PF-04449913 is a potent and selective inhibitor of the Hh signaling pathway through binding to the target, smoothened. PF-04449913 inhibits Hh signaling in vitro and has demonstrated significant antitumor activity in vivo. In the clinic, PF-04449913 is being evaluated both in hematological and solid malignancies, with a phase II trial currently underway in both fit and unfit patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS). Treatment-related adverse-events were nausea, dizziness, somnolence, QT prolongation and pruritus. Based on pre-clinical assessments, CYP3A4 is believed to be primarily involved in the metabolism of PF-04449913 that is why PF-04449913 plasma exposures and peak concentrations were increased following concurrent administration of ketoconazole (CYP3A4 inhibitor).

Vismodegib (trade name Erivedge) is a drug for the treatment of basal-cell carcinoma (BCC). It was approved by FDA on January 30, 2012 and by the European Commission on 12 July 2013, for the treatment of adult patients with symptomatic metastatic BCC, or locally advanced BCC inappropriate for surgery or radiotherapy. The drug is also undergoing clinical trials for metastatic colorectal cancer, small-cell lung cancer, advanced stomach cancer, pancreatic cancer, medulloblastoma and chondrosarcoma as of June 2011. The substance acts as a cyclopamine-competitive antagonist of the smoothened receptor (SMO) which is part of the hedgehog signaling pathway. The Hedgehog signaling pathway plays an important role in tissue growth and repair; aberrant constitutive activation of Hedgehog pathway signaling and uncontrolled cellular proliferation may be associated with mutations in the Hedgehog-ligand cell surface receptors PTCH and SMO. SMO inhibition causes the transcription factors GLI1 and GLI2 to remain inactive, which prevents the expression of tumor mediating genes within the hedgehog pathway. This pathway is pathogenetically relevant in more than 90% of basal-cell carcinomas.

Sonidegib, also known as LDE225 and marketed as Odomzo, is a Hedgehog signaling pathway inhibitor (via smoothened antagonism) developed as an anticancer agent by Novartis. It was approved by the FDA for treating basal cell carcinoma in July 2015 and is awaiting approval in the EU. The hedgehog pathway is involved in many human cancers. Sonidegib effectively inhibits the regulator called smoothened (Smo), preventing the hedgehog pathway from functioning. As a result, tumours that depend on the hedgehog pathway are unable to grow. Sonidegib is approved for use in the US and EU for treatment of adults with locally advanced basal cell carcinoma (BCC) that has recurred post surgery or radiation therapy. It is also approved for adult patients with BCC who are not eligible for surgery or radiation therapy.