Updated project metadata. Lenalidomide achieves its therapeutic efficacy by recruiting and removing proteins of therapeutic interest through the E3 ligase substrate adapter cereblon. Here, we report the rational design and characterization of 81 cereblon ligands for their ability to degrade the transcription factor Helios (IKZF2) and casein kinase 1 alpha (CK1α) in acute myeloid leukemia MOLM-13 cells. Using a structure-based approach, we identified a key naphthamide scaffold that depleted both intended targets. Structure-activity relationship studies for degradation of the desired targets over other targets (IKZF1, GSPT1) afforded an initial lead compound, termed DEG-35. A subsequent scaffold replacement campaign informed by degradation profiles against a panel of substrates identified DEG-77, which selectively degrades IKZF2 and CK1α, and possesses suitable pharmacokinetic properties, solubility, and selectivity for in vivo studies. Finally, we show that DEG-77 has antiproliferative activity in diffuse large B cell lymphoma (DLBCL) cell line OCI-LY3 and ovarian cancer cell line A2780, indicating that these dual degraders and their targets may have efficacy against additional cancer types.