Testing the Combination of Anti-cancer Drugs Actimab-A and Cemiplimab (REGN2810) to Improve Outcomes for Patients With Recurrent Glioblastoma

This phase I trial studies the side effects and best dose of Actimab-A when given together with cemiplimab (REGN2810) in treating patients with glioblastomas that have come back after a period of improvement (recurrent). Actimab-A consists of the monoclonal antibody lintuzumab combined with the radioactive drug actinium Ac 225. Lintuzumab specifically binds to the cell surface antigen CD33 which is found on the glioblastoma cells and delivers the actinium Ac 225. This may allow the glioblastoma to be found and treated by Actimab-A. Immunotherapy with monoclonal antibodies, such as cemiplimab (REGN2810), may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving Actimab-A with cemiplimab (REGN2810) may be safe, tolerable and/or effective in treating recurrent glioblastoma.

NCT Number	NCT07422363
Lead Sponsor	National Cancer Institute (NCI)
Conditions	Recurrent Glioblastoma, IDH-Wildtype, Recurrent Gliosarcoma, Recurrent WHO Grade 4 Glioma
Enrollment	30 participants
Start Date	2026-12-04
Primary Completion	2027-02-28 (estimated)
Study Completion	2027-02-28 (estimated)
Updated on ClinicalTrials.gov	2026-06-12