AdvertisementDrugmakers are slow to prove medicines that got a fast track to market really workPlay07:35Download AudioJuly 22, 2022Sydney LupkinfacebookEmailKristi Alcayaga's teenage son, Michael, was able to try a cancer drug called clofarabine that got an accelerated approval from the Food and Drug Administration. But the medicine didn't help him. (Jovelle Tamayo for NPR)