IKZF3 and neutropenia: Although this combination showed evidence of antitumor activity, it also resulted in rates of grade 3/4 neutropenia comparable to those seen in other treatment arms, despite the introduction of an intermittent dosing schedule and the use of a markedly lower CC‐122 dose in arm B than in arms A and D. This observation may be explained by pharmacodynamic data showing a trend towards enhanced Aiolos degradation with CC‐122 plus CC‐292, indicating possible synergistic effects.