Perspective Therapeutics recently announced updated interim data from its ongoing Phase 1/2a clinical trial evaluating [212Pb]VMT-α-NET in patients with unresectable or metastatic somatostatin receptor type 2 (SSTR2)-expressing neuroendocrine tumors (NETs). The data, set to be presented at the 2025 American Society of Clinical Oncology Gastrointestinal Cancers Symposium, reveal encouraging signs of anti-tumor activity and a favorable safety profile.
The study enrolled patients who had not received prior radiopharmaceutical therapy and whose tumors had shown radiological evidence of disease progression within the 12 months before enrollment.
Safety and Tolerability
Notably, the trial reported no dose-limiting toxicities, grade 4 or 5 treatment-emergent adverse events, or serious adverse events since its commencement. No new grade 3 adverse events were observed beyond the two previously reported. Renal function remained stable across the patient cohort. Hematologic adverse events, such as decreased lymphocyte count and anemia, were primarily grades 1 and 2. Importantly, no patients discontinued treatment due to adverse events.
Anti-Tumor Activity
With extended follow-up, further anti-tumor activity was observed. As of the data cut-off date of January 10, 2025, the trial reported one confirmed response and two unconfirmed responses, consistent with Cohort 2. The patient with a confirmed objective response has remained in response for 17 weeks and is still participating in the study. One patient experienced an initial unconfirmed response on the fifth scan post-first dose, with gradual tumor regression observed throughout the study, meeting response criteria on the most recent scan. Another patient showed an initial unconfirmed response on the seventh scan after the first dose. Five patients exhibited stable disease, while one patient experienced progressive disease after a single dose due to unambiguous progression of non-target lesions.
Clinical Implications
These early results suggest that [212Pb]VMT-α-NET may offer a potential therapeutic option for patients with advanced NETs who have limited treatment alternatives. The ongoing trial will continue to assess the safety and efficacy of this radiopharmaceutical therapy, with further data expected to provide a more comprehensive understanding of its clinical benefit.
