Evaluation of 68Ga-PSMA-11 PET/CT: a Phase 1 clinical study in Japanese patients with primary, recurrent, or suspected recurrent prostate cancer

Anri Inaki; Atsushi Mizokami; Hiroshi Wakabayashi; Kouji Izumi; Yoshifumi Kadono; Tadashi Toyama; Shizuko Takahara; Toshinori Murayama; Seigo Kinuya

doi:10.1007/s12149-024-01931-7

Evaluation of ⁶⁸Ga-PSMA-11 PET/CT: a Phase 1 clinical study in Japanese patients with primary, recurrent, or suspected recurrent prostate cancer

Ann Nucl Med. 2024 May 16. doi: 10.1007/s12149-024-01931-7. Online ahead of print.

Authors

Anri Inaki¹, Atsushi Mizokami², Hiroshi Wakabayashi³, Kouji Izumi², Yoshifumi Kadono², Tadashi Toyama⁴, Shizuko Takahara⁴, Toshinori Murayama^{4

5}, Seigo Kinuya³

Affiliations

¹ Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa, 920-8641, Japan. henri@staff.kanazawa-u.ac.jp.
² Department of Integrative Cancer Therapy and Urology, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa, 920-8641, Japan.
³ Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa, 920-8641, Japan.
⁴ Innovative Clinical Research Center, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa, 920-8641, Japan.
⁵ Department of Clinical Development, Kanazawa University Hospital, 13-1 Takara-Machi, Kanazawa-Shi, Ishikawa, 920-8641, Japan.

PMID: 38750331
DOI: 10.1007/s12149-024-01931-7

Abstract

Background: Prostate-specific membrane antigen (PSMA)-targeted radiopharmaceuticals allow whole-body imaging to detect prostate cancer (PC). Positron emission tomography imaging using gallium-68 (⁶⁸Ga)-PSMA-11 has been shown to have a favorable safety and tolerability profile and high diagnostic performance. The study evaluates the safety and pharmacokinetics of ⁶⁸Ga-PSMA-11 in Japanese patients with primary, recurrent, or suspected recurrent prostate cancer.

Methods: This single arm study enrolled Japanese patients with primary PC (n = 3), suspected recurrent PC following radical prostatectomy (n = 4), or suspected recurrent PC following radical radiotherapy (n = 3). All patients received a single intravenous dose of ⁶⁸Ga-PSMA-11 2.0 MBq/kg (±10%) followed by PSMA PET imaging and safety and pharmacokinetic evaluations. Based on the blood concentrations of ⁶⁸Ga-PSMA-11 and the radioactivity distribution rate in each organ/tissue, the absorbed doses in major organs/tissues and the whole-body effective dose were calculated by the Medical Internal Radiation Dose method.

Results: Ten patients were enrolled. Mean age was 73.3 ± 4.8 years, and median prostate-specific antigen was 8.250 ng/mL. Five patients (50%) experienced a total of 6 adverse events, and no grade ≥ 2 adverse events or serious adverse events were reported. No clinically significant changes in vital signs, haematology parameters, or blood chemistry or ECG abnormalities were observed. The estimated whole body effective dose of ⁶⁸Ga-PSMA-11 (mean ± standard deviation) was 2.524 × 10^-2 ± 2.546 × 10^-3 mSv/MBq. Time to maximum concentration (1.16 × 10^-4 ± 1.3 × 10^-5% ID/mL) in whole blood was 2.15 ± 0.33 min.

Conclusions: ⁶⁸Ga-PSMA-11 has a favourable safety and tolerability profile in Japanese patients with primary, recurrent, or suspected recurrent prostate cancer, which is comparable to previous observations in other populations.

Keywords: 68Ga-PSMA-11; PSMA PET; Positron emission imaging (PET); Prostate cancer; Prostate-specific membrane antigen (PSMA).