ESTRO 2023

Session Item

Monday

May 15

16:30 - 17:30

Business Suite 1-2

Lung 2

Chair: , France

Session Code: 3506

Session Type: Poster Discussion

Track: Clinical

Biodistribution Data of ImmunoPET: A Phase 0/1 Study Characterising PD-L1 with 89Zr- Durvalumab

Michael MacManus, Australia

Presentation Number: PD-0970

Abstract

Abstract Title:

Biodistribution Data of ImmunoPET: A Phase 0/1 Study Characterising PD-L1 with 89Zr- Durvalumab

Authors:

Fiona Hegi-Johnson¹, Stacey Rudd², Peter Roselt³, Christian Wichmann⁴, Jason Callahan⁵, Tim Akhurst³, Price Jackson³, Rod Hicks⁶, Andrew Scott⁷, Paul Donnelly², Tom John⁸, Gerard Hanna⁹, Michael MacManus⁹

¹Peter MacCallum Cancer Institute, Department of Radiation Oncology, Melbourne, Australia; ²University of Melbourne, School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, Melbourne, Australia; ³Peter MacCallum Cancer Centre, Department of Cancer Imaging, Melbourne, Australia; ⁴La Trobe University, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, Melbourne, Australia; ⁵Peter MacCallum Cancer Institute, Department of Cancer Imaging, Melbourne, Australia; ⁶St Vincent’s Medical School, University of Melbourne, Department of Medicine, Melbourne, Australia; ⁷La Trobe University, Melbourne Australia, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine , Melbourne, Australia; ⁸Peter MacCallum Cancer Centre, Department of Medical Oncology, Melbourne, Australia; ⁹Peter MacCallum Cancer Centre, Department of Radiation Oncology, Melbourne, Australia

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Purpose or Objective

Introduction
ImmunoPET is a multicentre, single arm, phase 0-1 study that investigates the use of 89Zr-durvalumab PET/CT to interrogate the expression of PD-L1 in patients with NSCLC, in preparation for large clinical trials. We present the initial biodistribution data, which has been used to establish the safety and scan timepoints for a multicentre study in Stage III NSCLC patients.

Material and Methods

Methods
The Phase 0 study recruited 5 PD-L1+ patients with metastatic NSCLC and PD-L1 expression >25%. Patients received 60MBq/70kg 89Zr-durvalumab up to a maximum of 74 MBq, with scan acquisition at day 0, 1, 3 or 5 ± 1 day. Baseline FDG PET/CT was also performed 7 days prior to injection of 89Zr-durvalumab. Data on 1) Percentage of injected 89Zr-durvalumab uptake found in organs of interest (%ID) 2) Absorbed organ uptake (µSv/MBq of administered 89Zr-durvalumab) and 3) Whole-body dose expressed as mSv/100MBq of administered dose from our initial 5 patients are presented here.

Results

Results
5 patients have been recruited to the Phase 0 study, with no significant toxicity observed after tracer injection. 89Zr-durvalumab uptake increases from Day 0 to 5 post-injection in accordance with the long half-life of durvalumab (Figure 1).

Safety Data
No significant toxicity was observed after tracer injection. However, 1 patient had a transient infusion reaction, developing tachypnoea that resolved within 1 hour after dexamethasone and anthistamines

Biodistribution Data
Normal biodistribution was characterized at 5 days by high levels of whole-body retention (mean 84%), low kidney dose 0.82 ±0.22 and 0.70 ±0.26 (Mean ± SD) %ID for right and left kidney respectively, and rapidly diminishing circulation in blood pool from Day 1 19.79 ± 3.5 (mean±SD) Suvmax to 8.31± 2.21 SUVmax at Day 5. A small diminishment in bone uptake from 10.97±1.21 to 9.60±1.60 (mean± SD) %ID was also observed over 5 days. Spleen uptake as measured by % ID increased slightly between rising from 2.22±0.27 (mean ± SD) on Day 1 to 2.94 ± 0.78 on Day 5. See Figure 2 for changes in SUVmax from Day 1 to 5.

Conclusion

Conclusion
Initial biodistribution data suggests that the optimal scan timepoint is Day 5. There is very favourable avidity in PD-L1 positive metastatic lesions in comparison to normal organs with minimal toxicity thus far, supporting the further evaluation of this tracer in a planned, multicentre trial in Stage III NSCLC patients.

Funding and Support

This is an investigator-led project, sponsored by Peter MacCallum Cancer Centre. This research was conducted with support from AstraZeneca Pty Ltd.