Albain, Kathy S.

PURPOSEThe phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin is a key pathway of survival and therapeutic resistance in breast cancer. We evaluated the pan-Akt inhibitor MK-2206 in combination with standard therapy in patients with high-risk early-stage breast cancer.PATIENTS AND METHODSI-SPY 2 is a multicenter, phase II, open-label, adaptively randomized neoadjuvant platform trial that screens experimental therapies and efficiently identifies potential predictive biomarker signatures. Patients are categorized by human epidermal growth factor receptor 2 (HER2), hormone receptor (HR), and MammaPrint statuses in a 2 × 2 × 2 layout. Patients within each of these 8 biomarker subtypes are adaptively randomly assigned to one of several experimental therapies, including MK-2206, or control. Therapies are evaluated for 10 biomarker signatures, each of which is a combination of these subtypes. The primary end point is pathologic complete response (pCR). A therapy graduates with one or more of these signatures if and when it has an 85% Bayesian predictive probability of success in a hypothetical phase III trial, adjusting for biomarker covariates. Patients in the current report received standard taxane- and anthracycline-based neoadjuvant therapy without (control) or with oral MK-2206 135 mg/week.RESULTSMK-2206 graduated with 94 patients and 57 concurrently randomly assigned controls in 3 graduation signatures: HR-negative/HER2-positive, HR-negative, and HER2-positive. Respective Bayesian mean covariate-adjusted pCR rates and percentage probability that MK-2206 is superior to control were 0.48:0.29 (97%), 0.62:0.36 (99%), and 0.46:0.26 (94%). In exploratory analyses, MK-2206 evinced a numerical improvement in event-free survival in its graduating signatures. The most significant grade 3-4 toxicity was rash (14% maculopapular, 8.6% acneiform).CONCLUSIONThe Akt inhibitor MK-2206 combined with standard neoadjuvant therapy resulted in higher estimated pCR rates in HR-negative and HER2-positive breast cancer. Although MK-2206 is not being further developed at this time, this class of agents remains of clinical interest.

PURPOSE Despite reported widespread use of dietary supplements during cancer treatment, few empirical data with regard to their safety or efficacy exist. Because of concerns that some supplements, particularly antioxidants, could reduce the cytotoxicity of chemotherapy, we conducted a prospective study ancillary to a therapeutic trial to evaluate associations between supplement use and breast cancer outcomes. METHODS Patients with breast cancer randomly assigned to an intergroup metronomic trial of cyclophosphamide, doxorubicin, and paclitaxel were queried on their use of supplements at registration and during treatment (n =1,134). Cox proportional hazards regression adjusting for clinical and lifestyle variables was used. Recurrence and survival were indexed at 6 months after enrollment using a landmark approach. RESULTS There were indications that use of any antioxidant supplement (vitamins A, C, and E; carotenoids; coenzyme Q10) both before and during treatment was associated with an increased hazard of recurrence (adjusted hazard ratio [adjHR], 1.41; 95% CI, 0.98 to 2.04; P = .06) and, to a lesser extent, death (adjHR, 1.40; 95% CI, 0.90 to 2.18; P = .14). Relationships with individual antioxidants were weaker perhaps because of small numbers. For nonantioxidants, vitamin B12 use both before and during chemotherapy was significantly associated with poorer disease-free survival (adjHR, 1.83; 95% CI, 1.15 to 2.92; P < .01) and overall survival (adjHR, 2.04; 95% CI, 1.22 to 3.40; P < .01). Use of iron during chemotherapy was significantly associated with recurrence (adjHR, 1.79; 95% CI, 1.20 to 2.67; P < .01) as was use both before and during treatment (adjHR, 1.91; 95% CI, 0.98 to 3.70; P = .06). Results were similar for overall survival. Multivitamin use was not associated with survival outcomes. CONCLUSION Associations between survival outcomes and use of antioxidant and other dietary supplements both before and during chemotherapy are consistent with recommendations for caution among patients when considering the use of supplements, other than a multivitamin, during chemotherapy.

Abstract Background: I-SPY2 is a multicenter, Phase II trial using response-adaptive randomization within biomarker subtypes to evaluate novel agents as neoadjuvant therapy for high-risk at least T2N0 breast cancer. The primary endpoint is pathologic complete response (pCR) at surgery. The goal is to identify regimens that have ≥ 85% Bayesian predictive probability of success in a 300-patient phase 3 neoadjuvant trial defined by hormone-receptor (HR) and HER2 status, and MammaPrint (MP). Regimens may leave the trial for futility (&lt; 10% probability of success), maximum sample size accrual (with probability of success ≥ 10% and &lt; 85%), or as recommended by the independent DSMB. For HER2- subjects the control arm is weekly paclitaxel x12 then doxorubicin & cyclophosphamide (AC) q2-3 weeks x4. For this arm, paclitaxel was omitted and replaced with maximum tolerated dose PARPi talazoparib with synergy dosed irinotecan (25mg/m2). Paclitaxel could be given adjuvantly for these subjects and non-responding subjects could be taken off of experimental therapy. Methods: Women with tumors ≥ 2.5cm were eligible for screening. MP low/HR+ tumors were ineligible. MRI scans (baseline, 3 cycles after start of therapy, prior to AC, and prior to surgery) were used in a longitudinal statistical model to predict pCR for individual patients. Talazoparib was given at 1mg daily with 25mg/m2 irinotecan q2wks. Analysis was intention to treat. Subjects who switched to non-protocol therapy count as non-pCR. Subjects on experimental therapy at time of arm closure are non-evaluable. Talazoparib/irinotecan (TI) was open only to HER2- tumors and eligible for graduation in 3 of 10 pre-defined signatures: HER2-, HR+HER2- and HR-/HER2-. Results: TI did not meet criteria for graduation and was stopped at the recommendation of the DSMB based on expectations of limited activity beyond that seen with standard treatment. Maximum sample size had been reached at the time of this recommendation and subjects currently receiving TI were allowed to continue or change to standard therapy. Exploratory “as treated” analysis for response in gBRCA mutation carriers showed 6/10 gBRCA carriers attained a pCR in the TI arm. Except for 1 patient these gBRCA pCR subjects had &gt;90% tumor reduction by MRI after TI and prior to AC (range: 68-96%). In the TI arm pCR rates were also higher in subjects with a PARPi7-High/MP2 gene expression signature (0.344 vs 0.146). Expected differences in toxicity were seen between arms including g3/4 peripheral neuropathy on control therapy which included paclitaxel (2.6% vs none) and g3/4 neutropenia with TI (30.2% vs 8.2%). Notably gBRCA mutation carriers receiving TI had higher rates of g3/4 neutropenia (60% vs 25.9%). Conclusion: The I-SPY2 study finds the probability that investigational regimens will be successful in a Phase III neoadjuvant trial; TI did not reach the efficacy threshold of 85% probability of success in Phase III in any of the 3 signatures. However by adding talazoparib with synergy dosed irinotecan we were able to omit paclitaxel and observe similar estimated pCR rates. This informs current work to evolve the I-SPY2 trial design to reduce toxicity without compromising outcomes and develop successful combinations targeted to biology, including DNA repair deficiency. Citation Format: Richard Schwab, Amy S. Clark, Christina Yau, Nola Hylton, Wen Li, Denise Wolfe, A Jo Chien, Anne M. Wallace, Andres Forero-Torres, Erica Stringer-Reasor, Rita Nanda, Nora Jaskowiak, Judy Boughey, Tufia Haddad, Heather S. Han, Catherine Lee, Kathy Albain, Claudine Isaacs, Anthony D. Elias, Erin D. Ellis, Payal Shah, Julie E. Lang, Janice Lu, Debasish Tripathy, Kathleen Kemmer, Douglas Yee, Barbara Haley, Melanie Majure, Erin Roesch, Christos Vaklavas, Cheryl Ewing, Teresa Helsten, W Fraser Symmans, Jane Perlmutter, Hope S. Rugo, Michelle Melisko, Amy Wilson, Ruby Singhrao, Laura van 't Veer, Angela DeMichele, Smita Asare, Don Berry, Laura J. Esserman. Evaluation of talazoparib in combination with irinotecan in early stage, high-risk HER2 negative breast cancer: Results from the I-SPY 2 TRIAL [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT136.

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: 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.