Supplementary Materials and Methods; Supplementary Figure S1. Binding kinetics of hedgehog antibodies to human and mouse hedgehog proteins using surface plasmon resonance. Supplementary Figure S2. Hedgehog ligands stimulate mGLI1 reporter activity and osteoblast differentiation in a dose-dependent manner. Supplementary Figure S3. Selective inhibition of mGLI1 or mPTC1 induction in C3H10T1/2 cells by hedgehog antibodies. Supplementary Figure S4. MEDI-5304 inhibits GLI1 expression in Colo205 xenograft stromal cells but not tumor cells. Supplementary Figure S5. Hedgehog pathway component RNA expression in primary pancreatic tumor explant model P479 and effects of MEDI-5304 on tumorspheres derived from pancreatic explant model 947. Supplementary Figure S6. Pharmacokinetics of MEDI-5304 in rats. Supplementary Figure S7. Exploratory toxicology of MEDI-5304 in rats. Supplementary Figure S8. Pharmacokinetics of MEDI-5304 from preliminary toxicology study in cynomolgus monkeys. Supplementary Figure S9. Pharmacodynamics of MEDI-5304 in cynomolgus monkeys.
ARTICLE ABSTRACT
The hedgehog pathway has been implicated in the tumorigenesis, tumor progression, and metastasis of numerous human cancers. We generated the first fully human hedgehog antibody MEDI-5304 and characterized its antitumor activity and preclinical toxicology. MEDI-5304 bound sonic hedgehog (SHH) and Indian hedgehog (IHH) with low picomolar affinity and neutralized SHH and IHH activity in cellular mGLI1 reporter assays. The antibody inhibited transcription of hedgehog target genes and osteoblast differentiation of C3H10T1/2 cells. We evaluated the activity of MEDI-5304 in vivo in model systems that allowed us to evaluate two primary hypotheses of hedgehog function in human cancer, paracrine signaling between tumor and stromal cells and cancer stem cell (CSC) self-renewal. MEDI-5304 displayed robust pharmacodynamic effects in stromal cells that translated to antitumor efficacy as a single agent in an HT-29/MEF coimplantation model of paracrine hedgehog signaling. MEDI-5304 also improved responses to carboplatin in the HT-29/MEF model. The antibody, however, had no effect as a single agent or in combination with gemcitabine on the CSC frequency or growth of several primary pancreatic cancer explant models. These findings support the conclusion that hedgehog contributes to tumor biology via paracrine tumor-stromal signaling but not via CSC maintenance or propagation. Finally, the only safety study finding associated with MEDI-5304 was ondontodysplasia in rats. Thus, MEDI-5304 represents a potent dual hedgehog inhibitor suitable for continued development to evaluate efficacy and safety in human patients with tumors harboring elevated levels of SHH or IHH. Mol Cancer Ther; 13(2); 386–98. ©2013 AACR.
