How are you dosing IVIG following BCMA CAR-T or bispecific antibodies in multiple myeloma?

At our institution, primary prophylaxis is the rule because we forget.

All patients on a bispecific get IVIG 0.4 g/kg (ideal body weight) starting day 1 of the second month and this continues while they remain on the BsAb. Each physician/APC team can stop the IVIG if the IgG > 500 and is self-sustaining. All patients receive varicella and pneumocystis prophylaxis while on BsAb.

This cuts down on acinetobacter meningitis and other such terrifying 'opportunistic' infections that we saw during th...