A Review of Selected Presentations From SABCS 2024
December 10-13, 2024 • San Antonio, Texas
Primary Results of the Randomized Phase 4 Trial Comparing First-Line Endocrine Therapy + Palbociclib vs Standard Mono-chemotherapy in Women With High-Risk HER2–/HR+ Metastatic Breast Cancer and Indication for Chemotherapy: PADMA Study
For several years, the guideline-recommended initial regimen for patients with hormone receptor–positive (HR+), human epidermal growth factor receptor 2 (HER2)–negative (HER2–) metastatic breast cancer (mBC) has been CDK4/6 inhibitors plus endocrine therapy (ET).1,2 However, despite the establishment of this regimen, many patients continued to receive chemotherapy as first-line treatment because of a lack of prospective data comparing ET with standard chemotherapy.
The randomized, open-label, multicenter, phase 4 PADMA trial was therefore designed to evaluate the efficacy and safety of a CDK4/6 inhibitor plus ET vs standard single-agent chemotherapy with or without maintenance ET in patients with high-risk mBC with an indication for chemotherapy. Primary results of the PADMA trial were presented at SABCS 2024 by Sibylle Loibl, MD, PhD (Table 1).3
The trial enrolled patients with HR+/HER2– breast cancer with an indication for single-agent chemotherapy with no prior treatment for metastatic or relapsed disease; no asymptomatic bone-only, oligometastatic disease; no uncontrolled or untreated central nervous system metastases; and a life expectancy exceeding 6 months. A total of 130 patients were stratified based on endocrine sensitivity and presence of symptoms, then randomly assigned to ET plus palbociclib (n=61) or chemotherapy treatment of the physician’s choice (TPC) with or without ET maintenance therapy (n=59). Options for ET given with palbociclib included an aromatase inhibitor (AI) or fulvestrant with or without a gonadotropin-releasing hormone agonist (GnRHa). Options for ET given as maintenance therapy included tamoxifen, an AI, or fulvestrant with or without GnRHa.
The median age of enrolled patients was 62 years (range, 31-85); 88.3% were postmenopausal, 41.7% had liver metastases, and 31.7% had endocrine resistance at baseline. Prior neoadjuvant chemotherapy had been administered to 45.0% of patients, and 66.4% of patients tested (n=71) had HER2-low disease. Pathogenic variants, tested in 81 patients, included PIK3CA (22.5%), BRCA1/2 (5.8%), and ESR1 (1.7%). Types of TPC included capecitabine (69.0%), paclitaxel (29.3%), and vinorelbine (1.7%). Post-chemotherapy maintenance with ET was administered to 22.4%. Types of ET administered in the palbociclib plus ET group included an AI (77.4%) and fulvestrant (22.6%). Types of ET administered in the TPC group included an AI (15.5%), tamoxifen (5.2%), and fulvestrant (1.7%). The median duration of treatment was 51.0 weeks for palbociclib and 19.5 weeks with chemotherapy.
After a median follow-up of 36.8 months, the trial met its primary endpoint, demonstrating an improvement in median time-to-treatment failure with palbociclib plus ET over chemotherapy (17.2 vs 6.1 months; hazard ratio [HR], 0.46; 95% CI, 0.31-0.69; P<.001). Median progression-free survival (PFS) was also significantly longer with palbociclib plus ET vs chemotherapy (18.7 vs 7.8 months; HR, 0.45; 95% CI, 0.29-0.70; P<.001). Median overall survival (OS) was 46.1 months and 36.8 months, respectively.
Investigators noted no new safety signals. Rates of hematologic toxicity were significantly higher in the palbociclib plus ET group than in the chemotherapy-based group (96.8% vs 58.6%; P<.001), whereas rates of nonhematologic treatment-related adverse events (AEs) were similar between groups at 82.3% and 93.1%, respectively. Rates of treatment-related serious AEs were 11.3% with palbociclib plus ET and 10.3% with chemotherapy. One treatment-related death occurred due to septic shock in the palbociclib plus ET group.
The investigators concluded that the findings support current international guidelines recommending the use of ET plus a CDK4/6 inhibitor as standard first-line treatment in patients with HR+/HER2– mBC.
References
1. Gennari A, André F, Barrios CH, et al. ESMO Clinical Practice Guideline for the diagnosis, staging and treatment of patients with metastatic breast cancer. Ann Oncol. 2021;32(12):1475-1495.
2. National Comprehensive Cancer Network® (NCCN) guidelines: invasive breast cancer. Version 6.2024. https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf.
3. Loibl S, Thill M, Rey J, et al. Primary results of the randomised Phase IV trial comparing first-line ET plus palbociclib vs standard mono-chemotherapy in women with high risk HER2–/HR+ metastatic breast cancer and indication for chemotherapy: PADMA study. Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract LB1-03.
Efficacy and Safety of Trastuzumab Deruxtecan vs Physician’s Choice of Chemotherapy by Pace of Disease Progression on Prior Endocrine-Based Therapy: Additional Analysis From DESTINY-Breast06
Aditya Bardia, MD, MPH, presented additional analyses from the DESTINY-Breast06 trial, a randomized, multicenter, open-label, phase 3 trial evaluating trastuzumab deruxtecan (T-DXd) vs TPC in patients with HR+, HER2-low or HER2-ultralow advanced or metastatic breast cancer previously treated with ET (Table 2).1
DESTINY-Breast06 trial enrolled patients who had received at least 2 prior lines of ET in the metastatic setting or had received 1 line of ET for mBC and either had disease progression within 6 months of starting first-line ET plus a CDK4/6 inhibitor or had a recurrence within 2 years of starting adjuvant ET.2
A total of 866 patients were randomly assigned to T-DXd 5.4 mg/kg every 3 weeks (n=436) or TPC (n=430) consisting of capecitabine (59.8%), nab-paclitaxel (24.4%), or paclitaxel (15.8%). Patients had disease that was either HER2-low (1+ or 2+ on immunohistochemical [IHC] analysis and negative results on in situ hybridization; n=713) or HER2-ultralow (IHC 0 with membrane staining; n=153). The median age of enrolled patients was 58 years. Approximately 42% had an Eastern Cooperative Oncology Group performance status of 1 or greater. Liver metastases were present at baseline in approximately 67% of patients, 85% of patients had visceral disease, and 31% of patients had de novo mBC. Primary endocrine resistance was present in 31% of patients.
As previously reported, the trial met its primary endpoint, demonstrating a significant improvement in PFS by blinded independent central review with T-DXd vs TPC in patients with HER2-low disease (median PFS, 13.2 vs 8.1 months; HR, 0.62; P<.001).2 T-DXd was also associated with an improvement in PFS over TPC in an intention-to-treat analysis in patients with HER2-low or HER2-ultralow disease (median PFS, 13.2 vs 8.1 months; HR, 0.64; P<.0001).
At SABCS 2024, investigators reported additional secondary outcomes from DESTINY-Breast06, including efficacy and safety outcomes in different patient subsets. T-DXd was associated with improvements in PFS over TPC regardless of the time to progression on first-line ET plus CDK4/6 inhibitor, whether the patient had progression within 6 months (HR, 0.38; 95% CI, 0.25-0.59), in 6 to 12 months (HR, 0.69; 95% CI, 0.43-1.12), or after 12 months (HR, 0.67; 95% CI, 0.51-0.88). T-DXd was also associated with improvements in PFS in patients with primary endocrine resistance (median PFS, 12.4 vs 6.6 months; HR, 0.57; 95% CI, 0.42-0.77) and in patients with secondary endocrine resistance (median PFS, 13.2 vs 9.5 months; HR, 0.68; 95% CI, 0.55-0.84). Objective response rates (ORR) and duration of response were also improved with T-DXd over TPC regardless of time to progression on first-line therapy or type of endocrine resistance.
To assess the efficacy of subsequent therapies after progression on T-DXd or TPC, investigators evaluated PFS2, defined as the time from randomization to second progression or death. T-DXd was associated with a significant improvement in PFS2 over TPC (median PFS2, 20.3 vs 14.7 months; HR, 0.62; 95% CI, 0.52-0.74; P<.0001), with the benefit observed regardless of time to progression on first-line therapy.
The PFS benefit with T-DXd over TPC was also observed regardless of disease burden, although the efficacy advantage was more evident in patients with lower disease burden. In patients with fewer than 3 metastatic sites at baseline, median PFS with T-DXd and TPC was 15.3 months and 8.4 months, respectively (HR, 0.55; 95% CI, 0.42-0.72). In patients with 3 or more metastatic sites at baseline, median PFS was 11.4 months and 7.2 months, respectively (HR, 0.71; 95% CI, 0.57-0.89). Safety outcomes with T-DXd and TPC in the time-to-progression and disease burden subgroups were consistent with the overall population.
Investigators concluded that T-DXd is an effective option for patients with HR+, HER2-low or HER2-ultralow mBC previously treated with at least 1 endocrine-based therapy.
References
1. Bardia A, Hu X, Dent R, et al. Efficacy and safety of trastuzumab deruxtecan (T-DXd) vs physician’s choice of chemotherapy (TPC) by pace of disease progression on prior endocrine-based therapy: additional analysis from DESTINY-Breast06. Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract LB1-04.
2. Bardia A, Hu X, Dent R, et al. Trastuzumab deruxtecan after endocrine therapy in metastatic breast cancer. N Engl J Med. Published online September 15, 2024.
PRESERVE 2: A Randomized, Phase 3, Double-Blind Trial of Trilaciclib or Placebo in Patients Receiving First-Line Gemcitabine/Carboplatin for Locally Advanced or Metastatic Triple-Negative Breast Cancer
Trilaciclib is an intravenously administered, selective, reversible CDK4/6 inhibitor that is approved by the US Food and Drug Administration (FDA) to reduce the frequency of chemotherapy-induced bone marrow suppression in adults receiving chemotherapy for extensive-stage small cell lung cancer.1 In a randomized, phase 3 trial in patients with previously treated metastatic triple-negative breast cancer (mTNBC), trilaciclib administered prior to gemcitabine and carboplatin (GCb) was associated with a significant OS improvement over GCb alone (median OS, 19.8 vs 12.6 months; HR, 0.37; P<.0001). The OS benefit occurred regardless of programmed death-ligand 1 (PD-L1) status but was greater in patients with PD-L1–positive TNBC.2
At SABCS 2024, Shom Goel, MD, PhD, presented results from the multinational, double-blind, placebo-controlled, phase 3 PRESERVE 2 trial, which further evaluated the efficacy and safety of trilaciclib prior to GCb in patients with previously untreated mTNBC (Table 3).3 The trial was open to patients who were ineligible for, or unable to receive, programmed cell death protein 1 (PD-1)/PD-L1 inhibitors. A total of 187 patients were randomly assigned to receive intravenous trilaciclib 240 mg/m2 (n=96) or placebo (n=91) prior to GCb on days 1 and 8 every 21 days.
The study did not meet its primary endpoint, reporting no significant difference in OS with trilaciclib vs placebo (median OS, 17.4 vs 17.8 months; HR, 0.91; P=.884). Among patients with PD-L1–positive disease (n=37 in each group), median OS with trilaciclib and placebo was 23.1 months and 21.8 months, respectively (HR, 1.0; P=.923) and in patients with PD-L1–negative disease (n=59 [trilaciclib] and n=54 [placebo]), median OS was 15.7 months and 14.9 months, respectively (HR, 0.92; P=.913).
Overall, the median PFS with trilaciclib and placebo was 6.3 months and 6.4 months, respectively (HR, 1.17; P=.434). Confirmed ORR among evaluable patients was 29.5% with trilaciclib (n=95) and 38.2% with placebo (n=89). The median duration of confirmed response was 7.6 months and 8.3 months, respectively.
The rate of grade 4 neutropenia was significantly lower with trilaciclib vs placebo (8.3% vs 28.6%; P=.018), as was the percentage of patients requiring granulocyte colony-stimulating factor (G-CSF) (58.3% vs 61.5%; P=.031). Results for other myeloprotection endpoints were not significantly different between groups. Any-grade and grade 3 or 4 AEs occurred at a similar frequency between groups. AEs led to discontinuation of any study drug in 22.6% of patients in the trilaciclib group and 25.8% of patients in the placebo group.
Investigators concluded that administering trilaciclib prior to GCb was not associated with a significant improvement in OS in patients with mTNBC but it was associated with a significant reduction in the frequency of grade 4 neutropenia and reduced the need for G-CSF administration.
References
1. U.S. Food & Drug Administration. FDA approves drug to reduce bone marrow suppression caused by chemotherapy. https://www.fda.gov/news-events/press-announcements/fda-approves-drug-reduce-bone-marrow-suppression-caused-chemotherapy. Accessed January 3, 2025.
2. Tan AR, Wright GS, Thummala AR, et al. Trilaciclib prior to chemotherapy in patients with metastatic triple-negative breast cancer: final efficacy and subgroup analysis from a randomized phase II study. Clin Cancer Res. 2022;28(4):629-636.
3. Goel S, O’Shaughnessy J, Xu B, et al. PRESERVE 2: a randomized, phase 3, double-blind trial of trilaciclib or placebo in patients (pts) receiving first-line gemcitabine/carboplatin (GCb) for locally advanced or metastatic triple-negative breast cancer (mTNBC). Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract PS2-05.
Quality-Adjusted Time Without Symptoms of Disease Progression or Toxicity of Treatment (Q-TWiST) Analysis of Sacituzumab Govitecan vs Chemotherapy in Previously Treated Patients with HR+/HER2– Metastatic Breast Cancer
The randomized, open-label, phase 3 TROPiCS-02 trial demonstrated a significant OS improvement with SG over chemotherapy TPC in patients with HR+/HER2– mBC previously treated with endocrine-based therapy and at least 2 additional systemic therapies.1 After a median follow-up of 12.5 months, median OS was 14.4 months with SG vs 11.2 months with TPC (HR, 0.79; P=.020). SG was also associated with significant improvements over TPC in time to deterioration of global health status and quality of life (median, 4.3 vs 3.0 months; HR, 0.75; P=.0059) and fatigue (median, 2.2 vs 1.4 months; HR, 0.73; P=.0021).
At SABCS 2024, Hope S. Rugo, MD, presented results of a Quality-adjusted Time Without Symptoms of disease progression or Toxicity of treatment (Q-TWiST) analysis from TROPiCS-02 to further assess the benefits and risks of SG vs chemotherapy while accounting for patient quality of life (QOL) (Table 4).2 Q-TWiST allows a comparison of treatments that weighs benefit vs risk in the context of patient preferences by incorporating survival differences and toxicity differences and adjusting for QOL utilities.
The analysis found a significant improvement in mean TWiST with SG vs chemotherapy (7.3 vs 5.2 months; P=.0417) and in mean Q-TWiST, which accounts for both survival and toxicity adjusted for QOL (9.7 vs 8.1 months; P=.0067). The related gain in Q-TWiST with SG of 10.8% exceeded the threshold for clinical importance of greater than 10%.
The analysis also confirmed the previously reported improvements with SG vs TPC in OS (mean, 17.0 vs 14.8 months; P=.0168) and PFS (mean, 8.3 vs 6.0 months; P=.0289). Initially there was a nonsignificant increase in time spent with grade 3 or higher treatment-emergent AEs (TEAEs) with SG vs TPC; however, this difference stabilized over time.
In sensitivity analyses, the relative gain in Q-TWiST with SG over TPC was primarily driven by differences in the amount of time patients spent experiencing TEAEs. In an analysis of Q-TWiST by follow-up time, the benefits of SG over TPC initially increased before stabilizing out to month 38. The relative Q-TWiST gain with SG over TPC exceeded the clinically important difference threshold at 17 months and remained there until month 38.
Investigators concluded that the long-term survival benefit observed with SG over TPC was attained without reducing QOL and without unmanageable toxicities, and continued to grow over time.
References
1. Rugo HS, Bardia A, Marmé F, et al. Overall survival with sacituzumab govitecan in hormone receptor–positive and human epidermal growth factor receptor 2–negative metastatic breast cancer (TROPiCS-02): a randomised, open-label, multicentre, phase 3 trial. Lancet. 2023;402(10411):1423-1433.
2. Rugo HS, Bardia A, Schmid P, et al. Quality-adjusted Time Without Symptoms of disease progression or Toxicity of treatment (Q-TWiST) analysis of sacituzumab govitecan vs chemotherapy in previously treated patients with HR+/HER2– metastatic breast cancer. Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract P2-01-05.
AFT-38 PATINA: A Randomized, Open-Label, Phase 3 Trial to Evaluate the Efficacy and Safety of Palbociclib + Anti-HER2 Therapy + Endocrine Therapy vs Anti-HER2 Therapy + Endocrine Therapy After Induction Treatment for HR+/HER2+ Metastatic Breast Cancer
The CDK4/6 inhibitor palbociclib has demonstrated a clinically meaningful improvement in PFS in patients with HR+/HER2– breast cancer.1 There is also a rationale for blocking CDK4/6 in patients with HER2+ disease.2 Moreover, blocking both HER2 and CDK4/6 pathways could enhance antiproliferative activity by suppressing Rb phosphorylation and mTORC1 activity.2
At SABCS 2024, Otto Metzger, MD, presented results from the randomized, open-label, phase 3 AFT-38 PATINA trial designed to evaluate the efficacy and safety of adding palbociclib to anti-HER2 therapy and ET in patients with previously untreated HR+/HER+ mBC (Table 5).3 Patients had received 6 to 8 cycles of treatment including trastuzumab with or without pertuzumab and taxane/vinorelbine. All patients had completed induction chemotherapy and had no evidence of disease progression.
A total of 518 patients were randomly assigned to palbociclib 125 mg orally once daily on days 1 to 21 plus trastuzumab with or without pertuzumab and ET (n=261), or trastuzumab with or without pertuzumab and ET (n=257). The median age of enrolled patients was 53.4 years; 91.7% of patients were White. Patients were stratified by pertuzumab use, which was allowed in up to 20% of the population, prior anti-HER2 therapy in the
(neo)adjuvant setting, response to induction therapy, and type of ET.
The trial met its primary endpoint, demonstrating a significant improvement in investigator-assessed PFS with palbociclib plus anti-HER2 therapy and ET over anti-HER2 therapy and ET (median PFS, 44.3 vs 29.1 months; HR, 0.74; nominal 1-sided P=.0074). The confirmed ORR was also significantly higher with palbociclib plus anti-HER2 therapy and ET over anti-HER2 therapy and ET (29.9% vs 22.2%; P=.046), as was the clinical benefit rate (CBR) (89.3% vs 81.3%; P=.01). Median OS was not reached in the palbociclib-containing treatment group vs 77 months in the control group; 5-year OS was 74.3% and 69.8%, respectively (HR, 0.86; 95% CI, 0.6-1.24).
The most frequent grade 3 or 4 AEs were neutropenia (67.8% vs 4.4%), decreased white blood cell count (11.9% vs 0%), and diarrhea (11.1% vs 1.6%). The incidence of grade 4 or higher AEs was similar in the palbociclib-containing treatment group and the control group (12.3% vs 8.9%; P=.21). The rate of treatment discontinuations due to AEs in the palbociclib-containing treatment group was 7.5%. No treatment-related deaths were reported in either study group.
The investigators concluded that the addition of palbociclib to anti-HER2 therapy and ET was associated with a significant improvement in PFS in patients with previously untreated HR+/HER2+ mBC, with a manageable safety profile.
References
1. Turner NC, Ro J, André F, et al. Palbociclib in hormone-receptor-positive advanced breast cancer. N Engl J Med. 2015;373(3):209-219.
2. Goel S, Wang Q, Watt AC, et al. Overcoming therapeutic resistance in HER2-positive breast cancers with CDK4/6 inhibitors. Cancer Cell. 2016;29(3):255-269.
3. Metzger O, DeMichele A, Gianni L, et al. AFT-38 PATINA: a randomized, open-label, phase 3 trial to evaluate the efficacy and safety of palbociclib + anti-HER2 therapy + endocrine therapy vs anti-HER2 therapy + endocrine therapy after induction treatment for HR+/HER2-positive metastatic breast cancer. Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract GS2-12.
Imlunestrant, an Oral Selective Estrogen Receptor Degrader, as Monotherapy and Combined With Abemaciclib, for Patients with ER+, HER2– Advanced Breast Cancer, Pretreated With Endocrine Therapy: Results of the Phase 3 EMBER-3 Trial
Currently, fulvestrant is the only selective estrogen receptor degrader (SERD) that is approved as monotherapy and in combination.1 However, there are limitations with fulvestrant, including limited efficacy in patients with ESR1 mutations and the requirement for intramuscular administration. Elacestrant is an orally administered SERD with dose-dependent estrogen receptor (ER) agonist and antagonist activity that is FDA approved as a single agent for patients with ER+/HER2–, ESR1-mutated advanced or metastatic breast cancer with progression after at least 1 line of ET.2 The next-generation oral SERD imlunestrant is an ER
antagonist that penetrates the central nervous system and delivers continuous ER inhibition.3 The phase 1 EMBER trial demonstrated the activity of imlunestrant plus abemaciclib in patients with ER+/HER2– advanced breast cancer.
At SABCS 2024, and concurrently published in the New England Journal of Medicine, Komal L. Jhaveri, MD, and colleagues reported results from the randomized, phase 3 EMBER-3 trial, comparing imlunestrant alone or with abemaciclib against standard-of-care (SOC) ET in patients with ER+/HER2– advanced breast cancer with recurrence while receiving or within 12 months of completing an AI with or without a CDK4/6 inhibitor, or with progression on a first-line AI with or without a CDK4/6 inhibitor, for advanced breast cancer (Table 6).4,5 No other therapies for advanced breast cancer were permitted. Patients were stratified by prior CDK4/6 inhibitor therapy, visceral metastases, and region, and randomly assigned 1:1:1 to imlunestrant 400 mg once daily (n=331), SOC ET with fulvestrant or exemestane (n=330), or imlunestrant 400 mg once daily plus abemaciclib (n=213). Baseline characteristics were generally well balanced, including in the approximately 32% to 42% of patients with ESR1 mutations.
The primary endpoint was investigator-assessed PFS in different comparisons and patient populations, including imlunestrant vs SOC ET in patients with ESR1 mutations, imlunestrant vs SOC ET in all patients, and imlunestrant plus abemaciclib vs imlunestrant alone in all patients.
In patients with ESR1 mutations, imlunestrant was associated with a significant PFS benefit over SOC ET (median PFS, 5.5 vs 3.8 months; HR, 0.62; P<.001) that was consistent across subgroups. In the overall population, there was no significant difference in PFS with imlunestrant vs SOC ET (median PFS, 5.6 vs 5.5 months; HR, 0.87; P=.12). However, the combination of imlunestrant plus abemaciclib was associated with a significant improvement in PFS over imlunestrant alone (median PFS, 9.4 vs 5.5 months; HR, 0.57; P<.001), and this benefit was consistent across clinical subgroups and ESR1 mutation status. OS analyses were immature and are ongoing.
Safety analyses showed a generally favorable toxicity profile with imlunestrant alone or with abemaciclib. The rate of grade 3 or higher TEAEs was 17% with imlunestrant, 21% with SOC ET, and 49% with imlunestrant plus abemaciclib. No oral SERD-specific events such as ocular or cardiac toxicities were noted. The rate of discontinuation due to AEs was 4%, 1%, and 6%, respectively. Investigators concluded that imlunestrant was associated with a significant PFS improvement over SOC ET in patients with ESR1-mutated ER+/HER2– advanced breast cancer, and that imlunestrant plus abemaciclib provides a significant PFS improvement over imlunestrant regardless of ESR1 mutation status.
References
1. National Cancer Institute. FDA expands approval of fulvestrant for advanced breast cancer. https://www.cancer.gov/news-events/cancer-currents-blog/2017/fda-fulvestrant-breast-cancer. September 22, 2017. Accessed January 4, 2025.
2. U.S. Food & Drug Administration. FDA approves elacestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-elacestrant-er-positive-her2-negative-esr1-mutated-advanced-or-metastatic-breast-cancer. Accessed January 4, 2025.
3. Jhaveri KL, Lim E, Jeselsohn R, et al. Imlunestrant, an oral selective estrogen receptor degrader, as monotherapy and in combination with targeted therapy in estrogen receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer: phase Ia/Ib EMBER Study. J Clin Oncol. 2024;42(35):4173-4186. [published correction appears in J Clin Oncol. 2025;43(1):114.]
4. Jhaveri KL, Neven P, Casalnuovo ML, et al. Imlunestrant, an oral selective estrogen receptor degrader, as monotherapy and combined with abemaciclib, for patients with ER+, HER2– advanced breast cancer, pretreated with endocrine therapy: results of the phase 3 EMBER-3 trial. Presented at: 2024 San Antonio Breast Cancer Symposium; December 10-13, 2024; San Antonio, Texas, USA. Abstract GS1-01.
5. Jhaveri KL, Neven P, Casalnuovo ML, et al. Imlunestrant with or without abemaciclib in advanced breast cancer. N Engl J Med. Published online December 11, 2024.