Phase II Study of Salvage Radiation Treatment After B-cell Maturation Antigen Chimeric Antigen Receptor T-cell Therapy for Relapsed Refractory Multiple Myeloma

Objectives

Primary Objective:

• The primary objective of the study is to evaluate the preliminary efficacy of salvage radiation therapy after BCMA CAR-T cell therapy in subjects with RRMM.

Secondary Objectives:

• Evaluate the safety of and other efficacy parameters of radiation treatment after BCMA CAR-T cell therapy in subjects with RRMM

Exploratory Objectives:

• Evaluate the immunophenotype and/or expression profile, and perform functional bulk and single cell analysis of CAR T cells, endogenous T cells as well as other immune cells in the blood, bone marrow and/or tumor tissue with BCMA CAR-T therapy and RT
• Evaluate changes in the levels of cytokines, chemokines, and soluble factors in the blood with BCMA CAR-T therapy and RT
• Evaluate changes in T cell receptor repertoire with BCMA CAR-T therapy and RT
• Evaluate gut microbiome of patients treated with BCMA CAR-T therapy and RT

Inclusion criteria

Subjects must satisfy the following criteria to be enrolled in the study:

• Subject is ≥ 18 years of age at the time of signing the informed consent form (ICF)
• Subject is diagnosed with multiple myeloma
• Subject previously received treatment with standard of care BCMA CAR-T cell therapy
• Day 30 or later PET scan or other imaging scan after CAR-T infusion shows active disease
• Subject has at least one myeloma lesion (plasmacytoma either in bone or soft tissue) that can be treated with radiation
• Able to provide informed consent

Exclusion criteria

The presence of any of the following will exclude a subject from enrollment:

• Subjects in whom salvage chemotherapy is planned less than 14 days after the completion of radiation treatment
• Subject is undergoing active treatment for another malignancy other than multiple myeloma
• Pregnant women will be excluded from this study.