Table 1. Cellular Activities of Imidazopyridazines.

	Cellular Ba/F3 assaysa
compd	TRKA	TRKB	TRKC	WTb
1	0.85	0.27	0.10	7.13
2	0.74	0.20	0.23	>10
3	0.050	0.021	0.006	3.92
4	0.17	0.12	0.075	1.01
5	0.076	0.027	0.040	1.92
6	0.006	0.007	0.003	3.00
7	0.027	0.013	0.004	2.53
8	0.52	0.13	0.020	5.89
9	0.17	0.050	0.011	>10
10	0.075	0.047	0.019	>10
11	0.068	0.029	0.008	>10
12	3.13	1.97	0.98	9.23
13	0.021	0.011	0.003	>10
14	0.003	0.001	0.001	>10
15	0.005	0.004	0.002	>10
16	0.001	0.001	<0.001	4.79
17	0.004	0.004	0.002	5.91

^aProliferation assays with Tel-TRK fusions; IC₅₀, μM.

^bProliferation assay using parental Ba/F3 cells.