Skip To Main Content
Lilly
Menu closed
Lilly
  • Account Login / Register
  • Medical Home
  • Medical Education
      • All Therapeutic Areas
        • Alopecia Areata
        • Atopic Dermatitis
        • Dermatology
        • Psoriasis
        • Diabetes
        • Hypoglycemia
        • Inflammatory Bowel Disease
        • Crohn's Disease
        • Ulcerative Colitis
        • Migraine
        • Alzheimer's Disease
        • Cognitive Health
        • Obesity
        • Obstructive Sleep Apnea
        • Breast Cancer - Early
        • Breast Cancer - Metastatic
        • Hematological Malignancy
        • Non-Small Cell Lung Cancer
        • Oncology Precision Medicine
        • Thyroid Cancer
        • Axial Spondyloarthritis
        • Psoriatic Arthritis
        • Resources
      • All Therapeutic Areas
        • Alopecia Areata
        • Atopic Dermatitis
        • Psoriasis
        • Diabetes
        • Hypoglycemia
        • Inflammatory Bowel Disease
        • Cluster Headache
        • Migraine
        • Alzheimer's Disease
        • Cognitive Health
        • Obesity
        • Obstructive Sleep Apnea
        • Breast Cancer - Metastatic
        • Gastrointestinal Cancer
        • Hematological Malignancy
        • Oncology
        • Osteoporosis
        • Rheumatoid Arthritis
        • Resources
  • Independent Medical Education
    • Cardiovascular
      • Alopecia Areata
      • Atopic Dermatitis
      • Psoriasis
      • Diabetes
      • Crohn's Disease
      • Ulcerative Colitis
      • Migraine
      • Alzheimer's Disease
      • Obesity
      • Obstructive Sleep Apnea
      • Breast Cancer
      • Gastrointestinal Cancer
      • Hematological Malignancy
      • Non-Small Cell Lung Cancer
      • Oncology
      • Oncology Precision Medicine
      • Prostate Cancer
      • Axial Spondyloarthritis
      • Psoriatic Arthritis
  • Chat Contact Us
Lilly

You are now leaving the Lilly Medical Education website

The link you clicked on will take you to a site maintained by a third party, which is solely responsible for its content. Lilly USA, LLC does not control, influence, or endorse this site, and the opinions, claims, or comments expressed on this site should not be attributed to Lilly USA, LLC. Lilly USA, LLC is not responsible for the privacy policy of any third-party websites. We encourage you to read the privacy policy of every website you visit.
Click "Continue" to proceed or "Return" to return to Lilly Medical Education.

HR+, HER2- Metastatic Breast Cancer

Loading icon

Overview

1L Treatment

Unmet Needs

ESR1m

ET Advancements

ET Advancements

Scientific Advancements in ET

Scientific advancements in endocrine therapy (ET) seek to maximize antagonizing the estrogen receptor (ER) pathway in ER-positive (ER+), human epidermal growth factor receptor 2–negative (HER2-) advanced breast cancer.1-3

ER pathway and novel therapies that target the ER pathway. ER pathway and novel therapies that target the ER pathway.

AIs block estrogen production by inhibiting aromatase. SERMs block ER transcription by competitively inhibiting the binding of estrogen to ER. SERDs block ER translocation to the nucleus, and upon binding to ER, results in degradation of the SERD-ER complex. PROTACs bind to both ER and the E3 ubiquitin ligase, resulting in ubiquitination and degradation. CERANs block both transcriptional activation domains of ER. SERCAs inhibit ER gene transcription by binding to the C530 cysteine residue on ER.3

Next-Generation Oral ETs
Research and development into next-generation oral ETs are enabling more potent endocrine pathway antagonism while conferring alternative properties, including exposure, binding, and degradation.1-3
Exposure
Cartoon depiction of a molecule.
  • Sustained high, dose-dependent exposure supporting oral options1-3
Binding
Blue ligand binding to a red receptor.
  • Potent and highly specific binding to both wildtype and mutated ER1,3
  • Maintain activity in aromatase inhibitor (AI)-resistant and ESR1-mutant models1-3
Degradation
Red circle dissolving into white space.
  • Selective estrogen receptor degraders (SERDs) and proteolysis targeting chimeras (PROTACs) have potent ER degradation and suppression of ER-dependent signaling1-3
Doctor discussing treatment advancements with a patient.
Scientific advancements in ETs seek to maximize antagonizing the ER pathway.

As healthcare providers, it is important to stay updated on next-generation oral ETs and how they may be used as monotherapy or in combination with targeted therapies. For more information on advancements in novel ETs and ongoing clinical trials, please see additional resources below.

Related Resources

Downloadable PDFs

Download PDF Medical Answer PDF Document Created with Sketch. DECK: Overview of ER+, HER2-, ABC including ER-Targeted Therapies

This slide deck provides an overview of the ER+, HER2- advanced breast cancer landscape, including information on ER targeted therapies, mechanisms of resistance to ET +/- CDK4/6 inhibitors, & scientific advancements in the form of next-generation ETs.

Download PDF Medical Answer PDF Document Created with Sketch. INFOGRAPHIC: Scientific Advancements: Next-Generation ETs in ER+, HER2-, ABC

This infographic provides an overview of the approved and investigational ET classes in ER+, HER2-, ABC; highlights the potential benefits of next-generation ETs, resulting in more potent endocrine pathway antagonism.



(00:00) Light music and animation

(00:16) Lower thirds title animates on as speaker responds to title card prompt. Music fades.

Endocrine therapies (ETs) either block the estrogen receptor (ER) or deprive the tumor of endogenous estrogen. And this class of drugs can be really used in various lines of treatment, as long as the tumors are endocrine sensitive. Selective ER down regulators or degraders (SERDs) are a type of ET that bind to the ER to suppress its transcriptional activity and trigger its degradation. The very first SERD, fulvestrant, was developed nearly 20 years ago and was described as a pure ER antagonist. It demonstrated efficacy in patients exposed previously to aromatase inhibitors (AIs). It is widely used as monotherapy and in combination with targeted agents in pre- and postmenopausal patients with hormone receptor–positive (HR+), HER2–negative (HER2-) metastatic breast cancer (MBC).

(01:07) Full-screen graphic. Question moves to Lower Third position. Reveals speaker. Question fades away.

Fulvestrant, while providing benefit to our patients, certainly has its limitations, including toxicity and pharmacologic limitations. For instance, the poor solubility of fulvestrant requires intramuscular (IM) administration by a healthcare professional at a medical office. Over the years, we've learned that fulvestrant's efficacy is dose dependent. The currently approved dose of 500 mg IM injection was superior than 250 mg, but we’re not able to go any higher. Fulvestrant is also historically used after progression on an AI monotherapy in the metastatic setting. Now that [a] majority of our patients, if not all, are receiving AI with CDK4/6 inhibitors (CDK4/6i) in the first-line (1L) metastatic setting, we have now begun to notice that fulvestrant offers a very modest efficacy in patients who are exposed to CDK4/6i, and this is in the order of a median progression-free survival (PFS) of only 2 to 3 months. Forty to 50 percent of our patients develop ESR1 mutations [due] to prior AI therapy, and fulvestrant is not very effective for certain ESR1 mutations including Y537S.

(02:26) Full-screen graphic. Question moves to Lower Third position. Reveals speaker. Question fades away.

We're starting to see a rise in the research of novel endocrine agents, with oral SERDs being the furthest in clinical development. And as of 2023, we already have regulatory approval for the very first oral SERD, which is indicated for postmenopausal women and adult men with HR+, HER2-, ESR1-mutant MBC, following progression on 1L standard-of-care (SOC) therapy. Clinical data from the first approved oral SERD suggests an improved PFS compared to SOC ET. An increased benefit was seen in patients with ESR1 mutations, suggesting that ESR1 mutations are a surrogate for endocrine sensitivity and continuing to target this pathway remains relevant despite progression on prior ET.

Selective Estrogen Receptor Degraders (SERDs)

Dr Komal Jhaveri reviews the clinical interest in SERDs.

References

  1. Llyod MR, et al. Ther Adv Med Oncol. 2022;14:17588359221113694.
  2. Mittal A, et al. Cancers (Basel). 2023;15(7):2015.
  3. Patel R, et al. NPJ Breast Cancer. 2023;9(20). doi: 10.1038/s41523-023-00523-4

VV-MED-156150

Please rate your satisfaction with the content on the following statements:

Very Dissatisfied

Dissatisfied

Neutral

Satisfied

Very Satisfied

Credibility of information
Credibility of information
Relevance of the information to my needs
Relevance of the information to my needs
Confidence to implement the learnings in my clinical practice
Confidence to implement the learnings in my clinical practice

Please rate your satisfaction with the content on the following statements:

Credibility of information
Credibility of information
Very Satisfied
Very Dissatisfied
Relevance of the information to my needs
Relevance of the information to my needs
Very Satisfied
Very Dissatisfied
Confidence to implement the learnings in my clinical practice
Confidence to implement the learnings in my clinical practice
Very Satisfied
Very Dissatisfied
  • Copyright
  • Terms of Use
  • Privacy Statement
  • Consumer Health Privacy Notice
  • Accessibility Statement
  • Sitemap

To speak to customer support:
Call (XXX) XXX-XXXX

This site is intended for US Healthcare Professionals only.

4.4.53 05/2025 | GLOOTH00001 04/2015 | © Lilly USA, LLC 2025. All rights reserved.

Product names listed above are trademarks or registered trademarks owned by or licensed to Eli Lilly and Company, its subsidiaries, or affiliates

California Consumer Privacy Act (CCPA) Opt-Out Icon Your Privacy Choices
Cookie Settings
Facebook X LinkedIn
Lilly