Therapy For Advanced Breast Cancer Research Articles

Abstract PO2-19-10: CAPItello-292 Phase 3: An open-label, randomized study of capivasertib, fulvestrant, and investigator’s choice of CDK4/6 inhibitor (palbociclib or ribociclib) in HR+/HER2– advanced breast cancer

Abstract Background: Overcoming resistance to endocrine therapy in advanced breast cancer (ABC) is a major challenge, and there remains an unmet need for safe and efficacious treatment options. AKT pathway activation is implicated in resistance to endocrine therapy and cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2–) ABC. In the Phase 3 CAPItello-291 study, capivasertib (a potent inhibitor of all three AKT isoforms) plus fulvestrant significantly improved progression-free survival (PFS) versus fulvestrant in patients with aromatase inhibitor-resistant HR+/HER2– ABC. Simultaneous inhibition of the AKT and CDK4/6 pathways may delay CDK4/6 inhibitor resistance or re-sensitize tumors to endocrine therapy plus CDK4/6 inhibitors, leading to improved clinical outcomes. CAPItello-292 is an ongoing Phase 1b/3 study examining the efficacy and safety of adding capivasertib to fulvestrant plus a CDK4/6 inhibitor in HR+/HER2– ABC. Phase 1b has previously confirmed the recommended Phase 3 dose (RP3D) in combination with palbociclib to be tolerable with preliminary signals of clinical activity; determination of the RP3D in combination with ribociclib is currently being explored. Trial design: The Phase 3 component of CAPItello-292 is an open-label, randomized study assessing the efficacy of the addition of capivasertib to fulvestrant and the investigator’s choice of CDK4/6 inhibitors (either palbociclib or ribociclib) in patients with HR+/HER2− ABC following recurrence or progression on or within 12 months of the end of (neo)adjuvant endocrine therapy (HER2− defined as immunohistochemistry [IHC] 0, or 1-positive or IHC2-positive/in situ hybridization-negative). Approximately 628 patients will be randomized 1:1 to receive capivasertib (400 mg, oral twice daily, 4 days on and 3 days off) plus fulvestrant (500 mg intramuscularly every 28 days plus loading dose on cycle 1, day 15) and investigator’s choice of CDK4/6 inhibitor (125 mg palbociclib once daily for 21 days of each 28-day cycle or ribociclib at the determined RP3D) or fulvestrant plus investigator’s choice of CDK4/6 inhibitor alone. Patients will be treated until disease progression, unacceptable tolerability, or withdrawal of consent. Treatment beyond progression is permitted for patients with clinical benefit at the investigator’s discretion. The primary endpoint is PFS (by blinded independent central review [BICR]). The secondary endpoints include PFS in patients with AKT pathway-altered tumors, overall survival, time to second progression or death, objective response rate, duration of response, clinical benefit rate (all by BICR), physical functioning, global health status/quality of life and safety. The study plans to enroll patients from 23 countries and is planned to start at the end of 2023. Clinical trial identification: NCT04862663. Funding: CAPItello-292 is supported by AstraZeneca Editorial acknowledgment: AstraZeneca-funded medical writing support was provided by Suzanne Patel, Ph.D., from BOLDSCIENCE Inc. Capivasertib was discovered by AstraZeneca subsequent to a collaboration with Astex Therapeutics (and its collaboration with the Institute of Cancer Research and Cancer Research Technology Limited). Citation Format: Hope Rugo, Barbara Pistilli, Julie Collins, Celina D’Cruz, Christopher Gresty, Roberto Sommavilla, Dhivya Sudhan, Claire Miller, Juyoung Ha, Patrick Neven. CAPItello-292 Phase 3: An open-label, randomized study of capivasertib, fulvestrant, and investigator’s choice of CDK4/6 inhibitor (palbociclib or ribociclib) in HR+/HER2– advanced breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-19-10.

Abstract GS01-12: MONARCH 3: Final overall survival results of abemaciclib plus a nonsteroidal aromatase inhibitor as first-line therapy for HR+, HER2- advanced breast cancer

Abstract Background: Abemaciclib is approved both for high-risk early breast cancer as well as advanced breast cancer (ABC) in the first- and second-line setting. In MONARCH 2, the addition of abemaciclib to fulvestrant significantly improved both progression-free survival (PFS) and overall survival (OS) in patients with HR+, HER2- ABC with disease progression on prior endocrine therapy (ET). In MONARCH 3, the addition of abemaciclib to a nonsteroidal aromatase inhibitor (NSAI) significantly improved PFS (HR, 0.540; 95% CI, 0.418-0.698; p=0.000002) as initial therapy in HR+, HER2- ABC. At the last interim OS analysis (~252 events, at 5.8 years follow-up [FU]), a numerically favorable median OS difference (12.6 months) was observed (HR, 0.754; 95% CI, 0.584-0.974; p=0.0301, non-significant [NS]). Here, we present the final OS analysis of MONARCH 3 (NCT02246621). Methods: MONARCH 3 is a randomized, double-blind, Phase 3 study of abemaciclib + NSAI (anastrozole or letrozole) vs placebo + NSAI in postmenopausal women with HR+, HER2- ABC without prior systemic therapy in the advanced setting. OS was a gated secondary endpoint and chemotherapy-free survival (CFS) an exploratory endpoint. Final OS analysis was planned after approximately 315 OS events had occurred in the intent-to-treat (ITT) population with a split alpha between the ITT population and the subgroup with visceral disease (sVD) according to a prespecified graphical testing scheme. Kaplan-Meier method and stratified Cox proportional hazards models were used for time-to-event analyses. All reported p-values are two-sided. Results A total of 493 women were randomized 2:1 to receive abemaciclib + NSAI (n=328) or placebo + NSAI (n=165). After a median FU of 8.1 years, 7% of patients were still receiving treatment in the abemaciclib arm vs 3% in the placebo arm. In the ITT population, 314 OS events were observed (198 deaths among 328 patients [60%] in the abemaciclib arm and 116 among 165 [70%] in the placebo arm; HR, 0.804; 95% CI, 0.637-1.015; p=0.0664, NS). Median OS was 66.8 months in the abemaciclib arm and 53.7 months in the placebo arm, a numerical difference of 13.1 months in the ITT population. In the sVD, 178 events were observed (113 deaths among 173 patients [65%] in the abemaciclib arm and 65 among 90 [72%] in the placebo arm; HR, 0.758; 95% CI, 0.558-1.030; p=0.0757, NS). Median OS was 63.7 months in the abemaciclib arm and 48.8 months in the placebo arm, a numerical difference of 14.9 months in the sVD. Consistent OS differences were observed across prespecified subgroups. PFS benefit was sustained (median 29.0 vs 14.8 months; HR, 0.535; 95% CI, 0.429-0.668; nominal p<0.0001) with substantial difference in 6-year PFS rates (23.3% vs 4.3% for abemaciclib vs placebo). CFS was also improved with abemaciclib vs placebo (median 46.7 vs 30.6 months; HR, 0.693; 95% CI, 0.557-0.863; nominal p=0.0010). No new safety signals were observed with longer term use. Conclusion In patients with HR+, HER2- ABC, abemaciclib in combination with a NSAI resulted in numerically longer OS compared to NSAI alone; however, statistical significance was not reached after a median FU of 8.1 years. The clinically meaningful improvement in median OS (>13 months) combined with the sustained significant improvement in median PFS (>14 months) and substantial extension in median CFS (>16 months) continue to support the use of abemaciclib in combination with NSAI as first-line therapy in ABC. Citation Format: Matthew Goetz, Masakazu Toi, Jens Huober, Joo Hyuk Sohn, Olivier Trédan, Inhae Park, Mario Campone, Shin-Cheh Chen, Luis Manual Manso, Shani Paluch-Shimon, Orit C. Freedman, Valerie Andre, Abhijoy Saha, Gertjan van Hal, Ashwin Shahir, Hiroji Iwata, Stephen RD Johnston, Joyce O'Shaughnessy, Xavier Pivot, Sara Tolaney, Sara Hurvitz, Antonio Llombart. MONARCH 3: Final overall survival results of abemaciclib plus a nonsteroidal aromatase inhibitor as first-line therapy for HR+, HER2- advanced breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS01-12.

The combination of breast cancer PDO and mini-PDX platform for drug screening and individualized treatment.

The majority of advanced breast cancers exhibit strong aggressiveness, heterogeneity, and drug resistance, and currently, the lack of effective treatment strategies is one of the main challenges that cancer research must face. Therefore, developing a feasible preclinical model to explore tailored treatments for refractory breast cancer is urgently needed. We established organoid biobanks from 17 patients with breast cancer and characterized them by immunohistochemistry (IHC) and next generation sequencing (NGS). In addition, we in the first combination of patient-derived organoids (PDOs) with mini-patient-derived xenografts (Mini-PDXs) for the rapid and precise screening of drug sensitivity. We confirmed that breast cancer organoids are a high-fidelity three-dimension (3D) model invitro that recapitulates the original tumour's histological and genetic features. In addition, for a heavily pretreated patient with advanced drug-resistant breast cancer, we combined PDO and Mini-PDX models to identify potentially effective combinations of therapeutic agents for this patient who were alpelisib + fulvestrant. In the drug sensitivity experiment of organoids, we observed changes in the PI3K/AKT/mTOR signalling axis and oestrogen receptor (ER) protein expression levels, which further verified the reliability of the screening results. Our study demonstrates that the PDO combined with mini-PDX model offers a rapid and precise drug screening platform that holds promise for personalized medicine, improving patient outcomes and addressing the urgent need for effective therapies in advanced breast cancer.

Preventing alpelisib-related hyperglycaemia in HR+/HER2−/PIK3CA-mutated advanced breast cancer using metformin (METALLICA): a multicentre, open-label, single-arm, phase 2 trial

Hyperglycaemia is an early and frequent adverse event during alpelisib treatment. METALLICA aimed to evaluate prophylactic metformin to prevent or reduce hyperglycaemia occurrence in patients with HR+/HER2-/PIK3CA-mutated advanced breast cancer (ABC). Between August 13th, 2020 and March 23rd, 2022, this 2-cohort, phase 2, multicentre, single-arm trial (NCT04300790) enrolled patients with HR+/HER2-/PIK3CA-mutated ABC: cohort A, normal glycaemia (fasting plasma glucose <100mg/dL [<5.6mmol/L] and HbA1c <5.7%), and cohort B, prediabetes (fasting plasma glucose 100-140mg/dL [5.6-7.8mmol/L] and/or haemoglobin A1C [HbA1c] 5.7-6.4%). Participants were at least 18 years old, with Eastern Cooperative Oncology Group performance status of 0-1, and up to two prior lines of endocrine therapy (ET) for ABC. Alpelisib plus ET were administered in 28-day cycles after initiation of prophylactic metformin plus ET. Primary endpoint was the incidence of grade 3-4 hyperglycaemia over the first 8 weeks. Secondary endpoints included safety, progression-free survival (PFS), objective response rate (ORR), and clinical benefit rate (CBR). The primary objective for cohort A and B is met with ≤7 (14.6%) and ≤4 (20%) patients with grade 3-4 hyperglycaemia over the first 8 weeks, respectively. 233 patients were screened, and 68 (20.2%) patients were enrolled in cohorts A (n=48) and B (n=20). Median follow-up was 7.8 months (IQR 1.4-19.6). Over the first 8 weeks, one (2.1%) of 48 patients in cohort A (95% CI: 0.5-11.1; P<0.0001), and three (15.0%) of 20 patients in cohort B (95% CI: 5.6-37.8; P=0.016) had grade 3-4 hyperglycaemia. Serious treatment-related adverse events occurred in seven patients (10.3%). The most common were rash (two [2.9%]), vomiting (two [2.9%]), and diarrhoea (two [2.9%]). Discontinuation of alpelisib caused by AEs was reported in nine patients (13.2%), none caused by hyperglycaemia. At data cutoff (15 June, 2022), no treatment-related deaths were observed. In the full analysis set, median PFS was 7.3 months (95% CI: 5.9-not reached), ORR was 20.6% (95% CI: 11.7-32.1%), and CBR was 52.9% (95% CI: 40.4-65.2). In HR+/HER2-/PIK3CA-mutated ABC, prophylactic metformin before alpelisib plus endocrine treatment has low incidence and severity of alpelicib-induced hyperglycaemia. Novartis Pharmaceuticals.

Global representativeness and impact of funding sources in cost-effectiveness research on systemic therapies for advanced breast cancer: A systematic review

BackgroundBreast cancer (BC) is the most incident tumor and, consequently, any new intervention can potentially promote a considerable budget impact if incorporated. Cost-effectiveness (CE) studies assist in the decision-making process but may be influenced by the country's perspective of analysis and pharmaceutical industry funding. MethodsA systematic review of Medline, Scopus, and Web of Science from January 1st, 2012 to July 8th, 2022 was conducted to identify CE studies of tumor-targeted systemic-therapies for advanced BC. Articles without incremental cost-effectiveness ratio calculations were excluded. We extracted information on the country and class of drug studied, comparator type, authors’ conflicts of interest (COI), pharmaceutical industry funding, and authors' conclusions. Results71 studies comprising 204 CE assessments were included. The majority of studies were from the United States and Canada (44%), Asia (32%) and Europe (20%). Only 8% were from Latin America and none from Africa. 31% had pharmaceutical industry funding. The most studied drug classes were cyclin-dependent-kinase inhibitors (29%), anti-HER2 therapy (23%), anti-PD(L)1 (11%) and hormone therapy (11%). Overall, 34% of CE assessments had favorable conclusions. Pharmaceutical industry-funded articles had a higher proportion of at least one favorable conclusion (82% vs. 24%, p-value<0.001), European countries analyzed (45% vs. 9%, p-value = 0.003), and CE assessments with same class drug comparators (56% vs. 33%, p-value = 0.004). ConclusionsBreast cancer CE literature scarcely represents low-and-middle-income countries' perspectives and is influenced by pharmaceutical industry funding which targets European countries', frequently utilizes comparisons within same-drug class, and is more likely to have favorable conclusions.

Effective therapy of advanced breast cancer through synergistic anticancer by paclitaxel and P-glycoprotein inhibitor

Multi-drug resistance (MDR) in advanced breast cancer (ABC) is triggered by the high expression of P-glycoprotein (P-gp), which reduces intracellular concentration of anti-tumor drugs, in turn preventing oxidative stress damage to cytoplasmic and mitochondrial membranes. It is therefore of clinical relevance to develop P-gp-specific targeted nanocarriers for the treatment of drug resistant ABC. Herein, a drug carrier targeting CD44 and mitochondria was synthesised for the delivery of encequidar (ER, P-gp inhibitor) and paclitaxel (PTX). HT@ER/PTX nanoparticles (ER:PTX molar ratio 1:1) had excellent P-gp inhibition ability and targeted mitochondria to induce apoptosis in MCF-7/PTX cells in vitro. Furthermore, HT@ER/PTX nanocarriers showed more anti-tumor efficacy than PTX (Taxol®) in a xenograft mouse model of MCF-7/PTX cells; the tumor inhibitory rates of HT@ER/PTX nanoparticles and Taxol® were 72.64% ± 4.41% and 32.36% ± 4.09%, respectively. The survival of tumor-bearing mice administered HT@ER/PTX nanoparticles was prolonged compared to that of the mice treated with Taxol®. In addition, HT@ER/PTX not only inhibited P-gp-mediated removal of toxic lipid peroxidation byproducts resulting from anti-tumor drugs but also upregulated the expression of mitochondrial dynamics-related protein, fostering oxidative stress damage, which induced activation of the Caspase-3 apoptosis pathway. Our findings indicate that mitochondria targeted co-delivery of anti-tumor drugs and P-gp inhibitors could be a practical approach in treating multi-drug resistance in ABC.

Ginsenoside Rh2-Based Multifunctional Liposomes for Advanced Breast Cancer Therapy.

Most solid tumors are not diagnosed and treated until the advanced stage, in which tumors have shaped mature self-protective power, leading to off-target drugs and nanomedicines. In the present studies, we established a more realistic large tumor model to test the antitumor activity of a multifunctional ginsenoside Rh2-based liposome system (Rh2-lipo) on advanced breast cancer. Both cholesterol and PEG were substituted by Rh2 to prepare the Rh2-lipo using ethanol-water system and characterized. The effects of Rh2-lipo on cell uptake, penetration of the tumor spheroid, cytotoxicity assay was investigated with 4T1 breast cancer cells and L929 fibroblast cells. The 4T1 orthotopic-bearing large tumor model was established to study the targeting effect of Rh2-lipo and inhibitory effect of paclitaxel loaded Rh2-lipo (PTX-Rh2-lipo) on advanced breast tumors. Rh2-lipo exhibit many advantages that address the limitations of current liposome formulations against large tumors, such as enhanced uptake in TAFs and tumor cells, high targeting and penetration capacity, cytotoxicity against TAFs, normalization of the vessel network, and depletion of stromal collagen. In in vivo study, PTX-Rh2-lipo effectively inhibiting the growth of advanced breast tumors and outperformed most reported PTX formulations, including Lipusu® and Abraxane®. Rh2-lipo have improved drug delivery efficiency and antitumor efficacy in advanced breast cancer, which offers a novel promising platform for advanced tumor therapy.

Comparative overall survival of CDK4/6 inhibitors in combination with endocrine therapy in advanced breast cancer

Individual trials of abemaciclib, palbociclib, and ribociclib show a similar impact on progression-free survival yet differing statistical significance for overall survival (OS). A robust comparative evaluation of OS, safety, and tolerability of the three drugs is warranted. A systematic literature search identified phase 3 randomized clinical trials reporting OS of CDK4/6 inhibitors (CDK4/6i) in combination with endocrine therapy in ER-positive/HER2-negative advanced breast cancer. Trial-level data on OS and common and serious adverse events (AE) were extracted for each drug. In the absence of direct comparisons, a network meta-analysis was performed to evaluate pairwise comparative efficacy, safety, and tolerability of each of the CDK4/6i. Seven studies comprising of 4415 patients met the inclusion criteria. Median follow-up was 73.3 months (range: 48.7–97.2 months). There were no statistically significant differences in OS between any of the CDK4/6i. Compared to palbociclib, ribociclib and abemaciclib both showed significantly higher GI toxicity (grade 1–2 vomiting OR 1.87 [95% CI 1.37–2.56] and OR 2.27 [95% CI 1.59–3.23] respectively). Compared to palbociclib, abemaciclib was associated with more grade 3–4 diarrhea OR 118.06 [95% CI 7.28–1915.32]. In contrast, palbociclib was associated with significantly more neutropenia than ribociclib and abemaciclib but significantly lower risk of grade 3–4 infections. Abemaciclib had significantly less grade 3–4 transaminitis and grade 3–4 neutropenia than ribociclib. Treatment discontinuation and death due to AE were significantly higher with abemaciclib than palbociclib and ribociclib. There is no statistically significant difference in OS between CDK4/6i despite differing statistical significance levels of individual trials. Real-world data analyses may help to identify if there is a meaningful inter-drug difference in efficacy. Significant differences between CDK4/6i are observed for safety and tolerability outcomes.

Computational insights into overcoming resistance mechanisms in targeted therapies for advanced breast cancer: focus on EGFR and HER2 co-inhibition

In the present study, the formation of a heterodimer involving both epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) has been explored as a potential therapeutic mechanism to inhibit the progression of breast cancer. Virtual screening using molecular docking resulted in the three hit compounds (ZINC08382411, ZINC08382438, and ZINC08382292) with minimum binding scores and commonly binding to both receptors. Further, MD simulation analysis of these complexes illustrated the high stability of these compounds with EGFR and HER2. RMSD showed that ZINC08382411 displayed the most stable RMSD of 2 - 3 Å when bound to both receptors, suggesting to have strong compatibility with the active site of the receptor. Hydrogen bond analysis showed that ZINC08382411 forms the maximum number of H-bonds (2 to 3) in both EGFR and HER2 bound complexes, with the highest occupancy of 62% and 79%, respectively. Binding free energy calculation showed that ZINC08382411 possesses maximum affinity towards both the receptors with ΔGbind = −129.628 and −164.063 kJ/mol, respectively. This approach recognizes the significance of EGFR and HER2 in breast cancer development and aims to disrupt their collaborative signaling, which is known to promote the antagonistic behavior of cancer cells. By focusing on this EGFR/HER2 heterodimer, the study offers a promising avenue for identifying a potential candidate (ZINC08382411) that may inhibit breast cancer cell growth and potentially improve patient outcomes. The study’s findings may contribute to the ongoing efforts to advance breast cancer treatment strategies. Communicated by Ramaswamy H. Sarma

Early Recognition and Management of Side Effects Related to Systemic Anticancer Therapy for Advanced Breast Cancer

ObjectivesAdvances in science and technology have meant there are numerous treatment options available for people with advanced breast cancer (ABC). However, each therapeutic approach can cause side effects or adverse events, which can significantly affect the person's quality of life, overall well-being, and, in some instances, safety. This report presents an overview of the common side effects of systemic anticancer therapy and ways to manage them. Data SourcesData sources include peer-reviewed articles sourced in electronic databases and national and international best practice guidelines (ESMO, ASCO, and MASCC guidelines). ConclusionSystemic anticancer therapies have side effects that healthcare professionals need to know about to monitor and manage them in early stages. Nurses play an important role in patient education, early identification, monitoring, and management of treatment side effects. Implications for Nursing PracticePeople with ABC face many challenges during their treatment journey. Oncology nurses, specialist nurses, and nurse practitioners can be of support by providing preventive measures and side effects management at an early stage. Nurses need to have a good understanding of toxicity management but also advanced tumor-specific cancer knowledge of the different subtypes of ABC and holistic assessment skills. They are also key to providing support and enhancing self-management and early recognition of side effects.

Key Considerations for the Treatment of Advanced Breast Cancer in Older Adults: An Expert Consensus of the Canadian Treatment Landscape.

The prevalence of breast cancer amongst older adults in Canada is increasing. This patient population faces unique challenges in the management of breast cancer, as older adults often have distinct biological, psychosocial, and treatment-related considerations. This paper presents an expert consensus of the Canadian treatment landscape, focusing on key considerations for optimizing selection of systemic therapy for advanced breast cancer in older adults. This paper aims to provide evidence-based recommendations and practical guidance for healthcare professionals involved in the care of older adults with breast cancer. By recognizing and addressing the specific needs of older adults, healthcare providers can optimize treatment outcomes and improve the overall quality of care for this population.

Landscape of Baseline and Acquired Genomic Alterations in Circulating Tumor DNA with Abemaciclib Alone or with Endocrine Therapy in Advanced Breast Cancer.

To identify potential predictors of response and resistance mechanisms in patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC) treated with the cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor abemaciclib ± endocrine therapy (ET), baseline and acquired genomic alterations in circulating tumor DNA (ctDNA) were analyzed and associated with clinical outcomes. MONARCH 3: postmenopausal women with HR+, HER2- ABC and no prior systemic therapy in the advanced setting were randomly assigned to abemaciclib or placebo plus nonsteroidal aromatase inhibitor (NSAI). nextMONARCH: women with HR+, HER2- metastatic breast cancer that progressed on/after prior ET and chemotherapy were randomly assigned to abemaciclib alone (two doses) or plus tamoxifen. Baseline and end-of-treatment plasma samples from patients in MONARCH 3 and nextMONARCH (monotherapy arms) were analyzed to identify somatic genomic alterations. Association between genomic alterations and median progression-free survival (mPFS) was assessed. Most patients had ≥1 genomic alteration detected in baseline ctDNA. In MONARCH 3, abemaciclib+NSAI was associated with improved mPFS versus placebo+NSAI, regardless of baseline alterations. ESR1 alterations were less frequently acquired in the abemaciclib+NSAI arm than placebo+NSAI. Acquired alterations potentially associated with resistance to abemaciclib ± NSAI included RB1 and MYC. In MONARCH 3, certain baseline ctDNA genomic alterations were prognostic for ET but not predictive of abemaciclib response. Further studies are warranted to assess whether ctDNA alterations acquired during abemaciclib treatment differ from other CDK4/6 inhibitors. Findings are hypothesis generating; further exploration is warranted into mechanisms of resistance to abemaciclib and ET. See related commentary by Wander and Bardia, p. 2008.

Trastuzumab Resistance in Patients With HER2-Positive Advanced Breast Cancer: Results From the SONABRE Registry

BackgroundThis study aims to explore whether first-line pertuzumab use modifies the effect of prior use of (neo-) adjuvant trastuzumab on the PFS of first-line HER2-targeted therapy in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced breast cancer (ABC). MethodsPatients diagnosed with HER2-positive ABC in 2008 to 2018 in 9 Dutch hospitals were derived from the SONABRE Registry (NCT03577197). Patients diagnosed with de novo metastatic breast cancer were excluded. Patients receiving first-line trastuzumab-based therapy for ABC were selected and divided into trastuzumab naïve (n = 113) and trastuzumab pretreated (n = 112). Progression-free survival (PFS) was compared using multivariable Cox proportional hazard models. The interaction effect of first-line pertuzumab was tested using the likelihood-ratio test. ResultsThe median follow-up time was 47 months (95% confidence interval [CI]: 42-52). When comparing trastuzumab pretreated with trastuzumab naïve patients, the hazard ratio for first-line progression was 2.07 (CI:1.47-2.92). For trastuzumab pretreated patients who received first-line trastuzumab without pertuzumab, the hazard ratio for progression was 2.60 (95% CI:1.72-3.93), whereas for those who received first-line trastuzumab with pertuzumab the hazard ratio was 1.43 (95% CI: 0.81-2.52) (P interaction = .10). ConclusionsPrior use of trastuzumab as (neo-)adjuvant treatment had a negative impact on PFS of first-line HER2-targeted therapy outcomes. Adding pertuzumab to first-line trastuzumab-based therapy decreased the negative impact of prior (neo-)adjuvant trastuzumab use on first-line PFS. Further studies are needed to assess the effect of prior (neo-)adjuvant pertuzumab use on the outcomes of first-line pertuzumab-based therapy.

Stratified endocrine therapy for advanced breast cancer: stratification guided, combination preferred

The endocrine therapy of hormone receptor (HR)-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer has stepped into an era of targeted combination therapy. Many targeted agents, led by cyclin-dependent kinase 4/6 inhibitor (CDK4/6i), have provided abundant treatment options for patients with HR-positive HER2-negative advanced breast cancer. To meet the needs of clinical practice in China and standardize the administration of targeted agents, the stratified endocrine strategy for advanced breast cancer has been proposed by Chinese Society of Clinical Oncology (CSCO) Breast Cancer guidelines based on medicine evidence and drug accessibility, offering scientific and organized decision-making guidance for clinical oncologists.

Primary outcome analysis of the phase 3 SONIA trial (BOOG 2017-03) on selecting the optimal position of cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors for patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC).

LBA1000 Background: The phase-3, randomized, investigator-initiated, nationwide SONIA trial is evaluating the efficacy, safety and cost-effectiveness of CDK4/6i added to either first- or second-line endocrine therapy (ET) in patients with HR+, HER2- ABC who have received no prior therapy for ABC. The addition of CDK4/6i to ET improves progression-free (PFS) and overall survival (OS) in HR+, HER2- ABC, as initial treatment (first-line) and after prior endocrine monotherapy (second-line). Most international guidelines advice first-line use, despite prolonged toxicity and a steep increase in costs compared to use in second-line. Evidence of superiority of first-line use over second-line based on a head-to-head comparison is lacking. Methods: Pre- and postmenopausal women (N=1050), who received no prior therapy for ABC, with measurable or evaluable disease and WHO performance status 0-2 were enrolled in 74 Dutch hospitals. (Neo)adjuvant therapy was allowed (disease-free interval after non-steroidal aromatase inhibitor (NSAI) &gt;12 months). Patients were randomized 1:1 to receive strategy A (first-line treatment with an NSAI + CDK4/6i, followed on progression by fulvestrant (F)) or strategy B (first-line treatment with an NSAI, followed on progression by F + CDK4/6i). Choice between one of the available CDK4/6i (abemaciclib, palbociclib, ribociclib) was a stratification factor and left to the discretion of the treating physician. The primary endpoint is time from randomization to second objective disease progression, as assessed by local investigators, or death (PFS2). Secondary endpoints include OS, safety, quality of life, and cost-effectiveness. Results: After a median follow-up of 37.3 months (data cut-off 1 December 2022), median PFS2 was 31.0 months in strategy A versus 26.8 months in strategy B (hazard ratio 0.87; 95% confidence interval, 0.74 to 1.03; P=0.10). The treatment effect was consistent across the levels of pre-defined subgroups. The safety profile was characteristic for ET + CDK4/6i. Median time on CDK4/6i was 24.64 months in strategy A and 8.08 months in strategy B (Δ 16.56 months). The number of grade ≥3 adverse events was 2782 for strategy A and 1620 for strategy B. Conclusions: First-line use of CDK4/6i + ET does not provide statistically significant, nor clinically meaningful PFS benefit compared to second-line use in women with HR+, HER2- ABC. Use in first-line prolongs the time on CDK4/6i by 16.56 months and increases toxicity and costs. Second-line use may thus be a preferred option for the majority of patients. (Funded by The Netherlands Organisation for Health Research and Development and Dutch Health Insurers; ClinicalTrials.gov number, NCT03425838). Clinical trial information: NCT03425838 .

Comparative overall survival of patients in trials of CKD4/6 inhibitors in combination with endocrine therapy in advanced breast cancer.

1056 Background: CDK4/6i and endocrine therapy (ET) are an international gold standard therapy in estrogen receptor (ER) positive and HER2-negative advanced breast cancer (aBC). Individual trials of abemaciclib, palbociclib and ribociclib show similar impact on progression-free survival yet differing statistical significance for OS. A robust comparative evaluation of the efficacy, safety, and tolerability of the three drugs is warranted. Methods: We searched PubMed, ASCO, ESMO and SABCS proceedings to identify phase 3 randomized clinical trials reporting OS of CDK4/6i in combination with ET in ER-positive aBC in first or second line. A network meta-analysis using WinBUGS was performed to evaluate comparative efficacy, based on the ET partner, in the absence of direct comparisons. Trial level data on common and serious adverse events (AE) were extracted for each drug. The odds ratio (OR) for each AE was calculated comparing each CDK4/6i to the respective endocrine therapy backbone (aromatase inhibitor (AI) or fulvestrant) alone. Results: Seven studies comprising 4087 patients met the inclusion criteria. Median follow up was 70.2 months. Four studies paired a CDK4/6i with an AI or tamoxifen, 3 studies were paired with fulvestrant. There were no statistically significant differences in OS between any of the CDK4/6i with any ET backbone. Compared to palbociclib, ribociclib and abemaciclib showed significantly lower grade 1-2 fatigue/asthenia (ribociclib OR 0.69 [95% CI 0.58, 0.83]; abemaciclib OR 0.6 [95% CI 0.49, 0.74]) and abemaciclib showed significantly lower grade 1-2 alopecia (abemaciclib 0.76 [95% CI 0.6, 0.97]). Compared to palbociclib, ribociclib and abemaciclib showed significantly higher GI toxicity (ribociclib any grade vomiting OR 1.71 [95% CI 1.36, 2.15]; abemaciclib any grade vomiting OR 2.1 [95% CI 1.61, 2.62], any grade diarrhea 13.2 [95% CI 10.31, 16.78]). Treatment discontinuation was highest with abemaciclib. Conclusions: In this network meta-analysis, there was no statistically significant difference in OS between CDK4/6i despite differences in individual trials. Real-world data analyses may help to identify if a there is a meaningful inter-drug difference in efficacy. Significant differences between CDK4/6i are observed for safety and tolerability outcomes. [Table: see text]

A disease registry study to prospectively observe treatment patterns and outcomes in patients with HER2+ unresectable locally advanced or metastatic breast cancer (aBC): Interim results of the ESTHER study (NCT02393924).

e13039 Background: Over the last decade the standard-of-care treatment for patients with HER2+ aBC has included anti-HER2 therapies often combined with chemotherapy. These approaches have shown efficacy in clinical trials which have recruited patients in restricted populations defined by lines of therapy and previous treatments. There are few data regarding the long-term outcomes of patients treated with these regimens, including those with brain metastases. We conducted a prospective, multicentre non-interventional study to observe anti-cancer treatment regimens and clinical outcomes in patients with HER2 positive aBC. Methods: Adult patients diagnosed with HER2-positive aBC within the last 6 months were included. No specific treatment approach or course was mandated by the protocol. Source data was taken from the patient’s chart and other medical records, then reported by means of an electronic data collection system. Data regarding treatment received, efficacy (progression-free and overall survival (PFS), response rates (RR) and development of CNS metastases) and safety (including cardiac toxicity) were captured. Results: Between February 2015 and April 2018, 311 eligible patients were recruited with median age 57 years (24-96). At diagnosis of aBC the most common distant metastatic sites were bone (n = 145;47%), liver (n=117;38%), lung (n=100;32%) and brain (n=21;7%). First line treatment was with pertuzumab (P)/trastuzumab(T)/chemotherapy (n=212;68%), T/chemotherapy (n=45;14%), other T combinations without P (n=19;6%), Trastuzumab Emtansine regimens without T or P (n=16;5%) (19; 5% other combinations). Patients’ status as of cut-off date for this analysis (28th Feb 2022, median follow-up 44.1 months) is shown. The median PFS of patients treated in the 1st, 2nd and 3rd lines was 26.7 months, 10.7 months and 8.6 months. At the time of this analysis an additional 60 patients (19%) had developed brain metastases during first line. The number of patients starting 2nd, 3rd and 4th line treatment with brain metastases were 28 (22%), 17 (40%), 7 (37%) respectively. Conclusions: In routine clinical practice, as reflected by this registry, at least 40% of patients who initiate first line therapy for advanced breast cancer do not proceed to 3rd line therapy, and brain metastases become increasingly common. These findings have implications for selection of optimal 2nd and 3rd line treatment. Clinical trial information: ISRCTN02393924 . [Table: see text]

Cost-effectiveness of novel systemic therapies for advanced breast cancer: Global representativeness and influence of funding.

e18924 Background: Approval of expensive novel treatments increases costs of cancer care and undermines access, particularly in low and middle-income countries. As the most incident neoplasm, breast cancer (BC) therapies have an enormous budget impact if incorporated. Therefore, cost-effectiveness (CE) studies are essential to guide such decisions. Methods: A systematic literature search of Medline, Scopus, and Web of Science from January 1st 2012 to July 8th 2022 was conducted to identify CE studies of tumor-targeted systemic therapies for advanced BC. Articles without CE (or utility) ratio calculations were excluded. Information on the country and drug studied, authors’ conflicts of interests (COI) and funding, and authors' conclusions were manually reviewed by two independent investigators. Results: Of 1103 screened records, 74 studies comprising 212 CE comparisons were included. Most studied scenarios were from high-income countries (70%, 141/212), with only 10% from Latin America and none from Africa. The most studied drug classes were iCDK4/6 (23%), anti-HER2 directed therapy (21%), anti-PD1/PDL1 (12%) and endocrine therapy (11%). In 46% of the comparisons, a new drug combined with standard of care was compared to placebo and/or standard of care, and in 37% the compared treatment were alternative same class therapies. Nearly 46% (97/212) had pharmaceutical industry funding or author’s COI associated with industry. Overall, 56% of authors’ conclusions were unfavorable. Pharmaceutical industry related-studies were associated with high-income countries (75% vs. 64%, p = 0.006), same-class drug comparators (52% vs. 33%, p = 0.047), and favorable conclusions (60% vs. 15%, p &lt; 0.001). A combination of drugs (addition to standard of care) was associated with unfavorable conclusions (56% vs 28%, p &lt; 0.001). Conclusions: Industry-related studies target high-income countries' scenarios and are more likely to have favorable conclusions. As expected, the addition of drugs to standard treatments (combinations) is less likely to be cost-effective. Government funding in low and middle-income countries is needed to decrease the current literature gap and provide stakeholders with proper information to make incorporation decisions.

Outcomes with first-line (1L) ribociclib (RIB) + endocrine therapy (ET) vs physician’s choice combination chemotherapy (combo CT) by age in pre/perimenopausal patients (pts) with aggressive HR+/HER2− advanced breast cancer (ABC): A subgroup analysis of the RIGHT Choice trial.

1063 Background: The progression-free survival (PFS; primary endpoint) results from the Phase II RIGHT Choice trial demonstrated a statistically significant median PFS (mPFS) benefit of ≈1 y with RIB + ET over combo CT (mPFS, 24.0 vs 12.3 mo; hazard ratio [HR], 0.54; 95% CI, 0.36-0.79; P = .0007) in pts with aggressive HR+/HER2− ABC. Younger pts with aggressive ABC have a worse prognosis, which impacts treatment (tx) decisions. Hence, a subgroup analysis of key efficacy endpoints from RIGHT Choice by age (&lt; 40 vs ≥ 40 y) was undertaken. Methods: Pre/perimenopausal pts (aged 18-59 y) with HR+/HER2− ABC and no prior systemic therapy for ABC were randomized 1:1 to either RIB with letrozole/anastrozole + goserelin or investigator’s choice of combo CT (docetaxel + capecitabine, paclitaxel + gemcitabine, or capecitabine + vinorelbine). Pts in the trial had ABC not amenable to curative therapy and for which combo CT was clinically indicated by physician’s judgment (ie, symptomatic visceral metastases, rapid progression of disease or impending visceral compromise, or markedly symptomatic non-visceral disease). Results: In total, 70 pts were aged &lt; 40 y and 152 were aged ≥ 40 y. In the combo CT arm, pts aged &lt; 40 y fared worse and had a shorter mPFS, shorter median time to tx failure (mTTF), and higher 3-month tx failure rate (TFR) than pts aged ≥ 40 y. Pts aged &lt; 40 y showed a significant PFS benefit with RIB + ET vs combo CT (mPFS, not reached [NR] vs 10.2 mo; HR, 0.38). This PFS benefit with RIB + ET over combo CT was also observed in pts aged ≥ 40 y (21.2 vs 16.0 mo; HR, 0.71). Regardless of age, the mTTF was longer and the 3-month TFR was lower in the RIB + ET arm than the combo CT arm. The median time to response (mTTR), overall response rate (ORR), and clinical benefit rate (CBR) were similar between the two tx arms in both age groups. Conclusions: This analysis demonstrated a clinically meaningful PFS benefit and improved secondary outcomes with 1L RIB + ET over combo CT along with similar treatment responses in both tx arms in pts aged &lt; 40 y as well as in those ≥ 40 y with aggressive HR+/HER2− ABC. This analysis supports RIB + ET as a preferred tx option in this pt population, including younger pts aged &lt; 40 y. Clinical trial information: NCT03839823 . [Table: see text]

Prediction of clinical response to neoadjuvant therapy in advanced breast cancer by baseline B-mode ultrasound, shear-wave elastography, and pathological information.

Neoadjuvant therapy (NAT) is the preferred treatment for advanced breast cancer nowadays. The early prediction of its responses is important for personalized treatment. This study aimed at using baseline shear wave elastography (SWE) ultrasound combined with clinical and pathological information to predict the clinical response to therapy in advanced breast cancer. This retrospective study included 217 patients with advanced breast cancer who were treated in West China Hospital of Sichuan University from April 2020 to June 2022. The features of ultrasonic images were collected according to the Breast imaging reporting and data system (BI-RADS), and the stiffness value was measured at the same time. The changes were measured according to the Response evaluation criteria in solid tumors (RECIST1.1) by MRI and clinical situation. The relevant indicators of clinical response were obtained through univariate analysis and incorporated into a logistic regression analysis to establish the prediction model. The receiver operating characteristic (ROC) curve was used to evaluate the performance of the prediction models. All patients were divided into a test set and a validation set in a 7:3 ratio. A total of 152 patients in the test set, with 41 patients (27.00%) in the non-responders group and 111 patients (73.00%) in the responders group, were finally included in this study. Among all unitary and combined mode models, the Pathology + B-mode + SWE model performed best, with the highest AUC of 0.808 (accuracy 72.37%, sensitivity 68.47%, specificity 82.93%, P<0.001). HER2+, Skin invasion, Post mammary space invasion, Myometrial invasion and Emax were the factors with a significant predictive value (P<0.05). 65 patients were used as an external validation set. There was no statistical difference in ROC between the test set and the validation set (P>0.05). As the non-invasive imaging biomarkers, baseline SWE ultrasound combined with clinical and pathological information can be used to predict the clinical response to therapy in advanced breast cancer.