A Study of LY3971297 in Participants With Heart Failure

June 15, 2026 updated by: Eli Lilly and Company

A Phase 1, Single-Blinded, Single-Ascending Dose Study to Evaluate the Safety and Tolerability of a Single Dose of LY3971297 in Participants With HFpEF and Participants With HFrEF

The main purpose of this study is to assess how well LY3971297 is tolerated and what side effects may occur in participants with heart failure with preserved ejection fraction (HFpEF) and participants with heart failure with reduced ejection fraction (HFrEF). Blood tests will be performed to investigate how the body processes the study drug and how the study drug affects the body. For each participant, the study will last about 2 months and will include 1 inpatient visit lasting approximately 4 days and 5 outpatient visits.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
90

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
  • Phone Number: 1-317-615-4559
  • Email: LillyTrials@Lilly.com

Study Contact Backup

Study Locations

  • Japan
      • Kobe, Japan, 650-0017
        • Kobe University Hospital
        • Contact:
          • Phone Number: 81120023812
        • Principal Investigator:
          • Hiromasa Otake
      • Kyoto, Japan, 606-8507
        • Kyoto University Hospital
        • Contact:
          • Phone Number: 81120023812
        • Principal Investigator:
          • Koh Ono
      • Suita-shi, Japan, 564-8565
        • National Cerebral and Cardiovascular Center
        • Contact:
          • Phone Number: 81120023812
        • Principal Investigator:
          • Takeshi Kitai
      • Tsuchiura-shi, Japan, 300-8585
        • Kasumigaura Medical Center
        • Contact:
          • Phone Number: 81120023812
        • Principal Investigator:
          • Hidekazu Maruyama
  • Moldova
      • Chisinau, Moldova, 2005
        • Institut de Cardiologie
        • Principal Investigator:
          • Valeriu Revenco
      • Chisinau, Moldova, 2025
        • ARENSIA Research Clinic at Republican Clinical Hospital
        • Principal Investigator:
          • Vasile Corcea
  • Netherlands
      • Groningen, Netherlands, 9713 GZ
        • University Medical Center Groningen
        • Contact:
          • Phone Number: 31 (0) 50-361-42-00
        • Principal Investigator:
          • Daan Westenbrink
  • Romania
      • Cluj-Napoca, Romania, 400347
        • ARENSIA Research Clinic at County Clinical Hospital
        • Principal Investigator:
          • Mihaela Mocan
  • United States
    • Missouri
      • St Louis, Missouri, United States, 63110
        • Washington University
        • Principal Investigator:
          • Gregory Ewald
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27599
        • University of North Carolina, Division of Cardiology
        • Principal Investigator:
          • Kirkwood Adams
        • Contact:
          • Phone Number: 919-843-5515

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Are diagnosed with chronic heart failure with New York Heart Association Class II-III (Heart Failure) HF symptomatology at screening and on guideline-directed HF therapy for at least 6 months prior to screening.
  • Have not changed optimal guideline-directed HF therapy, either medication or medication dose, in the last 4 weeks prior to screening and during screening period, and do not plan to change HF therapy for the next 90 days.
  • Must be on a stable dose of vasodilator therapy for at least 4 weeks prior to screening, with no dose adjustments planned during the study.
  • Have an estimated glomerular filtration rate of greater than or equal to (≥) 30 milliliter per minute per 1.73 square meters (mL/Minute/1.73m²) at screening.
  • Are between 30 days and within 12 months from recent heart failure hospitalization to screening.
  • Have systolic blood pressure (SBP) greater than (>) 110 millimeters of mercury (mmHg) at screening and at enrollment.
  • Have a body mass index within the range of 18.5 to 40 kilograms per square meter (kg/m²) (inclusive).
  • Are individuals assigned male or female at birth, who are not of childbearing potential.
  • Have venous access sufficient to allow blood sampling.

  • Applicable to heart failure with preserved ejection fraction (HFpEF) participants only

    • Have left ventricular ejection fraction (LVEF) >45 percent (%).
    • Left atrial volume index >34 milliliters per square meter (mL/m²) in participants in sinus rhythm, or >40 mL/m² in participants with atrial fibrillation (AF).
    • N-terminal pro-B-type natriuretic peptide (NT-proBNP) >300 picograms per milliliter (pg/mL) for participants without AF or >850 pg/mL for participants with AF.
    • Have a documented history of signs, symptoms, or both, consistent with HFpEF.

  • Applicable to heart failure with reduced ejection fraction (HFrEF) participants only:

    • Have LVEF <40% .
    • NT-proBNP >600 pg/mL for participants without AF or >900 pg/mL for participants with AF.
    • Have a documented history of signs, symptoms, or both, consistent with HFrEF.

Exclusion Criteria:

  • Have known allergies to related compounds of LY3971297 or any components of the formulation, or a history of significant atopy.
  • Had a myocardial infarction, unstable angina pectoris, coronary artery bypass graft surgery, revascularization or other major cardiovascular surgery, stroke, or transient ischemic attack in the last 90 days prior to screening.
  • Have New York Heart Association (NYHA) Class 4, acute decompensated HF (exacerbation of HF) requiring IV diuretics, IV inotropes, or IV vasodilators, within 30 days prior to screening, and/or during screening period until randomization.
  • Have SBP ≥180 mmHg at screening.
  • Have symptomatic hypotension.
  • Have resting heart rate >90 beats per minute (bpm) at screening.
  • Have known cardiac amyloidosis, infiltrative myocardial diseases, muscular dystrophies, cardiomyopathy with reversible causes, hypertrophic cardiomyopathy, pericardial constriction, or complex congenital heart disease.
  • Have any history of moderate-to-severe stenosis of the mitral and/or aortic valve or severe mitral and/or aortic regurgitation.
  • Have any history of moderate-to-severe tricuspid or pulmonic valve stenosis or severe tricuspid or pulmonic regurgitation.
  • Have a history of syncope that, in the opinion of the investigator, may affect the participant's safety.
  • Bioprosthetic valve replacement within 12 months prior to screening or any history of mechanical valve replacement, or planned valve replacement or repair during the study period.
  • Have any history of greater than moderate pulmonary hypertension.
  • Have a pacemaker or implantable cardioverter-defibrillator placement within 90 days prior to screening.
  • Have severe chronic obstructive pulmonary disease (COPD).
  • Have clinically significant or uncontrolled cardiac arrhythmia.
  • Have a significant history of, or presence of, hepatic disease, including any abnormal liver function tests.
  • Have, within 3 years prior to screening, a history of an active or untreated malignancy or are in remission from a clinically significant malignancy (Exceptions: basal or squamous cell skin cancer).
  • For US sites: have donated blood of more than 500 mL within the previous 90 days of screening or intend to donate blood during the course of the study.
  • For Japan sites: have donated any blood within the last 4 weeks, any apheresis (blood components) within the last 2 weeks, at least 400 mL of blood within the last 16 weeks for female participants or 12 weeks for male participants, or at least 800 mL of blood for female participants or 1200 mL of blood for male participants within 12 months.
  • Other sites: Participants who have recently donated blood or blood components, or who intend to donate during the course of the study.
  • Have not been on a stable dose of medications for at least 4 weeks prior to screening, or have planned dose adjustments during the study.
  • Participants must abstain from taking new prescription or nonprescription drugs.
  • Have concurrent use or intend to use phosphodiesterase 5 inhibitor or soluble guanylyl cyclase activators.
  • Have any history of intolerance to vasodilator medications that, in the opinion of the investigator, would put them at risk of not tolerating study drug.
  • Have BP and/or pulse rate constituting a risk when taking the Investigational Medicinal Product (IMP).
  • Are diagnosed with orthostatic hypotension.
  • Show evidence of an acute infection with fever or infectious disease at screening.

  • Applicable to HFrEF participants only

    • Have been listed for cardiac transplantation and/or anticipated or implanted ventricular assist device.
    • Have received cardiac resynchronization therapy for less than 6 months.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: LY3971297 Part A Cohort 1
LY3971297 administered subcutaneously (SC)
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part A Cohort 1
Placebo administered SC
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV
Experimental: LY3971297 Part A Cohort 2
LY3971297 administered SC
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part A Cohort 2
Placebo administered SC
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV
Experimental: LY3971297 Part A Cohort 3
LY3971297 administered SC
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part A Cohort 3
Placebo administered SC
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV
Experimental: LY3971297 Part A Cohort 4
LY3971297 administered SC
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part A Cohort 4
Placebo administered SC
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV
Experimental: LY3971297 Part A Cohort 5
LY3971297 administered intravenously (IV)
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part A Cohort 5
Placebo administered IV
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV
Experimental: LY3971297 Part B
LY3971297 administered SC or IV
Drug: LY3971297
Administered SC
Drug: LY3971297
Administered IV
Placebo Comparator: Placebo Part B
Placebo administered SC or IV
Drug: Placebo
Administered SC
Drug: Placebo
Administered IV

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
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 through Study Completion (Approximately 2 Months)
Baseline through Study Completion (Approximately 2 Months)
Number of Participants with One or More Treatment-Emergent Adverse Event
Time Frame: Baseline through Study Completion (Approximately 2 Months)
Baseline through Study Completion (Approximately 2 Months)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Pharmacokinetics (PK): Area Under the Concentration Versus Time Curve (AUC) of LY3971297
Time Frame: Predose on Day 1 up to Day 29 Post-Dose
Predose on Day 1 up to Day 29 Post-Dose
PK: Maximum Concentration (Cmax) of LY3971297
Time Frame: Predose on Day 1 up to Day 29 Post-Dose
Predose on Day 1 up to Day 29 Post-Dose

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Eli Lilly and Company

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: 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), Eli Lilly and Company

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 17, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 23, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 16, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 15, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 27777
  • J4O-MC-EZHB (Other Identifier: Eli Lilly and Company)
  • 2026-525663-40-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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