Cpd B

Cpd B is a potent small-molecule inhibitor of the serine/threonine kinase PIM2, utilized in preclinical research to investigate the role of PIM2 in hematological malignancies such as multiple myeloma. Unlike PIM2-targeting agents that induce protein degradation (e.g., JP11646 or Cpd A), Cpd B specifically inhibits the catalytic activity of the PIM2 kinase without significantly altering its protein levels. Research presented at ASH 2025 indicates that PIM2 possesses kinase-independent functions critical for maintaining mitochondrial mass and function in myeloma cells. Consequently, while Cpd B effectively inhibits PIM2 enzymatic activity, it does not significantly reduce mitochondrial DNA copy number or disrupt mitochondrial biogenesis in these models, suggesting that the pro-survival effects of PIM2 in multiple myeloma are partially mediated through kinase-independent mechanisms.