Imlunestrant

Imlunestrant, sold under the brand name Inluriyo, is an anti-cancer medication used for the treatment of breast cancer.^[1] It is an estrogen receptor antagonist.^[1] It is used as the salt, imlunestrant tosylate.^[2] It is taken by mouth.^[1] It was developed by Eli Lilly and Company.^[2]

Imlunestrant

Clinical data
Trade names	Inluriyo
Other names	LY3484356, LY-3484356
AHFS/Drugs.com	Inluriyo
License data	US DailyMed: Imlunestrant
Routes of administration	By mouth
Drug class	Estrogen receptor antagonist
ATC code	None
Legal status
Legal status	US: ℞-only[1]
Identifiers
IUPAC name (5R)-5-[4-[2-[3-(Fluoromethyl)azetidin-1-yl]ethoxy]phenyl]-8-(trifluoromethyl)-5H-chromeno[4,3-c]quinolin-2-ol
CAS Number	2408840-26-4 as tosylate: 2408840-41-3
PubChem CID	146603228
DrugBank	DB19043
ChemSpider	115010421
UNII	9CXQ3PF69U as tosylate: F7UDT90EW5
KEGG	D12216 as tosylate: D12217
ChEMBL	ChEMBL5095183
Chemical and physical data
Formula	C29H24F4N2O3
Molar mass	524.516 g·mol−1
3D model (JSmol)	Interactive image
SMILES 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 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

The most common adverse events and laboratory abnormalities include decreased hemoglobin, musculoskeletal pain, decreased calcium, decreased neutrophils, increased AST, fatigue, diarrhea, increased ALT, increased triglycerides, nausea, decreased platelets, constipation, increased cholesterol, and abdominal pain.^[2]

Imlunestrant was approved for medical use in the United States in September 2025.^[2]

Medical uses

Imlunestrant is indicated for the treatment of adults with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.^[1][2]

History

Efficacy was evaluated in EMBER-3 (NCT04975308), a randomized, open-label, active-controlled, multi-center trial that enrolled 874 participants with ER-positive, HER2-negative locally advanced or metastatic breast cancer previously treated with an aromatase inhibitor either alone or in combination with a CDK4/6 inhibitor.^[2] Participants were excluded if they were eligible to receive a PARP inhibitor.^[2]

Participants were randomized 1:1:1 to imlunestrant, an investigator's choice of endocrine therapy (fulvestrant or exemestane), or an additional investigational combination regimen.^[2] Randomization was stratified by previous treatment with a CDK4/6 inhibitor, presence of visceral metastasis, and geographic region.^[2] ESR1 mutational status was determined by blood circulating tumor deoxyribonucleic acid (ctDNA) analysis using the Guardant360 CDx assay and was limited to specific ESR1 mutations in the ligand-binding domain.^[2]

The US Food and Drug Administration granted the application of imlunestrant fast track designation.^[2]

Society and culture

Legal status

Imlunestrant was approved for medical use in the United States in September 2025.^[2][3]

Names

Imlunestrant is the international nonproprietary name.^[4]

Imlunestrant is sold under the brand name Inluriyo.^[1]