This company's promising cancer drug could challenge Merck's 25billioncrownjewel.Thepharmaceuticalindustryisoftenabouthittinghomeruns.Bigpharmaceuticalcompaniesstartsmall,andthenablockbusterproductcatapultsthemintothespotlight.SummitTherapeutics(SMMT2.5825 billion in sales last year. Those who got in early have gotten r ...