The risk and severity of CRS are higher in myeloma patients who have a greater disease burden during the initial doses of bispecific antibody therapy. In other words, the higher the number of myeloma cells before the bispecific antibody is administered, the greater the risk of serious CRS response.

This is why, often, when your myeloma counts are high at the time you qualify for bispecific antibody therapy, some kind of chemotherapy will be given before the bispecific antibody is administered to lower the number of myeloma cells in your bone marrow. Talk to your doctor if you think this applies to you to see what your options are.

The risk of high-grade CRS within those who receive bispecific antibody therapy continues to be proven lower than that of patients receiving CAR T-cell therapy.

What percentage of patients experience CRS when taking bispecific antibody therapy?

In the clinical trials that led to the FDA approval for each of the currently marketed bispecific antibody therapies (as of July 2024), the percentage of patients in whom CRS occurred are as follows:

Teclistamab: 72.1% of the patients overall experienced any grade CRS; 50% grade 1, 21% grade 2, 0.6% grade 3, none grade 4
Elranatamab: 58% experienced grades 1-2, grade 3 0.5%, no grade 4 reported
Talquetamab: 76% of patients experienced any grade CRS, 74% grades 1-2, 1.5% grade 3, none grade 4