Drug Trials Snapshots: INLURIYO
HOW TO USE THIS SNAPSHOT
The information provided in Snapshots highlights who participated in the key clinical trials that supported the original FDA approval of this drug, and whether there were differences among sex, race, age, and ethnic groups. The "MORE INFO" bar shows more detailed, technical content for each section. The Snapshot is intended as one tool for consumers to use when discussing the risks and benefits of the drugs.
LIMITATIONS OF THIS SNAPSHOT
Do not rely on Snapshots to make decisions regarding medical care. Always speak to your healthcare provider about the benefits and risks of a drug.
Some of the information in this Snapshot is for presentation purposes and does not represent the approved conditions of use of this drug. Refer to the INLURIYO Prescribing Information for all the approved conditions of use of this drug (e.g., indication(s), population(s), dosing regimen(s), safety information).
Snapshots are limited to the information available at the time of the original approval of the drug and do not provide information on who participated in clinical trials that supported later approvals for additional uses of the drug (if applicable).
INLURIYO (imlunestrant)
(ihn-LUUR-EE-oh)
ELI LILLY AND COMPANY
Approval date: September 25, 2025
DRUG TRIALS SNAPSHOT SUMMARY:
What is the drug for?
INLURIYO is a drug for the treatment of adults with a specific form of advanced breast cancer. The cancer had to progress (grew or got worse) during or after previous treatment with endocrine therapy.
It is to be used in patients whose cancer
- is estrogen receptor (ER)-positive, meaning it grows in response to estrogen,
- is human epidermal growth factor receptor 2 (HER2)-negative,
- contains an abnormal (mutated) ESR1 gene,
- and is advanced or has spread to other parts of the body (metastatic).
How is this drug used?
INLURIYO is a tablet. INLURIYO tablets are taken by mouth once daily on an empty stomach. For example, at least one hour before eating, or two hours after eating.
Who participated in the clinical trials?
The FDA approved INLURIYO based on results from one clinical trial named EMBER-3 (NCT04975308). The trial included 874 patients with a type of advanced breast cancer. Their cancer had to worsen after hormone treatment. Patients were split into three groups. Each group received a different treatment. Two of these groups compared how well INLURIYO worked to hormone therapy. In those two groups, 256 patients had cancer with a change in the ESR1 gene (efficacy population). Information on the side effects of INLURIYO comes from 651 trial patients who received at least one dose of INLURIYO or hormone therapy (safety population). The trial was conducted at 195 sites across 22 countries.
How were the trials designed?
Researchers studied how well INLURIYO works and what side effects it might cause in adults with locally advanced or metastatic ER-positive, HER2-negative breast cancer that had progressed following treatment with endocrine therapy. About 4 out of 10 trial patients had a change in the ESR1 gene.
Participants received INLURIYO, an endocrine therapy (chosen by their doctor), or a combination treatment that is still being tested. Treatment continued until the cancer got worse or the side effects became too strong.
To see how well the treatments worked, researchers measured how long the cancer stayed the same (did not get worse) before it started growing again. This is called progression-free survival (PFS).
How were the trials designed?
INLURIYO was evaluated in a randomized, open-label, active-controlled, multicenter trial. The trial enrolled 874 adult patients with ER-positive, HER2-negative, locally advanced or metastatic breast cancer. Patients had previously received an aromatase inhibitor. This could be alone or in combination with a CDK4/6 inhibitor.
To participate, patients had to show disease progression:
- Within 12 months of completing neoadjuvant (treatment before surgery) or adjuvant (treatment after surgery) aromatase inhibitor therapy with no systemic (whole body) treatment for recurrent disease, or
- Greater than 12 months after neoadjuvant or adjuvant endocrine therapy or newly diagnosed metastatic disease, having progressed on one line of aromatase inhibitor therapy for advanced cancer.
Patients were randomly assigned 1:1:1 to receive INLURIYO, investigator's choice of endocrine therapy (fulvestrant or exemestane), or an additional investigational combination regimen. Treatment continued until disease progression or unacceptable toxicity. ESR1 mutation status was determined by blood samples using the Guardant360 CDx assay.
The primary efficacy outcome was investigator-assessed PFS using standard imaging criteria (Response Evaluation Criteria in Solid Tumors [RECIST] v1.1). Other efficacy endpoints included overall survival (OS), blinded independent review committee (BIRC)-assessed PFS, and objective response rate (ORR).
DEMOGRAPHICS SNAPSHOT
Figure 1 summarizes how many male and female patients were enrolled in the clinical trial used to evaluate the efficacy of INLURIYO.
Figure 1. Baseline Demographics by Sex, Efficacy Population
Source: Adapted from FDA Review
Figure 2 summarizes how many male and female patients were enrolled in the clinical trial used to evaluate the side effects of INLURIYO.
Figure 2. Baseline Demographics by Sex, Safety Population
Source: Adapted from FDA Review
Figure 3 summarizes how many patients by race were enrolled in the clinical trial used to evaluate the efficacy of INLURIYO.
Figure 3. Baseline Demographics by Race, Efficacy Population
Source: Adapted from FDA Review
Figure 4 summarizes how many patients by race were enrolled in the clinical trial used to evaluate the side effects of INLURIYO.
Figure 4. Baseline Demographics by Race, Safety Population
Source: Adapted from FDA Review
Figure 5 summarizes how many patients by age were enrolled in the clinical trial used to evaluate the efficacy of INLURIYO.
Figure 5. Baseline Demographics by Age, Efficacy Population
Source: Adapted from FDA Review
Figure 6 summarizes how many patients by age were enrolled in the clinical trial used to evaluate the side effects of INLURIYO.
Figure 6. Baseline Demographics by Age, Safety Population
Source: Adapted from FDA Review
Figure 7 summarizes how many patients by ethnicity were enrolled in the clinical trial used to evaluate the efficacy of INLURIYO.
Figure 7. Baseline Demographics by Ethnicity, Efficacy Population
Source: Adapted from FDA Review
Figure 8 summarizes how many patients by ethnicity were enrolled in the clinical trial used to evaluate the side effects of INLURIYO.
Figure 8. Baseline Demographics by Ethnicity, Safety Population
Source: Adapted from FDA Review
Who participated in the trials?
Table 1. Baseline Demographics, Trial EMBER-3
Efficacy Population (ESR1 Mutation) | Safety Population | |||
|---|---|---|---|---|
| Category | INLURIYO N=138 n (%) | SOC N=118 n (%) | INLURIYO N=327 n (%) | SOC N=324 n (%) |
| Sex | ||||
| Female | 138 (100) | 118 (100) | 323 (98.8) | 323 (99.7) |
| Male | 0 | 0 | 4 (1.2) | 1 (0.3) |
| Age, years | ||||
| <65 | 91 (65.9) | 78 (66.1) | 209 (63.9) | 193 (59.6) |
| ≥65 | 47 (34.1) | 40 (33.9) | 118 (36.1) | 131 (40.4) |
| Race | ||||
| White | 80 (58.0) | 76 (64.4) | 183 (56.0) | 189 (58.3) |
| Asian | 35 (25.4) | 31 (26.3) | 91 (27.8) | 94 (29.0) |
| American Indian or Alaska Native | 7 (5.1) | 3 (2.5) | 23 (7.0) | 16 (4.9) |
| Black or African American | 7 (5.1) | 3 (2.5) | 11 (3.4) | 6 (1.9) |
| Multiple | 1 (0.7) | 1 (0.8) | 2 (0.6) | 7 (2.2) |
| Missing | 8 (5.8) | 4 (3.4) | 17 (5.2) | 12 (3.7) |
| Ethnicity | ||||
| Not Hispanic or Latino | 98 (71.0) | 83 (70.3) | 215 (65.7) | 211 (65.1) |
| Hispanic or Latino | 25 (18.1) | 23 (19.5) | 79 (24.2) | 80 (24.7) |
| Missing | 15 (10.9) | 12 (10.2) | 33 (10.1) | 33 (10.2) |
Source: Adapted from FDA Review
Abbreviations: ESR1, estrogen receptor 1; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
What are the benefits of this drug?
In patients with an abnormal (mutated) ESR1 gene, patients lived longer without their cancer worsening (PFS) when taking INLURIYO compared to other hormone treatments. Patients in the INLURIYO group had a longer median time to cancer worsening of 5.5 months. Patients who were treated with other hormone therapy had a median time to cancer worsening of 3.8 months.
What are the benefits of this drug (results of trials used to assess efficacy)?
Table 2 summarizes efficacy results for patients with ESR1 mutations based on investigator-assessed PFS and ORR. BIRC-assessed PFS was consistent with the investigator-assessed PFS. Interim OS results were immature at the time of data cutoff.
Table 2. Efficacy Results for Patients With ESR1 Mutations, Efficacy Population
| Endpoint | INLURIYO N=138 | SOC N=118 |
|---|---|---|
| Progression-free survivala, b | ||
| Number of PFS events, n (%) | 109 (79) | 102 (86) |
| Median in months (95% CI) | 5.5 (3.9, 7.4) | 3.8 (3.7, 5.5) |
| Hazard ratio (95% CI)c | 0.62 (0.46, 0.82) | |
| p-valued | 0.0008 | |
| Objective response rateb | ||
| Patients with measurable disease | 112 | 91 |
| ORR, % (95% CI) | 14.3 (7.8, 20.8) | 7.7 (2.2, 13.2) |
| Complete response rate, % | 0.9 | 0 |
| Partial response rate, % | 13.4 | 7.7 |
Source: Adapted from INLURIYO Prescribing Information
a Investigator Assessed
b Per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
c Based on the stratified Cox proportional hazard model
d Two-sided p-value based on stratified log-rank test (compared to a significance level of 0.04)
Abbreviations: CI, confidence interval; ESR1, estrogen receptor 1; ORR, objective response rate; PFS, progression-free survival; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
Were there any differences in how well the drug worked in clinical trials among sex, race, age, and ethnicity?
- Sex: Breast cancer is rare in males. INLURIYO was only tested in females with an ESR1 mutation. There was no information to assess whether the benefit of INLURIYO differs by sex. However, there was no biological reason for a different result for INLURIYO based on sex.
- Race: INLURIYO worked similarly in White and Asian patients. The number of patients of other races were limited, therefore, it could not be determined whether there were differences in how INLURIYO worked among other races.
- Age: INLURIYO worked similarly in patients younger than 65 years of age and those 65 years and older.
- Ethnicity: The number of patients who were Hispanic or Latino was limited, therefore, it could not be determined whether there were differences in how INLURIYO worked in patients based on ethnicity.
Were there any differences in how well the drug worked in clinical trials among sex, race, age, and ethnicity groups?
Table 3. Efficacy Results by Subgroup, Efficacy Population
| Subgroup | INLURIYO n | SOC n | Hazard Ratio (95% CI) |
|---|---|---|---|
| Sex | |||
| Female | 138 | 118 | 0.62 (0.46, 0.82) |
| Age | |||
| <65 | 91 | 78 | 0.61 (0.44, 0.86) |
| ≥65 | 47 | 40 | 0.57 (0.34, 0.95) |
| Race | |||
| Asian | 35 | 31 | 0.45 (0.25, 0.81) |
| White | 80 | 76 | 0.68 (0.48, 0.97) |
| Other | 15 | 7 | 0.78 (0.27, 2.28) |
| Ethnicity | |||
| Hispanic or Latino | 25 | 23 | 0.42 (0.22, 0.83) |
| Not Hispanic or Latino | 98 | 83 | 0.61 (0.43, 0.85) |
Source: Adapted from FDA Review
Abbreviation: CI, confidence interval; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
What are the possible side effects?
The most common side effects of INLURIYO, including laboratory abnormalities, include muscle and joint (musculoskeletal) pain, increased liver enzymes, feeling tired or weakness, diarrhea, increased blood fat (triglycerides and cholesterol) levels, decreased red blood cell levels, decreased white blood cell levels, decreased platelet levels, decreased calcium levels, nausea, constipation, and stomach-area (abdominal) pain. INLURIYO may harm an unborn baby.
What are the possible side effects (results of trials used to assess safety)?
Table 4. Adverse Reactions (≥10%) in Patients Who Received INLURIYO, Safety Population
INLURIYO, N=327 | SOC, N=324 | |||
|---|---|---|---|---|
| Adverse Reactiona | All Grades % | Grades 3 or 4 % | All Grades | Grades 3 or 4 % |
| Gastrointestinal disorders | ||||
| Diarrhea | 22 | 0.6 | 12 | 0.0 |
| Nausea | 17 | 0.3 | 13 | 0.0 |
| Constipation | 10 | 0 | 6 | 0.3 |
| Abdominal painb | 10 | 0.3 | 6 | 0.6 |
| General disorders and administration site conditions | ||||
| Fatigueb | 23 | 0.3 | 14 | 0.6 |
| Musculoskeletal disorders | ||||
| Musculoskeletal pain | 30 | 3.7 | 30 | 1.9 |
Source: Adapted from INLURIYO Prescribing Information
a Adverse reactions were graded using NCI CTCAE version 5.0.
b Includes other related terms
Abbreviations: N, number of patients in treatment arm; NCI CTCAE, National Cancer Institute Common Terminology Criteria for Adverse Events; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
Table 5. Select Laboratory Abnormalities (≥10%) That Worsened From Baseline in Patients Who Received INLURIYO, Safety Population
INLURIYOb | SOCb | |||
|---|---|---|---|---|
| Laboratory Abnormalitya | All Grades % | Grades 3 or 4 % | All Grades % | Grades 3 or 4 % |
| Hematology | ||||
| Hemoglobin decreased | 30 | 1.2 | 35 | 3.4 |
| Neutrophils decreased | 26 | 4 | 29 | 4.7 |
| Platelets decreased | 16 | 1.8 | 14 | 1.3 |
| Chemistry | ||||
| Aspartate aminotransferase increased | 25 | 1.9 | 27 | 2.3 |
| Alanine aminotransferase increased | 21 | 1.3 | 23 | 1.0 |
| Triglycerides increased | 21 | 0 | 22 | 1.2 |
Source: Adapted from INLURIYO Prescribing Information
a Graded according to NCI CTCAE version 5
b The denominator used to calculate the rate varied from 252 to 321 based on the number of patients with a baseline value and at least 1 posttreatment value
Abbreviations: NCI CTCAE, National Cancer Institute Common Terminology Criteria for Adverse Events; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
Were there any differences in side effects among sex, race, age, and ethnicity?
- Sex: Few participants in the trial were male. It is not known if the side effects are different between females and males.
- Race: Side effects were similar in White and Asian participants. There weren't enough participants from other racial groups to know if the side effects were different for those groups.
- Age: Participants younger and older than 65 years had similar side effects.
- Ethnicity: The trial did not look at side effects in different ethnic groups.
Were there any differences in side effects of the clinical trials among sex, race, age, and ethnicity groups?
Table 6. Overview of Adverse Events by Demographic Subgroup, Safety Population
| Subgroup | INLURIYO N=327 n/Ns (%) | SOC N=324 n/Ns (%) |
|---|---|---|
| Sex | ||
| Female | 267/323 (82.7) | 272/323 (84.2) |
| Male | 3/4 (75.0) | 1/1 (100) |
| Age | ||
| <65 | 172/209 (82.3) | 161/193 (83.4) |
| ≥65 | 98/118 (83.1) | 112/131 (85.5) |
| Race | ||
| Asian | 77/91 (84.6) | 74/94 (78.7) |
| White | 144/183 (78.7) | 159/189 (84.1) |
| Other1 | 33/36 (91.7) | 28/29 (96.6) |
Source: Adapted from FDA Review
1 Other includes Black or African American, American Indian or Alaska Native, and multiple races
Abbreviations: N, number of patients in treatment arm; n, number of patients with at least one treatment-emergent adverse events; Ns, total number of patients for each specific subgroup and were assigned to that specific arm; SOC, standard of care investigator's choice endocrine therapy of fulvestrant or exemestane
GLOSSARY
CLINICAL TRIAL: Voluntary research studies conducted in people. It is designed to answer specific questions about the safety or effectiveness of drugs, vaccines, other therapies. It may also look at new ways of using existing treatments.
COMPARATOR: Another available treatment (or placebo). It is compared to the drug being tested.
EFFICACY: How well the drug achieves the desired response when it is taken as described in a controlled clinical setting, such as during a clinical trial.
PLACEBO: An inactive substance or "sugar pill" that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo.
SUBGROUP: A subset of the population studied in a clinical trial. Demographic subsets include sex, race, and age groups.