Curium’s global Phase 3 ECLIPSE trial of 177Lu-PSMA-I&T met its primary endpoint with statistically significant, clinically meaningful benefit in metastatic castration-resistant prostate cancer, and the first-in-human Phase 1/2 SOLAR study of 64Cu-PSMA-I&T met co-primary detection endpoints on correct localization and patient-level detection.
Against that backdrop, Curium, PeptiDream, and PDRadiopharma have initiated a registrational Phase 2 study in Japan evaluating 64Cu-PSMA-I&T as a PET imaging agent. The open-label, single-arm trial will enroll roughly 70 men newly diagnosed with unfavorable intermediate, high, or very high-risk prostate cancer who are scheduled for prostatectomy with pelvic lymph node dissection. Sensitivity, specificity, and safety are the primary measures, with histopathology providing ground truth. The program will leverage bridging data from Curium’s ongoing global SOLAR RECUR and SOLAR STAGE Phase 3 studies, while a Japanese clinical trial of the therapeutic partner, 177Lu-PSMA-I&T, is being planned in mCRPC.
Strategically, this is a classic theranostic land-and-expand play tailored to Japan’s regulatory and supply realities. Curium is leading global development and transferring technology to establish a high-throughput copper-64 manufacturing line, while PDRadiopharma takes the lead on Japan’s regulatory filings, manufacturing, commercialization, and distribution. Choosing copper-64 for the diagnostic leg is a logistics decision as much as a clinical one: a longer half-life supports centralized production and regional distribution, alleviating generator constraints and scan scheduling pressure that can complicate Ga-68 programs. Coupling that with a locally anchored manufacturing partner reduces time-to-site and de-risks cold-chain complexity—key factors for nationwide PET rollout in Japan.
For sites, this registrational design compresses operational burden while aligning with PMDA expectations. A single-arm, pathology-validated readout is conventional for imaging approvals and will rely on tight integration between urology, nuclear medicine, central imaging reads, and pathology mapping at the regional level. Imaging teams should anticipate standardized PSMA read criteria, image archiving requirements, and reproducibility controls that mirror the global SOLAR program. Sites contemplating theranostic build-outs should view this as an early signal to secure radiopharmacy access to Cu-64, update PET scheduling workflows, and assess readiness for Lu-177 therapy infrastructure, including radiation safety, dose preparation, and multidisciplinary care pathways.
For sponsors and CROs, the use of bridging data to underpin a Japanese registrational package reflects an efficiency-first posture that is increasingly common for diagnostics. It compresses local enrollment, shortens timelines, and can harmonize labeling assumptions if PMDA remains aligned with the evidence framework used in ex-Japan. For regulators, the pathology-anchored endpoints in a surgical population offer a clean test of clinical validity that can translate to pre-operative staging claims and, potentially, to biochemical recurrence indications as the SOLAR program matures.
What to watch next is whether the Japanese Phase 2 can deliver sensitivity and specificity consistent with global datasets and whether the copper-64 operational advantages outweigh entrenched preferences for F-18 or Ga-68 agents once commercial. Any divergence in read performance by disease risk strata or pelvic nodal mapping could complicate the label scope. On the therapeutic side, timing and design of the planned Japanese Lu-177 trial—and how it interfaces with ECLIPSE data—will determine the speed of a full theranostic launch. Reimbursement, isotope supply resilience, and reader standardization will ultimately dictate how quickly adoption scales across Japan’s mixed academic and community networks.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
