 According to the indictment of American Cyanamid, Bristol Myers, Pfizer, and Cyanamid knew that tetracycline represented a threat to the continuation of their dominant positions and unreasonably high profits.To keep that threat in check, the indictment alleges, Cyanamid bought out Heyden's rights to the development and agreed to help Pfizer get the tetracycline patent.In return, charges the Justice Department, Pfizer licensed Cyanamid to produce the drug.