Imlunestrant

Imlunestrant
Clinical data
Pronunciation/ˌɪmlʊˈnɛstrənt/
IM-luu-NES-trənt
Trade namesInluriyo
Other namesLY3484356, LY-3484356
AHFS/Drugs.comMonograph
MedlinePlusa625104
License data
Routes of
administration		By mouth
Drug classEstrogen receptor antagonist
ATC code
  • None
Legal status
Legal status
Identifiers
  • (5R)-5-[4-[2-[3-(Fluoromethyl)azetidin-1-yl]ethoxy]phenyl]-8-(trifluoromethyl)-5H-chromeno[4,3-c]quinolin-2-ol
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
Chemical and physical data
FormulaC29H24F4N2O3
Molar mass524.516 g·mol−1
3D model (JSmol)
  • C1C(CN1CCOC2=CC=C(C=C2)[C@@H]3C4=C5C=CC(=CC5=NC=C4C6=C(O3)C=C(C=C6)C(F)(F)F)O)CF
  • InChI=1S/C29H24F4N2O3/c30-13-17-15-35(16-17)9-10-37-21-5-1-18(2-6-21)28-27-23-8-4-20(36)12-25(23)34-14-24(27)22-7-3-19(29(31,32)33)11-26(22)38-28/h1-8,11-12,14,17,28,36H,9-10,13,15-16H2/t28-/m1/s1
  • Key:UVBQMXOKKDCBJN-MUUNZHRXSA-N

Imlunestrant, sold under the brand name Inluriyo, is an anti-cancer medication used for the treatment of breast cancer. It is an estrogen receptor antagonist. It is used as the salt, imlunestrant tosylate. It is taken by mouth. It was developed by Eli Lilly and Company.

The most common adverse events and laboratory abnormalities include decreased hemoglobin, musculoskeletal pain, decreased calcium, decreased neutrophils, increased aspartate transaminase, fatigue, diarrhea, increased alanine transaminase, increased triglycerides, nausea, decreased platelets, constipation, increased cholesterol, and abdominal pain.

Imlunestrant was approved for medical use in the United States in September 2025, and in the European Union in January 2026.

Medical uses

Imlunestrant is indicated for the treatment of adults with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, estrogen receptor 1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.

In September 2026, the US indication for imlunestrant was expanded to be used in combination with abemaciclib for the treatment of adults with estrogen receptor-positive, human epidermal growth factor receptor 2-negative, ESR1-mutated locally advanced or metastatic breast cancer, as detected by an FDA-authorized test, with disease progression following at least one line of endocrine therapy.

Adverse effects

The US prescribing information for imlunestrant includes warnings and precautions for embryo-fetal toxicity.

When used with abemaciclib, the US prescribing information for abemaciclib includes warnings and precautions for diarrhea, neutropenia, interstitial lung disease or pneumonitis, hepatotoxicity, venous thromboembolism, and embryo-fetal toxicity.

History

Efficacy was evaluated in EMBER-3 (NCT04975308), a randomized, open-label, active-controlled, multi-center trial that enrolled 874 participants with estrogen receptor-positive, human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer previously treated with an aromatase inhibitor either alone or in combination with a CDK4/6 inhibitor. Participants were excluded if they were eligible to receive a PARP inhibitor.

The US Food and Drug Administration granted the application for imlunestrant fast track designation.

Society and culture

Imlunestrant was approved for medical use in the United States in September 2025.

In November 2025, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Inluriyo, intended for the treatment of adults with locally advanced or metastatic breast cancer with an activating ESR1-mutation. The applicant for this medicinal product is Eli Lilly Nederland B.V. Imlunestrant was authorized for medical use in the European Union in January 2026.

Names

Imlunestrant is the international nonproprietary name.

Imlunestrant is sold under the brand name Inluriyo.

References

  1. 1 2 3 4 5 6 "Inluriyo- imlunestrant tablet, film coated". DailyMed. 4 June 2026. Retrieved 26 September 2026.
  2. 1 2 3 4 5 "Inluriyo EPAR". European Medicines Agency (EMA). 14 November 2025. Retrieved 9 December 2025. Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledged.
  3. 1 2 3 "Inluriyo Product information". Union Register of medicinal products. 9 January 2026. Retrieved 16 February 2026.
  4. 1 2 3 4 5 6 7 8 9 "FDA approves imlunestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer". U.S. Food and Drug Administration (FDA). 25 September 2025. Retrieved 27 September 2025. Public Domain This article incorporates text from this source, which is in the public domain.
  5. 1 2 3 "FDA approves imlunestrant in combination with abemaciclib for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer". U.S. Food and Drug Administration (FDA). 18 September 2026. Retrieved 26 September 2026. Public Domain This article incorporates text from this source, which is in the public domain.
  6. ↑ "U.S. FDA approves Inluriyo (imlunestrant) for adults with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer" (Press release). Eli Lilly. 25 September 2025. Retrieved 27 September 2025 – via PR Newswire.
  7. ↑ "International nonproprietary names for pharmaceutical substances (INN): recommended INN: list 88". WHO Drug Information. 36 (3). 2022. hdl:10665/363551.

Further reading