In vivo activity of SGN-CD19B. Xenograft models for B-NHL were established by subcutaneous injection of WSU-DLCL2 (A), Ramos (B), and DoHH2 (C) cell lines, which are derived from DLBCL, follicular lymphoma, and Burkitt lymphoma, respectively. SGN-CD19B or control ADC was administered at a single dose as indicated by the arrowhead when tumor volume reached 100 mm3. Tumor delays occurred at 100 μg/kg dose, and complete durable regressions were achieved at the higher dose of 300 μg/kg. (D) DoHH2 (follicular lymphoma) xenografts were treated with 100 μg/kg of SGN-CD19B (single dose) in the presence or absence of 10 mg/kg of rituximab (every fourth day for 4 injections). Durable cures were attained in 100% of mice treated with SGN-CD19B plus rituximab. (E) A disseminated disease model for ALL was established by injecting 5 × 106 NALM-6 cells per mouse IV into female SCID mice (10 mice per group). Treatment of NALM-6 tumor-bearing mice was started 7 days post tumor implant only once at the doses indicated. Mice treated with ≥10 μg/kg of SGN-CD19B showed significantly improved survival out to >115 days, whereas mice in the untreated or control groups survived <40 days.
