Collaboration to support clinical development of PSMA-targeting theranostics in Japan

Curium has announced a partnership with PDRadiopharma, a wholly-owned subsidiary of PeptiDream, to further advance the clinical development, regulatory filing, and commercialization of the investigational PSMA-targeting theranostics ¹⁷⁷Lu-PSMA-I&T and ⁶⁴Cu-PSMA-I&T in Japan.¹

¹⁷⁷Lu-PSMA-I&T is being assessed in the phase 3 ECLIPSE trial, and ⁶⁴Cu-PSMA-I&T is being studied in the phase 3 SOLAR RECUR and SOLAR STAGE trials.

According to Curium, "Under the terms of the partnership, Curium and PDRadiopharma will jointly collaborate on clinical development activities of ¹⁷⁷Lu-PSMA-I&T and ⁶⁴Cu-PSMA-I&T in Japan, with PDRadiopharma leading regulatory filing, manufacturing, commercialization, and distribution activities in Japan."¹

Curium will continue to lead global development of the agents and support PDRadiopharma in the set-up of manufacturing lines in Japan.

Both agents are currently in phase 3 development for use in prostate cancer diagnostics and treatment.

“Targeted radiopharmaceuticals are rapidly revolutionizing how we both diagnose and treat cancer,” said Patrick C. Reid, president and CEO of PeptiDream, in the news release.¹ “At PeptiDream and PDRadiopharma, we are focused on expanding our pipeline of these powerful targeted therapies, and we are thrilled to be able to accelerate those efforts by partnering with Curium to bring their highly promising prostate cancer targeting radiopharmaceuticals to patients in Japan.”

Trial of ¹⁷⁷Lu-PSMA-I&T

¹⁷⁷Lu-PSMA-I&T is currently being assessed in the phase 3 ECLIPSE trial (NCT05204927), which is assessing the safety and efficacy of ¹⁷⁷Lu-PSMA-I&T in comparison with standard-of-care hormone therapy in patients with metastatic castration-resistant prostate cancer (mCRPC).

In total, the open-label, global trial has enrolled over 400 patients with mCRPC across 51 trial sites in the United States and Europe. For the study, patients will be randomly assigned 2:1 to receive ¹⁷⁷Lu-PSMA-I&T or hormone therapy with either abiraterone (Zytiga) with prednisone or enzalutamide (Xtandi) per clinician judgement.²

Patients in the hormonal therapy arm may choose to crossover to the investigational arm if they experience radiographic progression.

The primary end point for the study is radiographic progression-free survival, assessed for up to 34 weeks. Secondary end points include overall survival, progression-free survival, the rate of patients who achieve at least a 50% reduction in prostate-specific antigen (PSA), and quality-of-life measures.

Final study completion is anticipated for June 2029.

Trials of ⁶⁴Cu-PSMA-I&T

The diagnostic performance of ⁶⁴Cu-PSMA-I&T is being assessed in 2 multicenter phase 3 trials: SOLAR RECUR (NCT06235099) and SOLAR STAGE (NCT06235151). Both trials enrolled patients across 50 sites in the United States and over 30 sites in Europe.³

SOLAR RECUR is evaluating the performance of ⁶⁴Cu-PSMA-I&T in patients with suspected biochemically recurrent prostate cancer after radical prostatectomy or radiation therapy. In total, the prospective, open-label study plans to enroll approximately 200 patients.

The trial’s co-primary end points are the patient-level correct detection rate (CDR) and the region-level correct localization rate (CLR). Secondary outcome measures include CDR and CLR by PSA level, CDR and CLR by histopathology status, inter- and intra-reader agreement of ⁶⁴Cu-PSMA-I&T PET/CT interpretation, and the incidence of adverse events.

Additionally, the prospective, open-label SOLAR STAGE trial is assessing the performance of ⁶⁴Cu-PSMA-I&T in patients with newly diagnosed unfavorable intermediate-risk, high-risk, or very high-risk prostate cancer planning to undergo radical prostatectomy with pelvic lymph node dissection.

The study is seeking to enroll 323 patients who will receive an 8 mCi (± 10%) intravenous dose of ⁶⁴Cu-PSMA-I&T prior to PET/CT imaging. The primary end points are sensitivity and specificity of the theranostic. The study’s secondary end points are the inter- and intra-reader agreement of ⁶⁴Cu-PSMA-I&T PET/CT interpretation and the incidence of adverse events.⁴

Completion of both the SOLAR RECUR and SOLAR STAGE trials is expected in July 2025.^3,4

These phase 3 studies come after positive results from the phase 1/2 SOLAR trial (NCT05653856), which met its co-primary end points of patient-level CDR and region-level CLR in patients with metastatic prostate cancer in August 2023.⁵ In total, the trial enrolled 26 patients across clinical trial sites in the United States.

References

1. Curium announces strategic partnership with PeptiDream for prostate cancer theranostics in Japan. News release. Curium. October 1, 2024. Accessed October 14, 2024. https://www.curiumpharma.com/2024/10/01/s-strategic-partnership-for-prostate-cancer-theranostics/

2. 177Lu-PSMA-I&T for metastatic castration-resistant prostate cancer. ClinicalTrials.gov. Last updated February 29, 2024. Accessed October 14, 2024. https://clinicaltrials.gov/study/NCT05204927

3. Copper Cu 64 PSMA I&T PET imaging in men with suspected recurrence of prostate cancer (Solar-Recur). ClinicalTrials.gov. Last updated July 3, 2024. Accessed October 14, 2024. https://clinicaltrials.gov/study/NCT06235099

4. Copper Cu 64 PSMA I&T PET imaging in men with newly diagnosed prostate cancer (Solar-Stage). ClinicalTrials.gov. Last updated July 3, 2024. Accessed October 14, 2024. https://clinicaltrials.gov/study/NCT06235151

5. Curium announces achievement of co-primary endpoints in phase 2 of its phase 1/2 SOLAR clinical trial imaging men with histologically-proven prostate cancer using copper Cu 64 PSMA I&T. News release. Curium. August 15, 2023. Accessed October 14, 2024. https://www.curiumpharma.com/2023/08/15/phase-2-solar-study-of-copper-cu-64-psma-it/