Search results for "letrozole"
showing 10 items of 15 documents
ER+ Breast Cancers Resistant to Prolonged Neoadjuvant Letrozole Exhibit an E2F4 Transcriptional Program Sensitive to CDK4/6 Inhibitors
2018
AbstractPurpose: This study aimed to identify biomarkers of resistance to endocrine therapy in estrogen receptor–positive (ER+) breast cancers treated with prolonged neoadjuvant letrozole.Experimental Design: We performed targeted DNA and RNA sequencing in 68 ER+ breast cancers from patients treated with preoperative letrozole (median, 7 months).Results: Twenty-four tumors (35%) exhibited a PEPI score ≥4 and/or recurred after a median of 58 months and were considered endocrine resistant. Integration of the 47 most upregulated genes (log FC > 1, FDR < 0.03) in letrozole-resistant tumors with transcription-binding data showed significant overlap with 20 E2F4-regulated genes (P =…
Abstract P1-19-46: A phase Ib dose escalation study evaluating the mutant selective PI3K-alpha inhibitor GDC-0077 (G) in combination with letrozole (…
2020
Abstract Background: Dysregulation of the PI3K/AKT/mTOR signaling pathway occurs in solid tumor malignancies. GDC-0077 (G) is a potent p110α-selective, p110α-mutant degrading inhibitor with anti-tumor activity in PIK3CA-mutant breast cancer xenograft models as a single agent and in combination with endocrine therapies (ET) with or without a CDK4/6 inhibitor (i). An open-label, Phase I dose escalation study of Galone and in combination with ET and P is underway in patients (pts) with locally advanced or metastatic PIK3CA-mutant solid tumors. Data from the combinations of G and L with and without P in pts with PIK3CA-mutant HR+/HER2- breast cancer are presented herein. Methods: This study (NC…
Overall survival results from the randomized phase II study of palbociclib (P) in combination with letrozole (L) vs letrozole alone for frontline tre…
2017
1001 Background: Preclinical data identified a synergistic role for P and hormone blockade in blocking growth of ER+ breast cancer (BC) cell lines. PALOMA-1 was an open-label phase II trial comparing progression-free survival (PFS) in patients (pts) with advanced ER+/HER2– BC treated with P+L or L alone. Median PFS increased with addition of P to L to 20.2 mos (vs 10.2 mos with L alone; HR = 0.488), with an acceptable safety profile, leading to accelerated approval by the US FDA. These results were confirmed in the phase 3 PALOMA-2 trial. At the time of the final PFS analysis, overall survival (OS) data were immature with only 61 events in both arms and a median follow-up of < 30 mos wi…
Palbociclib - from Bench to Bedside and Beyond.
2016
Endocrine therapy is the cornerstone in the treatment of hormone receptor-positive breast cancer. During the last decades, much has been learned about the subtle regulation of the cell cycle. In this tightly regulated network, cyclin-dependent kinases (CDKs) play a pivotal role. Especially CDK4/6 is the key regulator of the G1-S transition. Realizing its importance, specific inhibitors of CDK4/6 were developed. The drug most advanced in clinical development in this class is palbociclib (PD 0332991). This review highlights preclinical data and brings into focus early clinical trials that led to an accelerated approval by the US Food and Drug Administration (FDA) as first-line treatment in co…
Abstract PS10-16: Real-world efficacy of ribociclib + aromatase inhibitor/fulvestrant, or endocrine monotherapy, or chemotherapy as first-line treatm…
2021
Abstract Background: In MONALEESA-3 and MONALEESA-7 trials, ribociclib (RIB, a selective CDK4/6 inhibitor) in combination with endocrine therapy (aromatase inhibitor [AI] or fulvestrant [FUL]) demonstrated a significant prolongation of overall survival among patients with breast cancer (BC), regardless of menopausal status and treatment-line. In the premenopausal or perimenopausal women, RIB + AI/FUL should be combined with a luteinizing hormone-releasing hormone agonist. The real-world evidence for the effectiveness, safety, and tolerability of RIB + AI/FUL in the routine clinical practice is needed to support the use of this combination. Methods: RIBANNA is a prospective, non-intervention…
Abstract PS11-11: Targeted safety events from a phase I/Ib study evaluating GDC-0077 alone and in combination with endocrine therapy (ET) ± palbocicl…
2021
Abstract Background Activating mutations in PIK3CA, encoding the p110α subunit of phosphatidylinositol 3-kinase (PI3K) occur in ~40% of HR+/HER2- BCs. GDC-0077, a PI3Kα-selective inhibitor and mutant PI3Kα degrader, is being developed as an anticancer agent. A phase I/Ib study of GDC-0077 alone and combined with other therapies is ongoing in pts with locally advanced or metastatic PIK3CAmut, HR+/HER2- mBC (NCT03006172). Targeted safety events are presented here. Methods Safety was assessed via NCI-CTCAE v4 for GDC-0077 administered alone (Arm A), with letrozole and palbo (Arm B), with letrozole (Arm C), with fulvestrant (Arm D), or with fulvestrant and palbo (Arm E, plus metformin in Arm F …
Preexisting musculoskeletal burden and its development under letrozole treatment in early breast cancer patients
2019
One of the most common adverse events (AEs) occurring during treatment with aromatase inhibitors (AIs) is musculoskeletal pain. The aim of our study was to analyze the influence of preexisting muscle/limb pain and joint pain on the development of AI-induced musculoskeletal AEs. Women eligible for upfront adjuvant endocrine therapy with letrozole were included in the PreFace study, a multicenter phase IV trial. During the first treatment year, they were asked to record musculoskeletal AEs monthly by answering questions regarding pain symptoms and rating the pain intensity on a numeric rating scale from 0 (no pain) to 10 (very strong pain). Pain values were compared using nonparametric statis…
Synthesis and PET studies of [11C-cyano]letrozole (Femara®), an aromatase inhibitor drug
2009
Abstract Introduction Aromatase, a member of the cytochrome P 450 family, converts androgens such as androstenedione and testosterone into estrone and estradiol, respectively. Letrozole (1-[bis-(4-cyanophenyl)methyl]-1 H -1,2,4-triazole; Femara) is a high-affinity aromatase inhibitor ( K i =11.5 nM) that has Food and Drug Administration approval for breast cancer treatment. Here we report the synthesis of carbon-11-labeled letrozole and its assessment as a radiotracer for brain aromatase in the baboon. Methods Letrozole and its precursor (4-[(4-bromophenyl)-1 H -1,2,4-triazol-1-ylmethyl]benzonitrile) were prepared in a two-step synthesis from 4-cyanobenzyl bromide and 4-bromobenzyl bromide,…
Phase 3 randomized study of adjuvant anastrozole (A), exemestane (E), or letrozole (L) with or without tamoxifen (T) in postmenopausal women with hor…
2017
515 Background: Uncertainty still exists regarding the optimal schedule of adjuvant treatment of breast cancer with aromatase inhibitors (AI) and no trial has ever compared all the three AI. Methods: FATA-GIM3 is a multicenter, open label, 2x3 factorial phase 3 randomized study of adjuvant A, E and L upfront (UP - for 5 years) or sequentially (SEQ - for 3 years after 2 years of T) in postmenopausal HR breast cancer pts. Two comparisons were planned: UP vs SEQ and A vs E vs L. DFS (including local or distant relapse, second breast or non-breast cancer, DCIS and death, whichever came first) was the primary end-point; 2% at 5 yrs (corresponding to a HR of 0.79) was defined as the minimum diff…
Intrinsic Subtypes and Gene Expression Profiles in Primary and Metastatic Breast Cancer.
2017
Biological changes that occur during metastatic progression of breast cancer are still incompletely characterized. In this study, we compared intrinsic molecular subtypes and gene expression in 123 paired primary and metastatic tissues from breast cancer patients. Intrinsic subtype was identified using a PAM50 classifier and χ2 tests determined the differences in variable distribution. The rate of subtype conversion was 0% in basal-like tumors, 23.1% in HER2-enriched (HER2-E) tumors, 30.0% in luminal B tumors, and 55.3% in luminal A tumors. In 40.2% of cases, luminal A tumors converted to luminal B tumors, whereas in 14.3% of cases luminal A and B tumors converted to HER2-E tumors. We ident…