Table 1.

Binding to HER3-expressing tumor cells of scDb/scFv-Fc and scDb/Fab-Fc variants

	LIM1215 20,000 HER3/cell	MCF-7 18,000 HER3/cell	SKBR-3 14,000 HER3/cell	FaDu 3000 HER3/cell	Jurkat
scDb/scFv-Fc (1-2)+1	31±7	39±5	29±11	41±40	1290±502
scDb/Fab-Fc (1-2)+1	53±13	17±9	12±3	138±121	2269±846
scDb/scFv-Fc (1-1)+2	882±588	390±327	317±257	879±308	688±189
scDb/Fab-Fc (1-1)+2	249±192	711±255	482±371	258±232	8655±6943
scDb/scFv-Fc (2-1)+1	82±46	31±4	33±8	45±37	1516±130
scDb/Fab-Fc (2-1)+1	172±115	137±103	38±8	210±159	1667±223

EC₅₀ (pM), mean±SD, n=3.

scDb, single-chain diabody.