Table 1.

Plasma and Brain Tumor Concentrations after Administration of Irinotecan or NKTR-102

Treatment	NKTR-102				Conventional Irinotecan
Time (hr)	6	24	72	168	2	6	12	24
	Irinotecan Equivalent Concentration ± SEM (ng/mL or ng/g)				Irinotecan Concentration ± SEM (ng/mL or ng/g)
Plasma	72450 ± 48790	210 ± 126	14 ± 7.5	5.0 ± 0.09	1100 ± 306	2.9 ± 1.4	0.7 ± 0.3	2.3 ± 1.8
Tumor	3200 ± 3700	2572 ± 1323	1207 ± 904	833 ± 240	554 ± 667	7.7 ± 5.8	2.8 ± 1.2	7.4 ± 5.2
Tumor/Plasma	0.4	12	80	170	0.5	2.7	3	4
SN38 Concentration ± SEM (ng/mL or ng/g)
Plasma	63 ± 50	34 ± 13	2.2 ± 1.4	0.65 ± 0.08	36 ± 12	2.4 ± 1.3	0.7 ± 0.1	0.4 ± 0.4
Tumor	13 ± 16	208 ± 126	60 ± 78	23 ± 28	29 ± 46	0.8 ± 0.4	0.6 ± 0.4	1.1 ± 1.1
Tumor/Plasma	0.2	6	27	31	0.8	0.3	0.9	2.8

Plasma and brain tumor concentrations for parent drug and active metabolite SN38 after a 50 mg/kg IV bolus injection of either NKTR-102 or irinotecan to NU/NU mice with established, orthotopic MDA-MB-231Br brain tumors. Results are expressed as mean ± SEM (N = 5 per time point)