← Back to Clinical Trials
Recruiting Phase 1 NCT05307705

NCT05307705 A Study of LOXO-783 in Patients With Breast Cancer/Other Solid Tumors

◆ AI Clinical Summary
Plain-language summary for patients
Clinical Trial Summary
NCT ID NCT05307705
Status Recruiting
Phase Phase 1
Sponsor Eli Lilly and Company
Condition Breast Cancer
Study Type INTERVENTIONAL
Enrollment 260 participants
Start Date 2022-05-11
Primary Completion 2026-12

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
LOXO-783FulvestrantImlunestrant

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

Phase 1 is the earliest stage of human testing — safety and dosage are the primary focus. Visits are frequent and medical supervision is intensive. You will be among the first people to receive this treatment.

This trial targets 260 participants in total. It began in 2022-05-11 with a primary completion date of 2026-12.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The main purpose of this study is to learn more about the safety, side effects, and effectiveness of LOXO-783. LOXO-783 may be used to treat breast cancer and other solid tumors that have a change in a particular gene (known as the PIK3CA gene). Participation could last up to 36 months (3 years) and possibly longer if the disease does not get worse.

Eligibility Criteria

Inclusion Criteria: * Have advanced breast cancer or another solid tumor with the presence of a phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) H1047R mutation (or other Sponsor and safety review committee (SRC)-approved, activating PIK3CA mutations other than H1047R mutation) * Have adequate archival tumor tissue sample available or be approved by the Sponsor for enrollment if no tumor sample is available. * Have stopped all cancer treatment and have recovered from the major side effects * Have adequate organ function, as measured by blood tests * Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale * Patients must have * Measurable disease \--- Patients with non-breast tumor types must have at least 1 measurable lesion * Non-measurable bone disease (at least 1 bone lesion in breast cancer patients only) * For patients with an estrogen receptor (ER)+ breast cancer diagnosis: * If female, must be postmenopausal * If male, must agree to use hormone suppression * Phase 1a: \-- Dose escalation and backfill patients: * Advanced solid tumor * Patients may have had up to 5 prior regimens for advanced disease * Phase 1b: * Part A: * ER+/human epidermal growth factor receptor 2 (HER2)- advanced breast cancer * Patients may have had up to 5 prior regimens for advanced disease ---- Prior cyclin dependent kinase (CDK)4/6 inhibitor therapy required * Part B: * ER+/HER2- advanced breast cancer * Patients may have had up to 2 prior regimens for advanced disease. * Part C: * ER+/HER2- advanced breast cancer * Patients may have had up to 5 prior regimens for advanced disease. \---- Prior CDK4/6 inhibitor therapy required. * Have a diagnosis of diabetes mellitus Type 2 * Part D: * Advanced breast cancer * Patients may have had up to 5 prior regimens for advanced disease. * Part E: * Advanced solid tumor * Patients may have had up to 3 prior regimens for advanced disease advanced disease * Part F: * ER+/HER2- advanced breast cancer * Patients may have had up to 5 prior regimens for advanced disease * Prior cyclin dependent kinase (CDK)4/6 inhibitor therapy required Exclusion Criteria: * Medical Conditions * Colorectal cancer * Endometrial cancers with specific concurrent oncogenic alterations * A history of known active or suspected * Diabetes mellitus Type 1 or * Diabetes mellitus Type 2 requiring antidiabetic medication (Phase 1a and all parts of Phase 1b except Part C). * Serious concomitant systemic disorder * Known or suspected history of untreated or uncontrolled central nervous system (CNS) involvement. * Active uncontrolled systemic bacterial, viral, fungal, or parasitic infection, or other clinically significant active disease process * Prior exposure to phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) inhibitor(s), except in certain circumstances

Contact & Investigator

Central Contact

There may be multiple sites in this clinical trial 1-877-CTLILLY (1-877-285-4559) or

✉ ClinicalTrials.gov@lilly.com

📞 13176154559

Principal Investigator

Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST)

STUDY DIRECTOR

Eli Lilly and Company

Frequently Asked Questions

Who can join the NCT05307705 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, studying Breast Cancer. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT05307705 trial and what does that mean for participants?

Phase 1 trials are the first stage of human testing. The primary goal is to assess safety and determine appropriate dosage levels. Participants are closely monitored. These trials typically involve a small number of volunteers.

Is NCT05307705 currently recruiting?

Yes, NCT05307705 is actively recruiting participants. Contact the research team at ClinicalTrials.gov@lilly.com for enrollment information.

Where is the NCT05307705 trial being conducted?

This trial is being conducted at Scottsdale, United States, Los Angeles, United States, San Francisco, United States, Stanford, United States and 11 additional locations.

Who is sponsoring the NCT05307705 clinical trial?

NCT05307705 is sponsored by Eli Lilly and Company. The principal investigator is Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST) at Eli Lilly and Company. The trial plans to enroll 260 participants.

Related Trials

Related Intelligence Guides

In-depth guides covering this condition's trials, eligibility, and what to expect.

ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: July 2026  ·  Data Methodology