CDk4/6 and Breast

Background: Cyclin-dependent kinase 4 and 6 (CDK4 and CDK6) inhibitors have changed the therapeutic management of hormone receptor-positive (HR+) metastatic breast cancer (mBC) by targeting the cell cycle machinery and overcoming endocrine resistance. However, a large number of patients present disease progression due to cancer cells resisting CDK4/6 inhibitors. Our research considers which clinicopathological characteristics could be useful in identifying patients who might respond to CDK4/6 inhibitors by analyzing a retrospective case series of patients with HR+ mBC who were treated with hormone therapy plus CDK4/6 inhibitors...

BACKGROUND/AIM: Everolimus in combination with exemestane was shown to offer benefit versus exemestane monotherapy in hormone receptor (HR)-positive, HER2-negative advanced breast cancer patients who progressed after aromatase inhibitor (AI) therapy. PATIENTS AND METHODS: The medical records of metastatic breast cancer patients, treated with everolimus, were retrospectively reviewed to generate real life safety and efficacy data. RESULTS: Sixty-eight percent of the patients had received chemotherapy (for early or metastatic disease) and 26% had received chemotherapy for metastatic disease...

BACKGROUND: The clinical outcomes of chemotherapy (CT) for the treatment of metastatic triple-negative (TN) and hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC) have proven to be disappointing. The phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway, a tumor-promoting signaling cascade frequently mutated in breast cancer (BC), has been implicated in chemoresistance...

INTRODUCTION: Cyclin-dependent kinases 4/6 inhibitors (CDK 4/6i) combined with endocrine therapy have become the gold standard in hormone receptor-positive (HR +) HER2-negative (HER2-) metastatic breast cancer (MBC). However, there is a significant lack of data regarding the efficacy and safety of these treatments in elderly patients. We present the results of a real-world data (RWD) cohort stratified by age at treatment initiation (≥ 70 years compared to patients < 70 years)...

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PURPOSE: Cyclin-dependent kinase (CDK) 4/6 inhibitors (CDK4/6is) are an important component of treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC), but it is not known if patients might derive benefit from continuation of CDK4/6i with endocrine therapy beyond initial tumor progression or if the addition of checkpoint inhibitor therapy has value in this setting. METHODS: The randomized multicenter phase II PACE trial enrolled patients with hormone receptor-positive/HER2- MBC whose disease had progressed on previous CDK4/6i and aromatase inhibitor (AI) therapy...

BACKGROUND: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors radically changed the treatment paradigm for breast cancer. Similar to estrogen receptor in breast cancer, androgen receptor signaling activates cyclin D-CDK4/6, driving proliferation and resistance to hormonal manipulation in prostate cancer. This study was designed to detect signals of clinical activity for abemaciclib in treatment-refractory metastatic castration-resistant prostate cancer (mCRPC). METHODS: Eligible patients had progressive mCRPC, measurable disease, and previously received ≥1 novel hormonal agent(s) and 2 lines of taxane chemotherapy...

The landscape of cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) resistance is still being elucidated and the optimal subsequent therapy to overcome resistance remains uncertain. Here we present the final results of a phase Ib/IIa, open-label trial (NCT02871791) of exemestane plus everolimus and palbociclib for CDK4/6i-resistant metastatic breast cancer. The primary objective of phase Ib was to evaluate safety and tolerability and determine the maximum tolerated dose/recommended phase II dose (100 mg palbociclib, 5 mg everolimus, 25 mg exemestane)...

BACKGROUND: The recent advent of the cyclin-dependent kinase (CDK) 4/6 inhibitors has considerably evolved hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer treatment. Palbociclib, an orally administered pyridopyrimidine derivative, was the first CDK4/6 inhibitor to be introduced into daily clinical practice in combination with classic endocrine backbone, based on progression-free survival (PFS) benefit assessed in the pivotal PALOMA series of randomized clinical trials...

BACKGROUND: The last years have seen unprecedented improvement in breast cancer (BC) survival rates. However, this entirely apply to female BC patients, since gender minorities (male, transgender/gender-diverse) are neglected in BC phase III registration clinical trials. METHODS: We conducted a scoping review of phase III clinical trials of agents with a current positioning within the therapeutic algorithms of BC. RESULTS: We selected 51 phase III trials...

BACKGROUND: The aim of this study was to evaluate the association between CDK4/6 inhibitors and QT interval prolongation (QTp) and Torsades de Pointes (TdP) in breast cancer patients. METHOD: The cases with breast cancer from 2015 to 2022 were extracted from the FDA adverse event database (FARES) and further divided into a CDK4/6 inhibitor group and a positive control group. The associations between CDK4/6 inhibitors and QTp and TdP adverse events were evaluated using the reporting odds ratio (ROR) and the information component (IC)...

CDK4/6 inhibitors (CDK4/6i) have improved survival of patients with estrogen receptor-positive (ER+) breast cancer. However, patients treated with CDK4/6i eventually develop drug resistance and progress. RB1 loss-of-function alterations confer resistance to CDK4/6i, but the optimal therapy for these patients is unclear. Through a genome-wide CRISPR screen, we identify protein arginine methyltransferase 5 (PRMT5) as a molecular vulnerability in ER+/RB1-knockout breast cancer cells. Inhibition of PRMT5 blocks the G1-to-S transition in the cell cycle independent of RB, leading to growth arrest in RB1-knockout cells...

BACKGROUND: CDK4/6 inhibitors in combination with traditional endocrine therapy (ET) have become the recommended first-line therapy for HR-positive/HER2-negative metastatic breast cancer (MBC). The aim of this prospective study was to evaluate the relationship between HER2-low expression and clinical outcomes in HR-positive/HER2-negative MBC patients receiving ET with or without CDK4/6 inhibitors. METHODS: Between April 2016 and November 2019, 233 women with HR-positive/HER2-negative MBC who received ET with or without CDK4/6 inhibitors were enrolled into the study...

A hallmark of cancer is the dysregulation of the cell cycle. The CDK4/6 inhibitor palbociclib is approved for treating advanced estrogen-receptor-positive breast cancer, but its success is limited by the development of acquired resistance owing to long-term therapy despite promising clinical outcomes. This situation necessitates the development of potential combination strategies. Here, we report that didox, an inhibitor of ribonucleotide reductase in combination with palbociclib, can overcome palbociclib resistance in ER-positive and ER-negative breast cancers...

BACKGROUND: Following the positive iDFS and OS results of the phase III clinical trials monarchE, NATALEE and OlympiA, new oral anticancer agents (the CDK4/6 inhibitors abemaciclib, ribociclib as well as the PARP inhibitor olaparib) have recently been introduced into the treatment of high-risk early breast cancer (eBC). However, only few male patients were included in these trials (0.4%, 0.6% and 0.3%, respectively). The objective of this real-world analysis was to determine the proportion of male patients with eBC fulfilling the clinical high-risk criteria of above-mentioned trials...

OBJECTIVES: CDK4/6 inhibitors dalpiciclib and abemaciclib have been approved by the Chinese National Medical Products Administration as first-line treatment for postmenopausal females with hormone receptor-positive (HR+) and human epidermal growth factor receptor-2 negative (HER2-) advanced breast cancer (ABC). We aimed to assess the cost-effectiveness of dalpiciclib plus letrozole/anastrozole (non-steroidal aromatase inhibitor [NSAI]) compared with abemaciclib plus NSAI as a first-line treatment for HR+/HER2- ABC in China...

ETHNOPHARMACOLOGICAL RELEVANCE: Rujifang (RJF) constitutes a traditional Chinese medicinal compound extensively employed in the management of triple-negative breast cancer (TNBC). However, information regarding its potential active ingredients, antitumor effects, safety, and mechanism of action remains unreported. AIM OF THE STUDY: To investigate the efficacy and safety of RJF in the context of TNBC. MATERIALS AND METHODS: We employed the ultra high-performance liquid chromatography-electrospray four-pole time-of-flight mass spectrometry technique (UPLC/Q-TOF-MS/MS) to scrutinize the chemical constituents of RJF...

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) are the mainstay of treatment of hormone receptor+ /human epidermal growth factor receptor 2-patients with advanced breast cancer (ABC). Despite improvements in overall survival, most patients experience disease progression. Biomarkers derived from a liquid biopsy are appealing for their potential to detect resistance to treatment earlier than computed tomography imaging. However, clinical data concerning microRNAs (miRNAs/miRs) in the context of CDK4/6is are lacking...

Aberrant cyclin-dependent kinase 2 (CDK2) activation has been identified as a main resistance mechanism to CDK4/6 inhibition in hormone-receptor positive (HR+) breast cancer. Additionally, consistent preclinical evidence states its crucial role in MYC and CCNE1 overexpressed cancer survival, such as triple-negative breast cancers (TNBC), thus representing an appealing and relatively unexplored target treatment opportunity. Despite emerging initial results of novel CDK2 inhibitors (CDK2i) activity, a comprehensive outcomes collection is currently absent from the scientific literature...

BACKGROUND: Chidamide is a selective histone deacetylase inhibitor approved for patients with hormone receptor (HoR)-positive and HER2-negative metastatic breast cancer (MBC). We aimed to investigate the efficacy, safety, and treatment patterns of chidamide and identify clinicopathological factors that predict the efficacy of chidamide in real-world scenarios. METHODS: Consecutive MBC patients treated with chidamide from January 2020 to August 2021 across 11 institutions were enrolled in this multicenter, retrospective study...