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Dayao, Zoneddy

https://orcid.org/0000-0003-2773-8382

Mayo Clinic

University of New Mexico

Citations 6

Abstract RF3-04: Tumor-informed circulating tumor DNA analysis to assess molecular residual disease for prognosis and prediction of benefit from palbociclib in the PALLAS trial
Parsons, H. A., Ballman, K., Heitzer, E., Watson, M., Balic, M., Renner, Derrick , Kalashnikova, E., Steger, G., Balko, J. M., Martín, M., Rodriguez, A. A., Dayao, Zoneddy , Chan, A., Gal-Yam, E. Nili, Liu, M. C., Isaacs, C., Los, Maartje, Gil, M. Gil, Felder, B., Denkert, C., Fasching, P. A., Liu, F., O'Donnell, T V, Mayer, E. L., Gnant, M., Symmans, W. F., DeMichele, A. M., Parsons, H. A., Ballman, K., Heitzer, Ellen , Hlauschek, Dominik , Kalashnikova, E. , Steger, G.G., Novik, Yelena , Rodriguez, A., Chan, Arlene , Gal‐Yam, Einav Nili , Liu, M. C., Isaacs, Claudine , Los, Maartje , Fasching, Peter A , O'Donnell, T., Gnant, Michael , Symmans, W. Fraser , DeMichele, Angela

Clinical Cancer Research | February 17, 2026 | Volume: 32 | Issue: 4_Supplement | Pages: RF3-04-RF3-04

10.1158/1557-3265.sabcs25-rf3-04 Get It

Abstract Background: PALLAS (PALbociclib CoLlaborative Adjuvant Study, NCT02513394) is a randomized phase III trial comparing two years of the CDK4/6 inhibitor palbociclib combined with the physician’s choice of adjuvant endocrine therapy, versus endocrine therapy alone for patients with Stage II-III hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer. Molecular residual disease (MRD) detection via circulating tumor DNA (ctDNA) testing was a predefined biomarker analysis to identify patients at highest risk of recurrence. Methods: PALLAS participants with available tumor block, at least a baseline (pre-study treatment) plasma sample, and either whole blood or buffy coat were randomly selected from the overall study population. Plasma samples on cycle 1 day 1 (C1D1), cycle 6 day 1 (C6D1), and at the end of treatment (EOT) were collected, processed, and stored. Nucleic acids were extracted from primary tumor tissue or, when primary tissue was insufficient, from post-neoadjuvant tumor tissue, provided the sample had sufficient material and tumor cellularity (>25 mm2 tissue area with ≥20% tumor nuclei). Data from next generation sequencing of tumor tissue and matched normal DNA were used to create a personalized ctDNA SignateraTM assay (Natera, Inc.) for MRD assessment in the peripheral blood. ctDNA was reported as mean tumor molecules/mL (MTM/mL) of plasma. The primary endpoint was distant recurrence-free interval (DRFI) based on ctDNA status. Cox Proportional Hazards models were used to evaluate prognosis and predictive interactions. To minimize bias, the biorepository and laboratory teams were blinded to participant identity. Results: In total, 1280 participants were randomly selected for inclusion in this preplanned ctDNA sub-study. WES and WGS are being conducted on tissue, and Signatera results will be generated. Results for association of MRD status (positive/negative) and MTM/mL with DRFI in the context of 7 year median follow up of this study cohort will be reported. Conclusions: The planned analysis is ongoing and the presented work will provide data from the first randomized phase 3 adjuvant study in HR+/HER2- breast cancer to report MRD status by treatment arm. Citation Format: H. A. Parsons, K. Ballman, E. Heitzer, M. Watson, M. Balic, D. Hlauschek, D. Renner, E. Kalashnikova, G. Steger, J. M. Balko, Y. Novik, M. Martin, A. A. Rodriguez, Z. Dayao, A. Chan, E. Nili Gal-Yam, M. C. Liu, C. Isaacs, M. Los, M. Gil Gil, B. Felder, C. Denkert, P. Fasching, F. Liu, T. O'Donnell, E. L. Mayer, M. Gnant, W. F. Symmans, A. DeMichele. Tumor-informed circulating tumor DNA analysis to assess molecular residual disease for prognosis and prediction of benefit from palbociclib in the PALLAS trial [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr RF3-04.
Abstract PO3-02-05: Racial and Ethnic Differences in Clinical Outcomes among North American Patients with Hormone Receptor-Positive, HER2-negative, Early Breast Cancer in the PALLAS Trial (AFT-05)
Kantor, Olga , Dueck, Amylou, Burstein, Harold J. , Shepherd, Lois E. , Hahn, Olwen, Anderson, D. Mark , Rugo, Hope, Dayao, Zoneddy , Clifton, Katherine , Lu, Dongrui R. , O’Brien, Patrick, Scovil, Sara, Fayanju, Oluwadamilola M. , Dueck, Amylou C. , Gnant, Michael , Goetz, Matthew P. , Isaacs, Claudine , Anderson, Daniel, Miller, Kathy D. , Traina, Tiffany A , Clifton, Katherine , Winer, Eric P. , Wolff, Antonio C. , Wolmark, Norman , DeMichele, Angela , Mayer, Erica L.

Cancer Research | May 2, 2024 | Volume: 84 | Issue: 9_Supplement | Pages: PO3-02-05-PO3-02-05

10.1158/1538-7445.sabcs23-po3-02-05 Get It

Abstract Introduction: Analyses of multiple clinical trials have suggested racial and ethnic disparities in outcomes for early-stage, hormone receptor-positive and HER2-negative (HR+HER2-) breast cancer, however, none of these studies examined the use of adjuvant CDK4/6 inhibitors. The objective of this study was to explore racial and ethnic differences in toxicity, treatment duration, and disease outcomes in patients (pts) with early-stage HR+HER2- breast cancer treated with or without adjuvant palbociclib on the PALLAS trial. Methods: The PALLAS phase III, global, open-label trial randomized 5,796 pts with stage II-III HR+HER2- breast cancer to 2 years of palbociclib plus ongoing provider/patient choice adjuvant endocrine therapy (ET+palbo) vs. ET alone (ET). The analytic cohort was limited to pts enrolled in North America with known self-reported race and ethnicity (Non-Hispanic White, Non-Hispanic Black, Hispanic, Asian or Pacific Islander). Descriptive statistics were used to examine treatment characteristics, early discontinuation, and toxicity by race and ethnicity. Kaplan-Meier curves were used to estimate 3-year locoregional recurrence-free survival (LRFS) and invasive disease-free survival (IDFS) stratified by racial and ethnic group. Cox proportional hazards models were used identify predictors of LRFS and IDFS. Results: 2,547 North American pts were randomized and included in the intent-to-treat population with a median follow-up of 59.8 months; 1,996 (78.4%) identified as Non-Hispanic White (NHW), 132 (5.2%) Non-Hispanic Black (NHB), 156 (6.1%) Hispanic, and 134 (5.3%) Asian or Pacific Islander (API). Stage, performance status, type of surgery, and prior radiation were similar across racial and ethnic groups. Age, body mass index, grade, and prior chemotherapy differed by race and ethnicity (p< 0.05). Median age was lowest in API pts and highest in NHW pts (47.5 vs 53.0 years, respectively). Median body mass index was lowest in API and highest in NHB pts (24.4 vs 30.9). NHB pts were most likely to have high-grade disease (40.9% vs 26.9-30.5% in other groups). NHW pts were least likely to have received prior chemotherapy (81.0% vs 87.1-91.0%). Palbociclib early discontinuation was lowest in NHB pts (50.7%) and highest in Hispanic pts (65.9%), p=0.14. ET early discontinuation was similar across all groups (p=0.35). Palbociclib grade 3-4 overall toxicity was variable across groups (NHW 71.6%, NHB 79.1%, Hispanic 69.5%, API 85.2%), but this variation did not reach statistical significance (p=0.07). Neutropenia was highest in API pts (90.0% vs 57.3% in NHW, 58.2% in NHB, and 51.2% in Hispanic pts, p< 0.01). Overall 3-year LRFS was 98% (95% CI 97-98%) and IDFS was 89% (95% CI 88-90%). LRFS and IDFS were statistically similar by race and ethnicity and within each study arm (Table). No differences in LRFS or IDFS were seen by race or ethnicity in adjusted models (p=0.95). Conclusions: In this clinical trial population of HR+HER2- breast cancer patients exposed to similar treatments, no racial/ethnic differences were seen in short-term LRFS or IDFS across study arms. Differences in palbociclib toxicity by racial and ethnic group, particularly neutropenia, were seen with the highest toxicity in API patients; however, this difference did not translate into early discontinuation of palbociclib or ET. Table: 3-year Kaplan-Meier Survival Outcomes Stratified by Race and Ethnicity Citation Format: Olga Kantor, Oluwadamilola (Lola) Fayanju, Amylou Dueck, Michael Gnant, Harold Burstein, Matthew Goetz, Claudine Isaacs, Lois Shepherd, Olwen Hahn, Daniel Anderson, Kathy Miller, Hope Rugo, Tiffany Traina, Zoneddy Dayao, Katherine Clifton, Eric Winer, Antonio Wolff, Norman Wolmark, Dongrui Lu, Patrick O'Brien, Sara Scovil, Angela DeMichele, Erica Mayer. Racial and Ethnic Differences in Clinical Outcomes among North American Patients with Hormone Receptor-Positive, HER2-negative, Early Breast Cancer in the PALLAS Trial (AFT-05) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-02-05.
Abstract P4-10-01: Quality of life and symptom severity in the PALLAS randomized trial of palbociclib with adjuvant endocrine therapy in early breast cancer (AFT-05)
Naughton, Michelle J. , Zahrieh, David M. , Bjelic‐Radisic, Vesna , Thomssen, Christoph , Neisel, Jane, Ruiz-Echarri, Manuel, Loibl, Sibylle, Carrasco, Fernando Manuel Henao, Wette, Viktor, Rugo, Hope, Miller, Kathy, Fitzal, Florian , Gil, Juan Miguel Gil, Park, Haeseong , Bajetta, Emilio, Dayao, Zoneddy , Ehrhardt, Karin, Arahmani, Amal, Partridge, Ann, Zoroufy, Alex, Gnant, Michael , Zdenkowski, Nicholas , Lemieux, Julie , Mao, Jun J. , Shinn, Eileen H. , Balić, Marija , Loibl, Sibylle , Isaacs, Claudine , Cameron, David , Goetz, Matthew P. , Werutsky, Gustavo , Vetter, Marcus , Tseng, Ling-Ming , Linderholm, Barbro Kristina , Prat, Aleix , Metzger, Otto , Law, Ernest H. , Carey, Lisa A. , Dueck, Amylou C. , Hlauschek, Dominik , DeMichele, Angela , Mayer, Erica L.

Cancer Research | March 8, 2022 | Volume: 82 | Issue: 4_Supplement | Pages: P4-10-01-P4-10-01

10.1158/1538-7445.sabcs21-p4-10-01 Get It

Abstract Background: Quality of life (QOL) in breast cancer patients (pts) can be greatly impacted by initial treatment and ongoing therapy, particularly if side effects and symptoms are not well tolerated. The PALLAS trial investigated whether the addition of 2 years of palbociclib (palbo) to adjuvant endocrine therapy (ET) improved invasive disease-free survival (iDFS) over adjuvant ET alone. We report on the main patient-reported outcome (PRO) quality of life (QOL) and symptom severity results of this trial by treatment arm. Methods: PALLAS is an ongoing multicenter, open label phase 3 trial that enrolled hormone receptor positive, HER2-negative, stage II-III breast cancer patients at 406 cancer centers across 21 countries. Patients were randomly assigned (1:1) to either 2 years of palbo (125mg/day, 3 weeks on 1 week off) plus ongoing provider or patient-choice adjuvant ET (palbo+ET) versus ongoing ET alone. The primary study endpoint was iDFS. Treatment with palbo in all pts stopped at the time of the second interim analysis (5/2020) due to futility; all pts then moved to follow up. The PRO analyses were triggered for completion after awareness of the pre-specified 469 iDFS cases in November 2020. Eight PRO endpoints were measured serially (i.e., day 1 of each monthly cycle for the first 3 months, then every 3 months for the first 2 years, and once at year 3). The endpoints were the EORTC QLQ-C30 global health status/QOL score, the Brief Fatigue Inventory score, the modified Brief Pain Inventory severity and pain interference scores, the EORTC QLQ-BR23 alopecia score, and the Breast Cancer Prevention Trial hot flash symptoms, vaginal problems, and musculoskeletal pain scores. Linear mixed models compared the average difference between arms across time points during the initial 2-year treatment period adjusting for cycle 1 day 1 (C1D1) PRO scores, demographic and clinical variables. The average differences between arms (palbo+ET vs ET alone) and the two-sided (1-[0.05/8]) x 100% confidence intervals, adjusted for multiple comparisons, were calculated. Analysis of covariance compared the average between-arm differences by endpoint at 3 years. Results: The PRO intention to collect population included 4688 (81%) of the overall trial pts, and was clinically and demographically representative of the remaining 1073 pts. Each analysis population, with measures at C1D1 and at least 1 post-C1D1 assessment for each PRO endpoint, comprised ≥ 89% of the 4688 pts and the proportions were similar between arms. After adjustment for baseline covariates, on average, no clinically important differences between arms were observed for any of the eight endpoints over the 2 year treatment period (Table 1). All effect sizes were below the pre-specified 0.2 threshold. These PRO results were similar at the 3 year time point. Conclusions: No clinically significant differences in either patient-reported QOL or symptom severity were found, on average, between participants in the two PALLAS treatment arms while either taking palbo+ET or ET alone, or after study-wide termination of palbo. In general, the addition of palbociclib in the adjuvant breast cancer setting did not contribute to increased symptom burden within this survivorship population. Further analyses will examine the relationship between PROs and treatment discontinuation by arm and study time point. Support: AFT, Pfizer, https://acknowledgments.alliancefound.org Table 1.Results of the Patient-Reported QOL and Symptom Severity Analyses Between the Two Treatment Arms During the First 2 Years of PALLASPRO Endpoint *Palbo + ET Adjusted average score (95% CI)ET alone Adjusted average score (95% CI)Average Difference + (Palbo + ET vs ET alone)[99.38% CI] Clinically ++ Important DifferenceEORTC QLQ-C30 Global Health Status/QOL71.7 (71.2, 72.2)74.0 (73.5, 74.5)-2.3 (-3.3, -1.4)**NoBrief Fatigue Inventory Score2.3 (2.2, 2.3)2.1 (2.0, 2.1)0.2 (0.1, 0.3)NoModified Brief Pain Inventory - Severity Score2.3 (2.2, 2.3)2.4 (2.4, 2.5)-0.2 (-0.3, -0.1)NoModified Brief Pain Inventory - Interference Score1.7 (1.6, 1.7)1.7 (1.6, 1.7)0.0 (-0.1, 0.1)NoEORTC QLQ-BR23 Alopecia1.4 (1.4, 1.4)1.3 (1.3, 1.3)0.1 (0.1, 0.1)NoBreast Cancer Prevention Trial - Hot Flash Symptoms1.2 (1.2, 1.3)1.2 (1.2, 1.3)0.0 (-0.1, 0.1)NoBreast Cancer Prevention Trial - Vaginal Problems0.8 (0.8, 0.8)0.8 (0.7, 0.8)0.0 (0.0, 0.1)NoBreast Cancer Prevention Trial - Musculoskeletal Pain1.2 (1.2, 1.2)1.3 (1.3, 1.3)-0.1 (-0.2, 0.0)No* For the EORTC QLQ-C30 Global Health Status/QOL subscale, higher scores indicate better QOL. For all other PRO endpoints, higher scores indicate worse symptom levels. ** The lower bound of the one-sided CI (adjusted for multiple comparisons) was -3.3. Because the lower limit is greater than the pre-specified non-inferiority margin of -3.44, non-inferiority of palbo+ET relative to ET-alone was concluded. The non-inferiority margin corresponds to a 0.2 SD in the EORTC QLQ-C30 global health/QOL score. +The average difference was adjusted for the following baseline covariates: Cycle 1 day 1 score, region (if applicable), age category, first adjuvant ET, race, ethnicity, N-stage, T-stage, histological grade, PgR, prior chemotherapy, ECOG Performance Status. ++Based on each instrument’s published clinically relevant cut-offs, if available. After calculating Cohen’s d treatment effect sizes, (i.e. by dividing the average difference by the ET-alone arm standard deviation from cycle 1 day 1), all effect sizes were below the pre-specified 0.2 threshold, and would not be considered clinically important. Citation Format: Michelle Joy Naughton, David Zahrieh, Michael Gnant, Nicholas Zdenkowski, Julie Lemieux, Jun J Mao, Vesna Bjelic-Radisic, Eileen Shinn, Marija Balic, Christoph Thomssen, Jane Neisel, Manuel Ruiz-Echarri, Sibylle Loibl, Claudine Isaacs, David Cameron, Fernando Manuel Henao Carrasco, Matthew Goetz, Viktor Wette, Gustavo Werutsky, Hope Rugo, Marcus Vetter, Ling-Ming Tseng, Kathy Miller, Florian Fitzal, Juan Miguel Gil Gil, Haeseong Park, Barbro Linderholm, Emilio Bajetta, Zoneddy Dayao, Aleix Prat, Karin Ehrhardt, Otto Metzger, Amal Arahmani, Ernest Law, Ann Partridge, Lisa Carey, Alex Zoroufy, Amylou Dueck, Dominik Hlauschek, Angela DeMichele, Erica Mayer. Quality of life and symptom severity in the PALLAS randomized trial of palbociclib with adjuvant endocrine therapy in early breast cancer (AFT-05) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-10-01.
A pilot randomized, placebo-controlled, double-blind study of omega-3 fatty acids to prevent paclitaxel-associated acute pain syndrome.
Dayao, Zoneddy , Brown‐Glaberman, Ursa, Lafky, Jacqueline M., Loprinzi, Charles L. , Barton, Debra L. , Pankratz, V. Shane , Chen, Lü

Journal of Clinical Oncology | May 25, 2020 | Volume: 38 | Issue: 15_suppl | Pages: e24115-e24115

10.1200/jco.2020.38.15_suppl.e24115 Get It

e24115 Background: Paclitaxel, a widely used chemotherapeutic agent, is associated with an acute pain syndrome (P-APS) and chronic chemotherapy-induced peripheral neuropathy (CIPN). Currently, there is no standard of care for P-APS. Commonly used analgesics, including NSAIDs and narcotics, have considerable toxicity profiles. Omega-3 fatty acids, a common dietary supplement, have well established anti-inflammatory and neuroprotective properties. The primary aim of the study was to assess if omega 3 fatty acids could prevent P-APS. Methods: Patients scheduled to receive weekly paclitaxel (70-90mg/m2) were randomized to receive 4 g of omega-3 acid ethyl esters (Lovaza) or placebo, beginning 1 week prior to starting paclitaxel and continued until paclitaxel was discontinued. Patients completed acute pain questionnaires at baseline, Days 2-7, prior to each subsequent treatment and one month after completion of therapy. The EORTC- QLQ CIPN 20 questionnaire was completed prior to each dose of paclitaxel and 1 month after completion. The primary objective was to compare the effect of omega 3 fatty acids, versus placebo, on the maximum pain score for the week following the 1st treatment and each subsequent paclitaxel treatment, and to compare pain medication use between the 2 arms. The secondary objective was to compare the effect of the intervention on the severity of CIPN. Results: 49 patients were randomized to treatment versus placebo. Linear mixed effects models were applied with the addition of a bootstrap approach to overcome limitations in the distributional assumptions to compare outcomes between treatment groups. Placebo results were similar to the reported natural history of P-APS. There was no significant difference in trends over time between the 2 groups in the maximum pain score at week 1 (p = .14) and over 12 weeks (p = .21). There was also no difference noted in the rates of use of over the counter analgesics (p = .39) and narcotics (p = .46). CIPN results did not differ between the 2 groups (p = .08). Conclusions: The results of this pilot study do not support the use of omega-3 fatty acids for the prevention of paclitaxel-associated pain syndrome. Clinical trial information: NCT01821833 .
Ki67 Proliferation Index as a Tool for Chemotherapy Decisions During and After Neoadjuvant Aromatase Inhibitor Treatment of Breast Cancer: Results From the American College of Surgeons Oncology Group Z1031 Trial (Alliance)
Gonçalves, Rodrigo , Sanati, Souzan , Creighton, Chad J. , DeSchryver, Katherine, Crouch, Erika C., Brink, Amy, Luo, Jingqin , Yu, Tao , Budd, G. Thomas , Silverman, Paula , Esserman, Laura J. , Cynthia, X. , Unzeitig, Gary, Whitworth, Pat W. , Babiera, Gildy V., Guenther, J. Michael, Dayao, Zoneddy , Ota, David M., Leitch, Marilyn , Allred, D. Craig, Ellis, Matthew J. , Hoog, Jeremy , Crouch, Erika, Barnes, Michael, Dowsett, Mitchell, Winer, Eric, Esserman, Laura, Carey, Lisa, Ma, Cynthia X., Pluard, Timothy , Whitworth, Pat, Babiera, Gildy, Ota, David, Olson, John A. , Hunt, Kelly, Suman, Vera J. , Watson, Mark A. , Barnes, Michael , Dowsett, Mitch , Winer, Eric P. , Carey, Lisa A. , Hunt, Kelly K. , Esserman, Laura J , Luo, Jingqin

Journal of Clinical Oncology | February 23, 2017 | Volume: 35 | Issue: 10 | Pages: 1061-1069

10.1200/jco.2016.69.4406 Get It

Purpose To determine the pathologic complete response (pCR) rate in estrogen receptor (ER) –positive primary breast cancer triaged to chemotherapy when the protein encoded by the MKI67 gene (Ki67) level was > 10% after 2 to 4 weeks of neoadjuvant aromatase inhibitor (AI) therapy. A second objective was to examine risk of relapse using the Ki67-based Preoperative Endocrine Prognostic Index (PEPI). Methods The American College of Surgeons Oncology Group (ACOSOG) Z1031A trial enrolled postmenopausal women with stage II or III ER-positive (Allred score, 6 to 8) breast cancer whose treatment was randomly assigned to neoadjuvant AI therapy with anastrozole, exemestane, or letrozole. For the trial ACOSOG Z1031B, the protocol was amended to include a tumor Ki67 determination after 2 to 4 weeks of AI. If the Ki67 was > 10%, patients were switched to neoadjuvant chemotherapy. A pCR rate of > 20% was the predefined efficacy threshold. In patients who completed neoadjuvant AI, stratified Cox modeling was used to assess whether time to recurrence differed by PEPI = 0 score (T1 or T2, N0, Ki67 < 2.7%, ER Allred > 2) versus PEPI > 0 disease. Results Only two of the 35 patients in ACOSOG Z1031B who were switched to neoadjuvant chemotherapy experienced a pCR (5.7%; 95% CI, 0.7% to 19.1%). After 5.5 years of median follow-up, four (3.7%) of the 109 patients with a PEPI = 0 score relapsed versus 49 (14.4%) of 341 of patients with PEPI > 0 (recurrence hazard ratio [PEPI = 0 v PEPI > 0], 0.27; P = .014; 95% CI, 0.092 to 0.764). Conclusion Chemotherapy efficacy was lower than expected in ER-positive tumors exhibiting AI-resistant proliferation. The optimal therapy for these patients should be further investigated. For patients with PEPI = 0 disease, the relapse risk over 5 years was only 3.6% without chemotherapy, supporting the study of adjuvant endocrine monotherapy in this group. These Ki67 and PEPI triage approaches are being definitively studied in the ALTERNATE trial (Alternate Approaches for Clinical Stage II or III Estrogen Receptor Positive Breast Cancer Neoadjuvant Treatment in Postmenopausal Women: A Phase III Study; clinical trial information: NCT01953588).
Abstract PD07-01: Z1031B Neoadjuvant Aromatase Inhibitor Trial: A Phase 2 study of Triage to Chemotherapy Based on 2 to 4 week Ki67 level > 10%.
Ellis, MJ, McCall, Lisa, Luo, Rui , Hoog, J, Watson, Mark , Unzeitig, Gary, Pluard, TJ, Whitworth, Pat W. , Babiera, Gildy V., Guenther, Michael, Dayao, Zoneddy , Leitch, M., Ota, David M., Hunt, Katie N. , Allred, C, Suman, Vera J. , Brink, Arjen , Ma, Chuang , Olson, John A.

Cancer Research | August 14, 2014 | Volume: 72 | Issue: 24_Supplement | Pages: PD07-01-PD07-01

10.1158/0008-5472.sabcs12-pd07-01 Get It

Abstract Background: Neoadjuvant aromatase inhibitor (AI) therapy would become a more acceptable alternative to chemotherapy if there was a way to identify AI-resistant cases early for triage to alternate systemic treatment. We therefore conducted a Phase 2 trial of post-menopausal patients with clinical stage 2 or 3 ER+ (Allred Score 6 to 8) breast cancer who were re-biopsied 2 to 4 weeks after initiating neoadjuvant AI therapy. If the tumor Ki67 level was &gt; 10% (AI resistant) the patient was triaged to either chemotherapy or immediate surgery and if &lt; 10% (AI sensitive) the patient completed 16 to 18 weeks of neoadjuvant AI treatment. Co-primary endpoints were: 1) to confirm that the pathological complete response (pCR) rate to standard NCCN chemotherapy in the AI resistant population is in the range of 20% (similar to ER− disease). This required the observation of least 4/35 pCRs; 2) whether patients were willing to accept a recommendation of no chemotherapy when the preoperative endocrine prognostic index score was zero (PEPI-0) (pStage 1 or 2A, Ki67&lt;2.7% and ER+) since, according to the PEPI model, these patients have such a low relapse risk that chemotherapy is unlikely to be of value (Ellis, M JNCI 100:1380–8, 2008). Feasible was defined as &lt;10% PEPI-0 cases receiving adjuvant chemotherapy. Secondary endpoints included a determination of the distribution of intrinsic subtypes in the AI sensitive and resistant groups (using a research use only assay). Results: 51 patients (21%) had 2 to 4 week Ki67&gt;10%, of these 36 received chemotherapy per protocol (27) anthracycline (A) and taxane (T)-based, 7 T-based, 1 A-only based and 1 other (non-NCCN) regimen but only 2 patients had a pCR (5.5%). 194 patients (79%) had a Ki67 &lt;10%, of these 176 had PEPI score information. 65 had a PEPI-0 (37%), of which 61 (94%) reported a treatment plan that did not include adjuvant chemotherapy. The AI resistant group had a significantly higher frequency of baseline high-risk intrinsic subtypes (LumB: 26, HER2-E: 2 versus LumA: 7) at baseline than the AI sensitive group (LumB: 40, HER2-E: 0 versus LumA: 66) Fishers exact test p = 7.16E−6. Additional molecular data will be presented at the meeting. Conclusion. A Ki67 value &gt;10% at 2 to 4 weeks strongly enriches for high-risk molecular subtypes (mainly LumB) however standard neoadjuvant chemotherapy did not meet pre-assigned criteria for adequate Phase 2 activity in this group. Novel neoadjuvant approaches for AI resistant-disease defined by high on treatment Ki67 are therefore a high priority. Management of patients with excellent response to neoadjuvant endocrine therapy (PEPI-0) without adjuvant chemotherapy is feasible. The ALTERNATE trial will enroll over 2000 patients to establish a new standard of care for neoadjuvant treatment of ER+ HER2− disease based on these principles. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD07-01.