a. Presence of at least one clinically measurable lesion: i. nodal lesion that measures ≥ 1.5 cm in longest dimension (LD) and ≥ 1.0 cm in longest perpendicular dimension (LPD), or ii. spleen that measures ≥ 14 cm in longest vertical dimension (LVD) with a minimum of 2 cm enlargement, or iii. liver that measures ≥ 20 cm in LVD with a minimum of 2 cm enlargement, or iv. peripheral blood B lymphocyte count > 5000/uL.