Brufsky, Adam M

503 Background: TAILORx established that endocrine therapy (ET) alone is non-inferior to adjuvant chemotherapy (CT) plus ET in EBC and a 21-gene RS of 11-25, with some benefit if ≤50 years (y) with RS 16-25 (PMID: 29860917). We evaluated whether clinical risk (tumor size & histologic grade) provides additional prognostic information to RS, a secondary trial objective. Methods: Clinical risk by was assessed by Adjuvant! (version 8.0) using MINDACT criteria (PMID 27557300), defined as low clinical risk (LCR - tumor ≤3 cm and low grade, <2 cm and intermediate grade, or ≤1 cm and high grade) or high clinical risk (HCR -not meeting LCR criteria). Results: Of 9427 women with RS and clinical risk information, 70% were LCR and 30% HCR, with comparable distribution by age ( ≤50 vs. >50). The RS was 26-100 in 9% of LCR and 27% of HCR patients, with similar distributions by age. Although LCR/HCR provided additional prognostic information in each RS category for iDFS, including RS 0-10 (9-year rates 86.7% vs. 75.7% LCR vs. HCR), 11-25 (85.4% vs. 78.9%), and 26-100 (82.0% vs. 70.4%), iDFS rates were similar irrespective of CT (no vs. yes) in the entire RS 11-25 cohort whether LCR (85.8% vs. 85.1%) or HCR (79.8% vs. 77.9%). DRFI rates were also similar irrespective of CT in the RS 11-25 cohort or > 50y group whether LCR (96.0% vs. 96.1% overall; 96.5% vs. 96.0% > 50y) or HCR (92.3% vs. 89.9% overall; 91.7% vs. 90.7% >50y). For women ≤50y, the absolute reduction in distant recurrence from CT with a RS of 16-20 (N=923) was -0.2% (standard error [SE]±2.1%) for LCR vs. 6.5%(SE±4.9%) for HCR (vs. 1.6%[SE±1.9%] overall), whereas for a RS 21-25 (N=492) it was 6.4% (SE±4.9%) for LCR vs. 8.6% (SE±6.2%) for HCR (vs. 6.5%[SE±3.7%] overall). Conclusions: Clinical risk stratification provides additional prognostic information to the 21-gene RS, but not prediction of CT benefit in the overall TAILORx population or those > 50y, and facilitates more refined estimates of absolute CT benefit for women ≤50y with a RS 16-25. (Funded by National Cancer Institute, Komen Foundation, Breast Cancer Research Foundation). Clinical trial information: NCT00310180.

Abstract Background: Thirty percent of patients with breast cancer may experience chest wall recurrence, which is associated with a higher risk of developing distant metastases and a poor prognosis. Cancer cells may evade immune rejection through the programmed cell death 1 (PD-1) pathway. Pembrolizumab, an anti-PD-1 antibody, binds PD-1 and inhibits its interaction with the programmed death ligand 1 (PD-L1) to facilitate tumor immune rejection. We hypothesize that pembrolizumab may be an effective therapy in chest wall recurrence, given the inflammatory nature, and the high expression of PD-1 in tumors with lymphovascular invasion. Platinum agents may enhance anti-tumor immunity in a synergistic manner, and the combination of pembrolizumab and carboplatin has demonstrated efficacy in advanced lung cancer. In this study, the combination of pembrolizumab and carboplatin is being evaluated in breast cancer patients with chest wall disease. Methods: This is a randomized phase II study of breast cancer patients with advanced, unresectable breast cancer involving the chest wall, being conducted through the Translational Breast Cancer Research Consortium (TBCRC). Patients may have hormone resistant disease (at least 2 prior lines of hormone therapy), triple negative breast cancer, or refractory HER2+ disease for enrollment. They may have other sites of distant metastases, have received any number of prior lines of therapy, have had prior surgery, but prior chest wall radiation is not necessary. Eighty-four patients at 7 TBCRC sites will be randomized 2:1 to treatment with pembrolizumab 200 mg IV and carboplatin AUC 5 IV every 3 weeks followed by pembrolizumab 200 mg IV alone every 3 weeks (Arm A, n=56) or carboplatin AUC 5 IV every 3 weeks (Arm B, n=28), with an option for patients in Arm B to cross-over to single agent pembrolizumab 200 mg IV every 3 weeks (arm Bx) on progression. Patients will undergo imaging with CT chest, abdomen, and pelvis at baseline and every 2 cycles of treatment for response evaluation. The primary endpoint is the disease control rate in the chest wall and distant sites at 18 weeks of treatment, and this study is powered to determine a 20% difference in disease control rates between arms A and B (hazard ratio of 0.52, α= 0.10, β= 0.20). After 18 patients are enrolled into Arm B, an interim analysis for futility will be conducted to enable early closure of that arm for lack of efficacy. Secondary endpoints in the study are toxicity, progression free survival, and response based on PD-L1 expression and irRECIST. Exploratory endpoints, which will be studied using peripheral blood testing and chest wall tumor biopsies at baseline and after 2 cycles of treatment, include determining associations of response with changes in tumor and peripheral blood immune composition, soluble PD-L1 expression, circulating tumor cells, cell free DNA, and tumor PD-L1 and MYC genomic expression. Ultimately this study promises to improve our understanding of checkpoint inhibition and chemotherapy for chest wall disease, and the underlying mechanism of action. This study is open for enrollment and 2 patients are currently enrolled. (NCT03095352). Citation Format: Vidula N, Goga A, Hwang J, Liu MC, Park BH, Nanda R, Pohlmann PR, Storniolo AM, Brufsky A, Abramson V, Rugo HS. A randomized phase II study of pembrolizumab in combination with carboplatin versus carboplatin alone in breast cancer patients with chest wall disease, with immunologic and genomic correlative studies [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 OT3-04-04.

Abstract Background: Black race is associated with worse outcomes in localized hormone receptor (HR)-positive breast cancer in population-based and in clinical trial cohorts, whether using self-identified race (Albain et al. JNCI 2009 [PMID: 19584328; Sparano et al. JNCI 2012 [PMID: 22250182) or genetically-identified race (Schneider et al. J Precision Oncol 2017 [PMID: 29333527]). This disparity persists after adjustment for treatment delivery parameters (Hershman et al. JCO 2009 [PMID:19307504]). We evaluated clinicopathologic characteristics, treatment delivered and clinical outcomes in the Trial Assigning Individualized Options for Treatment (TAILORx) by race and ethnicity (Sparano et al. NEJM 2018 [PMID: 29860917]). Methods: The analysis included 9719 evaluable TAILORx participants. The association between clinical outcomes and race (white, black, Asian, other/unknown) and ethnicity (Hispanic vs. non-Hispanic) was examined, including invasive disease-free survival (iDFS), distant relapse-free interval (DRFI), relapse-free interval (RFI), and overall survival (OS). Proportional hazards models were fit including age (5 categories), tumor size (&gt;2 cm vs. &lt;=2 cm), histologic grade (high vs. medium vs. low vs. unknown), continuous recurrence score (RS), race, and ethnicity in the overall population and randomized treatment arms in the RS 11-25 cohort. Results: The study population included 8189 (84%) whites, 693 (7%) blacks, 405 (4%) Asians, and 432 (4%) with other/unknown race. Regarding ethnicity, 7635 (79%) were non-Hispanic, 889 (9%) Hispanic, and 1195 (12%) unknown. There was no significant difference in RS distribution (p=0.22) in blacks compared with whites, or in median (17 vs. 17) or mean RS (19.1 vs. 18.2). There was likewise no difference in Hispanic vs. non-Hispanic ethnicity for RS distribution (p=0.72) or median (17 vs. 17) or mean RS (18.5 vs. 18.0). Black race (39% vs. 30%) and Hispanic ethnicity (39% vs. 30%) were both associated with younger age (&lt;/=50 years) at diagnosis. The use and type of adjuvant chemotherapy and endocrine therapy, and duration of endocrine therapy, were similar in black (vs. white) and Hispanic (vs. non-Hispanic) populations. In proportional hazards models, black race (compared with white race) was associated with worse clinical outcomes in the entire population and in those with a RS 11-25 (see table). Hispanic ethnicity was generally associated with better outcomes (compared with non-Hispanic ethnicity). For the cohort with a RS of 11-25, there was no evidence for chemotherapy benefit for any racial or ethnic group. Race (black vs.white) and clinical outcomes in proportional hazards modelsClinical endpointEntire Population (N=693 black) Hazard ratio for eventRS 11-25 (N=471 black) Hazard ratio for eveniDFS1.33 (p=0.005)1.49 (p=0.001)DRFI1.21 (p=0.28)1.60 (p=0.02)RFI1.39 (p=0.02)1.80 (p&lt;0.001)OS1.52 (p=0.005)1.67 (p=0.003 Conclusions: In patients eligible and selected for participation in TAILORx, black women had worse clinical outcomes despite similar 21-gene assay RS results and comparable systemic therapy. This adds to an emerging body of evidence suggesting a biologic basis or other factors contributing to racial disparities in HR-positive breast cancer that requires further evaluation. Citation Format: Albain K, Gray RJ, Sparano JA, Makower DF, Pritchard KI, Hayes DF, Geyer, Jr. CE, Dees EC, Goetz MP, Olson, Jr. JA, Lively T, Badve SS, Saphner TJ, Wagner LI, Whelan TJ, Ellis MJ, Paik S, Wood WC, Ravdin PM, Keane MM, Gomez HL, Reddy PS, Goggins TF, Mayer IA, Brufsky AM, Toppmeyer DL, Kaklamani VG, Berenberg JL, Abrams J, Sledge, Jr. GW. Race, ethnicity and clinical outcomes in hormone receptor-positive, HER2-negative, node-negative breast cancer: results from the TAILORx trial [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 GS4-07.

PurposeBevacizumab improves progression-free survival but not overall survival in patients with metastatic breast cancer. E5103 tested the effect of bevacizumab in the adjuvant setting in patients with human epidermal growth factor receptor 2–negative disease.Patients and MethodsPatients were assigned 1:2:2 to receive placebo with doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (arm A), bevacizumab only during AC and paclitaxel (arm B), or bevacizumab during AC and paclitaxel followed by bevacizumab monotherapy for 10 cycles (arm C). Random assignment was stratified and bevacizumab dose adjusted for choice of AC schedule. Radiation and hormonal therapy were administered concurrently with bevacizumab in arm C. The primary end point was invasive disease–free survival (IDFS).ResultsFour thousand nine hundred ninety-four patients were enrolled. Median age was 52 years; 64% of patients were estrogen receptor positive, 27% were lymph node negative, and 78% received dose-dense AC. Chemotherapy-associated adverse events including myelosuppression and neuropathy were similar across all arms. Grade ≥ 3 hypertension was more common in bevacizumab-treated patients, but thrombosis, proteinuria, and hemorrhage were not. The cumulative incidence of clinical congestive heart failure at 15 months was 1.0%, 1.9%, and 3.0% in arms A, B, and C, respectively. Bevacizumab exposure was less than anticipated, with approximately 24% of patients in arm B and approximately 55% of patients in arm C discontinuing bevacizumab before completing planned therapy. Five-year IDFS was 77% (95% CI, 71% to 81%) in arm A, 76% (95% CI, 72% to 80%) in arm B, and 80% (95% CI, 77% to 83%) in arm C.ConclusionIncorporation of bevacizumab into sequential anthracycline- and taxane-containing adjuvant therapy does not improve IDFS or overall survival in patients with high-risk human epidermal growth factor receptor 2–negative breast cancer. Longer duration bevacizumab therapy is unlikely to be feasible given the high rate of early discontinuation.

LBA1 Background: In hormone receptor (HR)-positive, HER2-negative, axillary node (AN)-negative breast cancer, the 21-gene expression assay (Oncotype DX Recurrence Score [RS]) is prognostic for distant recurrence, prognostic for low recurrence with endocrine therapy alone if low (0-10), and predictive of chemotherapy benefit if high (26 or higher). We performed a prospective, randomized trial of endocrine therapy (ET) versus chemoendocrine therapy (CET) in women with a mid-range RS of 11-25. Methods: Eligibility criteria included women 18-75 years of age with HR-positive, HER2-negative, axillary node (AN)-negative breast cancer and tumors 1.1-5.0 cm in size (or 0.6-1.0 cm and int/high grade) and agreed to have chemotherapy assigned or randomized based on the RS. Women with a mid-range RS (11-25) were randomized to receive ET or CET. The primary endpoint was invasive disease-free survival (iDFS), and the trial was designed to show non-inferiority for ET alone by not rejecting equality (hazard ratio [HR] margin up to 1.322 for omission of chemotherapy, 1-sided type I error rate 10%, type II error rate 5%). The target sample size was adjusted to compensate for non-adherence to randomized treatment, and the protocol-specified final analysis was triggered after 835 iDFS events. Results: Of the 10,253 eligible women enrolled between 4/7/06-10/6/10, 6711 (65.5%) had a RS of 11-25 and adequate information. There were 836 iDFS events at final analysis with a median followup of 90 months. ET was non-inferior to CET for iDFS (HR 1.08, 95% confidence intervals [CI] 0.94, 1.24, p=0.26) in the intention-to-treat (ITT) population. ET was also non-inferior for distant recurrence-free interval (DRFI; HR 1.03, p=0.80), recurrence-free interval (RFI; HR 1.12, p=0.28), and overall survival (OS; HR 0.97, p=0.80). Nine year rates were similar for iDFS (83.3% vs. 84.3%), DRFI (94.5% vs. 95.0%), RFI (92.2% vs. 92.9%), and OS (93.9% vs. 93.8%). Recurrence accounted for 338 (41.6%) the first iDFS event, of which 199 (23.8%) were distant recurrences. Treatment interaction tests were significant for age (iDFS p=0.03; RFI p= 0.02), but not menopause, tumor size, grade, or RS (continuous or RS 11-15, 16-20, 21-25). Conclusions: In women with HR-positive, HER2-negative, AN-negative breast cancer and a RS of 11-25, adjuvant ET was not inferior to CET in the ITT analysis. (Funded by NCI, BCRF, and Komen Foundation.) Clinical trial information: NCT00310180.

36 Background: Black race is associated with worse outcomes in localized breast cancer. We evaluated the characteristics of patients enrolled in the Trial Assigning Individualized Options for Treatment (TAILORx) by race and ethnicity. Methods: The analysis included 10,071 evaluable patients with Recurrence Score (RS) data. Eligibility criteria included: (1) T1-2, N0 disease, (2) estrogen receptor (ER) and/or progesterone receptor (PR) positive disease that was also HER2/neu negative, (3) age 75 years or younger and medically appropriate for adjuvant systemic chemotherapy. Results: The study population included 8,501 whites (84%), 722 blacks (7%), 423 Asians (4%), and the remainder other/unknown race. With regard to ethnicity, 7,916 were nonHispanic (79%), 919 were Hispanic (9%), and 1,236 were of unreported ethnicity (12%). There was no significant difference in RS distribution (p = 0.14), median RS (17 vs. 17), and mean RS (19.6 vs. 18.4) in blacks compared with nonblacks. There was likewise no difference in Hispanic vs. nonHispanic ethnicity for RS distribution (p = 0.53), median RS (17 vs. 17), and mean RS (18.6 vs. 18.4). Blacks were significantly more likely to be younger (39% vs. 30% < 50 years), have larger tumors (37% vs. 31% > 2 cm), poor histologic grade (25% vs. 17%), and PR-negative disease (14% vs. 10%) (Chi square test p < 0.05). Hispanic women were also significantly younger (39% vs. 30% < 50 years), and demonstrated marginal but statistically significant differences in tumor size (65% vs. 69% > 2 cm), histologic grade (20% vs. 18% poor), and PR expression (12% vs. 10% negative) (Chi square test < 0.05). In 974 patients with information on body mass index (BMI), there was no correlation between BMI and RS (r = -0.04). BMI was higher for blacks than whites (medians 31.6 vs. 28.9, p = 0.02, Wilcoxon test), but not in Hispanics. Conclusions: In patients selected for participation in TAILORx there were no significant differences in RS by race, ethnicity, and BMI. Black and Hispanic patients were significantly younger, and blacks had tumors that were larger and more likely to be associated with poor grade. Clinical trial information: NCT00310180.

100 Background: Combining BEV with CT significantly improved progression-free survival (primary endpoint) in the E2100, AVADO, and RIBBON-1 trials in the 1st-line setting and the RIBBON-2 trial in the 2nd-line setting. Primary efficacy and safety results from RIBBON-2 have been published; here we present final OS results. Methods: Eligible patients (pts) had MBC that had progressed on 1st-line CT without BEV. 2nd-line CT (taxane, gemcitabine, capecitabine, or vinorelbine) was chosen before 2:1 randomization to CT with either BEV (10 mg/kg q2w or 15 mg/kg q3w) or PL continued until progression. Stratification factors were 2nd-line CT, hormone receptor status, and time from MBC diagnosis to 1st progression. All pts could receive BEV at progression. The primary endpoint was PFS. Final analysis of OS, a secondary endpoint, in the intent-to-treat population was planned after 557 events and provided 80% power to detect a hazard ratio (HR) of 0.77 (median OS increased from 14.0 to 18.2 months) at α=0.04. Results: At the time of data cutoff (Oct. 31, 2011), 184 (82%) of 225 pts in the CT/PL arm and 376 (82%) of 459 pts in the CT/BEV arm had died. BEV was administered in subsequent treatment lines in 12% vs 6% of pts, respectively. There was no difference in OS between treatment arms: HR 1.013 (95% CI 0.845–1.215), log-rank p=0.8843. Median OS was 17.8 months with CT/PL vs 18.6 months with CT/BEV. The 1-year OS rates were 69% vs 71%, respectively. Subgroup analyses by CT cohort showed HRs ranging from 0.86 (95% CI 0.58–1.29) in the capecitabine cohort (n=144) to 1.44 (95% CI 0.82–2.53) in the vinorelbine cohort (n=76). HRs were close to 1 for the two largest CT cohorts (taxane and gemcitabine). Exploratory analysis in the subgroup of patients with triple-negative MBC showed a HR of 0.85 (95% CI 0.58–1.26). Updated safety results were similar to those previously reported from the primary analysis. There were fewer fatal adverse events in the CT/BEV arm (1.5%) than in the CT/PL arm (3.2%). Conclusions: Final OS results from RIBBON-2 reveal no difference between treatment arms. No new safety signals were observed.