89Zr-olaratumab Dosimetry in Participants With PDGFR Alpha Positive Solid Tumours and Soft Tissue Sarcoma (ZOLAR)

August 12, 2026 updated by: Telix Pharmaceuticals (Innovations) Pty Ltd

An Open-label, Phase 1 Study to Assess Safety, Tolerability, Dosimetry, Pharmacokinetics and Imaging Properties of 89Zr-olaratumab (89ZrTLX300-CDx) in Participants With PDGFR Alpha Positive Solid Tumours and Soft Tissue Sarcoma

Soft Tissue Sarcoma (STS) is a cancer of soft tissues that often expresses Platelet-Derived Growth Factor Receptor (PDGFR)α, a potential therapeutic target. PDGFRα is also found in other advanced solid tumours.

Olaratumab, a PDGFRα-targeted antibody, may be used to deliver radioactive isotopes for imaging or therapy. This first-in-human study will evaluate zirconium-89-labelled olaratumab (⁸⁹Zr-TLX300-CDx) for imaging in patients with STS, selected PDGFRα-positive solid tumours and identification of patients that may benefit from future treatments.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Platelet-derived growth factor receptor α (PDGFRα) is expressed in soft tissue sarcoma (STS) and other solid tumours, where it may serve as a therapeutic target. Olaratumab is a PDGFRα-targeted antibody with potential to act as a targeting moiety for both imaging and therapeutic radioisotopes. Its favourable safety profile and ability to bind and be internalised by PDGFRα-expressing tumour cells make it a promising radionuclide targeting agent. ⁸⁹Zr-TLX300-CDx is being developed for PDGFRα PET imaging in STS and selected PDGFRα-positive solid tumours. The aim of this study is to demonstrate tumour targeting of ⁸⁹Zr-TLX300-CDx and assess its safety and radiation dosimetry, to support future development of olaratumab as a radiopharmaceutical.

SCHEDULE OF ASSESSMENTS

Part A

IMAGING:

1 single injection of 89Zr-TLX300-CDx on Day 1 followed by whole-body imaging at 4h ± 0.5h and Day 6 ± 1 post-injection.

OPTIONAL:

Imaging at Day 4 ± 1 post-injection.

Blood Collection for Pharmacokinectics:

Pre-injection, 4h ± 0.5h and 6 days ± 1 day post-injection.

OPTIONAL:

Blood collection at Day 4 ± 1 post-injection.

Part B

IMAGING:

1 single injection of 89Zr-TLX300-CDx on Day 1 followed by whole-body imaging at Day 6 ± 1 post-injection.

OPTIONAL:

Imaging at 4h ± 0.5h post-injection and at Day 4 ± 1 post-injection.

Blood Collection for Pharmacokinectics:

Pre-injection, 4h ± 0.5h and 6 days ± 1 day post-injection.

OPTIONAL:

Blood collection at Day 4 ± 1 post-injection.

Part C:

IMAGING:

1 single injection of 89Zr-TLX300-CDx on Day 1 followed by whole-body imaging at 24h ± 4h, 4 days ± 1 post-injection and 7 days ± 1 day post-injection.

OPTIONAL:

Dynamic imaging 15 min ± 2 min post-injection at selected sites (extended field-of-view scanner available) and static imaging at 4h ± 0.5h post-injection.

Blood Collection for Pharmacokinectics:

Pre-injection, 4h ± 0.5h, 24h ± 4h, 4 days ± 1 day and 7 days ± 1 day post-injection.

Study Type

Interventional

Enrollment (Estimated)

50

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 Contact Backup

Study Locations

  • Australia
    • Queensland
    • Victoria
      • Melbourne, Victoria, Australia, 3051
        • Recruiting
        • Precision Molecular Imaging & Theranostics Pty Ltd
        • Principal Investigator:
          • Rodney Hicks, Prof.
        • Contact:
        • Contact:
    • Western Australia
      • Perth, Western Australia, Australia, 6150

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:

  1. ≥18 years of age at the time of signing the informed consent.
  2. Histologically confirmed diagnosis of soft tissue sarcoma (STS). Patients with indications other than STS, that could be PDGFRα positive, will also be considered This would be subject to case-by-case approval by the Sponsor.
  3. At least one mass of > 2cm in largest diameter seen on standard care imaging (CT or MRI) or at least one lesion detected positive via FDG-PET.

  4. Participants must have consented to provide prior/archival FFPE tumour tissue or biopsy/resected tissues collected up to 30 days after visit 2 (89Zr-TLX300-CDx administration) - please refer to the Laboratory manual for description of tissue requirements.

    It is preference that biopsies have been collected within 3 months of trial participation (but not mandatory).

  5. Adequate haematologic function as defined by an absolute neutrophil count (ANC) ≥ 1500/ μL, haemoglobin ≥ 9.0 g/dL, and a platelet count of 100,000/μL obtained.
  6. Adequate hepatic function as defined by a total bilirubin ≤ 1.5 mg/dL, and aspartate transaminase (AST) and alanine transaminase (ALT) ≤ 3.0 times the upper limit of normal (ULN).
  7. Adequate renal function as defined by serum creatinine ≤ 1.5 × the institutional ULN. If creatinine is above the ULN, the participant's creatinine clearance is ≥ 45 mL/min.
  8. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2.

  9. Female participants of childbearing potential must have negative pregnancy tests at screening, as well as confirmation of negative pregnancy test result within 24 hours prior to receiving 89Zr-TLX300-CDx. Female participants of childbearing potential or male participants with female partners of childbearing potential must:

    1. be willing to practice full and true sexual abstinence; or
    2. be surgically/permanently sterile or with a history of hysterectomy for women; or
    3. be willing to practice highly effective contraception by using: a non-oral, injected or implanted non-oestrogen progesterone based hormonal method, male condom, vaginal diaphragm, cervical cap, intrauterine device, for 3 months after the administration of 89Zr-TLX300-CDx.

11. Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.

EXCLUSION CRITERIA:

  1. Known or suspected hypersensitivity to olaratumab, DFOsq, 89Zr or any of the excipients.
  2. IgE antibodies against galactose-α-1,3-galactose (α-Gal) above the ULN, >0.7 kU/L.
  3. Exposure to any experimental diagnostic or therapeutic drug within 30 days from the date of planned administration of 89Zr-TLX300-CDx.
  4. Surgery ≤ 2 weeks prior to the administration of 89Zr-TLX300-CDx or significant ongoing complications of surgery. Biopsy ≤ 2 weeks prior to the administration of 89Zr-TLX300-CDx is allowed.
  5. Exposure to any radiopharmaceutical within 10 half-lives prior to the administration of 89Zr-TLX300-CDx.
  6. Planned to commence systemic antineoplastic therapies, immunotherapy, targeted therapy, radiotherapy and/or surgery for the period between administration of 89Zr-TLX300-CDx and last imaging timepoint, i.e., (Visit 4 for Parts A and B; Visit 5 for Part C). Existing or ongoing therapies may be continued during the imaging window, without washout period.
  7. Serious non-malignant disease (e.g., psychiatric, infectious, autoimmune or metabolic), unresolved serious symptoms from previous therapies, or any disease that may interfere with the objectives of the study or with the safety or compliance of the participant, as judged by the Investigator.
  8. Pregnant or lactating person.
  9. Participants unable to declare meaningful informed consent on their own (e.g., with legal guardian for mental disorders) or unable to tolerate the study procedures.

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Part A
One Injection of 89Zr-TLX300-CDx
Drug: 89Zr-DFOsq-olaratumab (89Zr-TLX300-CDx)
Single administration of 89Zr-TLX300-CDx
Experimental: Part B
One Injection of 89Zr-TLX300-CDx
Drug: 89Zr-DFOsq-olaratumab (89Zr-TLX300-CDx)
Single administration of 89Zr-TLX300-CDx
Experimental: Part C
One Injection of 89Zr-TLX300-CDx
Drug: 89Zr-DFOsq-olaratumab (89Zr-TLX300-CDx)
Single administration of 89Zr-TLX300-CDx

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evaluate clinical safety and tolerability of 89Zr-TLX300-CDx
Time Frame: 30 days
Number of Adverse events (AEs)
30 days
Pharmacokinetics (PK)
Time Frame: 6 days
Measure the antibody concentration at each timepoint to determine a PK curve.
6 days
Biodistribution of 89Zr-TLX300-CDx
Time Frame: 6 days
Measurement of absorbed radiation doses to organs.
6 days
Radiation dosimetry of 89Zr-TLX300-CDx
Time Frame: 6 days
Measurement of absorbed radiation doses to tumour(s) and whole body.
6 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Determine a suitable antibody mass for administration
Time Frame: 6 days
SUV values of tumour lesions and tumour to background organ (e.g. blood/liver/muscle) ratios.
6 days

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Compare the tumour uptake and detection of lesions between 89Zr-TLX300-CDx and standard of care imaging
Time Frame: 30 days
89Zr-TLX300-CDx uptake within tumours and organs and Localisation of tumour deposits on conventional imaging (CT, MRI and/or FDGPET)
30 days
Evaluate the correlation between tumour uptake of 89Zr-TLX300-CDx and PDGFRα expression
Time Frame: 30 days
Immunohistochemistry expression of PDGFRα in tumour tissue AND SUV tumour values and tumour to background ratios.
30 days

Collaborators and Investigators

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

Sponsor

Telix Pharmaceuticals (Innovations) Pty Ltd

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 (Actual)

October 31, 2024

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

April 29, 2024

First Submitted That Met QC Criteria

July 31, 2024

First Posted (Actual)

August 5, 2024

Study Record Updates

Last Update Posted (Actual)

August 14, 2026

Last Update Submitted That Met QC Criteria

August 12, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 89Zr-TLX300-101

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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