HealthyPhase 1NCT07765498
A Study of LY4355756 in Healthy Participants
A Phase 1 study testing LY4355756 and Midazolam in people with Healthy, run by Eli Lilly and Company at 1 site in United States.
Trial summary
The purpose of the study is to assess how LY4355756 is absorbed by the body and how safe it is to healthy participants. There will be four inpatient stays at the clinical research unit (CRU). Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- LY4355756 and Midazolam
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 123 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Aug 2026to Jan 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Are overtly healthy as determined by medical evaluation, including medical history, physical examination, laboratory tests, electrocardiogram (ECGs), and vital signs
- Have a body mass index within the range 18.0-32.0 kilograms per square meter (kg/m²) (inclusive)
- Individuals assigned male at birth (AMAB) or assigned female at birth (AFAB)
- Contraceptive use by participants should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies
Who cannot join
- Have presence of significant uncontrolled respiratory, cerebrocardiovascular, cardiovascular, hepatic, renal, gastrointestinal, endocrine, hematologic, neurologic, or psychiatric disorders, or abnormal laboratory values at screening
- Have an abnormality in 12-lead ECG at screening that, in the opinion of the investigator, may increase the risk associated with participating in the study or may confound ECG data analysis
- Have a diagnosis or history of malignancy within 5 years prior to screening
- Exceptions:
- basal cell or squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years
- cervical carcinoma in situ, with no evidence of recurrence within the 5 years prior to screening
Show all 12Show fewer
- Have had breast cancer within the past 10 years
- Have a history or presence of multiple or severe allergies, or an anaphylactic reaction, to prescription or nonprescription drugs or food
- Have a current or recent acute, active infection. For at least 30 days before screening and up to the randomization visit, participants must have no symptoms or signs of confirmed or suspected infection and must have completed any appropriate anti-infective treatment
- Have a current infection with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV)
- Have received any live (including attenuated live vaccines), non-live, or inactivated vaccine(s) within less than 4 weeks before randomization or intend to receive them during the study
- Are individuals AFAB who, during the study, are pregnant, have positive pregnancy testing, intend to become pregnant, are lactating, or intend to breastfeed
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or contact
Physicians interested in becoming principal investigators please contact contact
United States1 site, 1 recruiting
- Recruiting
Fortrea Clinical Research Unit
Dallas, Texas, 75247
866-429-3700
Gene Voskuhl
About this study
Official title: A Single- and Multiple-Ascending Dose Study to Evaluate the Safety and Pharmacokinetics of LY4355756 in Healthy Participants
The purpose of the study is to assess how LY4355756 is absorbed by the body and how safe it is to healthy participants.
There will be four inpatient stays at the clinical research unit (CRU). For Part A there will be 5 continuous days, Part B 22 continuous days, Part C 5 continuous days in each of the 3 periods, and Part D 18 continuous days in the CRU.
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LY4355756Drug
Administered orally as capsule
LY4355756Drug
Administered orally as tablet
MidazolamDrug
Administered orally as liquid
| Study group | Role | What they receive |
|---|---|---|
| LY4355756 Part A | Experimental | Single-ascending dose (SAD) of LY4355756 administered orally Receives: Drug: LY4355756 |
| LY4355756 Part B | Experimental | Multiple-ascending doses (MAD) of LY4355756 administered orally Receives: Drug: LY4355756 |
| LY4355756 Part C | Experimental | Single dose of LY4355756 administered orally in each of three study periods Receives: Drug: LY4355756 |
| LY4355756 + Midazolam Part D | Experimental | LY4355756 and midazolam co-administered orally Receives: Drug: LY4355756; Drug: Midazolam |
| Midazolam Part D | Experimental | Midazolam administered orally Receives: Drug: Midazolam |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration
Measured: Baseline up to the Safety Follow up Visit (6 months)
Number of Participants with One or More Treatment-Emergent Adverse Event(s) (TEAEs) Considered by the Investigator to be Related to Study Drug Administration
Measured: Baseline up to the Safety Follow up Visit (6 months)
Secondary outcomes (4)
Pharmacokinetics (PK): Area Under the Curve (AUC) of LY4355756
Measured: Baseline up to Day 18
PK: Maximum Plasma Concentration (Cmax) of LY4355756
Measured: Baseline up to Day 18
PK: AUC of Midazolam
Measured: Baseline up to Day 14
PK: Cmax of Midazolam
Measured: Baseline up to Day 14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Aug 2026
- Study start17 Aug 2026
- Primary completionJan 2027 (estimated)
- Study completionJan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies of the same condition, open and under way.
- More trials run by Eli Lilly and CompanyThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parts A and B are parallel; Part C is crossover; Part D is sequential
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 123 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Eli Lilly and Company
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST), Study director, Eli Lilly and Company
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07765498
- Sponsor's protocol ID
- 27803
- Other IDs
- J6U-MC-KZAA
- Status last verified
- Oct 2026
- First submitted
- 11 Aug 2026
- Last updated
- 8 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Single- and Multiple-Ascending Dose Study to Evaluate the Safety and Pharmacokinetics of LY4355756 in Healthy Participants
- ClinicalTrials.gov ID
- NCT07765498
- Acronym / sponsor ID
- 27803
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 123 participants (estimated)
- Lead sponsor
- Eli Lilly and CompanyIndustry (pharma, biotech, devices)
- Study start
- 17 Aug 2026 (actual)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jan 2027 (estimated)
- First posted
- 14 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the study is to assess how LY4355756 is absorbed by the body and how safe it is to healthy participants.
There will be four inpatient stays at the clinical research unit (CRU). For Part A there will be 5 continuous days, Part B 22 continuous days, Part C 5 continuous days in each of the 3 periods, and Part D 18 continuous days in the CRU.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 5
- Model description
- Parts A and B are parallel; Part C is crossover; Part D is sequential
| Arm | Type | Receives |
|---|---|---|
| LY4355756 Part A | Experimental | Drug: LY4355756Single-ascending dose (SAD) of LY4355756 administered orally |
| LY4355756 Part B | Experimental | Drug: LY4355756Multiple-ascending doses (MAD) of LY4355756 administered orally |
| LY4355756 Part C | Experimental | Drug: LY4355756Single dose of LY4355756 administered orally in each of three study periods |
| LY4355756 + Midazolam Part D | Experimental | Drug: LY4355756, Drug: MidazolamLY4355756 and midazolam co-administered orally |
| Midazolam Part D | Experimental | Drug: MidazolamMidazolam administered orally |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Are overtly healthy as determined by medical evaluation, including medical history, physical examination, laboratory tests, electrocardiogram (ECGs), and vital signs
- Have a body mass index within the range 18.0-32.0 kilograms per square meter (kg/m²) (inclusive)
- Individuals assigned male at birth (AMAB) or assigned female at birth (AFAB)
Key exclusion criteria (12 listed)
- Have presence of significant uncontrolled respiratory, cerebrocardiovascular, cardiovascular, hepatic, renal, gastrointestinal, endocrine, hematologic, neurologic, or psychiatric disorders, or abnormal laboratory values at screening
- Have an abnormality in 12-lead ECG at screening that, in the opinion of the investigator, may increase the risk associated with participating in the study or may confound ECG data analysis
- Have a diagnosis or history of malignancy within 5 years prior to screening
- Have had breast cancer within the past 10 years
- Have a history or presence of multiple or severe allergies, or an anaphylactic reaction, to prescription or nonprescription drugs or food
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LY4355756Administered orally as capsule | Drug | LY4355756 + Midazolam Part D, LY4355756 Part A, LY4355756 Part B, LY4355756 Part C |
| LY4355756Administered orally as tablet | Drug | LY4355756 Part C |
| MidazolamAdministered orally as liquid | Drug | LY4355756 + Midazolam Part D, Midazolam Part D |
Primary outcome
Number of Participants with One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration
Time frame: Baseline up to the Safety Follow up Visit (6 months)
Number of Participants with One or More Treatment-Emergent Adverse Event(s) (TEAEs) Considered by the Investigator to be Related to Study Drug Administration
Time frame: Baseline up to the Safety Follow up Visit (6 months)
4 secondary outcomes
Pharmacokinetics (PK): Area Under the Curve (AUC) of LY4355756
Time frame: Baseline up to Day 18
PK: Maximum Plasma Concentration (Cmax) of LY4355756
Time frame: Baseline up to Day 18
PK: AUC of Midazolam
Time frame: Baseline up to Day 14
PK: Cmax of Midazolam
Time frame: Baseline up to Day 14
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or contact
Physicians interested in becoming principal investigators please contact contact
Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 8 AM - 8 PM Eastern time (UTC/GMT - 5 hours, EST) study director
Eli Lilly and Company
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing LY4355756 and Midazolam in people with Healthy, run by Eli Lilly and Company at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or (1-317-615-4559, LillyTrials@Lilly.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants with One or More Serious Adverse Event(s) (SAEs) Considered by the Investigator to be Related to Study Drug Administration (time frame: Baseline up to the Safety Follow up Visit (6 months)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2026.