A combination of an anti-CD19 maytansinoid immunoconjugate and rituximab is used for treating CD19+ CD20+ B-cell malignancies symptom, in particular Non-Hodgkin’s lymphoma.本發明係關於一種抗-CD19類美登素(maytansinoid)免疫結合物及利妥昔單抗(rituximab)之組合,其係用於治療CD19+ CD20+ B-細胞惡性症狀,特別是非霍奇金淋巴瘤(Non-Hodgkins lymphoma)。