Key TakeawaysNovo Nordisk's U.S.-listed shares lost ground Friday after a Phase 2a trial of the pharmaceutical firm’s latest obesity treatment showed less effectiveness in higher doses.Based on the results, Novo Nordisk said it would be initiating a larger Phase 2b study next year.Novo Nordisk shares were down over 5% in intraday trading Friday, though even with Friday's losses, they've gained more than 22% since the start of the year. Novo Nordisk's (NVO) U.S.-listed shares lost ground Friday after a study ...