Perspective Therapeutics, Inc. announced that the first patient was dosed at Washington University in St Louis in the Company's Phase 1/2a trial evaluating the safety and efficacy of [(212) Pb]VMT--NET, a targeted alpha-particle therapy (TAT), in patients with unresectable or metastatic somatostatin receptor type 2 (SSTR2) expressing neuroendocrine tumors (NETs). The trial is a multi-center, open-label dose escalation, dose expansion study of [(212) Pb]VMT--NET in patients who have not received prior peptide receptor radionuclide therapy (PRRT). This is a multi-center open-label study (clinicaltrials.gov identifier NCT05636618) of [212Pb]VMT-a-NET, a targeted alpha-particle therapy, for patients with advanced SSTR2-positive neuroendocrine tumors.

The first part of this Phase 1/2a trial is a dose-escalation study designed to determine the Maximum Tolerated Dose (?MTD?) or Maximum Feasible Dose (?MFD?) following a single administration of [212Pb]VMT-a-NET. Patients who have not received prior PRRT will be scheduled to receive up to 4 administrations of [212Pb]VMT-a-NET approximately 8 weeks apart. The first patient cohort will receive 111 MBq (3mCi) per dose.

The second cohort will receive administered activities of 185 MBq (5mCi), with cohorts 3 and 4 receiving 370 MBq (10 mCi) and 555 MBq (15 mCi), respectively, if the MTD or MFD is not reached during escalation. According to the Modified Toxicity Probability Interval 2 (mTPI-2) study design, intermediate de-escalation doses are also possible to allow selection of the optimal activity dose to take forward into the dose expansion part of the study. The second part of the study is a dose expansion phase based on the identified MTD/MFD.

Patients with positive uptake on FDA-approved SSTR2 PET/CT will receive a fixed dose of [212Pb]VMT-a-NET IV administered at the recommended Phase 2 dose and schedule determined in the Phase I dose escalation. Neuroendocrine tumors form in cells that interact with the nervous system or in glands that produce hormones. They can originate in various parts of the body, most often in the gut or the lungs and can be benign or malignant.

Neuroendocrine tumors are typically classified as pancreatic neuroendocrine tumors or non-pancreatic neuroendocrine tumors. According to cancer.net, it is estimated that more than 12,000 people in the United States are diagnosed with a NET each year. Importantly, neuroendocrine tumors are associated with a relatively long duration of survival compared to other tumors and as a result, there are approximately 175,000 people living with this diagnosis.

VMT-a-NET is a clinical stage targeted alpha particle therapy (TAT) radiopharmaceutical being developed for the treatment and diagnosis of somatostatin receptor subtype 2 (SSTR2) expressing neuroendocrine tumors, which are a rare and difficult-to-treat type of cancer. VMT-a-NET incorporates Perspective Therapeutics' proprietary lead-specific chelator (PSC) to bind 203Pb for SPECT imaging, and 212Pb for alpha particle therapy.