 0.039, HR 0.375 CI 0.142–0.988) as compared to CG. The GP2 arm had no significant difference in DFS as compared to CG, but on subgroup analysis, HER2 positive patients had no recurrences with a trend toward improved DFS (p = 0.052) in VG as compared to CG.ConclusionsThis phase II trial reveals that AE37 and GP2 are safe and possibly associated with improved clinical outcomes of DFS in certain subgroups of breast cancer patients. With these findings, further evaluations are warranted of AE37 and GP2 vaccines given in combination and/or separately for specific subsets of breast cancer patients based on their disease biology.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Abstract Background In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy. Methods This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled. Acknowledgement This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018). Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [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 OT2-04-02.

Abstract P5-11-02: Survival benefit needed to undergo chemotherapy: Patients and physicians preferences

Abstract Background: Data regarding patients (pts) and physicians' preferences for modern adjuvant chemotherapy (CT) are limited. Prior studies suggested that most pts with early stage breast cancer were willing to receive 6 months of adjuvant cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) for modest survival benefits (e.g. most women would have accepted 3-6 months extension of life). Methods: E5103 was a phase III trial which randomized node positive or high risk node negative breast cancer pts to receive adjuvant CT (doxorubicin, cyclophosphamide and paclitaxel) with either placebo or bevacizumab. Telephone based surveys were administered to all pts enrolled on E5103 between 01/Jan/10 and 08/Jun/10, as part of a Decision-Making/Quality of Life component. Results presented here are part of the 18 months post-enrollment follow-up. Pts were asked to rate the survival benefit needed to justify 6 months of CT. A complementary survey was sent to all physicians who registered at least one pt on E5103. Results: 465 out of 519 eligible pts (90%) responded to this survey at 18 months. Main reasons for non response were: inability to reach the patient (6%) or patient refusal (2%). Median pts age was 51 (25-76); 42% of pts had at least a college degree. The majority had at least Stage II cancer. 179 (16%) physicians participated, among whom median age was 50 (35-70). The median years in practice was 17 (3-38); 78% of physicians worked on large size practices, 72% saw at least 5 new breast cancer pts/month, and 77% enroll between 1-4 pts on trials/month. We found considerable variation in pts preferences particularly for modest survival benefits: a substantial minority of pts (24%) would consider 6 months of CT definitely worthwhile for 1 month survival benefit, 18% would possibly consider it and 56% would not. The percentage considering CT definitely worthwhile increased with greater benefit, but did not reach 100%, even with 24 months survival benefit. About half of pts considered 6 months of CT definitely worthwhile for 9 months benefit, 70% for 12 months and 84% for 24 months. Physicians were less likely to accept CT for a small chance of benefit (34% of pts vs. 5% of physicians would definitely consider CT worthwhile for 2 months of benefit). For longer benefit, pts and physicians choices were similar (84% of pts vs. 92% of physicians would definitely consider CT worthwhile for 24 months benefit). Table Yes, definitely worthwhileYes, maybeNo, not worthwhileNo answerConsider 6 months of CT to live:PtsPhysiciansPtsPhysiciansPtsPhysiciansPts/Physicians*1 month longer24%3%18%15%56%80%2%2 months longer34%5%23%32%41%60%2%6 months longer44%32%35%54%19%12%2%9 months longer53%51%34%42%11%5%2%12 months longer70%75%23%22%5%1%2%24 months longer84%92%12%5%2%1%2%n Pts= 465; n Physicians= 179; * equal results in both groups Conclusions: This subgroup of pts who had undergone modern adjuvant CT in a large multicenter randomized controlled trial and these physicians who registered pts on the same trial had different cutoffs for acceptable levels of benefits and risks when considering adjuvant chemotherapy. It is important to engage pts in determining whether CT is or is not a "reasonable" option for treatment. Citation Format: Vaz Luis I, O'Neill A, Sepucha K, Miller KD, Baker E, Dang CT, Northfelt DW, Winer EP, Sledge GW, Schneider BP, Partridge A. Survival benefit needed to undergo chemotherapy: Patients and physicians preferences. [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 P5-11-02.

Abstract P1-12-02: Sequential versus concurrent administration of epirubicin and docetaxel as adjuvant chemotherapy in women with high-risk axillary lymph node negative early breast cancer. An interim analysis of a multicenter randomized study from the Hellenic oncology research group

Abstract Purpose: To compare the sequential versus the concurrent administration of epirubicin and docetaxel as adjuvant therapy in high risk axillary node negative women with early breast cancer. Patients and treatment: Women 18-75 years old with invasive breast adenocarcinoma surgically resected with no infiltrated axillary lymph nodes and absence of metastatic disease were randomized to receive 4 cycles of epirubicin 90mg/m2 followed by 4 cycles of docetaxel 75mg/m2 (sequential regimen) or 6 cycles of epirubicin 75mg/m2 followed by docetaxel 75mg/m2 (concurrent regimen). All chemotherapy cycles were administered every 21 days with prophylactic G-CSF support for days 3-10 only for the concurrent regimen. Stratification was based on menopausal status, tumor size and hormone receptor expression. By protocol amendment in 2008 women with HER2 positive tumors were excluded. The primary endpoint of the study was to compare the disease-free survival (DFS) at 5 years and 329 patients were scheduled to enroll on each arm. Results: Between 2001-2013, 658 women were randomized and received the sequential (n=329) or the concurrent (n=329) regimen. The median age was 53 and 52 years, premenopausal status 43.8% versus 44.1%, tumor size <2cm in 44.1% versus 44.4%, histological grade 3 tumor in 52% versus 53.5% and hormone receptor negative disease in 33.1% versus 37.4% of patients in the sequential and concurrent regimens, respectively. After a median follow up of 70.5 and 70 months, there were 29 (8.8%) versus 42 (12.8%) disease relapses (p=0.102) and 11 (3.3%) versus 19 (5.8%) deaths (p=0.135), in the sequential and concurrent arms, respectively. The median DFS has not yet been reached in either arm (p=0.053) and the 5-year DFS rates were 92.6% versus 88.2% for sequential and concurrent arms, respectively. Dose reduction was required in 1.2% versus 3% (p=0.001) of the treatment cycles in the sequential and concurrent arms, respectively. Toxicity included grade 2-4 neutropenia in 54% versus 41% (p=0.001), febrile neutropenia 2.7% versus 6.1% (p=0.06), anemia 12% versus 17% (p=0.07), nausea/vomiting 18.5% versus 12.4% (p=0.03) of patients in the sequential and concurrent arms, respectively. There were no toxic deaths. Conclusion: In this interim analysis both the efficacy and the toxicity profile seem to favor the sequential over the concurrent regimen. Citation Format: Mavroudis D, Saloustros E, Boukovinas I, Papakotoulas P, Kakolyris S, Ziras N, Christophylakis C, Kentepozidis N, Timotheadou E, Rigas G, Varthalitis I-I, Kalbakis K, Agelaki S, Georgoulias V. Sequential versus concurrent administration of epirubicin and docetaxel as adjuvant chemotherapy in women with high-risk axillary lymph node negative early breast cancer. An interim analysis of a multicenter randomized study from the Hellenic oncology research group. [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 P1-12-02.

Primary analysis of the prospective, randomized, phase II trial of GP2+GM-CSF vaccine versus GM-CSF alone administered in the adjuvant setting to high-risk breast cancer patients.

134 Background: GP2 is a HER2 derived, HLA-A2+-restricted immunogenic peptide designed to stimulate CD8+T cells to recognize tumor cells with any level of HER2 expression (IHC 1-3+). Accrual to a prospective, randomized, multi-center, phase II trial of the GP2 vaccine for prevention of breast cancer recurrence has completed. Here, the planned primary analysis of disease-free survival (DFS) is presented. Methods: HLA-A2+ node positive or high-risk node negative breast cancer patients (pts) with any level of HER2 expression rendered disease-free by standard of care therapy (to include trastuzumab where appropriate) were randomized to receive GP2+GM-CSF (VG) or GM-CSF (CG) alone. Pts received 6 monthly inoculations (primary vaccine series = PVS) followed by 4 boosters administered every 6 months. The Kaplan Meier method was used for statistical analysis. The intention-to-treat (ITT) population is defined as the entire randomly assigned population. The per-treatment (PT) group excluded pts who recurred during the PVS or developed a second malignancy. A pre-specified subgroup analysis was performed based on HER2 expression level. HER2 overexpression (OE) is defined as IHC 3+or FISH >2.2. Results: With 89 VG and 91 CG pts enrolled and vaccinated, there are no differences between groups with respect to age, node positivity, tumor size, grade, ER/PR status, and HER2 expression (p>0.05). The vaccine has been well tolerated with toxicities comparable between the VG and CG. Only one grade 3 local and systemic toxicity reaction has been reported in the VG. At 34 (1-60) month median follow-up, DFS was compared in the ITT (85% VG v 81% CG, p = 0.57) and PT (94% VG v 85% CG, p = 0.17) populations. In OE patients (51 VG and 50 CG) DFS was 94% VG v 89% CG, p = 0.86 (ITT) and 100% VG v 89% CG, p = 0.08 (PT). Conclusions: GP2+GM-CSF is a novel vaccine that is safe and well tolerated. This phase II trial demonstrates potentially greater benefit in pts with HER2 OE tumors, in whom there have been no recurrences in the PT group. This may be due to synergism with trastuzumab therapy, thus justifying a phase III trial evaluating GP2 administered in the adjuvant setting to a HER2 OE population. Clinical trial information: NCT00524277.

Persistence of HER2 overexpression on circulating tumor cells in patients after systemic treatment for HER2-positive breast cancer: Follow-up results of the German Success B trial.

11043 Background: The discordance between HER2-expression on circulating tumor cells (CTC) in peripheral blood and the primary tumor has already been shown by our study group for early breast cancer patients with HER2-positive tumors. Here, we compare the results to CTC prevalence and HER2-status of CTC after adjuvant chemotherapy. Methods: The SUCCESS B trial compares FEC-Docetaxel vs. FEC-Docetaxel-Gemcitabine and HER2-targeted therapy as adjuvant treatment for patients with early, HER2-positive, node positive or high risk node negative primary breast cancer. We prospectively analyzed 23ml peripheral blood before and after chemotherapy. CTC and HER2-status were assessed with the CellSearchSystem (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labeled with anti-CK 8/18/19, anti-CD45 antibodies as well as a fluorescein conjugate antibody for HER2-phenotyping. Cutoff for CTC positivity was ≥ 1 CTC. HER-positivity of CTC was assigned if at least one CTC showed strong HER2 staining (3+). Results: CTCs and their HER2-status both before and after chemotherapy were available for 392 patients. In 179 (45.7%) patients no CTC were detected before and after chemotherapy. CTC status changed from positive before to negative after chemotherapy in 104 (26.5%) patients and from negative before to positive after chemotherapy in 69 (17.6%) patients, while 40 (10.2%) patients had a consistently positive CTC status. Patients were significantly more likely to change their CTC status from positive to negative than from negative to positive (p = 0.01). Of the 40 patients with CTC both before and after chemotherapy, 14 (35%) patients had HER2-positive CTC before and after therapy, and 9 (22%) patients had HER2-negative CTC at both time points. 7 (18%) patients had HER2-positive CTC before but not after chemotherapy, while 10 (25%) patients showed the reverse pattern (p = 0.63). Conclusions: Cytotoxic treatment does not seem to influence the HER2-status on CTC. Follow-up data within the Success B trial will analyze the relevance of the HER2-expression of CTC to predict the efficacy of targeted treatment.

NSABP B-47: A randomized phase III trial of adjuvant therapy comparing chemotherapy alone to chemotherapy plus trastuzumab in women with node-positive or high-risk node-negative HER2-low invasive breast cancer.

TPS1139 Background: Adjuvant trastuzumab trials in HER2+ breast cancer (BC) demonstrated a large reduction in recurrence and death. Central testing showed HER2 non-amplified participants derived similar benefit. Among HER2-amplified patients (pts), multiple studies showed no effect on benefit by degree of amplification. Blinded internal and external review confirmed the non-amplified nature of the HER2 normal group. Based on these findings, NSABP B-47, sponsored by the NCI, was activated January 2011 and is actively accruing. The study is NCI central IRB approved, open via the CTSU, and endorsed by SWOG, ECOG, and RTOG. Methods: Study: Chemotherapy treatment is by physician choice: The non-anthracycline regimen is TC (docetaxel 75 mg/m2, cyclophosphamide (C) 600 mg/m2) IV q 3 wks for 6 cycles; the anthracycline regimen is AC → WP (doxorubicin 60 mg/m2 and C 600 mg/m2 IV either q 3 wks or q 2 wks [investigator discretion] for 4 cycles → paclitaxel 80 mg/m2 IV wkly for 12 doses). Pts are randomly assigned to chemotherapy with or without trastuzumab for 1 year. Pts receive adjuvant radiation therapy and endocrine therapy, as clinically indicated. Detailed menstrual history, concurrent medications, weight changes, and biomarkers (estrogen, stress, inflammation), are being collected. Eligibility: Eligibility includes: node positive or high risk node negative BC pts; HER2 IHC 1+ or 2+ scores, but non amplified by FISH; normal cardiac, renal, and liver function. Detailed eligibility will be provided. Statistical Design: The primary aim is to determine whether the addition of trastuzumab to chemotherapy improves invasive disease-free survival (IDFS). 3,260 pts will be enrolled to provide statistical power of 0.9 to detect a 33% reduction in the hazard rate of IDFS using a one-sided alpha level of 0.025. Progress: Protocol was activated in January 2011. First pt was entered in February 2011. As of January 23, 2013, 1,416 of 3,260 (43.4 %) pts have been enrolled. Updated information on enrollment and study background will be provided. Support: NCI U10-12027, -37377, 69651, 69974, and Genentech, Inc. Clinical trial information: NCT01275677.

Booster inoculations of the AE37 peptide vaccine enhance immunological responses in a phase II study.

3095 Background: We are conducting a multicenter randomized phase II trial of AE37, the Ii-Key hybrid peptide of HER2 776-790 (AE36). The purpose of the study is to determine if the AE37 vaccine can prevent recurrence in disease-free conventionally treated node-positive (NP) and high-risk node-negative (NN) breast cancer patients at significant risk for recurrence. Since clinical efficacy is anticipated to occur as the result of long lasting memory immune responses induced by vaccination, repeated booster inoculations were scheduled as part of the trial. Here we present data on immune responses in patients who received boosters up to 24 months after completion of the primary vaccination series (PVS). Methods: The trial is enrolling NP or high-risk NN patients with any degree of HER2 expression (IHC 1-3+ or FISH > 1.2) rendered disease-free following standard of care therapy. The vaccine group (VG) received AE37+GM-CSF and control group (CG) GM-CSF alone in 6 monthly i.d. inoculations followed by boosters administered every 6 months x 4. Immunologic responses were assessed in vivo by dermal reactions at the inoculation site, and in vitro, against the AE36 peptide, with proliferation and IFN-γ ELISPOT assays. Results: 25 patients in the VG and 23 in the CG have completed their boosters. After the last booster (BRC24), 100%, 54% and 54% in the VG (vs. 9%, 18% and 27% in the CG) responded by dermal reaction, proliferation and IFN-γ ELISPOT, respectively. Mean dermal reactions (orthogonal mean in mm) in vaccinated patients was 25.9±3.13 at completion of the PVS (R6) and increased to 35.47±4.35 at BRC24 (p=0.01). VG patients increased their proliferation response (stimulation index, SI) to AE36 from 0.97±0.046 at baseline (R0) before vaccination to 2.27±0.57 at R6 (p=0.0003) which was maintained until BRC24 (SI 2.21±0,33, p<0.0001). The number of IFN-γ specific spots/106 PBMC increased from 26.88±12.36 at R0 to 40.35±17.02 (p=0.07) at R6, up to 62±16.82 (p=0.0076) at BRC24. Conclusions: Our data demonstrate that AE37 vaccine boosters enhance the immune responses against HER elicited during the PVS, thus sustaining long lasting immunity, a prerequisite for possible clinical efficacy which is currently being evaluated. Clinical trial information: NCT00524277.

Abstract P1-13-01: A randomized trial of CEF versus dose dense EC followed by paclitaxel versus AC followed by paclitaxel in women with node positive or high risk node negative breast cancer, NCIC CTG MA.21: Results of the final relapse free survival analysis.

Abstract Background: In 2000, cyclophosphamide(C), epirubicin(E) and fluorouracil (F) (CEF) and doxorubicin (A) and C followed by paclitaxel (T) (AC/T) given every three weeks were commonly used regimens in Canada and the USA to treat women with node positive or high risk node negative operable breast cancer. In a previous trial in women with locally advanced breast cancer, 3 months of dose-dense EC was equivalent to six months of CEF. We hypothesized that the addition of 3 months of a taxane following dose-dense EC would be superior to CEF alone or AC/T. In a randomized trial in women with early breast cancer we compared CEF, dose dense EC/T and AC/T. An interim analysis (JCO, 2010) conducted when 50% of the events for the relapse-free-survival (RFS) analysis were observed, demonstrated that AC/T administered every 3 weeks was significantly inferior to CEF or EC/T. The results of the final RFS including CEF versus EC/T will be presented. Methods: Women, 60 years or younger, with operable axillary node positive or high risk node negative breast cancer were randomized to adjuvant CEF, EC/T or AC/T. CEF was given for 6 cycles and consisted of: C 75 mg/m2 orally on Days 1–14, and E 60 mg/m2 and F 500 mg/m2, IV on Days 1 and 8. CEF patients received concurrent antibiotic prophylaxis. EC/T consisted of 6 cycles of EC every 14 days; E 120 mg/m2 and C 830 mg/m2, both IV on Day 1 with filgrastim 5 [ug]/kg/day subcutaneous from Days 2–13 and epoetin alpha 40,000 units subcutaneous once weekly. After completion of EC, 4 cycles of T 175 mg/m2 every 21 days with filgrastim and epoetin alpha were given. The AC/T regimen consisted of A 60 mg/m2 and C 600 mg/m2 IV every 21 days for 4 cycles. This was followed by T 175 mg/m2 every 21 days for 4 cycles. The final analysis for RFS was planned when 453 events were observed permitting the detection of a hazard ratio (HR) of 1.43 between CEF and AC/T and a HR of 1.43 between EC/T and the best of the other two arms. Quality of Life data using the EORTC C-30 and the Breast Cancer Chemotherapy questionnaires were collected throughout the study. The results will be available at the time of the presentation. Results: A total of 2104 women were enrolled between December 2000 and April 2005. The required 453 events for the RFS analysis were observed by the clinical cut-off date of March 30, 2012. At this point 369 deaths had been observed. The median follow-up is 87.5 months. Outstanding data and queries are currently being collected and reviewed with an expected database lock and final analysis mid August, 2012. Febrile neutropenia remains higher on the CEF and EC/T arms while more neuropathy was seen in the taxane containing regimens. Conclusions: Although the two regimens considered a standard of care at the time the study was initiated are no longer widely used, the trial results will enhance our understanding of the magnitude of benefit of taxane following an anthracycline, the significance of cumulative anthracycline dose, and the role of dose density/ intensity as backbone of conventional chemo regimens. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-01.

Abstract P1-13-04: Optimal duration of adjuvant chemotherapy for high risk node negative breast cancer patients: 6-year results of the prospective randomized phase III trial PACS 05.

Abstract BACKGROUND: In 2000, the NIH Consensus meeting concluded that 4 to 6 cycles of adjuvant chemotherapy appeared to provide an optimal benefit; So, we underwent a prospective randomized trial comparing 4 and 6 cycles of FEC 100 (JCO 2005; 23: 2686–2693) for high risk node negative breast cancer patients. METHODS: This study enrolled 18–65 y women with operable breast cancer, without axillary lymph node involvement, or presence of isolated tumor cells, with size superior to 1 cm and another poor prognostic factor: T > 2 cm, HR –, SBR grade II or III, age < 35 y. After adequate breast surgery and axillary lymph node dissection or sentinel node technique, they were randomized between arm A, 6 cycles of FEC 100, and arm B, 4 cycles, every three weeks. The local regional treatment was completed following usual recommendations. All HR+ patients received hormonal therapy for 5 years. After August 2005, patients with HER2+ tumors were excluded from this study. The primary end point was PFS at 5 years. This study was powered to detect a 6% difference in favour of 6 cycles. Between August 2002 and September 2006, 1516 patients were randomized; 1515 are analysed in ITT. Three patients in the B group did not receive any chemotherapy. There is no significant difference between the two arms for tumor and patient characteristics. RESULTS At a median follow-up of 73 months we observed regarding PFS a low event rate, 197 for the entire population (13%) 91 in arm A median PFS, vs. 106 in arm B median PFS, without any difference between the two groups for DFS, DDFS, local relapse, overall survival. There was no unexpected toxicity. In the arm A we observed more grade III and IV neutropenia, without congestive heart failure. CONCLUSION At a follow-up of 73 months, we observed a low relapse rate, with no significant difference between the two arms. Duration of FEC100 does not induce different outcomes in this population. Question of length of adjuvant treatment is still open with and without taxanes. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-04.

Abstract P1-13-03: Mature analysis of UK Taxotere as Adjuvant Chemotherapy (TACT) trial (CRUK 01/001); effects of treatment and characterisation of patterns of breast cancer relapse.

Abstract Introduction: TACT, an investigator-led study in 4162 women with node positive (N+ve) or high risk node negative (N-ve) early breast cancer (EBC), is the largest taxane trial unconfounded by treatment (trt) duration. At principal analysis, with 5 years follow-up (fup), no evidence of improved disease-free survival (DFS) was observed by switching to 4 cycles of docetaxel (D) after 4 cycles of FEC (Ellis, Lancet 2009). Results were provocative in suggesting differential effects according to ER & HER2 status. Longer fup provides opportunity to detect emergence of late trt effects overall & within phenotypic subgroups & explore patterns of recurrence, by tumor characteristics. Patients & methods: TACT recruited women with histologically confirmed completely resected invasive EBC from 104 centers (UK (103), Belgium (1)) between 02/2001 & 07/2003. Centers chose FEC (600/60/600 mg/m2 q3wk × 8) or E-CMF (E 100mg/m2 q3wk × 4 → CMF 100mg/m2 PO d1-14 or 600mg/m2 IV d1&8/40/600 mg/m2 q4wk × 4) as their control, reflecting standard UK practice. Patients (pts) were randomized to FEC-D (FEC q3wk × 4 → D 100 mg/m2 q3wk × 4) or control. 2523 pts were from FEC centers (FEC = 1265: FEC-D = 1258) & 1639 from E-CMF centers (E-CMF = 824; FEC-D = 815). Endocrine therapy was given for 5 years. Few pts received HER2 directed therapy; 589 pts had unknown HER2 status. Median fup is now 97.5 months; this analysis updates DFS & overall survival in the ITT population. It also explores patterns of relapse by phenotypic & clinical characteristics. Analyses of trt effect are stratified by ER status due to issues of non-proportionality of hazard associated with length of fup. Results: DFS events have been reported for 1329 pts (FEC-D=640, Control=689) giving an unadjusted hazard ratio (HR) & 95%CI (stratified by control regimen & ER status) of 0.93 (0.83, 1.03) overall; p = 0.16 in favor of FEC-D & for ER+ve/HER2-ve of 0.99 (0.84, 1.17), for ER+ve/HER2+ve) 0.97 (0.73, 1.30), for ER-ve/HER2+ve 0.74 (0.53, 1.03), & ER-ve/HER2-ve 0.93 (0.73, 1.17). 1017 patients have died (FEC-D=500, Control=517); unadjusted HR=0.98 (95%CI: 0.86, 1.10); p = 0.69 with intercurrent deaths (prior to distant relapse) reported for 80 pts (FEC-D=40, Control=40). Annual event rates show different pattern of disease relapse by phenotypic subgroup Graphical representation will further explore these patterns & associated sites of relapse. Discussion: With a median fup of >8 years no clear benefit has emerged for D over standard anthracyclines within the TACT pt group. Differential effects associated with different patterns of relapse remain of interest. TACT precedes use of antiHER2 therapy which is known to have impacted on early relapse risk in HER2+ve pts. The high relapse risk observed for pts with ER-ve/HER2-ve disease remains a current clinical challenge. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-13-03.

Abstract P2-01-02: Circulating Tumor Cells (CTC) may Express HER2/neu in Patients With Early HER2/neu Negative Breast Cancer – Results of the German SUCCESS C Trial

Abstract Background: There is growing evidence that the HER2/neu-status of distant metastases or minimal residual disease in blood and bone marrow may differ from the primary tumor in patients with breast cancer. The HER2/neu-status of CTCs was prospectively evaluated in patients with HER2/neu negative primary breast cancer randomized into the German multicenter SUCCESS C study. Methods: The SUCCESS C trial is a randomized Phase III study comparing FEC-Docetaxel (FEC-Doc) vs. Docetaxel-Cyclophosphamid (DC) as well as 2 years of a lifestyle-intervention in patients with early, HER2/neu negative, node positive or high-risk node negative primary breast cancer. As part of the translational research program, 23ml peripheral blood were drawn after adjuvant chemotherapy. In 505 samples, the prevalence of CTCs and their HER2/neu-status were assessed using the CellSearch System (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labelled with anti-CK8/18/19 and anti-CD45 antibodies. A fluorescein conjugate antibody with anti-CK-Fluorescein Isothiocyanate (FITC) was used for HER2/neu phenotyping. The cut-off for CTC-positivity was ≥ 1 CTC and for HER2/neu ≥ 1 CTC with strong HER2/neu-staining (+++). Results: 26,9% of pts (n = 136) were positive for CTCs (mean 1.78; range 1–7; median = 1). The number of detected CTC was distributed as follows: 1 CTC (n = 76; 55.9%), 2 CTCs (n = 35; 25.7%), 3 CTCs (n = 13; 9.6%), 4 CTCs (n = 7; 5.2%) and ≥ 5 CTCs (n = 5; 3.7%). HER2/neu staning of CTCs was not detectable or weak in 26.5% (n = 36) and 4.4% (n = 6) of CTC positive patients respectively and therefore categorized as HER2/neu negative. In 32.4% of the CTC-positive patients (n = 44), we detected moderate and in 36.8% (n = 50) strong HER2/neu-staining of ≥ 1 CTC per sample. No association was found between CTCs or the HER2/neu-status of CTCs with tumor size, histopathological grading, hormone receptor status or axillary lymph node involvement. Conclusions: The data of this trial confirm previous findings that patients with HER2/neu negative primary breast cancer can show HER2/neu positive minimal residual disease. These results underline the importance of frequent HER2/neu determination during follow up and disease progression. Survival data within the Success C trial will give further insight into the tumor biology of HER2/neu negative disease. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-01-02.

Early efficacy analysis of the AE37 vaccine in patients with HER2 low-expressing and triple-negative breast cancer.

109 Background: Peptide vaccines comprised of HLA class II epitopes, which elicit CD4+ T cell responses, play a critical role in potentiating immune responses. We are conducting a randomized phase II trial of AE37, a hybrid peptide created by the addition of the Ii-Key moiety (LRMK) to the HER2 helper epitope, AE36 (HER2 aa776-790). Here, we present efficacy data focusing on outcomes in patients with low HER2 (IHC 1+ or 2+) expression and triple negative breast cancer (TNBC). Methods: The trial is enrolling node positive or high risk node negative breast cancer patients with any degree of HER2 expression (IHC 1+, 2+ or 3+ or FISH > 1.2) rendered disease-free following standard of care therapy. Patients are randomized to receive either AE37+GM-CSF or GM-CSF alone in 6 monthly intradermal inoculations followed by booster inoculations administered every 6 months. Results: The trial has enrolled 254 patients; 105 in the vaccine group (VG) and 149 in the control group (CG). After a median follow-up of 22.3 months, the disease-free survival (DFS) rate in the VG is 90.3% vs 81.1% in the CG (p=.46), a 49% risk reduction. Evaluating patients with low HER2 expression (IHC 1+ or 2+), there are 53 VG patients and 77 CG patients. The groups are well-matched with respect to the percentage of patients with high grade tumors, tumors > 2cm, the rate of node positivity and ER/PR status (all p>.5). The DFS rate in the VG of low HER2 expressers is 89.8% vs 68.2% in the CG (p=.12), a 68% risk reduction. When limiting analyses to patients with TNBC (ER/PR negative, HER2 1+ or 2+), there are 13 VG patients and 23 CG patients. The groups are again well-matched with the exception of control patients having a larger percentage of tumors > 2 cm (70% vs 31%; p=.02). The DFS rate in the VG of TNBC patients is 83.3% vs 47.6% in the CG (p=.23), a 68% risk reduction. Conclusions: Early analyses suggest clinical benefit to vaccination with AE37, particularly in patients with low HER2-expressing tumors. Importantly, the benefit appears to persist in TNBC patients. Patients will continue to be followed per protocol for 5 years; however, these data suggest that a subsequent phase III trial should evaluate the vaccine in patients with low HER2-expressing disease to include TNBC.

Chemotherapy-induced amenorrhea in premenopausal breast cancer patients treated with adjuvant anthracycline and taxane based chemotherapy within the SUCCESS study.

554 Background: Chemotherapy induced amenorrhea (CIA) is often used as a surrogate marker for cytotoxic gonadal damage. The aim of this analysis was to identify predicitve factors for CIA in premenopausal breast cancer patients treated with adjuvant chemotherapy. Methods: The German multicenter, phase III SUCCESS trial compared 3 cycles of FEC q3w followed by 3x docetaxel q3w vs. FEC followed by Doc+gemcitabine as adjuvant treatment in patients with node positive or high risk node negative primary breast cancer. Premenopausal patients with hormone receptor positive tumors underwent endocrine treatment with tamoxifen (Tam) for 5 years. Additional goserelin (GnRH) for 2 years was given in the following cases: Age <40 years at study entry, premenopausal hormone status or regular menses within 6 months after chemotherapy. We retrospectively investigated CIA rates of 1.189 initially premenopausal patients during disease-free follow-up. Results: Median age at diagnosis was 44 years (range 21-50). The median follow up time was 44 months (range 1-62). 791 patients (66.5%) received endocrine treatment. Tam intake was reported in 370 patients, GnRH in 29 patients, Tam+GnRH in 392 patients. In 963 patients (81.0%) CIA occurred for ≥3 months after chemotherapy. In 22.7% of initially amenorrheic patients CIA was temporary. 192 patients (16.2%) had continuous menstrual bleeding. In multivariate analysis the risk of CIA was significantly higher in older patients, increasing by factor 1.32 per life year (p<0.0001). Tam intake was also associated with increased CIA rates (p=0.0032). Patients with combined Tam+GnRH were more likely to resume menses compared to patients without endocrine therapy (p=0.0056). Factors like the cytotoxic regimen, tumor stage, grading, the patient`s BMI or the use of GnRH analogues as ovarian protectants during chemotherapy did not correlate with CIA rates. Conclusions: Age was the strongest predictor for CIA. Tam administered alone increased CIA rates. Opposite effects were observed for patients who received Tam+GnRH. The addition of gemcitabine to sequential anthracyline-taxane based chemotherapy did not influence CIA.

Correlation of BMI with tumor stage in early breast cancer patients (pts): Pooled analysis of the German SUCCESS A, B, and C trials.

1602 Background: Independent from known prognostic factors, e.g., tumor size and nodal status, obesity is a risk factor for poor disease free, distant disease free, and overall survival in breast cancer. The aim of this analysis was to examine the correlation of the body mass index (BMI) with tumor characteristics in early breast cancer. Methods: We analyzed the data of 7,997 pts with early, node positive or high risk node negative primary breast cancer treated with adjuvant taxan-based chemotherapy within the German multicenter phase III SUCCESS A, B, or C trials. The pts’ tumor stage at primary diagnosis was classified according to the UICC tumor-node-metastasis (TNM) classification. Additionally, the tumor’s hormone-receptor status and HER2/neu status were determined. Before enrollment into the study each patient was grouped according to the WHO global database on BMI. Contingency table methods were used to analyze the correlation of BMI and tumor characteristics. Results: Among the 7,997 pts 100 (1.3%) pts were underweight, 3,556 (44.5%) pts were normal weight, 2,569 (32.1%) pts were overweight and 1,772 (22.2%) were obese. Of all pts 4,508 pts (56.4%) suffered from a pT2-4 tumor, 4830 (60.4%) showed lymph node involvement (pN1-3) and 7509 (93.9%) had G2-3 tumors. 5839 pts (73.0%) showed positivity for ER or PR and 935 (11.7%) for HER2/neu. Overweight and obese pts had significantly larger tumors compared to pts with normal BMI (p<0.0001; p<0.0001). Furthermore, overweight and obesity were associated with a significantly higher rate of lymph node involvement (p=0.0001; p=0.0003) respectively. In contrast neither grading, tumor histology, ER/PR-status nor HER2/neu-overexpression were correlated with BMI. Conclusions: These data are the first to show in a large number of pts that both obese and overweight women suffering from primary breast cancer have significantly larger tumors and more often positive axillary lymph nodes. As there are no differences in tumor biology, the advanced tumor stage might be due to more difficult and delayed detection of breast cancer and lymph node lesions in these women.

NSABP B-47: A phase III trial of adjuvant therapy comparing chemotherapy alone (six cycles of docetaxel plus cyclophosphamide or four cycles of doxorubicin plus cyclophosphamide followed by weekly paclitaxel) to chemotherapy plus trastuzumab in women with node-positive or high-risk, node-negative, HER2-low invasive breast cancer.

TPS1142 Background: Adjuvant studies utilizing trastuzumab in early HER2+ breast cancer demonstrated a large reduction in recurrence and death. Post-enrollment central testing showed HER2 non-amplified participants derived similar benefit. Methods: Selection of one of the two chemotherapy regimens is by physician choice: The non-anthracycline regimen is TC (docetaxel 75 mg/m2, cyclophosphamide 600 mg/m2) administered IV every 3 weeks for 6 cycles; the anthracycline regimen is AC followed by WP (doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 administered IV either every 3 weeks or every 2 weeks [per investigator discretion] for 4 cycles followed by paclitaxel 80 mg/m2 IV weekly for 12 doses). Patients are randomly assigned to receive chemotherapy with or without trastuzumab therapy. For patients receiving the TC chemotherapy regimen, trastuzumab is given every 3 weeks during and following chemotherapy until 1 year after the first trastuzumab dose (8 mg/kg loading dose; 6 mg/kg for the remaining doses). For patients receiving the AC followed by WP chemotherapy regimen, trastuzumab begins with the first dose of weekly paclitaxel and will be given weekly for 12 doses (4 mg/kg loading dose; 2 mg/kg for the remaining weekly doses). Following completion of WP, trastuzumab therapy continues with 6 mg/kg doses given every 3 weeks for a total of 1 year. Eligibility: Eligibility includes: node positive or high risk node negative female breast cancer patients; HER2 IHC 1+ or 2+ scores, but non amplified by FISH Statistical Design: The primary aim is to determine whether the addition of trastuzumab to chemotherapy improves invasive disease-free survival (IDFS). 3260 patients will be enrolled to provide statistical power of 0.9 to detect a 33% reduction in the hazard rate of IDFS using a one-sided alpha level of 0.025. Progress: Protocol was activated in January 2011. As of January 27, 2012, 486 of 3260 patients have been enrolled. Supported by NCI U10-12027, -37377, 69651, 69974, and Genentech, Inc.

HER2 expression on circulating tumor cells (CTC) in patients with early HER2-positive breast cancer: Results of the German SUCCESS B trial.

10540 Background: Recent reports showed a discrepancy in the Her2-status of metastases or minimal residual disease in blood and bone marrow compared to the primary tumor in patients with breast cancer. The Her2-status of CTC was prospectively evaluated in the German multicenter SUCCESS B study. Methods: The SUCCESS B trial is a randomized Phase III study comparing FEC-Docetaxel (Doc) vs. FEC-Docetaxel-Gemcitabine (Doc-G) as well as Her2 targeted therapy with Trastuzumab as adjuvant treatment in patients with early, Her2 positive, node positive or high risk node negative primary breast cancer. As part of the translational research program, 23ml of peripheral blood were drawn before adjuvant chemotherapy. In 638 samples CTC and Her2-status were assessed using the CellSearch System (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labeled with anti-CK8/18/19, anti-CD45 antibodies as well as a fluorescein conjugate antibody for Her2 phenotyping. Cutoff for CTC-positivity was ≥1 CTC and for Her2 ≥1 CTC with strong Her2-staining (+++). Results: 40.2% of pts (n=257) were positive for CTC (mean 4.52; range 0-1689). The number of detected CTC was distributed as follows: 1 CTC (n=112; 43.6%), 2 CTC (n=65; 25.3%), 3 CTC (n=36; 14.0%), 4 CTC (n=12; 4.7%) and ≥5 CTC (n=31; 12.1%). Her2 status on CTC was negative or weak in 12.5% (n=32) and 8.9% (n=23) of CTC positive patients respectively and therefore categorized as Her2 negative. In 21.4% (n=55) we detected moderate and in 57.2% (n=147) strong Her2-staining of ≥1 CTC per sample. Therefore 57.2% of CTC-positive samples were diagnosed as Her2 positive and 21.4% as questionable. No association was found between the detection of CTC or the Her2-status on CTC with tumor size, histopathological grading, hormone receptor status or axillary lymph node involvement. Conclusions: The data of this trial confirms the frequent discordance of Her2 expression on CTC compared to the primary tumor. Survival data within the Success B trial will give further insight into the tumor biology of Her2 positive disease and the role of the Her2-status on CTC to predict treatment efficacy.

Abstract LB-218: Immune response assessment in a phase II trial of AE37 HER2 peptide vaccine

Abstract Introduction: AE37 is the Ii-Key hybrid of the HER2 derived peptide AE36 (776-790). A phase I trial administering AE37 with the immunoadjuvant GMCSF demonstrated the vaccine to be safe and capable of stimulating CD4+helper T cells with HER2 specific anti-tumor activity. Here we present an analysis of our immunologic testing of our prospective, randomized, single-blinded, phase II trial of the AE37+GMCSF vs. GMCSF alone for the prevention of breast cancer recurrence. Methods: After completion of indicated standard therapy; disease-free, node positive or high risk node negative breast cancer patients were randomized to receive either AE37+GMCSF (VG) or GMCSF (CG) in 6 monthly intradermal inoculations. Patients were enrolled with any level of HER2 expression (IHC 1+ 2+ or 3+). Specific immunologic responses to both AE36 and AE37 were evaluated. In vitro responses were measured using [3H]-thymidine incorporation assay and in vivo responses using delayed-type hypersensitivity (DTH) reactions. T regulatory cells (Tregs) were measured throughout vaccination series. Data was analyzed using Pearson chi-squared tests. Results: To date 217 patients have enrolled (VG=109, CG=108). HER2 over-expression was present in 54 (49.5%) VG and 51 (47.2%) CG, p=0.783. VG had 59 (51.4%) ER positive and CG had 58 (53.7%, p=0.985). The in vitro proliferation responses with a stimulation index (SI) ≥2 were classified as high responders VG 36 (33.0%) vs CG 8 (7.4%, p<0.001), SI 1.5-2 were classified as low responders VG 19 (17.4%) vs CG 16 (14.8%, p=0.600) or SI <1.5 as non responders VG 54(49.5%) vs CG 84(77.8%, p<0.001). The in vivo DTH reactions measured in 149 (VG n=86, CG n=63) were stratified as responders with ≥5mm (VG 74(86.0%) vs CG 17(27.0%) p<0.0001) or non responders with <5mm (VG 12 (14.0%) vs CG 46(73.0%) p<0.001). Tregs responses were measured in 107 patients (VG n=56, CG=51) and categorized according to percent change from pre-vaccination baseline as an increase >110% (5(8.9%) VG vs 10 (19.6%) CG, p=0.112), no change 90-110% (10 (17.9%) VG vs 13 (25.5%) CG, p=0.337), or decrease <90% (41 (73.2%) VG vs 28 (54.9%), p=0.048). Conclusion: VG patients had significant immunologic responses compared to CG. VG had a statistical decrease in Tregs compared to CG. Monitoring immunologic tests and Tregs throughout the vaccination process may stratify patients into responders and non responders and thus assist in identifying patients that will have recurrence. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-218. doi:1538-7445.AM2012-LB-218

P1-13-01: An Update of a Phase II Trial of the HER2 Peptide AE37 Vaccine in Breast Cancer Patients To Prevent Recurrence.

Abstract Introduction AE37 is the Ii-Key hybrid of the HER2−derived peptide AE36 (HER2:776–790). A phase I trial administering AE37 with the immunoadjuvant GM-CSF demonstrated the vaccine to be safe and capable of stimulating CD4+helper T-cells with HER2−specific anti-tumor activity. Here we present an update of our prospective, randomized, single-blinded, phase II trial of the AE37 vaccine for the prevention of breast cancer recurrence in disease-free, high risk patients. Methods After completion of standard therapy, disease-free, node positive or high risk node negative breast cancer patients were randomized to receive either AE37+GM-CSF (vaccine) or GM-CSF alone (control) in six monthly intradermal inoculations. Patients were enrolled with any level of HER2 expression, (IHC 1+ 2+ or 3+). Specific immunologic responses to both AE36 and AE37 were evaluated in all patients at pre-determined intervals: before (RO), mid-series (R3), upon completion (R6), and at six (RC6) and 12 (RC12) months after completion of the vaccine series. In vitro responses were measured using the [3H]-thymidine incorporation assay and in vivo responses using delayed-type hypersensitivity (DTH) reactions. The trial's primary endpoint is disease recurrence. Results To date, 215 patients have enrolled (vaccine=92, control=123). 99% of local and systemic toxicities were ≤grade 2 or less. There were no grade 4–5 local or systemic toxicities and no difference between toxicity profiles of vaccine and control groups. Vaccine patients exhibited a statistically significant increase from baseline in AE36 and AE37 proliferative responses at each time point, including maintenance of this response up to 12 months post-vaccination (AE36 (cpm): R0=0, R3=1335, R6=1242, RC6=1586, RC12=1360; AE37: R0=0, R3=2859, R6=2300, RC6=3235, RC12=3279, p<0.001) while there have been no proliferative changes for control patients (AE36: R0=91, R3=95, R6=97, RC6=126, RC12=48; AE37: R0=291, R3=399, R6=319, RC6=103, RC12=0). Vaccine patients also had statistically significant increases in DTH reactions to both AE36 and AE37 (AE36 (mm): R0=0, R6=15, RC6=15, RC12=15; AE37: R0=0, R6=24, RC6=17, RC12=20 p=<0.001) while controls had no response (AE36: R0, R6, RC6, RC12=0; AE37: R0, R6, RC6, RC12=0). With a median follow up of 17 months, breast cancer recurrences were reduced by 42% in vaccine patients compared to control patients (7.6% vs. 13.2%, p=0.15). In an analysis of patients with low HER2 expression (IHC 1 or 2+), vaccine patients experienced a 49% reduction in recurrence compared to controls (9.5% vs. 18.6%, p=0.16) with no reduction seen in HER2 over-expressing patients (6.0% vs. 7.9%, p=0.49). Conclusions The AE37 vaccine is safe and well tolerated with only mild toxicity, which is attributable to the GM-CSF immunoadjuvant. The AE37 vaccine elicits strong peptide specific in-vivo and ex-vivo immune responses, which are maintained for 12 months after completion of the vaccine series. While the number of recurrences are still low, the recurrence rate appears to decrease in vaccinated patients. Administration of the AE37 vaccine may reduce the risk of breast cancer recurrence with the greatest benefit in patients with low levels of HER2 expression. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-13-01.