STX-003

STX-003 is a self-replicating mRNA circuit in lipid nanoparticle (intravenous) from Strand Therapeutics. A systemically delivered self-replicating mRNA encoding IL-12 with microRNA target sites, so that it is expressed in tumour cells and switched off elsewhere. Its furthest stage is phase 1, for non-small cell lung cancer and advanced solid tumours. ClinicalTrials.gov registers it in one study linked below. Phase 1/2 recruiting, started 2026-06-30 (registry), alone and with pembrolizumab. Whether it works in people has not been established unless a trial below reports it.