Kimmick, Gretchen

1037 Background: TBCRC041, a randomized phase 2 trial of alisertib (A) ± fulvestrant (F) in women with HR+/HER2- MBC demonstrated promising clinical activity for alisertib (1). Interrogation of baseline (PreC1) and end of cycle 1 (EOC1) cfDNA and CTCs may identify biomarkers associated with response to A±F. Methods: Plasma cfDNA was sequenced using the Guardant INFINITY platform, which includes genomic and methylated tumor fraction (mTF) analysis. Pathogenic variants were determined using publicly available databases and Mayo Clinic annotation pipelines. CTCs were identified as nucleated, EpCAM+/ cytokeratin+/ CD45- cells and assessed for ER/HER2 staining (RareCyte, Seattle). PFS was defined as the time from randomization to progression or death. EOC1-PFS differs from PFS as time starts at C2D1. Stratified log-rank tests and conditional Cox modeling were used to assess whether PFS or EOC1-PFS differed by mutations in ESR1 or PIK3CA, pre-CTC ≥ 5, or mTF>1%. Results: Of the 91 eligible pts, 84 progressed, and 73 were deceased. In the 86 pts with PreC1-cfDNA results, variants were identified in ESR1 (42; 48.8%), PIK3CA (36; 41.9%), AKT1 (7; 8.1%), PTEN(7; 8.1%), BRCA1 (4; 4.7%), and BRCA2 (7; 8.1%). Pts with a PIK3CAmut had significantly decreased PFS (HR 1.8; 95%CI: 1.1 -2.9, p=0.014) but not by ESR1mut status (p=0.583). PreC1 and EOC1-mTF were determined for 78 and 76 pts, respectively. PreC1-mTF was 0-1% in 21; 1.1-10.0% in 27; and 10.1-100% in 30. mTF levels remained between 0-1% in 17 pts fell to 0-1% in 11 pts, and was 0-1% in 5 pts without a preC1-mTF determination. PFS did not differ with respect to PreC1-mTF (p=0.210), but EOC1-PFS was worse in pts with mTF >1% (HR 3.0; 95%CI: 1.6 -5.2, p<0.001). PreC1 and EOC1-CTC were determined for 78 and 76 pts. 36 (46.2%) pts had a PreC1 CTC count ≥ 5. EOC1-CTC levels remained at (n=17) or increased to (n=1) ≥ 5 and was ≥ 5 in 2 pts without a preC1-CTC determination. EOC1-PFS was not significantly different for EOC1-CTC ≥ 5 (p=0.065), but was significantly decreased in pts with PreC1-CTC≥5 (HR=1.8; 95%CI: 1.1-3.0; p=0.018). Broader cfDNA NGS panel and CTC-derived ER/HER2 staining results will be presented at the meeting. Conclusions: Among patients receiving A±F, PFS varied based on the PIK3CAmutation status. cfDNA and CTC assessment PreC1 and EOC1 provided complementary information. Further validation in larger datasets is needed. 1. JAMA Oncol 2023;9:815. Clinical trial information: NCT02860000 .

Abstract Purpose: HER2 mutations (HER2mut) induce endocrine resistance in estrogen receptor–positive (ER+) breast cancer. Patients and Methods: In this single-arm multi-cohort phase II trial, we evaluated the efficacy of neratinib plus fulvestrant in patients with ER+/HER2mut, HER2 non-amplified metastatic breast cancer (MBC) in the fulvestrant-treated (n = 24) or fulvestrant-naïve cohort (n = 11). Patients with ER-negative (ER−)/HER2mut MBC received neratinib monotherapy in an exploratory ER− cohort (n = 5). Results: The clinical benefit rate [CBR (95% confidence interval)] was 38% (18%–62%), 30% (7%–65%), and 25% (1%–81%) in the fulvestrant-treated, fulvestrant-naïve, and ER− cohorts, respectively. Adding trastuzumab at progression in 5 patients resulted in three partial responses and one stable disease ≥24 weeks. CBR appeared positively associated with lobular histology and negatively associated with HER2 L755 alterations. Acquired HER2mut were detected in 5 of 23 patients at progression. Conclusions: Neratinib and fulvestrant are active for ER+/HER2mut MBC. Our data support further evaluation of dual HER2 blockade for the treatment of HER2mut MBC.

Abstract Introduction: The irreversible pan-HER inhibitor NER showed modest single agent activity for HER2mut MBC in Part I of MutHER trial. In Part II, we hypothesized that (1) N+F would improve activity in estrogen receptor positive (ER+) HER2mut MBC due to ER-HER2 crosstalk and (2) dual HER2 blockade by adding trastuzumab at disease progression (PD) could overcome resistance. Methods: Pts with ER+HER2mut MBC were enrolled to 2 cohorts (FUL treated or naive) to receive N+F with diarrhea prophylaxis. ER- pts received NER in an exploratory ER- cohort. Trastuzumab was added at PD if approved by insurance. Simon's Minimax 2-stage phase II design with the primary endpoint of clinical benefit rate (CBR: rates of complete/partial response [CR/PR] plus stable disease [SD] &gt;24 weeks [wks]), with anticipated vs null hypothesis being CBR of 55% vs 35% (FUL treated) or 65% vs 40% (FUL naïve) with 80% power, 1 sided 0.05 alpha, was used. Secondary endpoints included progression free survival (PFS) and adverse events (AEs). Serial blood samples were analyzed for circulating tumor DNA (ctDNA) by Guardant360 for concomitant mutations, HER2mut variant allele frequency (VAF) dynamics, and resistance mechanisms. Results: Between Sep. 2015 and Oct. 2020, 40 pts with HER2mut MBC were enrolled, completing the 1st stage of each ER+ cohort. 35 pts (21 FUL treated, 10 FUL naïve, 4 ER-) were evaluable for response, with median age 63 (35-82) years, 3 (0-12) prior MBC regimen, lobular BC in 13 (37%) and visceral mets in 32 (91%) pts. 21 (68%) ER+ pts had prior CDK4/6 inhibitor. All but 1 pt has come off study due to PD. Table 1 shows the efficacy by cohort. Further enrollment is closed per protocol. Adding trastuzumab at PD induced CB in 4 (3 PR, 1 SD≥24 wks) of 5 pts (1 ER-, 4 ER+), with PFS 28 (95% CI 18~NA) wks. Common AEs across cohorts were diarrhea (G3 21%) and fatigue (G3 5%). No G4 AEs. ctDNA HER2mut was detected in 72% (23/32) baseline (BL) samples tested. In pts with paired samples, HER2mut VAF decreased at C1D15/C2D1 from BL in 75% (15/20) and rose in 89% (16/18) at PD. Acquired HER2mut, including the T798I gatekeeper mutation, were detected in 2 pts at PD. Mutations in TP53 (53%), PIK3CA (43%), and CDH1 (35%) were common, but none significantly associated with PFS in all or ER+ pts. Conclusions: NER, or N+F, is active for HER2mut MBC with good tolerability. Adding trastuzumab at PD induced further response, supporting dual HER2 blockade for HER2mut MBC. Table 1.EfficacyCohortFUL treatedFUL naïveER-Best Response, n evaluablen = 21n = 10n = 4CR, n100PR, n431SD (≥ 24 wks), n300SD (&lt; 24 wks), n1030PD, n343CBR, n with CB/total n evaluable, % (95% CI)8 of 20*, 40% (19~64%)3 of 10, 30% (7~65%)1 of 4, 25% (0.6~81%)mPFS (95% CI), wks, ITT (n)24 (16~31) wks, (n = 24)20 (8~NA) wks, (n = 11)8.5 (8~NA) wks, (n = 5)*20 of 21 pts are evaluable for CBR in the FUL treated Cohort as 1 pt had SD as best response and treatment is still ongoing. ITT (intent to treat) population is used for mPFS estimate. Citation Format: Cynthia X. Ma, Jingqin Luo, Rachel A. Freedman, Timothy Pluard, Julie Nangia, Janice Lu, Frances Valdez-Albini, Melody Cobleigh, Jason Jones, Nancy U. Lin, Eric Winer, P. Kelly Marcom, Shana Thomas, Jill Anderson, Brittney Haas, Kimberly M. Hamann, Richard Bryce, Alshad S. Lalani, Lisa Carey, Matthew Goetz, Feng Gao, Gretchen Kimmick, Mark Pegram, Matthew J. Ellis, Ron Bose. A phase II trial of neratinib (NER) or NER plus fulvestrant (FUL) (N+F) in HER2 mutant, non-amplified (HER2mut) metastatic breast cancer (MBC): Part II of MutHER [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT026.

Abstract Cancer is a disease of aging and, as the world's population ages, the number of older persons with cancer is increasing and will make up a growing share of the oncology population in virtually every country. Despite this, older patients remain vastly underrepresented in research that sets the standards for cancer treatments. Consequently, most of what we know about cancer therapeutics is based on clinical trials conducted in younger, healthier patients, and effective strategies to improve clinical trial participation of older adults with cancer remain sparse. For this systematic review, the authors evaluated published studies regarding barriers to participation and interventions to improve participation of older adults in cancer trials. The quality of the available evidence was low and, despite a literature describing multifaceted barriers, only one intervention study aimed to increase enrollment of older adults in trials. The findings starkly amplify the paucity of evidence‐based, effective strategies to improve participation of this underrepresented population in cancer trials. Within these limitations, the authors provide their opinion on how the current cancer research infrastructure must be modified to accommodate the needs of older patients. Several underused solutions are offered to expand clinical trials to include older adults with cancer. However, as currently constructed, these recommendations alone will not solve the evidence gap in geriatric oncology, and efforts are needed to meet older and frail adults where they are by expanding clinical trials designed specifically for this population and leveraging real‐world data.

Abstract Background: Side effects of and adherence to aromatase inhibitors in women with ductal carcinoma in situ are not well described. Methods: Postmenopausal women in a prospective phase II study of neoadjuvant letrozole for estrogen receptor positive DCIS completed questionnaires on side effects [Menopause Specific Quality of Life Questionnaire (MENQOL), Brief Pain Inventory-short form (BPI-SF), Arthritis Impact Measurement Scales (AIMS2)], well-being (FACT-G), and adherence [Medication-Taking questionnaire] at baseline, 1, 3 and 6 months (mo), and study completion. We used descriptive statistics and paired t-tests to compare 1, 3 and 6 mo results to baseline. Hierarchical linear mixed modeling, controlling for baseline symptom or well-being level, was used to examine effect of symptoms and well-being on intentional and nonintentional nonadherence, based on the Medication-Taking Questionnaire. Results: Included were 84 women, mean age 63 (39-83) years. In univariate analyses, compared to baseline, menopausal symptoms increased [physical (p=0.001 at 3, p&lt;0.001 at 6 mo); vasomotor (p&lt;0.001 at 1, 3, 6 mo), psychosocial (p=0.006 at 6 mo) and sexual (p=0.01 at 6 mo)]. Joint pain and stiffness increased [BPI-SF pain subscale (p=0.048 at 3, p=0.01 at 6 mo); AIMS2 joint pain subscale (p=0.03 at 1, p&lt;0.001 at 3 and 6 mo); AIMS2 stiffness subscale (p=0.004 at 3, p=0.01 at 6 mo)]. Intentional and nonintentional adherence did not significantly change over time (p&gt;0.05). Lower emotional (p=0.049) and functional (p=0.002) well-being by FACT-G and higher joint pain (p=0.03) by AIMS2 were associated with higher nonintentional nonadherence; higher physical side effects of menopause (p=0.001) by MENQOL were associated with lower intentional nonadherence. Conclusions: Among women taking letrozole for DCIS, menopausal symptoms and joint pain/stiffness increased over time with most differences noted at 3 and 6 mo. Lower well-being and higher symptom levels were associated with higher nonintentional nonadherence. NCT01439711.U10CA180821, U10CA180882, UG1CA189823, Breast Cancer Research Foundation, https://acknowledgments.alliancefound.org. Citation Format: Gretchen Kimmick, Amylou C Dueck, Rebecca Shelby, Michelle Naughton, Abigail Caudle, Briant Fruth, E. Shelley Hwang. Musculoskeletal side effects over time and association with adherence in women taking neoadjuvant letrozole for estrogen receptor positive DCIS: CALGB 40903 (Alliance) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-14-17.

1007 Background: Determining optimal adjuvant chemotherapy for early stage breast cancer depends on efficacy and toxicity. We sought to determine if T is equivalent to AC but with reduced toxicity. Methods: Pts with operable breast cancer with 0-3 positive nodes were enrolled on a 2x2 factorial design study which addressed (1) superiority of 6 vs. 4 cycles of therapy (previously reported, Shulman, JCO 2012) and (2) equivalence of single-agent T to standard AC, defined as upper bound of 95% confidence interval (CI) of hazard ratio (HR) of T vs. AC < 1.30 for the primary endpoint of relapse-free survival (RFS). A planned target of 567 RFS events required 4,646 pts with 4 yrs FU. At activation in 2002, T (80mg/m2) was q1wk for 12 or 18 wks and AC (60/600 mg/m2) was q3wk for 4 or 6 cycles. In 2003 (570 pts enrolled) schedules were revised to 4 or 6 cycles q2wk for both T (175 mg/m2) and AC. The 6-cycle arms were dropped in 2008 (3,171 pts enrolled) due to slow accrual. Relative effectiveness of T to AC is shown by hazard ratio (HR). Logrank p-values are measures of discordance but are not relevant for the equivalence question and are not adjusted for multiple comparisons. Results: After enrolling 3,871 pts, the study closed in 2010 due to slowing accrual. With a median follow-up of 6.1 yrs there are 437 RFS events. The HR of 1.26 (95% CI: 1.05-1.53; p = 0.02) does not allow a conclusion of equivalence of T with AC. With 266 deaths the HR for overall survival (OS) is 1.27 (95% CI=1.00-1.62; p = 0.05), favoring AC. The estimated absolute advantage of AC at 5 yrs is 3% (91 vs. 88%) for RFS and 1% (95 vs. 94%) for OS. All 9 treatment-related deaths were in pts receiving AC and are included in the survival analysis. The incidence of Grade 3+ toxicity for AC vs T was 33% vs. 4% for hematologic toxicity and 36% vs 22% for non-hematologic toxicity. Conclusions: This trial did not show equivalence of T to AC, a conclusion that is very unlikely to change with additional follow-up. T was less toxic than AC. Clinical trial information: CDR0000069444/NCT00041119.

6015 Background: Comorbidity increases with age. We evaluated how comorbidity was associated with toxicity and clinical outcomes among older women with BC who received adjuvant chemotherapy. Methods: Cancer and Leukemia Group B (CALGB 49907) enrolled 633 women ≥65 years with early stage BC and randomized them to standard adjuvant chemotherapy (AC or CMF) or capecitabine (N Eng J Med 360:2055, 2009). 329 women on the Quality of Life companion study completed a pre-treatment health survey (Older American Resources and Services Questionnaire, physical health subscale). The survey evaluates 14 conditions and the degree to which each interferes with daily activities (rated from 1 “not at all” to 3 “a great deal”). Comorbidity was analyzed as follows: 1) total number 2) comorbidity burden score (summed conditions multiplied by interference rating); and 3) individual diseases. Primary outcomes were: 1) grade 3-5 toxicity (incident and cumulative); 2) time to relapse (TTR), and 3) overall survival (OS). Contingency table methods were used to evaluate the association between comorbidity and toxicity. Cox proportional hazards models were used to evaluate TTR and survival outcomes. Results: Among 329 women [median age 71 years (range 65-89), 86% white, 98% ECOG performance score 0-1, 75% stage 1-2] the median number of comorbidities was 2 (0-10), median comorbidity burden score was 3 (0-25), and most common conditions were arthritis (58%) and hypertension (54%). Few patients had diabetes (17%), heart disease (16%), and pulmonary disease (9%). No comorbidity measure was associated with toxicity or TTR. With a median follow-up of 5.4 years, increasing comorbidity was associated with shorter OS. For each additional comorbid condition the hazard of death increased by 18% (HR 1.18 [95% CI; 1.06-1.33]) after adjusting for age, tumor size, treatment, node status and receptor status. Comorbidity burden score was similarly associated with OS (HR 1.08 [95% CI; 1.03-1.14]), while no specific condition was independently associated. Conclusions: Among older women with good functional status, comorbidity was not associated with toxicity or BC relapse. However, comorbidity burden was associated with shorter OS.

Members of the Translational Breast Cancer Research Consortium conducted an expert‐driven literature review to identify a list of domains and to evaluate potential measures of these domains for inclusion in a list of preferred measures. Measures were included if they were easily available, free of charge, and had acceptable psychometrics based on published peer‐reviewed analyses. A total of 22 domains and 52 measures were identified during the selection process. Taken together, these measures form a reliable and validated list of measurement tools that are easily available and used in multiple cancer trials to assess patient‐reported outcomes in relevant patients.

Abstract Purpose A few previous studies report a direct relationship between older age and chemotherapy-induced neuropathy. This study further evaluated this adverse event's age-based risk. Methods CALGB 40101 investigated adjuvant paclitaxel (80 mg/m2 once per week or 175 mg/m2 every 2 weeks) in patients with breast cancer and served as a platform for the current study that investigated age-based differences in neuropathy. Grade 2 or worse neuropathy, as per Common Terminology Criteria for Adverse Events version 4, was the primary endpoint; patients were assessed at baseline, every 6 months for 2 years, and then annually for 15 years. Results Among these 1,881 patients, 230 were 65 years of age or older, 556 were 55–64 years, and 1,095 were younger than 55; 1,226 neuropathy events (commonly grade 1 or 2) were reported in 65% of the cohort. The number of grade 2 or worse events was 63 (27%), 155 (28%), and 266 (24%) within respective age groups (p = .14). In univariate analysis, only motor neuropathy had a higher age-based incidence: 19 (8%), 43 (8%), and 60 (5%), respectively (p = .04); in multivariate analyses, this association was no longer statistically significant. Other endpoints, such as time to onset of neuropathy (time from trial enrollment to neuropathy development) and time to improvement (time from maximal grade sensory neuropathy to a one-category improvement), showed no statistically significant age-based differences. In contrast, obesity was associated with neuropathy, and every 2-week paclitaxel was associated with trends toward neuropathy. Conclusion Although paclitaxel-induced neuropathy is common, older age is not an independent risk factor. Clinical trial identification number. NCT00041119 (CALGB 40101).