PK profiles for CLL-1/CD3 TDBs in target-deficient and target-expressing mice. Animals were administered a single IV dose of 0.5 mg/kg of either nontargeting (NT) TDBs or CLL-1–specific TDBs over a period of 14 to 21 days. (A) Target-deficient SCID.Beige mice PK values, (B) target-expressing 2xBACT-Tg (human CLL-1 and human CD3ε) PK values.