Mean polyclonal IgG adjusted cells during treatment. IgG was assessed monthly. The majority of samples collected were based on central laboratory testing. Polyclonal IgG was estimated for patients with IgG MM by subtracting M-spike protein values from total IgG values. These calculated values, along with measured IgG levels for patients with non-IgG MM, were assessed to derive mean IgG levels during treatment. Patients who received IV immunoglobulin before receiving talquetamab were included.