A Phase 1/2 interventional study of [203Pb]Pb-PSV359 and [212Pb]Pb-PSV359 in Pancreatic Ductal Adenocarcinoma, Gastric Cancer and Esophageal Cancer, sponsored by Perspective Therapeutics. Recruiting at 11 sites in United States. Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-07-06.
Sponsored by Perspective Therapeutics · Phase 1/2, Interventional, and Treatment
Phase I/IIa image-guided, alpha-particle therapy study of [203Pb]Pb-PSV359 and [212Pb]Pb-PSV359 in patients with solid tumors that are known to be Fibroblast Activation Protein (FAP)-positive.
This is a prospective, multi-center open label dose finding, dose expansion study of [212Pb]Pb-PSV359 in subjects with a positive Fibroblast Activation Protein (FAP) imaging scan with imaging agent.
FAP is specifically expressed on the surface of cancer-associated fibroblasts in some tumor tissues and therefore is an attractive target in the diagnosis and treatment of various cancers. Lead-212 ([212Pb]Pb-) based peptide-radiopharmaceuticals are an emerging class of targeted alpha-particle cancer therapies that have potential to improve delivery of a highly effective form of radiation.
This study will be conducted in 2 parts:
Part 1: Dose-escalation: [212Pb]Pb-PSV359 is administered in escalating doses to determine the Maximum Tolerated radioactivity (MTD) Dose and potential recommended Phase 2 dose (RP2D).
Part 2: Dose-expansion: This part will enroll subjects in expansion cohorts based on the identified MTD and RP2D for the selection of [212Pb]Pb-PSV359 doses for further clinical development.
A Dosimetry sub-set utilizing an imaging surrogate, [203Pb]Pb-PSV359, has been incorporated into the study in order to assess organ biodistribution and tumor uptake of the investigational products. This sub study will also estimate radiation dosimetry and correlate uptake of the investigation products with observed toxicities and efficacy.
Exclusion Criteria:
* Enrolled subjects are administered \[203Pb\]Pb-PSV359 (7mCi) for imaging FAP-expressing cancers. * Approximately Four cohorts of \[212Pb\]Pb-PSV359 dose levels will be explored for determining Recommended Phase 2 Dose (RP2D). Study subjects will be assigned to cohorts sequentially.
Drug: [203Pb]Pb-PSV359 · Drug: [212Pb]Pb-PSV359
* Enrolled subjects are administered \[203Pb\]Pb-PSV359 (7mCi) for imaging FAP-expressing cancers. * Enrolled subjects are administered \[212Pb\]Pb-PSV359 (RP2D determined previously) for treatment of FAP-expressing cancers
Drug: [203Pb]Pb-PSV359 · Drug: [212Pb]Pb-PSV359
\[203Pb\]Pb-PSV359 is administered by intravenous bolus injection for single-photon emission computed tomography imaging.
\[212Pb\]Pb-PSV359 is administered by intravenous infusion for treatment of FAP expressing cancers.
Determination of safety and tolerability of [203Pb]Pb-PSV359
Incidence and severity of treatment-related adverse events following a single administration of \[203Pb\]Pb-PSV359 is determined
Time frame: 30 days (±1day) post dose
Determination of safety and tolerability of [212Pb]Pb-PSV359
Incidence and severity of treatment-related adverse events following a single and each repeated administration of \[212Pb\]Pb-PSV359 is determined
Time frame: Up to 3 years
To determine the recommended phase 2 dose of [212Pb]Pb-PSV359
The recommended phase 2 dose as determined by cohort observations and review by the Safety Monitoring Committee
Time frame: Up to approximately 6 months
Determination of duration of response following treatment with [212Pb]Pb-PSV359
Median duration of response for subjects receiving at least 1 administration of \[212Pb\]Pb-PSV359 is assessed by RECIST V1.1 criteria
Time frame: Up to 3 years
Determination of progression free survival following treatment with [212Pb]Pb-PSV359
Progression free survival for subjects receiving at least 1 administration of \[212Pb\]Pb-PSV359 is assessed by RECIST V1.1 criteria
Time frame: Up to 3 years
Determination of pharmacokinetic properties of [203Pb]Pb-PSV359 and [212Pb]Pb-PSV359
Blood radioactivity pharmacokinetic parameter such as area under the plasma concentration versus time curve (AUC) is determined.
Time frame: Up to approximately 3 yrs
Determination of pharmacokinetic properties of [203Pb]Pb-PSV359 and [212Pb]Pb-PSV359
Blood radioactivity pharmacokinetic parameter such as peak plasm concentration (Cmax) is determined
Time frame: up to approximately 3 years
Determination of pharmacokinetic properties of [203Pb]Pb-PSV359 and [212Pb]Pb-PSV359
Blood radioactivity pharmacokinetic parameter such as the time (Tmax) to reach the maximum concentration (Cmax) is determined
Time frame: up to approximately 3 years
Estimation of biodistribution of 203Pb PSV 359 using SPECT/CT scans
Activity in tumor(s) and organs as percentage of injected dose is assessed
Time frame: Up to approximately 3 years
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