URMC-099

URMC-099 has moderate terminal elimination half-life (t_1/2=1.92 h, 2.14 h and 2.72 h for C57 BL/6 mice (10 mg/kg, oral dosing), C57 BL/6 mice (2.5 mg/kg, iv), C57 BL/6 mice (10 mg/kg, iv))^[1]. The effect of URMC-099 (URMC099) on tumor formation in vivo is analyzed using a well characterized mouse xenograft model of breast cancer brain metastasis. For these experiments, eGFP8.4 cells are inoculated into the left ventricle of immunodeficient nu/nu mice; animals are then treated with either URMC-099 (10 mg/kg) or vehicle alone, every 12 hours for 20 days. This dose of URMC-099 is chosen because it has been shown to be sufficient to effectively inhibit MLK3 in mice, with good penetration of the blood-brain barrier and potent inhibition of the phosphorylation of Jun N-terminal kinase (JNK) in brain tissue. On day 21 the mice are sacrificed and number of BM is assessed. Fifteen mice are used for each treatment group. BM are detected in 60% of mice, which is consistent with previous studies using this xenograft model by other investigators. URMC-099 treatment significantly (p<0.05, two-tailed t-test) increases the total number of brain metastasis (BM) in mice. For micrometastases, the pattern is similar to that observed for total BM. The number of macrometastases is statistically indistinguishable between mice treated with URMC-099 or vehicle^[2].