Dr Fisher said the lack of progress in skin cancer - the most common type of cancer - was a "very significant frustration".
He added: "Our real goal is a novel strategy for protecting skin from UV radiation and cancer.
Eventually the scientists want to combine their drug with sun-cream to give maximum protection from solar radiation.
Dr Fisher said everyone should "absolutely" use sun-cream but its weakness was it "keeps you pale".
The way the drug works could also allow a ginger tan, as the genetic mutation that causes red hair and fair skin disrupts the normal process where UV light leads to dark melanin.
The researchers want to do more safety testing, although so far there has been "no hint of problems".