pharmacopeia
GET
/api/v1/drug/imlunestrant

Mechanism of action

Sourced from openFDA

Imlunestrant is an estrogen receptor (ER) antagonist that binds to ERα. In vitro, imlunestrant induced degradation of ERα, leading to inhibition of ER-dependent gene transcription and cellular proliferation in ER+ breast cancer cells.

Breast Cancer Resistance ProteinEstrogen ReceptorP-Glycoprotein

Indications

Sourced from openFDA
  • INLURIYO is indicated for the treatment of adults with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, estrogen receptor-1 ( ESR1 )-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.ICD-10: C50.919

Contraindications

Sourced from openFDA
  • None. None.contraindicated

Dosage & administration

Sourced from openFDA

Select patients for treatment based on the presence of ESR1 mutations. ( 2.1 ) The recommended dosage is 400 mg orally once daily, on an empty stomach. ( 2.2 ) Reduce the dose in patients with moderate or severe hepatic impairment ( 2.4 , 8.6 ) Dosage modifications may be required. ( 2.3 , 2.4 , 2.5 ) 2.1 Patient Selection Select patients for treatment of ER-positive, HER2-negative advanced or metastatic breast cancer with INLURIYO based on the presence of ESR1 mutation(s) in a plasma specimen using an FDA-approved test [see Indications and Usage ( 1 ) and Clinical Studies (14.1)] . Information on FDA-approved tests for the detection of ESR1 mutations in breast cancer is available at: https://www.fda.gov/CompanionDiagnostics . 2.2 Recommended Dosage and Administration The recommended dosage of INLURIYO is 400 mg orally once daily until disease progression or unacceptable toxicity. Take on an empty stomach at least 2 hours before food, or 1 hour after food [see Clinical Pharmacology ( 12.3 )] . Take INLURIYO tablets at approximately the same time daily. Swallow the tablets whole. Do not split, crush, or chew the tablets. Pre/perimenopausal women and men should receive a gonadotropin-releasing hormone agonist (GnRH) according to current clinical practice standards. If patient misses a dose by 6 or more hours or vomits, instruct the patient to take the next dose the following day at its scheduled time. 2.3 Dosage Modifications for Adverse Reactions The recommended INLURIYO dosage modifications for adverse reactions are provided in Tables 1 and 2 .

Warnings & precautions

Sourced from openFDA

Embryo-Fetal Toxicity: INLURIYO can cause fetal harm. Advise of the potential risk to a fetus and to use effective contraception. ( 5.1 , 8.1 , 8.3 ) 5.1 Embryo-Fetal Toxicity Based on findings in animals and its mechanism of action, INLURIYO can cause fetal harm when administered to a pregnant woman. In an animal reproduction study, oral administration of imlunestrant to pregnant rats during the period of organogenesis led to embryo-fetal mortality and structural abnormalities at maternal exposures that were below the human exposure at the recommended dose based on AUC. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with INLURIYO and for 1 week after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with INLURIYO and for 1 week after the last dose [see Use in Specific Populations ( 8.1 , 8.3 ) and Clinical Pharmacology ( 12.1 )] .

Adverse reactions

Sourced from openFDA

The most common (incidence ≥10%) adverse reactions, including laboratory abnormalities were: hemoglobin decreased, musculoskeletal pain, calcium decreased, neutrophils decreased, AST increased, fatigue, diarrhea, ALT increased, triglycerides increased, nausea, platelets decreased, constipation, cholesterol increased, and abdominal pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Eli Lilly and Company at 1-800-LillyRx (1-800-545-5979) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The safety of INLURIYO was evaluated in 651 patients with ER+, HER2- locally advanced or metastatic breast cancer previously treated with endocrine therapy with or without a prior CDK4/6 inhibitor in EMBER-3 [see Clinical Studies (14.1)] . Patients received INLURIYO 400 mg orally, once daily (n=327), or standard of care (n=324) consisting of either fulvestrant (n=292) or exemestane (n=32). Among patients who were treated with INLURIYO, the median duration of exposure was 5.6 months (range: 0.2 to 28.6 months) in EMBER-3. Serious adverse reactions occurred in 10% of patients who received INLURIYO. Serious adverse reactions in > 1% of patients included pleural effusion (1.2%).

Use in specific populations

Sourced from openFDA

Lactation: Advise not to breastfeed. ( 8.2 ) 8.1 Pregnancy Risk Summary Based on findings in animals and its mechanism of action, INLURIYO can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology ( 12.1 )] . There are no available human data on INLURIYO use in pregnant women to inform the drug-associated risk. In an animal reproduction study, oral administration of imlunestrant to pregnant rats during the period of organogenesis led to embryo-fetal mortality and structural abnormalities at maternal exposures below the human exposure at the recommended dose based on AUC ( see Data ). Advise pregnant women and females of reproductive potential of the potential risk to a fetus. The background risk of major birth defects and miscarriage for the indicated population is unknown. However, the background risk in the U.S. general population of major birth defects is 2 to 4% and of miscarriage is 15 to 20% of clinically recognized pregnancies. Data Animal Data In an embryo-fetal development study, imlunestrant was administered orally to pregnant rats during the period of organogenesis from gestation day 6 to 17 at doses of 0.3, 3, and 30 mg/kg/day. Imlunestrant caused embryo-fetal mortality (increased resorption, reduced number of live fetuses) at ≥0.3 mg/kg/day, approximately 0.1 times the human AUC at the recommended dose.

Pharmacokinetics

Sourced from openFDA
Metabolism
Imlunestrant pharmacokinetics were observed at steady state at the approved recommended dosage and are presented as mean (%CV) unless otherwise specified. The maximum concentration (C max ) of imlunestrant is 141 ng/mL (45%) and the area under the concentration-time curve (AUC) is 2,400 ng*h/mL (46%).

Approval history

Sourced from openFDA
  • Sep 25, 2025NDANDA218881Eli Lilly And Co

FAERS reports

View JSON
Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
23 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Diarrhoea417%
  2. 2Hot Flush313%
  3. 3Hyponatraemia313%
  4. 4Nausea313%
  5. 5Decreased Appetite28.7%
  6. 6Disease Progression28.7%
  7. 7Fatigue28.7%
  8. 8Headache28.7%
  9. 9Hypokalaemia28.7%
  10. 10Neuropathy Peripheral28.7%
  11. 11Pneumonitis28.7%
  12. 12Pruritus28.7%
  13. 13Thrombocytopenia28.7%
  14. 14Abdominal Pain14.3%
  15. 15Abdominal Pain Upper14.3%

Clinical trials

View JSON

The 10 most recently updated of 16 ClinicalTrials.gov registrations naming Imlunestrant as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Imlunestrant work?
Imlunestrant is an estrogen receptor (ER) antagonist that binds to ERα. In vitro, imlunestrant induced degradation of ERα, leading to inhibition of ER-dependent gene transcription and cellular proliferation in ER+ breast cancer cells.
What is Imlunestrant used for?
According to FDA labeling, Imlunestrant carries indications including: INLURIYO is indicated for the treatment of adults with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, estrogen receptor-1 ( ESR1 )-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Imlunestrant?
Imlunestrant is classified as Estrogen Receptor Antagonist, Breast Cancer Resistance Protein Inhibitors, Estrogen Receptor Antagonists, P-Glycoprotein Inhibitors, Cellular Proliferation Alteration, Decreased Transcription to RNA.
What are the brand names for Imlunestrant?
Imlunestrant is marketed under brand names including Inluriyo.
What are the contraindications for Imlunestrant?
Imlunestrant labeling lists contraindications including: None. None.. Always consult the full prescribing information and a clinician.
Note. Data for imlunestrant is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

Search pharmacopeia

Search drugs, classes, and ingredients