French pharmaceutical giant Sanofi slashed the price of a key anti-tuberculosis drug on Thursday, boosting the battle against the world’s deadliest disease alongside the US launch of tests for a new treatment. The initiatives came as the United Nations seeks to galvanize the campaign against TB, which killed 1.5 million people last year and saw 10 million more infected. Scientists, who hailed Sanofi’s decision to cut the price of its rifapentine drug by two thirds, said the medical shield offered by such treatments would be crucial to the UN aim of eradicating the disease by 2030.