Figure 6. RXDX-105 inhibits tumor xenograft growth and inhibits RET phosphorylation and intracellular signaling in orthotopic neuroblastoma tumors.

(A) SK-N-AS and SK-N-SH cells were injected into the left adrenal glands of nude mice as shown. Mice were then randomized and treated once daily orally with vehicle control or RXDX-105. SK-N-AS tumors were harvested at 4 weeks and SK-N-SH tumors at 6 weeks, based on tumor growth rates. (B) Final tumor weight was measured in harvested tumors and weights of tumors from treated mice were compared to weights of tumors from control mice. (C) Images and measurements from harvested tumors are shown, with untreated tumors in the top rows and treated tumors in the bottom rows. (D) Tumor cell lysates were analyzed by Western blot for expression and phosphorylation of RET, MEK and ERK in tumors from treated and control mice.