A Phase 1, Dose-escalation Study of MEDI-551 in Japanese Adult Patients With Relapsed or Refractory Advanced B-cell Malignancies

A MEDI-551 treatment-related AE of any toxicity grade that lead to an inability to receive a full cycle (2 doses) of MEDI-551, or, any Grade 3 or higher toxicity that could not be reasonably ascribed to another cause, such as disease progression or accident.

A dose was considered non-tolerated and dose escalation stopped if ≥2 of up to 6 evaluable patients experienced a DLT at any dose level. MTD is the last dose level before the non-tolerated dose.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Lower limit of quantification for MEDI-551 was 0.1 μg/mL.

Only 1 patient was tested positive for ADA at pre-dose of Cycle 1 Day 1. However, it was considered as false-positive because the titer value was close to the cut point, and this patient was tested negative for ADA at all subsequent cycles post-baseline.

Tumour response is defined as complete remission (CR) or partial remission (PR) (Cheson BD et al 2007).

CR: Nodal Masses: (a) FDG-avid or PET positive prior to therapy; mass of any size permitted if PET negative; (b) Variably FDG-avid or PET negative; regression to normal size on CT; Spleen, Liver: Not palpable, nodules disappeared. Bone Marrow: Infiltrate cleared on repeat biopsy; if indeterminate by morphology, immunohistochemistry should be negative.

PR: Nodal Masses: ≥50% decrease in sum of the product of the diameters (SPD) of up to 6 largest dominant masses; no increase in size of other nodes; (a) FDG-avid or PET positive prior to therapy; ≥1 PET positive at previously involved site; (b) Variably FDG-avid or PET negative; regression on CT. Spleen, Liver: ≥50% decrease in SPD of nodules (for single nodule in greatest transverse diameter); no increase in size of liver or spleen. Bone Marrow: Irrelevant if positive prior to therapy; cell type should be specified.

Tumour response is defined as complete remission (CR) or partial remission (PR) (Cheson BD et al 2007).

CR: Nodal Masses: (a) FDG-avid or PET positive prior to therapy; mass of any size permitted if PET negative; (b) Variably FDG-avid or PET negative; regression to normal size on CT; Spleen, Liver: Not palpable, nodules disappeared. Bone Marrow: Infiltrate cleared on repeat biopsy; if indeterminate by morphology, immunohistochemistry should be negative.

PR: Nodal Masses: ≥50% decrease in sum of the product of the diameters (SPD) of up to 6 largest dominant masses; no increase in size of other nodes; (a) FDG-avid or PET positive prior to therapy; ≥1 PET positive at previously involved site; (b) Variably FDG-avid or PET negative; regression on CT. Spleen, Liver: ≥50% decrease in SPD of nodules (for single nodule in greatest transverse diameter); no increase in size of liver or spleen. Bone Marrow: Irrelevant if positive prior to therapy; cell type should be specified.

Tumour response is defined as complete remission (CR) or partial remission (PR) (Hallek M et al 2008).

CR: all of the following criteria have to be met, and patients have to lack disease-related constitutional symptoms; Lymphadenopathy: None; Hepatomegaly: None; Splenomegaly: None; Blood lymphocytes: <4000/μL; Marrow: Normocellular, <30%lymphocytes, no B-lymphoid nodules, hypocellular marrow defines CR with incomplete marrow recovery; Platelet count: >100000/μL; Hemoglobin: >11.0 g/dL; Neutrophils: >1500/μL PR: at least 2 of the criteria of group A plus 1 of the criteria of group B have to be met.

Group A: Lymphadenopathy: Decrease ≥50%; Hepatomegaly: Decrease ≥50%; Splenomegaly: Decrease ≥50%; Blood lymphocytes: Decrease ≥50% from baseline; Marrow: 50% reduction in marrow infiltrate, or B-lymphoid nodules.

Group B: Platelet count: 100000/μL or increase ≥50% over baseline; Hemoglobin: >11.0 g/dL or increase ≥50% over baseline; Neutrophils: >1500/μL or >50% improvement over baseline.

Tumour response is defined as complete response (CR) or partial response (PR) (Durie M et al 2006).

CR: Negative immunofixation on the serum and urine, and Disappearance of any soft tissue plasmacytomas and 5% or less plasma cells in bone marrow PR: ≥50% reduction of serum M-protein and reduction in 24-h urinary M-protein by ≥90% or to <200mg per 24 h. If the serum and urine M-protein are unmeasurable, a ≥50% decrease in the difference between involved and uninvolved FLC levels is required in place of the M-protein criteria. If serum and urine M-protein are unmeasurable, and serum free light assay is also unmeasurable, ≥50% reduction in plasma cells is required in place of M-protein, provided baseline bone marrow plasma cell percentage was ≥30%. In addition to the above listed criteria, if present at baseline, a ≥50% reduction in the size of soft tissue plasmacytomas is also required.