Testing the safety and body distribution of LY4066708 in healthy adults

A Single- and Multiple-Ascending Dose Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of LY4066708 in Healthy Participants

Phase 1 Interventional Eli Lilly and Company · NCT07046559

This tests LY4066708 in healthy adults to see if it is safe and how much reaches the blood and central nervous system over up to 24 weeks.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment104 (estimated)
Ages18 Years to 65 Years
SexAll
SponsorEli Lilly and Company Industry-sponsored
Locations1 site (Holbeck, Leeds)
Trial IDNCT07046559 on ClinicalTrials.gov

What this trial studies

This Phase 1 single- and multiple-ascending dose study gives healthy adult participants increasing doses of LY4066708 (or placebo) to characterize safety, tolerability, and pharmacokinetics in blood and the central nervous system. Participants undergo medical screening, regular safety monitoring, and scheduled blood and CNS sampling to measure drug levels and how quickly the body clears the drug. Some cohorts are limited to participants of specific ancestry (first‑generation Japanese or Chinese descent) and all participants must meet BMI and contraception requirements. The study is sponsored by Eli Lilly and conducted at a clinical research unit in Leeds, with individual participation lasting up to 24 weeks.

Who should consider this trial

Good fit: Healthy adults who pass medical screening, have a BMI between 18.5 and 30 kg/m², meet the study's ancestry cohort rules where applicable, and agree to the contraception and visit requirements are the intended participants.

Not a fit: People with active medical conditions, current cancer patients, or those who do not meet the BMI, ancestry, or contraception requirements are unlikely to receive direct benefit from participation.

Why it matters

Potential benefit: If successful, the results could identify safe dose ranges and how the drug distributes in the body to guide later cancer studies and dosing decisions.

How similar studies have performed: Single- and multiple-ascending dose studies in healthy volunteers are a standard first step and have successfully defined safe dosing for many drug programs, but LY4066708 itself is a novel compound being tested in humans in this protocol.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring.
* Japanese Participants Only: To qualify as a participant of first-generation Japanese origin, the participant, the participant's biological parents, and all the participant's biological grandparents must be of exclusive Japanese descent and born in Japan.
* Chinese Participants Only: To qualify as Chinese for the purpose of this study, all 4 of the participants' biological grandparents must be of exclusive Chinese descent and born in China, Hong Kong, Macau, or Taiwan.
* Have a body mass index (BMI) at the time of screening within the range 18.5 to 30 kilogram per meter squared (kg/m²) (inclusive).
* Participants assigned female at birth (AFAB) not of childbearing potential and participants assigned male at birth (AMAB) willing to practice effective contraception throughout the study may participate.
* Willingness to undergo study procedures which may include repeated lumbar punctures

Exclusion Criteria:

* Are individuals of childbearing potential (IOCBP). Notwithstanding their IOCBP status, participants AFAB are excluded if they are breastfeeding.
* A history of additional risk factors for Torsades de Pointes (for example, heart failure, hypokalemia, family history of Long QT Syndrome).
* The use of concomitant medications that prolong the QT/QTc interval.
* Have known allergies to LY4066708 or any components of the formulation, or history of allergic reactions to any transferrin receptor (TfR) antibodies.
* Have participated, within the 3 months of screening, in a clinical trial involving a study intervention (other than the study intervention used in this study). If the previous investigational product has a long half-life (t½), 3 months or 5 half-lives (whichever is longer) should have passed.
* Are persons who have previously completed or withdrawn from this study and have previously received the study intervention. This exclusion criterion does not apply to subjects who are allowed to rescreen prior to randomization.
* Have a 12-lead electrocardiogram (ECG) abnormality at screening that, in the opinion of the investigator, increases the risks associated with participating in the study, or may confound ECG data analysis.
* Show evidence of hepatitis C and/or positive hepatitis C antibody.
* Current infection with hepatitis B virus (HBV) or evidence of past infection with HBV, that is, positive for Hepatitis B surface antigen (HBsAg) or Hepatitis B core total antibody (anti-HBc).
* A marked baseline prolongation of time from the start of the Q wave to the end of the T wave/ corrected QT interval (QT/QTc) interval (for example, repeated demonstration of a corrected time from the start of the Q wave to the end of the T wave interval - Fridericia formula (QTcF) interval greater than 450 ms).

Where this trial is running

Holbeck, Leeds

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions HealthyCancer
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.