Viking aims to enter the billion-dollar weight loss drug market.Viking Therapeutics (VKTX -1.12%) has intrigued investors over the past year and a half because it's involved in a potential David and Goliath story. Today, pharma giants Eli Lilly and Novo Nordisk dominate the weight loss drug market, and other big pharmas such as Pfizer are working to get in on this valuable space. Facing these market powerhouses, Viking, a biotech worth about $3 billion, has set its sights on becoming a player of importance. ...