Imlunestrant

Estrogen Receptor Antagonist

Key facts

Imlunestrant is an onp drug in the Estrogen Receptor Antagonist class catalogued in DrugCentral. It was first approved by the FDA in 2025. Its mechanism of action is classified as Breast Cancer Resistance Protein Inhibitors, Estrogen Receptor Antagonists and P-Glycoprotein Inhibitors. DrugCentral lists 2 molecular targets, including ESR2 and ESR1. Recorded indications include Malignant neoplasm of breast.

• Approval status: onp (first approved 2025 by the FDA).
• Drug class: Estrogen Receptor Antagonist.
• Mechanism of action: Breast Cancer Resistance Protein Inhibitors; Estrogen Receptor Antagonists; P-Glycoprotein Inhibitors.
• Molecular targets: ESR2 and ESR1 (2 listed in DrugCentral).
• Indications: Malignant neoplasm of breast.
• Molecular formula: C29H24F4N2O3; molecular weight 524.51 g/mol.

Indications & contraindications

Drug–disease relationships curated by DrugCentral (OMOP / SNOMED concepts).

Indications (1)

• Malignant neoplasm of breast

Mechanism & targets

• Mechanism of action (MoA): Breast Cancer Resistance Protein Inhibitors; Estrogen Receptor Antagonists; P-Glycoprotein Inhibitors
• Established pharmacologic class: Estrogen Receptor Antagonist

Molecular targets (2)

Target	Gene	Action	Activity
Estrogen receptor beta	ESR2	antagonist	Ki 9.96
Estrogen receptor	ESR1	antagonist	Ki 9.19

Regulatory approvals (3)

Date	Agency	Marketed as	Applicant	Orphan
2026-12-22	PMDA	—	Eli Lilly Japan K.K.
2026-01-09	EMA	—	Eli Lilly Nederland B.V.
2025-09-25	FDA	—	ELI LILLY AND CO

Chemical structure

Full physicochemical, ADMET and 3D-structure analysis of Imlunestrant is on its molecule page.

• Molecular formula: C₂₉H₂₄F₄N₂O₃
• Molecular weight: 524.51 g/mol
• CAS number: —
• InChIKey: UVBQMXOKKDCBJN-MUUNZHRXSA-N
• PubChem CID: 146603228

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

Frequently asked questions

Answers are generated from the structured data on this page, not written by hand.

What is Imlunestrant used for?

DrugCentral lists the following indications for Imlunestrant: Malignant neoplasm of breast.

How does Imlunestrant work?

Imlunestrant is classified as Breast Cancer Resistance Protein Inhibitors, Estrogen Receptor Antagonists and P-Glycoprotein Inhibitors; its molecular targets in DrugCentral include ESR2 (antagonist) and ESR1 (antagonist).

When was Imlunestrant first approved?

Imlunestrant was first approved by the FDA in 2025.

What drug class does Imlunestrant belong to?

Imlunestrant is in the Estrogen Receptor Antagonist class.

What is the chemical formula of Imlunestrant?

Imlunestrant has the molecular formula C29H24F4N2O3 and a molecular weight of 524.51 g/mol.

Sources

• DrugCentral drug card 5783 — structure, indications, targets, approvals, pharmacologic classes (CC BY-SA 4.0)
• ChEMBL CHEMBL5095183 — compound record and bioactivity
• PubChem CID 146603228 — chemical identifiers
• FDA UNII 9CXQ3PF69U — substance identity
• DailyMed: FDA labels for Imlunestrant — current prescribing information (label search)
• UniProt Q92731 (ESR2) — target protein
• UniProt P03372 (ESR1) — target protein

How this page is built: methodology · editorial policy & corrections.