Home › Trials › NCT07114601

LY4257496 for GRPR-positive advanced breast, colorectal, prostate, and endometrial cancer (OMNIRAY)

A Phase 1a/b Multicenter, Open-Label Trial to Evaluate Safety, Tolerability, and Dosimetry of LY4257496, a GRPR-Targeted Radioligand Therapy, in Adults With GRPR-Positive Advanced Solid Tumors (OMNIRAY)

PHASE1 · Eli Lilly and Company · NCT07114601

This Phase 1 test tries LY4257496, with GRPR imaging using LY4257529 and sometimes standard treatments, to see if it is safe and helps people with GRPR-positive advanced breast, colorectal, prostate, or endometrial cancer.

Quick facts

PhasePHASE1
Study typeInterventional
Enrollment421 (estimated)
Ages18 Years and up
SexAll
SponsorEli Lilly and Company (industry)
Drugs / interventionsradiation
Locations28 sites (Duarte, California and 27 other locations)
Trial IDNCT07114601 on ClinicalTrials.gov

What this trial studies

This is an open-label Phase 1, two-part interventional study that uses GRPR-targeted imaging (LY4257529) to identify eligible tumors and then treats participants with LY4257496 alone or combined with relevant standard-of-care anticancer therapies. The trial focuses on safety, tolerability, and early signs of anti-tumor activity in adults with locally advanced, unresectable, or metastatic GRPR-positive disease across several tumor types. Participants must have measurable disease by RECIST v1.1 (or documented active bone metastases) and will be followed for up to 36 weeks or until disease progression. Dose and combination regimens are guided by investigator determination within the protocol's Phase 1 framework.

Who should consider this trial

Good fit: Adults with histologically or cytologically confirmed locally advanced, unresectable, or metastatic GRPR-positive breast (ER+/HER2 +/-), colorectal, metastatic castration-resistant prostate, or endometrial cancer with at least one measurable lesion are the intended participants.

Not a fit: Patients whose tumors are GRPR-negative, who have only resectable disease, or who fail to meet required organ function or performance status criteria are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, LY4257496 could offer a new targeted treatment option for patients with GRPR-positive advanced breast, colorectal, prostate, and endometrial cancers.

How similar studies have performed: GRPR-targeted approaches are relatively novel; there are encouraging early-phase signals from related agents but no definitive large-scale successes yet.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Must have histologically or cytologically proven diagnosis of locally advanced, unresectable, or metastatic cancer.
* Must be assessed by computed tomography (CT)/magnetic resonance imaging (MRI) to confirm at least 1 of the following:

  * At least 1 measurable target lesion per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
  * If only bone lesions are present without a soft-tissue component, a bone scan or MRI must confirm at least 2 detectable lesions considered to represent active metastases
* Must have GRPR-positive disease, defined by investigator assessment of GRPR imaging.
* Must have the following histologically or cytologically confirmed diagnosis:

  * Estrogen receptor (ER+)/human epidermal growth factor receptor 2 (HER2-) breast cancer
  * ER+/HER2+ breast cancer
  * Colorectal carcinoma
  * Metastatic castration-resistant prostate cancer
  * Endometrial carcinoma. Carcinosarcoma is eligible. Uterine leiomyosarcoma, adenosarcoma, or endometrial stromal sarcoma is not eligible.
  * Other GRPR-positive solid tumor
* For participants with breast cancer diagnosis, where possible, ER and HER2 status should be assessed from the most recent tissue biopsy taken at the time of presentation with recurrent or metastatic disease.

  * To fulfill the requirement for ER+ disease by local testing, a tumor must express the ER immunohistochemistry, as defined in the relevant American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.
  * HER2 status should be determined by local testing, as defined in the relevant ASCO/CAP Guidelines.
* Must have an Eastern Cooperative Oncology Group (ECOG) performance status of less than or equal to 1.
* Must be able to comply with outpatient treatment, laboratory monitoring, imaging, and required clinic visits for the duration of trial participation.

Exclusion Criteria:

* Phase 1a (Cohort A1 and A2) only: Previously received radiopharmaceutical or radioligand therapy. For participants with metastatic castration-resistant prostate cancer (mCRPC), prior ¹⁷⁷Lu-prostate-specific membrane antigen (PSMA)-617 is permitted.
* Has a history of ongoing acute pancreatitis within 1 year of screening.
* Previously received any prior hemi-body or whole-body radiotherapy, or prior external beam radiation therapy (EBRT) to greater than 25% of the bone marrow.
* A bone superscan, defined as a bone scan that demonstrates markedly increased skeletal radioisotope uptake relative to soft tissues in association with absent or faint genitourinary tract activity.
* Has evidence of ongoing and untreated urinary tract obstruction or unmanageable urinary incontinence.
* Have known active hepatitis B virus (HBV) defined as positive for hepatitis B surface antigen (HBsAg) or Polymerase Chain Reaction (PCR) positive for HBV deoxyribonucleic acid (DNA) . Exception: Individuals with chronic HBV if they:

  * Have positive HBsAg
  * Are on suppressive antiviral therapy, as allowed per local regulations prior to C1D1
  * Remain on the same antiviral treatment throughout study, and should follow local standards for continuation of therapy after completion of trial therapy.
  * Have undetectable HBV DNA ≤14 days of C1D1.
* Have known active hepatitis C virus (HCV) defined as positive for anti-HCV antibodies. Exception: Individuals previously treated for HCV if they:

  * Completed curative antiviral therapy.
  * Have an HCV viral load below the limit of quantification ≤14 days of C1D1 and.
  * Are positive for anti-HCV antibodies and negative for HCV ribonucleic acid (RNA) before randomization.
* Have untreated human immunodeficiency virus (HIV) infection. Exception: Individuals who have well-controlled HIV infection/disease and they:

  * Are on a stable and permitted antiretroviral therapy (ART) regimen without changes in drug or dose, for at least 4 weeks prior to C1D1
  * Have a viral load of \<400 copies/mL ≤14 days of C1D1.
  * Have a CD4+ T-cell count ≥350 cells/mL ≤14 days of C1D1.
  * Have not had an opportunistic infection within the past 12 months.
* Has an active second malignancy unless in remission with life expectancy greater than 2 years.
* Has known hypersensitivity to any component or excipient of LY4257496.

Where this trial is running

Duarte, California and 27 other locations

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.

View on ClinicalTrials.gov →

Conditions: Breast Neoplasms, Colorectal Neoplasms, Prostate Neoplasm, Endometrial Neoplasms, Neoplasm Metastasis, GRPR-positive

Last reviewed 2026-05-15 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.