A Study of [177Lu]Lu-A9-0631 and [225Ac]Ac-A9-0642 With [68Ga]Ga-A9-6217 or [177Lu]Lu-A9-0631 Imaging in GRPR+ Solid Tumors

June 16, 2026 updated by: Alpha-9 Oncology USA Inc.

A Phase 1-1b Study to Evaluate the Safety, Efficacy, and Dosimetry of [177Lu]Lu-A9-0631, [225Ac]Ac-A9-0642, and [68Ga]Ga-A9-6217 in Participants With GRPR+ Tumors

This is a Phase 1-1b multicenter clinical study to evaluate the safety, efficacy, and dosimetry of [177Lu]Lu-A9-0631 and [225Ac]Ac-0642 in participants with Gastrin-Releasing Peptide Receptor (GRPR) expressing locally advanced, unresectable or metastatic solid tumors.

Study Overview

Detailed Description

This is a multicenter, open-label Phase 1-1b study of [177Lu]Lu-A9-0631 and [225Ac]Ac-A9-0642 in subjects with Gastrin-Releasing Peptide Receptor (GRPR) expressing locally advanced, unresectable or metastatic solid tumors.

The study consists of two parts (Phase 1 and 1b).

Phase 1 is the dose escalation portion of the study. The aim of the Phase 1 is to evaluate the safety and tolerability as well as the normal organ and tumor dosimetry of [177Lu]Lu-A9-0631 and [225Ac]Ac-A9-0642, and to determine the maximum tolerated dose (MTD) and the recommended Phase 2 dose (RP2D).

Phase 1b will be the dose expansion portion of the study. The aim of the Phase 1b will be to further evaluate the safety, efficacy, and normal organ and tumor dosimetry of [177 Lu]Lu-A9-0631 and [225Ac]Ac-A9-0642 administered at the RP2D in subjects with (1) Locally advanced, unresectable, or metastatic HR+/HER2- breast cancer; (2) Locally advanced, unresectable, or metastatic prostate cancer; (3) Locally advanced, unresectable, or metastatic CRC; and (4) Other locally advanced, unresectable, or metastatic GRPR-positive solid tumors.

Study Type

Interventional

Enrollment (Estimated)

115

Phase

  • 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 Locations

    • Victoria
      • Melbourne N., Victoria, Australia, 3051
        • Recruiting
        • Melbourne Theranostic Innovation Center
        • Contact:
        • Principal Investigator:
          • Prof. Rod Hicks
    • Western Australia
      • Murdoch, Western Australia, Australia, 6150
        • Not yet recruiting
        • GenesisCare Murdoch
        • Contact:
        • Principal Investigator:
          • Prof. Joe Cardaci

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Participant has provided written informed consent prior to any study-specific procedure.
  • Age ≥ 18 years old.
  • Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1.
  • Have measurable target lesion per RECIST v1.1.
  • Progression from, intolerant to, or ineligible for (due to unavailability or contraindication) local standard of care therapies and have one of the following locally advanced or metastatic tumor types: prostate cancer; HR+/HER2- breast cancer; colorectal cancer; and GRPR-positive solid tumors.
  • Have GRPR-expressing disease as confirmed by PET / CT or SPECT imaging.
  • Adequate organ function within 14 days of first administration of investigational therapeutic product.
  • At least 4 weeks from prior major surgery.

Exclusion Criteria:

  • Received anticancer treatment including but not limited to chemotherapy, antibody therapy, immunotherapy, gene therapy, vaccine therapy, angiogenesis inhibitors, or experimental drugs ≤ 14 days prior (≤ 28 days prior in case of checkpoint inhibitor therapy and other antibody therapies) or 5 half-lives, (t1/2) whichever is shorter, to the administration of therapeutic investigational product.
  • History of uncontrolled allergic reactions and/or known or expected hypersensitivity to a peptide-based imaging or therapeutic agent or any excipient present in either of the therapeutic investigational products.
  • Major surgery within 4 weeks of planned first dose of the therapeutic investigational product.
  • Prior external beam radiation therapy to more than 25% of the bone marrow.
  • Pregnant, breastfeeding, or unwilling to practice birth control during participation in the study.
  • Any active infection.

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: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Phase 1 Dose Escalation
Administered IV
Administered IV
Administered IV
Administered IV
Experimental: Phase 1B Dose Expansion
Administered IV
Administered IV
Administered IV
Administered IV

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Phase 1-1b: Incidence of Adverse Events by Frequency, Duration, and Severity
Time Frame: From the first dose of study drug up to the End of Treatment (30 days after the last dose)
An AE is defined as any untoward medical occurrence in a participant administered study drug, which does not necessarily have to have a causal relationship with the study drug. The number of patients experiencing an AE in Part 1 will be reported.
From the first dose of study drug up to the End of Treatment (30 days after the last dose)
Phase 1: Number of Patients with Dose-Limiting Toxicities (DLTs).
Time Frame: Up to 28 days following first study treatment
DLTs is defined as any predefined AE occurring during the DLT observation period.
Up to 28 days following first study treatment
Phase 1: Maximum tolerated dose (MTD)
Time Frame: Up to 28 days following first study treatment
Incidence of dose-limiting toxicity (DLT) per dose level of [177Lu]Lu-A9-0631 and/or [225Ac]Ac-A9-0642.
Up to 28 days following first study treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Phase 1-1b: Absorbed dose estimates (Gy) in normal organs for [177Lu]Lu-A9-0631 and/or [225Ac]Ac-A9-0642
Time Frame: Up to 7 days after each injection for up to 6 cycles (each cycle is 28 days)
Up to 7 days after each injection for up to 6 cycles (each cycle is 28 days)
Phase 1-1b: Objective Response Rate (ORR)
Time Frame: Every 8 ± 1 weeks until radiographic disease progression or up to 12 months after the last dose of [177Lu]Lu-A9-0631 and/or [225Ac]Ac-A9-0642
Objective response rate is defined as the percentage of patients who achieved a best overall response of confirmed Complete Response (CR) or Partial Response (PR), as determined by the investigator based on RECIST 1.1, by dose level.
Every 8 ± 1 weeks until radiographic disease progression or up to 12 months after the last dose of [177Lu]Lu-A9-0631 and/or [225Ac]Ac-A9-0642

Collaborators and Investigators

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

Investigators

  • Study Director: Stephen Hull, MD, Alpha 9 Oncology

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)

July 1, 2026

Primary Completion (Estimated)

December 1, 2028

Study Completion (Estimated)

December 1, 2029

Study Registration Dates

First Submitted

June 9, 2026

First Submitted That Met QC Criteria

June 16, 2026

First Posted (Actual)

June 22, 2026

Study Record Updates

Last Update Posted (Actual)

June 22, 2026

Last Update Submitted That Met QC Criteria

June 16, 2026

Last Verified

June 1, 2026

More Information

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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