Endocrine therapy (ET) is the cornerstone of management in hormone receptor (HR)+ breast cancer (BC). Indeed, targeting the estrogen receptor (ER) signaling at different levels is a successful strategy, since BC largely relies on the ER signaling as a driver of tumorigenesis and progression. In metastatic BC, progression of disease typically occurs due to either ligand-independent ER signaling, which favors tumor proliferation and survival in the absence of hormonal stimuli, or an ER-independent signaling, which exploits alternative transcription pathways. For instance, estrogen receptor 1 (ESR1) mutations induce constitutive ER activity, in turn upregulating ER-dependent gene transcription and causing resistance to estrogen depleting therapies. The largest unmet need lies after progression on ET + cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors, where fulvestrant alone provides an average 2-3-month PFS. In this context, novel oral selective estrogen receptor degraders (SERDs) and other next-generation ETs are being investigated, both as single agents and in combination with targeted therapies. Elacestrant, the next generation ET in most advanced clinical development and the first to be FDA approved, demonstrated improved outcomes compared to standard ETs in ET pre-treated HR+/HER2- metastatic BC in the phase 3 EMERALD clinical trial. Additionally, other agents are showing promising results in both preclinical and early phase clinical settings. In this review, emerging data related to oral SERDs and other novel ETs in managing HR+/HER2- BC are presented. Major challenges and future perspectives related to the optimal sequence of therapeutic options and the molecular landscape of endocrine resistance are also provided., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: CCo, has no potential conflicts of interest to disclose. CDA is a consultant and/or advisory board member for AstraZeneca, Eli Lilly, GlaxoSmithKline, Novartis, Pfizer and Roche. All the competing interests were outside the submitted work. GB is a consultant and/or advisory board member for Amgen, AstraZeneca, Chugai, Daiichi Sankyo, EISAI, Eli Lilly, Genomic Health, Merck Sharp & Dohme, Neopharm, Novartis, Pfizer, Roche and Sanofi. All the competing interests were outside the submitted work. LM reports speaker/consultant honoraria by Novartis, Pfizer, Lilly. Research Grant from Novartis and Pfizer. All the competing interests were outside the submitted work. MG reports honoraria from Roche, Pfizer, AstraZeneca, Novartis, Celgene, Eli Lilly, Amgen, and Eisai. All the competing interests were outside the submitted work. EH reports institutional research funding from OncoMed, Genentech/Roche, Zymeworks, Rgenix, ArQule, Clovis, Silverback Therapeutics, Millenium, Acerta Pharma, Sermonix Pharmaceuticals, Torque, Black Diamond, Karyopharm, Infnity Pharmaceuticals, Curis, Syndax, Novartis, Boehringer Ingelheim, Immunomedics, FujiFilm, Taiho, Deciphera, Fochon, Molecular Templates, Onconova Therapeutics, Hutchinson MediPharma, MedImmune, SeaGen, Puma Biotechnology, Compugen, TapImmune, Lilly, Pfzer, H3 Biomedicine, Takeda, Merus, Regeneron, Arvinas, StemCentRx, Verastem, eFFECTOR Therapeutics, CytomX, InventisBio, Lycera, Mersana, Radius Health, AbbVie, Nucana, Leap Therapeutics, Zenith Epigenetics, Harpoon, Orinove, AstraZeneca, Tesaro, Macrogenics, EMD Serono, Daiichi Sankyo, Syros, Sutro, G1 Therapeutics, Merck, PharmaMar, Olema, Polyphor, Immunogen, Plexxicon, Amgen, Akesobio Australia, and Shattuck Labs; consultancy/advisory roles with Genentech/Roche, Boehringer Ingelheim, Novartis, Dantari, Eli Lilly, Merck, Puma, Silverback Therapeutics, CytomX, Pfzer, Mersana, Black Diamond, H3 Biomedicine, Daiichi Sankyo, AstraZeneca, Arvinas, Deciphera Pharmaceuticals, Eisai, and Seattle Genetics. All the competing interests were outside the submitted work. RJ receives research funding from Pfizer and Lilly and is a consultant for Carrick Therapeutics and Luminex. All the competing interests were outside the submitted work. KJ reports fees for consulting or advisory role for Novartis, Pfizer, AstraZeneca, Jounce Therapeutics, Synthon, Intellisphere, Bristol Myers Squibb, Genentech, AbbVie, Lilly, BluePrint Medicines, Seattle Genetics, Daiichi Sankyo, Biotheranostics, SunPharma Pvt Ltd, Taiho Oncology, Sanofi. Research Funding from Novartis (Inst), Genentech (Inst), Debiopharm Group (Inst), ADC Therapeutics (Inst), Pfizer (Inst), Novita Pharmaceuticals (Inst), Clovis Oncology (Inst), Lilly (Inst), Zymeworks (Inst), Immunomedics (Inst), Puma Biotechnology (Inst), VelosBio/Merck (Inst), AstraZeneca (Inst), Travel, Accommodations, travel expenses from Taiho Pharmaceutical, Jounce Therapeutics, Pfizer, AstraZeneca, Intellisphere. All the competing interests were outside the submitted work. GC reports personal fees for consulting, advisory role and speakers’ bureau from Roche/Genentech, Novartis, Pfizer, Lilly, Foundation Medicine, Samsung and Daiichi Sankyo; honoraria from Ellipses Pharma and fees for travel and accommodations from Roche/Genentech and Pfizer. All the competing interests were outside the submitted work. CCr reports personal fees for consulting, advisory role and speakers’ bureau from Lilly, Roche, Novartis, MSD, Seagen, Gilead and Pfizer. All the competing interests were outside the submitted work., (Copyright © 2023 Elsevier Ltd. All rights reserved.)