NUCLIDIUM Announces First Patient Imaged in Phase 2 Study Evaluating 61Cu-NU101 Diagnostic in Patients with Metastatic Prostate Cancer

Basel, Switzerland / Munich, Germany, October 6, 2026 – NUCLIDIUM AG, a clinical-stage radiopharmaceutical company, today announced that the first patient has been successfully imaged in a Phase 2 clinical trial evaluating the diagnostic accuracy and safety of the Company’s ⁶¹Cu-NU101 radiotracer in patients with metastatic prostate cancer. ⁶¹Cu-NU101 is a positron emission tomography (PET) imaging agent that effectively combines high-radiopure Copper-61 with a targeting peptide to specifically bind to Prostate-Specific Membrane Antigen (PSMA), an established biomarker for prostate cancer. ⁶¹Cu-NU101 is the diagnostic component of NUCLIDIUM’s NU101 theranostic program for metastatic prostate cancer, paired with the ⁶⁷Cu-NU101 therapeutic.

“PSMA-targeted PET is currently the best method of imaging metastatic prostate cancer, and we are always striving to do better. In a phase 1 trial, we showed that ⁶¹Cu-NU101 was safe and able to detect additional lesions in 50% of patients compared to the currently most sensitive imaging agents”, said Dr. Gary Ulaner, MD, PhD, Chair of Molecular Imaging and Therapy at the Hoag Family Cancer Institute and Professor of Radiology at the University of Southern California.  “These data supported the opening of our phase 2 trial, which is statistically powered to compare against currently available imaging agents and uses pathology as the reference standard of truth.”

The investigator-initiated, non-randomized Phase 2 trial will enroll approximately 34 patients with biopsy-confirmed metastatic prostate cancer at clinical sites in the United States. Patients will receive a single intravenous dose of ⁶¹Cu-NU101, followed by PET/CT imaging at 1 and 4 hours post-dose. The primary endpoint will evaluate the sensitivity of tumor lesion detection of ⁶¹Cu-NU101 compared to an ¹⁸F-based, FDA-approved PSMA-targeting radiotracer. Secondary endpoints include a sensitivity comparison to CT and bone scans, and safety evaluation.

“The supportive Phase 1 diagnostic data and differentiated clinical profile reinforce our belief in the best-in-class potential of NU101 as a Next -generation copper-based radiotheranostic for prostate cancer. Importantly, progress in our diagnostic program will inform and strengthen our therapeutic development strategy, enabling our true radiotheranostic approach of direct diagnosis to treatment conversion. The initiation of this Phase 2 trial represents an important step in executing our broad and robust development plan, with multiple clinical trials expected over the coming months and expansion into new cancer patient populations,” said Thomas Reiner, PhD, CSO of NUCLIDIUM.

NUCLIDIUM’s ⁶¹Cu-NU101 program can be manufactured in 5 minutes at room-temperature, allowing for on-demand preparation and seamless integration into existing hospital infrastructure. These manufacturing advantages, coupled with the longer half-life, delayed imaging capability and beneficial tumor-to-background ratio, further underscore the benefits of this copper-based approach compared with alternative radioligands. Phase 1 data previously presented at the Society of Nuclear Medicine & Molecular Imaging (SNMMI) 2025 Annual Meeting highlight the favorable clinical profile of ⁶¹Cu-NU101.

About NUCLIDIUM
NUCLIDIUM AG is pioneering Next -generation copper-based radiotheranostics that enable the direct conversion from cancer diagnosis to treatment. Leveraging copper isotopes, Copper-61 for diagnostics and Copper-67 for therapeutics, NUCLIDIUM has built a pipeline of differentiated candidates combining superior clinical performance, easy-to-scale production, and seamless integration into hospital workflows. The company’s lead programs NU101 in metastatic castration-resistant prostate cancer (mCRPC) and NU201 in metastatic breast cancer (mBC) have demonstrated compelling efficacy and safety in Phase 1/2 diagnostics trials and are advancing into Phase 1/2 theranostics trials. Our goal is to expand the reach and clinical profile of radiotheranostics to deliver the full value of the modality and address critical unmet medical needs in oncology and women’s health.

For more information, please contact:

NUCLIDIUM
Leila Jaafar, PhD, CEO
Email: info@nuclidium.com

Investor /Media Contact NUCLIDIUM
Trophic Communications
Stephanie May
Email: nuclidium@trophic.eu
Phone: +49 171 1855682

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