 I'm Nicole Murray with Your Money Now. The FDA has declined to approve Merck and Japan-based Daiichi Sengyo's lung cancer treatment, which belongs to a lucrative class of cancer therapies that work like guided missiles. The denial does not relate to the treatment's effectiveness, but instead has to do with a third-party manufacturer. The treatment is one of three antibody drug conjugates that were part of Merck's $22 billion joint development deal with Daiichi Sengyo signed last year.