The Phase 3 ECLIPSE trial evaluating 177Lu-PSMA-I&T in patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) has met its primary endpoint, demonstrating a statistically significant improvement in radiographic progression-free survival (rPFS). The trial, sponsored by Curium, compared the safety and efficacy of 177Lu-PSMA-I&T with hormone therapy in this patient population.
Targeting PSMA in mCRPC
177Lu-PSMA-I&T is a radioligand therapy that targets PSMA, a protein found on the surface of prostate cancer cells. By binding to PSMA, the therapy delivers radiation directly to the cancer cells, destroying them while minimizing damage to surrounding healthy tissue. This approach offers a targeted treatment option for patients with mCRPC who express PSMA.
The ECLIPSE trial enrolled approximately 439 patients across 51 sites in the United States and Europe. Patients were administered 177Lu-PSMA-I&T at a dose of 200 millicurie (mCi) every six weeks for up to six doses. The trial focused on patients with mCRPC who had not yet received taxane-based chemotherapy.
Clinical Significance
"ECLIPSE is the first Phase 3 trial investigating a 200 mCi [7.4 GBq] dose of 177Lu-PSMA-I&T administered every six weeks for up to six doses, demonstrating clinical benefit, in mCRPC patients before receiving taxane-based chemotherapy," said Dr. Sakir Mutevelic, chief medical officer of Curium. The achievement of the primary endpoint marks a significant milestone in the development of this prostate theranostic program.
In addition to radiographic progression-free survival, the trial also assessed secondary endpoints including safety, overall survival, and quality of life. All enrolled patients were monitored for side effects and underwent safety labs throughout the study. Disease progression was assessed radiographically, through conventional imaging, prostate-specific antigen (PSA) levels, and symptom recording.
Future Directions
Curium plans to work with the FDA on a regulatory submission for 177Lu-PSMA-I&T. "Curium will continue to work with the FDA as the clinical trial data matures, on a regulatory submission plan for this potentially important product for patients, their caregivers and the health care providers treating prostate cancer," added Dr. Mutevelic.
Michael Patterson, chief medical officer of Curium North America, stated, "This underscores Curium’s continued commitment and focus on nuclear medicine diagnostics and therapeutics...by ensuring unrestricted access to this important product, if approved."
