---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-389785"
form_type: "8-K"
ticker: "CATX"
cik: "0000728387"
company_name: "Perspective Therapeutics, Inc."
filed_at: "2026-09-14T10:20:15+00:00"
generated_at: "2026-09-14T10:25:28.725510+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Perspective Therapeutics and Merck collaborate on PSV359 + Keytruda for FAP-α solid tumors

## Summary
- Clinical collaboration with Merck (NYSE: MRK) to evaluate [212Pb]PSV359 plus Keytruda in FAP-α positive solid tumors.
- Amendment to ongoing Phase 1/2a study (NCT06710756) in NSCLC and colorectal cancer; first three monotherapy dose cohorts completed enrollment.
- Merck supplies pembrolizumab at no cost; Perspective sponsors the study.
- FAP-α expressed in majority of solid tumors; combination aims to reshape tumor microenvironment and improve outcomes.

## SEC filing metadata
- accession: 0001193125-26-389785
- form_type: 8-K
- ticker: CATX
- cik: 0000728387
- company_name: Perspective Therapeutics, Inc.
- filed_at: 2026-09-14T10:20:15+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/728387/000119312526389785/0001193125-26-389785-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/728387/000119312526389785/catx-20260914.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-389785
- JSON: https://secwatch.observer/filing/0001193125-26-389785.json
- Plain text: https://secwatch.observer/filing/0001193125-26-389785.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.