workers are staging a walkout against president macron's plans to overhaul france's retirement system. protests are mostly peaceful, but police fired tear gas at small groups of rioters. there is new debate tonight over a drug that aims to be the first medication to slow mental decline from alzheimer's disease. well, today, the drug maker, biogen, said its alzheimer's drug deserves serious consideration from the f.d.a. biogen recently stopped testing the drug after determining that it wasn't effective, but in a reversal, the company says new evidence presented today shows the drug can possibly slow alzheimer's by removing harmful plaque from the brain. up next, what you didn't know about civil rights icon rosa parks. l rights icon rosa parks.