Trial of 225Ac-DOTATATE (RYZ101) in Subjects With ER+, HER2-negative Unresectable or Metastatic Breast Cancer Expressing SSTRs.

NCT06590857 | Active Not Recruiting Phase 1 FDA Drug

• 1 other identifier: RYZ101-201
• Study Type: interventional
• Target: 16
• Locations: 3 countries
• Sites: 31

Brief Summary

Phase 1b/2 open-label trial of 225Ac-DOTATATE (RYZ101) in subjects with ER+, HER2-negative unresectable or metastatic breast cancer expressing SSTRs.

Conditions

Metastatic Breast Cancer; HER2-negative Breast Cancer; ER+ Breast Cancer; Advanced Breast Cancer

Keywords

Actinium; Alpha-Emitter; SSTR+ MBC; ER+, HER2-, MBC; RYZ101; 225Ac; Targeted Radiotherapy; Radiopharmaceutical; SSTR+ ABC; ER+, HER2-, ABC

Outcome Measures

Primary Outcomes (2)

• Dose Escalation

  Incidence rate of DLTs during the first 6 weeks of RYZ101 treatment

  6 weeks of RYZ101 treatment

• Expansion

  Overall Response Rate, defined as rate of subjects achieving a Complete Response or Partial Response as determined by BICR using RECIST v1.1

  Up to approximately 5 years after the last subject has completed RYZ101 treatment

Study Arms (2)

Dose Escalation

EXPERIMENTAL

RYZ101 Dose Level -1 RYZ101 Dose Level 1 RYZ101 Dose Level 2 RYZ101 Dose Level 3

Drug: RYZ101

Expansion

EXPERIMENTAL

RYZ101 RP2D Regimen

Drug: RYZ101

Interventions

RYZ101 DRUG

Ac-225

Dose Escalation; Expansion

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Subjects must meet all the following criteria for enrollment in the study:
• Eastern Cooperative Oncology Group performance status ≤2.
• Histologically confirmed, ER+, HER2-negative, locally advanced and unresectable or metastatic breast cancer not amenable to treatment with curative intent.
• At least one RECIST v1.1-measurable tumor lesion that is SSTR-PET positive (defined as maximum standard uptake value (SUVmax) higher than liver mean standard uptake value (SUVmean) on SSTR-PET imaging) and at least 80% of RECIST v1.1measurable tumor lesions are SSTR-PET positive
• Sufficient renal function, as evidenced by eGFR ≥60 mL/min/1.73m2 calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation
• Adequate hematologic and hepatic function

You may not qualify if:

• Subjects who meet any of the following criteria will be excluded from the study:
• Prior radiopharmaceutical therapy, including radioembolization.
• Any toxicities from prior treatments that have not recovered to CTCAE Grade ≤1, except for alopecia.
• Significant cardiovascular disease
• Known active uncontrolled or symptomatic central nervous system (CNS) metastases, carcinomatous meningitis, spinal cord compression, or leptomeningeal disease.
• History of hypersensitivity or allergy to 225Ac, 68Ga, 64Cu, octreotate, or any of the excipients of DOTATATE imaging agents.
• Prior or concurrent malignancy whose natural history or treatment has the potential to interfere with the study safety or efficacy assessments.
• Pregnancy or lactation.

Sponsors & Collaborators

• RayzeBio, Inc.: lead

Study Sites (31)

Research Facility

Phoenix, Arizona, 85054, United States

Location

Research Facility

Irvine, California, 92618, United States

Location

Research Facility

San Diego, California, 92093, United States

Location

Research Facility

Santa Monica, California, 90404, United States

Location

Research Facility

Longmont, Colorado, 80504, United States

Location

Research Facility

Jacksonville, Florida, 32224, United States

Location

Research Facility

Atlanta, Georgia, 30322, United States

Location

Research Facility

Indianapolis, Indiana, 46202, United States

Location

Research Facility

Boston, Massachusetts, 02215, United States

Location

Research Facility

Detroit, Michigan, 48202, United States

Location

Research Facility

Rochester, Minnesota, 55905, United States

Location

Research Facility

St Louis, Missouri, 63130, United States

Location

Research Facility

Omaha, Nebraska, 68124, United States

Location

Research Facility

Albuquerque, New Mexico, 87109, United States

Location

Research Facility

Buffalo, New York, 14203, United States

Location

Research Facility

New York, New York, 10016, United States

Location

Research Facility

New York, New York, 10021, United States

Location

Research Facility

Cleveland, Ohio, 44195, United States

Location

Research Facility

Philadelphia, Pennsylvania, 19104, United States

Location

Research Facility

Pittsburgh, Pennsylvania, 15213, United States

Location

Research Facility

Dallas, Texas, 75246, United States

Location

Research Facility

Houston, Texas, 77024, United States

Location

Research Facility

Salt Lake City, Utah, 84132, United States

Location

Research Facility

Norfolk, Virginia, 23502, United States

Location

Research Facility

Seattle, Washington, 98109, United States

Location

Research Facility

Victoria, British Columbia, V8R 6V5, Canada

Location

Research Facility

Toronto, Ontario, M4N 3M5, Canada

Location

Research Facility

Toronto, Ontario, M5G 2M9, Canada

Location

Research Facility

Québec, Quebec, G1S 4L8, Canada

Location

Research Facility

Seoul, Seoul, 03080, South Korea

Location

Research Facility

Seoul, Seoul, 05505, South Korea

Location

MeSH Terms

Conditions

Breast Neoplasms

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Study Officials

• Petrus de Jong, MD, PhD

  RayzeBio, Inc.

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 3, 2024
• First Posted: September 19, 2024
• Study Start: July 19, 2024
• Primary Completion (Estimated): October 1, 2028
• Study Completion (Estimated): January 1, 2033
• Last Updated: March 18, 2026

Record last verified: 2026-03

Locations

US (25); KR (2); CA (4)