AKT-1465

A 54-year-old alcoholic man presents with a 5-month history of a painless non-healing ulcer on the underside of his penis. On examination, there is a 1 cm × 1 cm deep, ulcerated lesion of the ventral aspect of the glans penis on retraction of the foreskin. There is no associated discharge or lymphadenopathy.
What is the most likely diagnosis?