Comparison of isatuximab and daratumumab sensitivity ex vivo in patients who were Dara refractory. (A) Waterfall plot showing the isatuximab (Isa) and daratumumab (Dara) sensitivity measured in BM samples from patients who were Dara refractory, with significantly different results between the 2 agents indicated. (B) Dara and isatuximab ex vivo sensitivity was correlated, with Pearson r and its associated P value shown. (C) Waterfall plot showing My-DST of PB samples with similar results for Dara and isatuximab. (D) PB samples sensitivity to anti-D38 antibodies compared with each other, again showing correlation between results for the 2 agents. Comparisons between the mean Dara and isatuximab sensitivities in panels A and C were performed using t tests.