CCR4 and CD25 are highly expressed on the surface of cutaneous T-cell lymphoma (CTCL). The two receptors can be used for targeted therapy of CTCL. We have developed a truncated diphtheria toxin-based recombinant human CCR4-IL2 bispecific immunotoxin (CCR4-IL2-IT) for targeted therapy of CTCL (Wang et al., 2020). CCR4-IL2-IT demonstrated superior efficacy to prolong the survival of the tumor-bearing mice in an immunodeficient mouse CTCL model (Wang et al., 2020). Recently, we have compared the in vivo efficacy of CCR4-IL2-IT versus Brentuximab (an antibody–drug conjugate targeting CD30+ cancers, FDA approved leading drug in CTCL market) in the same immunodeficient mouse CTCL model. The comparison demonstrated that CCR4-IL2-IT was significantly more effective than Brentuximab and the combination treatment of CCR4-IL2-IT and Brentuximab was more effective than either CCR4-IL2-IT or Brentuximab alone (Wang et al., 2023). Since CCR4 and CD25 are also highly expressed on the cell surface of tumor-infiltrating effector Tregs, CCR4-IL2-IT also has potential to deplete tumor-infiltrating effector Tregs for broad-spectrum cancer immunotherapy. Our current goal is to prepare an investigational new drug data package including good manufacturing practice production and good laboratory practice (GLP) toxicology studies. However, outsourced GLP-toxicology studies in contract research organization facilities could be quite costly. To de-risk the GLP-toxicology studies, we first performed the non-GLP toxicology studies including maximal tolerant dose, pharmacokinetics, and immunogenicity in both rats (as rodent model) and minipigs (as non-rodent model) at University of Colorado Anschutz Medical Campus Animal Facility.