Safety and Preliminary Efficacy of SA53-OS in Patients With Locally Advanced or Metastatic Solid Tumors

Dose escalation phase in which participants receive SA53-OS on 3 consecutive days every 3 weeks for a maximum of 2 years. Single participant cohorts will be enrolled until a Grade 2 or greater toxicity is observed and then 3+3 multi-participant cohorts will be enrolled until the MTD is identified.

Dose expansion phase in which participants receive SA53-OS on 3 consecutive days every 3 weeks for a maximum of 2 years at the MTD identified in phase 1.