PeptiDream, PDR Pharma, and Curium Complete Patient Administration in Domestic Clinical Trial for Prostate Cancer Diagnostic Candidate 64Cu-PSMA-I&T

PeptiDream Inc. (President and CEO: Patrick Reid, Headquarters: Kawasaki City, Kanagawa Prefecture, hereinafter "the Company"), its subsidiary PDR Pharma Inc. (President: Masato Murakami, Headquarters: Chuo-ku, Tokyo, hereinafter "PDR Pharma"), and the Curium Group (CEO: Renaud Dehareng, Headquarters: Boston, USA, hereinafter "Curium") announced today the completion of patient administration in a clinical trial (jRCT2031250225, hereinafter "the Trial") aiming to obtain domestic approval for 64Cu-PSMA-I&T.

About the Radiodiagnostic Agent 64Cu-PSMA-I&T

64Cu-PSMA-I&T is a PET diagnostic candidate compound that targets PSMA (prostate-specific membrane antigen), which is typically highly expressed on prostate cancer cells. Labeled with the radionuclide 64Cu, 64Cu-PSMA-I&T is being evaluated as a candidate for PET diagnosis.

Overview of the Clinical Trial

This trial is being conducted based on a strategic partnership between the Company's subsidiary, PDR Pharma, and Curium. It is an open-label, single-arm study evaluating the sensitivity, specificity, and safety of 64Cu-PSMA-I&T in Japanese patients with initial prostate cancer who are at intermediate, high, or very high risk with a poor prognosis, and who are scheduled for radical prostatectomy with pelvic lymph node dissection.

The results of this study, along with data from clinical trials conducted overseas by Curium, will be utilized for the domestic application for approval.

Implementation of the Theranostics Approach

Simultaneously, as announced in February 2026, a trial aiming for domestic approval is underway to verify the efficacy and safety of the paired therapeutic agent, 177Lu-PSMA-I&T, in patients with metastatic castration-resistant prostate cancer (mCRPC). This is part of an initiative to implement a theranostics approach that integrates diagnostic and therapeutic agents.

Executive Comments

Patrick Reid, President and CEO of PeptiDream, stated: "The completion of patient administration is a significant milestone in the development of 64Cu-PSMA-I&T in Japan. This program holds a crucial position in PeptiDream's expanding radiopharmaceutical pipeline and theranostics strategy. I would like to thank the patients, physicians, and clinical facilities who participated in the trial."

Masato Murakami, President of PDR Pharma and EVP of PeptiDream, stated: "We are extremely pleased to have completed patient administration for 64Cu-PSMA-I&T in Japan. This was achieved through the strong partnership between PDR Pharma, PeptiDream, and Curium, representing an important step in the development of PSMA-targeted theranostics treatments for prostate cancer patients in Japan. We extend our gratitude to the patients, doctors, and clinical staff who supported this trial. We will continue to collaborate with our partners toward the next stage of development in Japan."

Renaud Dehareng, CEO of the Curium Group, stated: "Conducting clinical trials toward regulatory submission through our partnership with PeptiDream and PDR Pharma is a critical step in Curium's mission to bring cutting-edge radiopharmaceuticals to prostate cancer patients in Asia as well. By combining Curium's global development capabilities with PDR Pharma's deep insights and infrastructure in Japan, we believe we can deliver innovative healthcare to Japanese prostate cancer patients."

About Prostate Cancer

The number of prostate cancer patients is growing in Japan, with reported annual new cases ranging from approximately 90,000 to 100,000 (*1).

*1: National Cancer Center Japan, Cancer Information Service

Status of Overseas Development

Phase 3 ECLIPSE Trial

For 177Lu-PSMA-I&T, which combines the radionuclide 177Lu with a PSMA-targeted ligand, Curium conducted the global Phase 3 ECLIPSE trial (ClinicalTrials.gov identifier; NCT05204927). It was announced that statistically significant and clinically meaningful results were achieved in the primary endpoints for patients with mCRPC.

Phase 3 SOLAR RECUR / SOLAR STAGE Trials

For 64Cu-PSMA-I&T, trials are ongoing for patients with biochemical recurrence of prostate cancer (SOLAR RECUR trial, ClinicalTrials.gov identifier NCT06235099) and for patients with initial prostate cancer at intermediate to very high risk with a poor prognosis scheduled for surgery (SOLAR STAGE trial, ClinicalTrials.gov identifier; NCT06235151). In the Phase 1/2 SOLAR trial, a first-in-human study targeting patients pathologically diagnosed with metastatic prostate cancer, both primary endpoints—exact localization rate per lesion and exact detection rate per patient—were met.

Details of the Partnership

PDR Pharma and Curium will collaborate on the clinical development of 64Cu-PSMA-I&T and 177Lu-PSMA-I&T. PDR Pharma will lead the regulatory application, manufacturing, and commercialization in Japan, while Curium will lead the overseas development of both agents and support PDR Pharma through technology transfers, including Curium's proprietary high-throughput manufacturing technology for 64Cu.

About PeptiDream

PeptiDream Inc. (TSE Prime Market Security Code 4587) aims to address unmet medical needs and improve the quality of life for people worldwide by creating new, innovative drugs from special cyclic peptides. In the radiopharmaceutical (RI) domain, it sells radiopharmaceuticals in Japan through its wholly-owned subsidiary, PDR Pharma. Leveraging its proprietary drug discovery platform technology, the Peptide Discovery Platform System (PDPS), it creates innovative radiotherapeutics and radiodiagnostics, developing them as in-house or partnered programs. In the non-RI domain, the company is advancing a broad range of therapeutic and diagnostic applications utilizing PDPS for peptide drugs, peptide-drug conjugates (PDCs), and multifunctional peptide conjugates (MPCs), establishing an extensive global network with joint research and development partners. PeptiDream is headquartered in Kawasaki City. For more details on the Company, its technologies, and pipeline, please visit https://www.peptidream.com.

About PDR Pharma

PDR Pharma Inc. (joined the PeptiDream Group in 2022) has been engaged in the radiopharmaceutical business since its establishment in 1968.