^
    1d
    CDK2 inhibition enhances CDK4/6 inhibitor antitumor activity in comprehensive breast cancer PDX model screen. (PubMed, NPJ Breast Cancer)
    Early clinical data demonstrated activity of BLU-222, a potent and selective CDK2 inhibitor, both as monotherapy (CCNE1 amplified) and in combination with ribociclib and fulvestrant in patients with HR+/HER2- breast cancer. These findings provide evidence that CDK2i combined with CDK4/6i can address multiple known mechanisms of resistance to CDK4/6i, enhancing antitumor responses in preclinical breast cancer models.
    Journal
    |
    HER-2 (Human epidermal growth factor receptor 2) • CDKN2A (Cyclin Dependent Kinase Inhibitor 2A) • RB1 (RB Transcriptional Corepressor 1) • CCND1 (Cyclin D1) • CCNE1 (Cyclin E1)
    |
    HR positive • HER-2 negative
    |
    Kisqali (ribociclib) • fulvestrant • cirtociclib (BLU-222)
    1d
    Imlunestrant: First Approval. (PubMed, Drugs)
    In September 2025, imlunestrant was approved for the treatment of adults with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy in the USA. This article summarizes the milestones in the development of imlunestrant leading to this first approval for use in patients with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer.
    Journal
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor)
    |
    ER positive • HER-2 negative • HER-2 mutation • ESR1 mutation
    |
    Inluriyo (imlunestrant)
    2d
    OPERA-02: Palazestrant in Combination With Ribociclib for the First-line Treatment of ER+/HER2- Advanced Breast Cancer (clinicaltrials.gov)
    P3, N=1000, Recruiting, Olema Pharmaceuticals, Inc. | Not yet recruiting --> Recruiting
    Enrollment open
    |
    Kisqali (ribociclib) • letrozole • palazestrant (OP-1250)
    4d
    POP-ELA: A Short-term Preoperative, Evaluating Activity and Safety of Elacestrant Monotherapy as Compared to Elacestrant + Ovarian Function Suppression (LHRH Agonist) in Premenopausal Patients With Stage I-II ER+/HER2- Breast Cancer (clinicaltrials.gov)
    P2, N=140, Recruiting, Gustave Roussy, Cancer Campus, Grand Paris | Not yet recruiting --> Recruiting
    Enrollment open
    |
    ER positive
    |
    Orserdu (elacestrant) • leuprolide acetate for depot suspension
    7d
    Safety evaluation of selective estrogen receptor degraders (SERDs) using real-world evidence from the FDA Adverse Event Reporting System (FAERS). (PubMed, Sci Rep)
    The analysis commenced with elacestrant (2022) and fulvestrant (2004), concluding in the fourth quarter of 2024. For fulvestrant, increased vigilance is necessary regarding cancer metastasis and adverse events impacting the hematological and lymphatic systems. It is recommended that targeted monitoring be enhanced in clinical practice in accordance with the distinct characteristics of each drug.
    Journal • Adverse events • HEOR • Real-world evidence
    |
    ER (Estrogen receptor)
    |
    fulvestrant • Orserdu (elacestrant)
    10d
    OP-1250-002: A Phase 1 Study of Oral OP-1250 in Combination With Palbociclib in HR+/HER2- Breast Cancer Patients (clinicaltrials.gov)
    P1, N=60, Active, not recruiting, Olema Pharmaceuticals, Inc. | Trial completion date: Jul 2025 --> Mar 2026 | Trial primary completion date: Jan 2025 --> Mar 2026
    Trial completion date • Trial primary completion date
    |
    Ibrance (palbociclib) • palazestrant (OP-1250)
    13d
    ADAPTela: Marker - Adjusted Therapy Comparing Adjuvant Elacestrant With Standard Endocrine Treatment in Genomically and/or Clinically High-risk ER+/HER2- eBC (clinicaltrials.gov)
    P3, N=1520, Not yet recruiting, West German Study Group
    New P3 trial
    |
    MammaPrint • Oncotype DX Breast Recurrence Score®Test
    |
    Orserdu (elacestrant)
    13d
    Health-related quality of life with first- vs second-line CDK4/6 inhibitor use in advanced breast cancer: results from the SONIA trial. (PubMed, J Natl Cancer Inst)
    HRQoL was comparable between patients receiving CDK4/6i in first- versus second-line across all measures, despite differences in toxicity rates.
    Journal • HEOR
    |
    CDK4 (Cyclin-dependent kinase 4)
    |
    fulvestrant
    15d
    Kinetics and determinants of ESR1 mutation detection in metastatic breast cancer. (PubMed, Ann Oncol)
    We identified factors associated with the detection of bESR1mut mutations at baseline and during treatment that could help identify patients who may benefit from ESR1-targeted therapies.
    Journal
    |
    HER-2 (Human epidermal growth factor receptor 2) • ER (Estrogen receptor)
    |
    HER-2 negative • LDH elevation • ESR1 mutation
    |
    Ibrance (palbociclib) • fulvestrant
    17d
    A Trial of Itraconazole Effect on HRS-8080 Pharmacokinetics in Healthy Participants (clinicaltrials.gov)
    P1, N=16, Not yet recruiting, Shandong Suncadia Medicine Co., Ltd.
    New P1 trial
    |
    itraconazole
    17d
    Surfactant-enhanced emulsification liquid-liquid microextraction combined with sweeping micellar electrokinetic chromatography-tandem mass spectrometry for therapeutic drug monitoring of alpelisib and fulvestrant in human plasma. (PubMed, Anal Bioanal Chem)
    Application to patient samples validated the method's clinical relevance, with measured concentrations aligning with the expected ones. This is the first capillary electrophoresis method for ALP in biological matrices and the only method for simultaneous TDM of ALP and FUL, offering a robust, cost-effective, and eco-friendly alternative to traditional chromatographic approaches.
    Journal
    |
    HER-2 (Human epidermal growth factor receptor 2) • PIK3CA (Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha)
    |
    HER-2 negative • PIK3CA mutation
    |
    Piqray (alpelisib) • fulvestrant
    17d
    WEE1 inhibition delays resistance to CDK4/6 inhibitor and antiestrogen treatment in ER+ MCF7 cells. (PubMed, NPJ Syst Biol Appl)
    We treated ER+ MCF7 breast cancer cells with palbociclib alternating with a combination of fulvestrant and WEE1 inhibitor AZD1775 for 12 months. We developed a mathematical model that can simulate cell proliferation under monotherapy and alternating drug treatments. Finally, we showed that the mathematical model can be used to minimize the number of fulvestrant plus AZD1775 treatment periods while maintaining its efficacy.
    Journal
    |
    ER (Estrogen receptor)
    |
    ER positive
    |
    Ibrance (palbociclib) • fulvestrant • adavosertib (AZD1775)