On January 5, Zafgen, a start-up pharmaceutical company based in Cambridge, Massachusetts, announced positive results of its first human testing of a drug designed to fight fat.

The drug, named ZGN-433, was tested on 24 obese women, and caused them to lose, on average, a kilogram a week for a month, with no harmful side effects. Detailed results will be reported next week at a conference on obesity in Keystone, Colorado.