In the phase 1 dose-climbing and expansion study following a bispecific CAR-T-cell therapy targeting BCMA and CD38 (BM38) in 23 patients with R/R MM (26), HT was the most common adverse event; severe neutropenia occurred in 83% of the patients, severe anemia occurred in 13% and severe thrombocytopenia occurred in 48%, with 40% of the patients with severe neutropenia and 55% with severe thrombocytopenia not having recovered within 1 month. Here, CD38 is linked to neutropenia.