J Matro

Antimullerian hormone and inhibin B are hormone measures of ovarian function in late reproductive-aged breast cancer survivors.

In late reproductive‐aged breast cancer survivors, there is a need for real‐time biomarkers of postchemotherapy ovarian function. The objective was to determine whether antimullerian hormone (AMH) and inhibin B are such biomarkers. The authors tested whether AMH and inhibin B were impacted by breast cancer treatment by comparing cancer survivors to age‐matched control women and determined the association between these hormones and postchemotherapy menstrual pattern.

Association of cyclophosphamide drug–metabolizing enzyme polymorphisms and chemotherapy-related ovarian failure in breast cancer survivors

OBJECTIVE To determine if genetic variation in chemotherapy metabolism are associated with risk of ovarian failure in breast cancer patients after adjuvant chemotherapy. DESIGN Prospective cohort study. SETTING Comprehensive cancer center. PATIENT(S) Early-stage breast cancer patients who were premenopausal at cancer diagnosis and treatment. INTERVENTION(S) None. MAIN OUTCOMES MEASURE(S) Chemotherapy-related ovarian failure (CROF). RESULT(S) A total of 127 breast cancer subjects who were premenopausal at cancer diagnosis and underwent cyclophosphamide-based chemotherapy were genotyped for nine single-nucleotide polymorphisms (SNPs) in enzymes involved in cyclophosphamide activation (CYP3A4, CYP2B6, CYP3A5) and detoxification (GSTA1, GSTM1, GSTP1, GSTT1). Median age at chemotherapy was 43.2 years. Median follow-up after chemotherapy was 5.2 years. For the entire cohort, there was no significant association between CROF and SNPs. However, the association between CROF and SNPs was modified by age at chemotherapy. In subjects younger than 45 years old at chemotherapy, CYP3A4 *1B variants had significantly longer time to CROF than CYP3A4 *1A homozygotes in an adjusted multivariable Cox model. Age and tamoxifen use were also independently associated with CROF. CONCLUSION(S) A common SNP in a cyclophosphamide drug-metabolizing enzyme appears to be related to ovarian failure after cyclophosphamide-based chemotherapy in young women with breast cancer. Larger prospective studies to validate these results should be directed toward women younger than 45 years of age at chemotherapy.

Safety and Efficacy of Intratumoral Injections of Chimeric Antigen Receptor (CAR) T Cells in Metastatic Breast Cancer

Transiently expressed chimeric antigen receptor T cells specific for c-Met, expressed in breast cancer, were injected into breast cancer tumors of six patients in a phase 0 clinical trial. Injections resulted in tumor necrosis and were well tolerated. Chimeric antigen receptors (CAR) are synthetic molecules that provide new specificities to T cells. Although successful in treatment of hematologic malignancies, CAR T cells are ineffective for solid tumors to date. We found that the cell-surface molecule c-Met was expressed in ∼50% of breast tumors, prompting the construction of a CAR T cell specific for c-Met, which halted tumor growth in immune-incompetent mice with tumor xenografts. We then evaluated the safety and feasibility of treating metastatic breast cancer with intratumoral administration of mRNA-transfected c-Met-CAR T cells in a phase 0 clinical trial (NCT01837602). Introducing the CAR construct via mRNA ensured safety by limiting the nontumor cell effects (on-target/off-tumor) of targeting c-Met. Patients with metastatic breast cancer with accessible cutaneous or lymph node metastases received a single intratumoral injection of 3 × 107 or 3 × 108 cells. CAR T mRNA was detectable in peripheral blood and in the injected tumor tissues after intratumoral injection in 2 and 4 patients, respectively. mRNA c-Met-CAR T cell injections were well tolerated, as none of the patients had study drug–related adverse effects greater than grade 1. Tumors treated with intratumoral injected mRNA c-Met-CAR T cells were excised and analyzed by immunohistochemistry, revealing extensive tumor necrosis at the injection site, cellular debris, loss of c-Met immunoreactivity, all surrounded by macrophages at the leading edges and within necrotic zones. We conclude that intratumoral injections of mRNA c-Met-CAR T cells are well tolerated and evoke an inflammatory response within tumors. Cancer Immunol Res; 5(12); 1152–61. ©2017 AACR.

Abstract P4-22-14: Single agent palbociclib with or without trastuzumab for the treatment of Rb+ advanced breast cancer

Background: The Cyclin D/CDK4/6/Rb axis is dysregulated in breast cancer (BC). Palbociclib (P) is an oral agent that specifically inhibits CDK 4/6 and is FDA approved for hormone-receptor positive (HR+) disease in combination with letrozole or fulvestrant. We performed a Phase II, multi-disease, basket trial of single agent P in patients (pts) with retinoblastoma positive (Rb+), advanced cancer. We now report the full expansion cohort in BC, including a subcohort of pts with HER2+ disease. Methods: Pts with Rb+ BC were eligible for enrollment if they had measureable metastatic disease, adequate organ function and ECOG PS ≥ 1, with no limit on number of prior therapies. Pts were stratified on HER2-status, with a planned HER2-positive (HER2+) cohort, with or without trastuzumab (T). Pts with active brain metastases were excluded. Pts received P 125mg for 21 days on, 7 days off of each 28 day cycle. The protocol was amended on May 12, 2014 to allow concomitant T (given every 3 weeks 6mg/kg) for pts with HER2+ disease. Toxicity was assessed every 28 days. Response was assessed every 2 cycles using RECIST 1.0 guidelines. Results: A total of 62 pts were enrolled: 46 (74.2%) HR+/HER2-, 12% HER2+ (19.3%), and 4 (6.5%) ER/PR/HER2-. 10 of the 12 pts with HER2+ disease received T. As of June 10, 2016 one HER2+ patient (pt) remains on study who is also receiving T. Median age is 58 (range 34-88). Median prior lines of therapy is 6 (range 1-15). Response rates, progression free survival (PFS) and overall survival (OS) are depicted in Table 1 and are stratified by HER2 status and receipt of concomitant T. The most common adverse event was Grade 3 or 4 (G3/4) neutropenia (ntp) which occurred in 30 (48%) pts. There was one episode of febrile ntp in a pt who was progressing and had received 13 prior therapies. Other G3/4 events were leucopenia (n=10, 16.1%) thrombocytopenia (n=9, 14.5%), anemia (n=3, 4.8%). Conclusions: P is well tolerated in heavily pretreated pts. Grade 3/4 ntp occurred in 48% of pts and required dose reduction without necessity to add growth factor support; febrile ntp was uncommon. Single agent activity is modest (22% in the overall population) in this heavily pretreated cohort. 3 of the 4 partial responses observed were in pts with HER2+ disease 2 of whom received concurrent T. Prolonged stable disease was observed in 9 pts, 8 of whom had HR+ disease. Given the response rate of 30% in those with HER2+ disease receiving T, and PFS of 6.7 months, further investigation into this combination is warranted. Biomarker studies are underway. Citation Format: Clark AS, Wang X, Troxel A, Burrell J, Feldman M, Lal P, Zhang P, Rosen M, Gallagher M, Ndicu J, Nivar I, Matro J, Domchek SM, Fox KR, O9Dwyer P, DeMichele A. Single agent palbociclib with or without trastuzumab for the treatment of Rb+ advanced breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-14.

Abstract P6-13-08: Palbociclib and paclitaxel on an alternating schedule for advanced breast cancer: Results of a phase Ib trial:

Background: Palbociclib (P) is an oral CDK 4/6 inhibitor (CDKi) that was recently FDA approved in combination with endocrine therapy for metastatic breast cancer. We have performed a Phase I trial of P in combination with paclitaxel (T) based on preclinical studies suggesting that P synergizes with T when given on an alternating schedule, enabling cell cycle synchronization in tumor cells. We now present the dose expansion cohort. Methods: Patients (Pts) enrolled on the trial had Rb-expressing tumors of any estrogen/progesterone/HER2 receptor type, adequate organ function, and ≤3 prior chemotherapy regimens for metastatic breast cancer (mBC). Prior adjuvant or metastatic taxane was allowed. Dose escalation led to expansion at P100mg or 75mg, starting with 3 days of P (run-in) and reduction of P dosing from 5-day to 3-day intervals (days 2-4, 9-11, 16-18 of each 28 day cycle). T at 80mg/m2 was given weekly for 3 cycles; thereafter, T was administered days 1, 8 and 15 of 28 day cycle. Weekly toxicity assessments were performed; RECIST 1.0 response was assessed every 2 cycles as partial response (PR), stable disease (SD) or progressive disease (PD). Pts had the option to discontinue T and continue on P alone (3 on/1 off schedule) if they attained SD after cycle 6. Results: 27 pts enrolled on study (15- dose escalation, 12- dose expansion). Results are shown in the Table. 21 pts had received prior taxane; pts had received a median of 2 chemotherapy regimens for mBC. DLTs were grade 3 AST/ALT (n=1, at 125 mg) and febrile neutropenia (FN) (n=1, at 100 mg). Uncomplicated grade 3/4 NTP was common and frequently led to dose reduction or dose interruption during the first cycle of therapy. Frequency of NTP did not change with reducing the days of P. Among 24 evaluable patients, 14 (58%), had PR or SD ≥ 6 months across all dose levels. Of 14 pts who responded, 10 (71%) had received prior taxane. 20 pts are off study; 19 for PD, and 2 for toxicity (NTP in cycle 17 and FN in cycle 1); 7 pts remain on study. Prolonged tumor responses were seen. Conclusions: P and T can be safely combined on an alternating dosing schedule; the optimal combination dose is 75 mg of P and 80mg/m2 of weekly T. The high response rate warrants a randomized trial to determine the incremental benefit over T alone. Additional mechanistic studies are in progress to understand the in vivo effects of the alternating dosing schedule on cell cycle activity and tumor proliferation. Citation Format: Clark AS, O9Dwyer P, Troxel A, Lal P, Feldman M, Gallagher M, Driscoll A, Colameco C, Lewis D, Rosen M, Matro J, Bradbury A, Domchek S, Fox K, DeMichele A. Palbociclib and paclitaxel on an alternating schedule for advanced breast cancer: Results of a phase Ib trial. [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 P6-13-08.

Abstract P6-07-05: Mutational spectrum and tumor response in metastatic breast cancer:

Background : While several comprehensive genomic sequencing tests are clinically available for breast cancer(BC), little is known about the spectrum of findings reported in the general population and clinical utility of findings for patients(pts). Here we report tumor sequencing from the METAMORPH study, a comprehensive genomic testing approach in pts with metastatic(met) BC. Methods : Pts with either known or suspected BC mets consented to and clinically underwent concurrent diagnostic and research tumor biopsies(bx). FFPE specimens were profiled via Illumina TruSeq Cancer Panel next generation sequencing platform covering 212 amplicons in 47 cancer genes. Pathology, treatment and outcome data were prospectively collected and tracked. Aside from Her2-directed treatment, therapy was not mutation (mut)-matched. Results : 64 pts enrolled between 11/2013 – 05/2015. Of these, 48 had bx successfully sequenced (75%). Of those without sequencing, 5 had negative/insufficient tissue, 2 had insufficient DNA, remainder no bx/pending. Median age of those sequenced was 56 (range 31-78); 81% Caucasian, 17% African American. 25% (12 pts) presented with de novo stage IV disease. Of those with recurrence (n=36), 83% had prior adjuvant chemotherapy; 81% hormone receptor positive(HR+) had prior endocrine therapy. Median # prior lines of therapy for met disease was 2 (IQR 0 – 8). Tumor characteristics, including mut analyses, are shown in Table 1. # muts did not differ significantly by subtype(p=0.22). Frequency of TP53 and PIK3CA hotspot muts was nearly identical to TCGA. Median # muts was 1 for pts with both de novo mets and recurrence(p=0.79). # of muts was not associated with time to recurrence(p=0.80). Excluding pts found to have TP53 mut only or ERBB2 alterations in known Her2+ disease, 42% of pts were identified as having at least one potentially actionable alteration ( PIK3CA mut, AKT1 mut or EGFR amplification). Median time to treatment failure(TTF) on subsequent therapy was 4.1 months for overall group, and 4.1, 6.2, and 1.6 months for HR+/Her2-, any Her2+ and TN, respectively, adjusted for line of therapy(p=0.03). After adjustment for # lines of prior met therapy, TTF was 4.7 vs. 4.1 months for pts with any mut vs. none(p=0.89); 5.7 vs 4.1 months for PIK3CA + vs. not (p=0.94); 3.3 vs. 6.5 months for TP53 + vs. not (p=0.03). Conclusion : Pts with met BC have frequent and potentially actionable muts.While overall # of muts did not affect response, tumors with TP53 muts had shorter response to subsequent therapy in this cohort. Additional data are needed to determine the clinical utility of mut testing in met BC, for both standard and mut-matched therapy. Citation Format: Soucier-Ernst D, Colameco C, Troxel AB, Clark C, Shih N, Maxwell KN, Morrissette J, Lieberman D, Feldman M, Goodman N, Bradbury A, Clark A, Domchek S, Fox K, Glick J, Matro J, Nathanson K, Chodosh L, DeMichele A. Mutational spectrum and tumor response in metastatic breast cancer. [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 P6-07-05.

Abstract CT114: A phase II trial of exemestane and ruxolitinib for aI-resistant ER+ breast cancer: Interim safety, efficacy, and biomarker analysis

Resistance to aromatase inhibitors in ER+ breast cancer leads to recurrence and progression in the metastatic setting. JAK/STAT pathway activation is a resistance mechanism that could potentially be overcome with the use of JAK inhibitor therapy. Methods: We performed a phase II trial of exemestane, 25 mg daily, and ruxolitinib, 25 mg BID, in postmenopausal women with advanced, ER+ breast cancer who had progressed on a non-steroidal aromatase inhibitor and had either measureable or bone-only disease. A Simon 2-stage design was employed. A “go” decision to second stage would occur if fewer than 5/15 patients experienced any grade 3/4 toxicity requiring discontinuation from the study within the first treatment cycle. Results: Fifteen patients were enrolled; during cycle 1, no patient discontinued for toxicity and 1 patient went off study for progression of bone disease. 36 grade 3 events occurred; anemia was most common (n = 5), requiring transfusion in all patients. 47% required dose reduction. No partial or complete responses occurred; 3/15 (20%) had stable disease ≥6 months (clinical benefit, CB). Baseline CRP ≥8 was significantly associated with CB (3/3 CB vs. 1/11 non-CB; p = 0.011); other markers, including baseline ESR, IL-6 genotype status and primary tumor phosphoSTAT3 expression were not associated with CB in this small sample, though high tumoral pSTAT3 was seen in 66% of CB and 33% of non-CB. A novel pharmacodynamic (PD) assay to assess STAT3 phosphorylation in peripheral blood mononuclear cells after ruxolitinib exposure demonstrated differential effects in patients with CB vs. those without CB. Conclusions: The combination of exemestane and the JAK2 inhibitor ruxolitinib met safety criteria for continued enrollment. Anemia, an expected toxicity of R, was common and the high rate of severe anemia and need for dose reductions has led to a decision to reduce the starting dose of ruxolitinib to 15 mg BID moving forward. Promising predictive markers, including CRP, tumor pSTAT3 and a novel PD assay for pSTAT3 will be further evaluated. Citation Format: Angela M. DeMichele, Christopher B. Colameco, Anna Kalota, Andrea B. Troxel, Robin Holmes, Rebecca Cimildoro, Kelly Zafman, Kevin R. Fox, Susan M. Domchek, Keerthi Gogineni, Angela R. Bradbury, Jennifer M. Matro, Natalie Shih, Michael D. Feldman, Amy S. Clark, Elizabeth O. Hexner, Jacqueline F. Bromberg. A phase II trial of exemestane and ruxolitinib for aI-resistant ER+ breast cancer: Interim safety, efficacy, and biomarker analysis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT114. doi:10.1158/1538-7445.AM2015-CT114