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.

PURPOSE: Imlunestrant is a next-generation oral selective estrogen receptor (ER) degrader designed to deliver continuous ER target inhibition, including in ESR1-mutant breast cancer. This phase Ia/b trial determined the recommended phase II dose (RP2D), safety, pharmacokinetics, and efficacy of imlunestrant, as monotherapy and in combination with targeted therapy, in ER-positive (ER+) advanced breast cancer (ABC) and endometrial endometrioid cancer. The ER+/human epidermal growth factor receptor 2-negative (HER2-) ABC experience is reported here. METHODS: An i3+3 dose-escalation design was used, followed by dose expansions of imlunestrant as monotherapy or in combination with abemaciclib with or without aromatase inhibitor (AI), everolimus, or alpelisib. Imlunestrant was administered orally once daily and with the combination partner per label. RESULTS: Overall, 262 patients with ER+/HER2- ABC were treated (phase Ia, n = 74; phase Ib, n = 188). Among patients who received imlunestrant monotherapy (n = 114), no dose-limiting toxicities or discontinuations occurred. At the RP2D (400 mg once daily), patients (n = 51) reported grade 1-2 nausea (39.2%), fatigue (39.2%), and diarrhea (29.4%). Patients at RP2D had received previous cyclin-dependent kinase 4/6 inhibitor (CDK4/6i; 92.2%), fulvestrant (41.2%), and chemotherapy (29.4%) for ABC and achieved a median progression-free survival (mPFS) of 7.2 months (95% CI, 3.7 to 8.3). Among patients who received imlunestrant + abemaciclib (n = 42) and imlunestrant + abemaciclib + AI (n = 43), most (69.4%) were treatment-naïve for ABC; all were CDK4/6i-naïve. Patients treated with imlunestrant + everolimus (n = 42)/alpelisib (n = 21) had received previous CDK4/6i (100%), fulvestrant (34.9%), and chemotherapy (17.5%) for ABC. No new safety signals or interactions with partnered drugs were observed. The mPFS was 19.2 months (95% CI, 13.8 to not available) for imlunestrant + abemaciclib and was not reached for imlunestrant + abemaciclib + AI. The mPFS with imlunestrant + everolimus/alpelisib was 15.9 months (95% CI, 11.3 to 19.1)/9.2 months (95% CI, 3.7 to 11.1). Antitumor activity was evident regardless of ESR1 mutation status. CONCLUSION: Imlunestrant, as monotherapy or in combination with targeted therapy, had a manageable safety profile with evidence of preliminary antitumor activity in ER+/HER2- ABC.

Clinical Practices and Institutional Protocols on Prophylaxis, Monitoring, and Management of Selected Adverse Events Associated with Trastuzumab Deruxtecan.

The treatment of metastatic breast cancer (mBC) has evolved significantly in the past several years with the approval of new targeted agents. Trastuzumab deruxtecan (T-DXd), an antibody-drug conjugate with a topoisomerase I inhibitor payload, is a new addition to the class of therapies that target the human epidermal growth factor 2 (HER2) receptor. T-DXd was approved in the US in December 2019 for patients with HER2-positive metastatic or unresectable breast cancer who have received 2 or more prior anti-HER2-based regimens in the metastatic setting. In the DESTINY-Breast01 phase II trial (NCT03248492), T-DXd demonstrated high rates of durable responses in heavily pretreated patients with HER2-positive mBC, with a confirmed objective response rate of 62%, median duration of response of 18.2 months, and median progression-free survival of 19.4 months. In addition to efficacy, successful implementation of any new anticancer therapy includes learning how to prevent, monitor, and manage treatment-related adverse events. As T-DXd becomes more widely used, information can be gained from real-world clinical practices, institutional approaches, and the collaboration of multidisciplinary oncology teams who treat patients with T-DXd. This article reviews practical insights and management of nausea and vomiting, neutropenia, interstitial lung disease, risk of cardiotoxicity, and other adverse events associated with T-DXd administration from the perspective of health care providers who have experience utilizing T-DXd.

Elacestrant (oral selective estrogen receptor degrader) Versus Standard Endocrine Therapy for Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Results From the Randomized Phase III EMERALD Trial.

PURPOSE: Patients with pretreated estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer have poor prognosis. Elacestrant is a novel, oral selective ER degrader that demonstrated activity in early studies. METHODS: This randomized, open-label, phase III trial enrolled patients with ER-positive/HER2-negative advanced breast cancer who had one-two lines of endocrine therapy, required pretreatment with a cyclin-dependent kinase 4/6 inhibitor, and ≤ 1 chemotherapy. Patients were randomly assigned to elacestrant 400 mg orally once daily or standard-of-care (SOC) endocrine monotherapy. Primary end points were progression-free survival (PFS) by blinded independent central review in all patients and patients with detectable ESR1 mutations. RESULTS: Patients were randomly assigned to elacestrant (n = 239) or SOC (n = 238). ESR1 mutation was detected in 47.8% of patients, and 43.4% received two prior endocrine therapies. PFS was prolonged in all patients (hazard ratio = 0.70; 95% CI, 0.55 to 0.88; P = .002) and patients with ESR1 mutation (hazard ratio = 0.55; 95% CI, 0.39 to 0.77; P = .0005). Treatment-related grade 3/4 adverse events occurred in 7.2% receiving elacestrant and 3.1% receiving SOC. Treatment-related adverse events leading to treatment discontinuations were 3.4% in the elacestrant arm versus 0.9% in SOC. Nausea of any grade occurred in 35.0% receiving elacestrant and 18.8% receiving SOC (grade 3/4, 2.5% and 0.9%, respectively). CONCLUSION: Elacestrant is the first oral selective ER degrader demonstrating a significant PFS improvement versus SOC both in the overall population and in patients with ESR1 mutations with manageable safety in a phase III trial for patients with ER-positive/HER2-negative advanced breast cancer.

Management of Chemotherapy-Induced Nausea and Vomiting with Trastuzumab Deruxtecan: A Case Series.

INTRODUCTION: Trastuzumab deruxtecan is a monoclonal antibody linked to a chemotherapy moiety that was recently approved by the Food and Drug Administration (FDA) for the treatment of metastatic human epidermal growth factor receptor 2 (HER2) positive breast cancers. There are labeled black box warnings for interstitial lung disease (ILD)/pneumonitis and embryo-fetal toxicity. Additionally, chemotherapy-induced nausea and vomiting (CINV) was reported to be as high as 78% (∼8% grade 3 or higher) in phase I and II clinical trials. Clinical trial and package insert recommendations for the management of CINV are not available, making real-world management difficult. CASE PRESENTATION: We reviewed the first 10 patients who received trastuzumab deruxtecan at our hospital-based community cancer center to determine if CINV management was adequate. We found a rate of 28.9% CINV (all grade 1 and 2) despite treatment as a moderate emetic potential regimen. Interventions by the treatment team to manage trastuzumab deruxtecan as a high-risk emetic regimen resulted in reduced CINV and ongoing treatment for all patients. DISCUSSION AND CONCLUSION: This review indicates that management of CINV for patients receiving trastuzumab deruxtecan should follow recommendations for regimens with a high-risk emetic potential.

Integration of Multitargeted Polymer-Based Contrast Agents with Photoacoustic Computed Tomography: An Imaging Technique to Visualize Breast Cancer Intratumor Heterogeneity.

One of the primary challenges in breast cancer diagnosis and treatment is intratumor heterogeneity (ITH), i.e., the coexistence of different genetically and epigenetically distinct malignant cells within the same tumor. Thus, the identification of ITH is critical for designing better treatments and hence to increase patient survival rates. Herein, we report a noninvasive hybrid imaging technology that integrates multitargeted and multiplexed patchy polymeric photoacoustic contrast agents (MTMPPPCAs) with single-impulse panoramic photoacoustic computed tomography (SIP-PACT). The target specificity ability of MTMPPPCAs to distinguish estrogen and progesterone receptor-positive breast tumors was demonstrated through both fluorescence and photoacoustic measurements and validated by tissue pathology analysis. This work provides the proof-of-concept of the MTMPPPCAs/SIP-PACT system to identify ITH in nonmetastatic tumors, with both high molecular specificity and real-time detection capability.

Routine use of zoledronic acid in early-stage breast cancer.

Zoledronic acid, a potent nitrogen-containing bisphosphonate, plays a key role in preventing complications of bone metastases in metastatic breast cancer, but its affect on early-stage breast cancer has been unclear. The preclinical data supporting the anticancer effects of zoledronic acid are compelling and several recent clinical trials have suggested that it reduces breast cancer recurrence in certain patient subgroups. Given these anticancer effects and reasonable safety profile, this therapeutic option could be discussed with patients. This article focuses on the results of supporting preclinical and clinical data evaluating the role of zoledronic acid in adjuvant breast cancer therapy.

Next generation sequencing and tumor mutation profiling: are we ready for routine use in the oncology clinic?

Next generation sequencing (NGS) coupled with sophisticated bioinformatics tools yields an unprecedented amount of information regarding tumor genetics, with the potential to reveal insights into tumor behavior. NGS and other multiplex genomic assays are rapidly spilling from the laboratory into the clinic through numerous commercial and academic entities. This raises the important question as to whether we are ready to use these data in clinical decision-making. While genetic lesions are clearly targeted by a new generation of biological cancer therapies, and certain regulatory approvals are actually coupled to single gene assays, we still do not know if the vast information on other genomic alterations is worth the added cost, or even worse, the inappropriate and unproven assignment of patients to treatment with an unapproved drug carrying potentially serious side effects. On the other hand, the trend toward a precision medicine pathway is clearly accelerating, and clinical trials validating pathway-driven personalized cancer therapeutics will be necessary in both the community and academic settings. Lower cost and wider availability of NGS now raises a debate over the merit of routine tumor genome-wide analysis.