Phase 1 Study of RYZ401 Radiopharmaceutical Therapy With Actinium-225 in Neuroendocrine and Other Solid Tumors Expressing Somatostatin Receptors

What this Trial Is About

Researchers are evaluating RYZ401, a new radiopharmaceutical therapy labeled with Actinium-225, for people with neuroendocrine tumors (NETs) and other solid tumors that express somatostatin receptors (SSTRs). This Phase 1 study aims to find the best dose and treatment schedule, assess safety and tolerability, and gather early information on how well RYZ401 works in these cancers. The trial is sponsored by RayzeBio, Inc. The study includes two parts: a dose escalation phase to identify the recommended Phase 2 dose by carefully increasing doses and monitoring side effects during the first 4 weeks of treatment, and a dose expansion phase where more participants receive the selected dose to further evaluate safety and effectiveness over the treatment cycle and six weeks after the last dose. Participants receive RYZ401, administered as a drug labeled with Actinium-225, targeting tumors that show SSTR positivity. Participants will be monitored closely with assessments during treatment and follow-up visits that include safety checks and evaluations of tumor response. The main outcome measured is the incidence of dose-limiting toxicities early in treatment and responses during the dose expansion period. The study starts in December 2025 and continues through April 2033, with no maximum age limit for enrollment.

Study of RYZ401 in Subjects With Solid Tumors Expressing SSTRs.