U.S. health officials on Thursday approved the first injectable form of the leading medication to treat patients recovering from addiction to heroin, prescription painkillers and other opioids. The Food and Drug Administration approved once-a-month Sublocade for adults with opioid use disorder who are already stabilized on addiction medication. The monthly injection has the potential to reduce dangerous relapses that occur when patients stop taking the currently available daily medication. But that benefit has not yet been shown in studies and the new drug comes with a hefty price: $1,580 per monthly dose. The older version of the drug, Suboxone, costs...