1066 Background: Camizestrant, a next-generation oral selective estrogen receptor antagonist and degrader (ngSERD), was compared at two dose levels to fulvestrant 500 mg (F) in post-menopausal women with advanced ER+, HER2˗ breast cancer with disease recurrence or progression after ≤1 endocrine therapy in the advanced setting in the Phase 2 randomized SERENA-2 study (NCT04214288). Camizestrant demonstrated statistically significant and clinically meaningful benefit vs F in progression-free survival (PFS) in the overall study population (Oliveira M et al. SABCS 2022 Annual Meeting. Abstract GS3-02.). Methods: Baseline circulating tumour DNA was collected at screening and/or Cycle 1 Day 1 and analysed by next-generation sequencing. A post hoc exploratory analysis compared investigator assessed PFS with camizestrant (data from 75 and 150 mg combined) vs F in patients with detectable baseline ESR1 (the gene that encodes ERα) hotspot mutations ( ESR1m). Patients were divided into subgroups based on whether 1 or >1 ESR1m variants were detected, the specific ESR1m, and whether mutations were detected in BRCA1/2 or the MAPK pathway. The most prevalent mutations are presented. A Cox proportional hazards model was used to compare PFS. Results: 48/147 (32.7%) patients treated with camizestrant and 35/73 (47.9%) treated with F had a detectable ESR1m in at least 1 baseline sample. ESR1m were detected in 6/9 (67%) patients with a BRCA1/2 mutation and 5/26 (19%) with a MAPK pathway alteration; however, the numbers were too small to analyse efficacy in these subgroups. Conclusions: Camizestrant showed improved outcome vs F in patients with a detectable ESR1m at baseline and in the subgroups tested. The greatest median PFS improvement was seen in patients where a single ESR1m variant was detected, suggesting that early intervention upon detection of an ESR1m may provide the maximum patient benefit for camizestrant, a hypothesis that is being tested in the SERENA-6 clinical trial (NCT04964934). Clinical trial information: NCT04214288 . [Table: see text]
Aim. The aim of the study is to examine the efficacy and safety of eribulin in HER2-negative metastatic breast cancer (BC) in Russian clinical practice. Materials and methods. The analysis included 459 patients with advanced BC from 44 federal and municipal medical clinics in Russia and received at least 2 courses of treatment with eribulin in accordance with the registered indications for drug. The average age of women was 56 years (between 29 and 81 years), 83% of patients had HER2-negative tumor subtype (49.9% - luminal BC and 33.1% - triple-negative BC) HER2-positive biological tumor subtype was registered in 17% of patients. Visceral metastases were diagnosed in 73% of patients and three-zone and multiple zone metastases were diagnosed in 41.6% of cases. The median number of prior lines of therapy in patients with disseminated disease was 2; anthracycline and taxane chemotherapy was applied in 94.3% of patients, and 38.1% of patients were recived CT plus capecitabine. Standard treatment regimen with eribulin was cotinuing (1.4 mg/m² as a 2-5-minute intravenous infusion administrated on days 1, 8 of a 21-day cycle) until disease progression, unacceptable toxic effects, or impossibility of the drug administration for any other reason. We estimated the efficacy and safety of treatment with eribulin in Russian patients with HER2-negative BC. Results. Objective response rate was achieved in 20.5% of cases, complete response rate was in 3.2%, partial - 17.3%, and the stable disease rate was marked in 52.7% of women, and in 19.7% of these cases was prolonged more than 6 months. The frequency of objective response was higher in luminal BC group compared with triple-negative BC: 23.5% vs 15.8%; tumor growth control 76.9% vs. 67.8%, respectively; p
