The Sonic hedgehog (Hh) pathway is known to be important in basal cell carcinoma (BCC), which as an extremely common skin cancer that only rarely invades and metastasizes. An approved drug for patients with advanced BCC, Vismodegib (Erivedge), interferes with the Hedgehog pathway. The Patched (12 membrane-spanning receptor protein) normally disables Smoothened (7 membrane-spanning protein) rendering it functionally inert. This maintains transcription factor Gli in a cleaved state, acting as a transcriptional repressor. When Hedgehog proteins bind to Patched, Smoothened is released and protects Gli from cleavage. Uncleaved Gli travels to the nucleus and is an inducer of transcription, increasing Cyclin D1 and stimulating the cell cycle (proliferation). Vismodegib blocks the actions of Smoothened. It is administered orally in 150 mg capsules.
Eli Lilly has licensed exclusive worldwide rights to Ignyta’s Phase I taladegib oncology development program, in a deal the San Diego biotech said could generate up to $53 million-plus. Taladegib is an oral bioavailable small molecule hedgehog/smoothened antagonist. The compound has achieved clinical proof-of-concept and a recommended Phase II dose based on earlier clinical studies. Continue reading