TAK-441 is a potent inhibitor of the hedgehog pathway (IC 4.4 nM) developed for the treatment of basal cell carcinoma that is active against the vismodegib-resistant Smoothened receptor D473H mutant...The cutaneous biodistribution profile demonstrated that TAK-441 was predominantly delivered to the viable epidermis and upper dermis. Delivery from the HPMC hydrogel formulation resulted in TAK-441 epidermal concentrations that were several thousand-fold higher than the IC, with almost negligible transdermal permeation, thereby decreasing the risk of systemic side effects in vivo.