Shares of GlaxoSmithKline are falling on Wednesday after the drugmaker cut its full-year earnings outlook. In a statement, Glaxo said full-year sales are unlikely to increase, while earnings per share will be similar to last year. Glaxo reported second-quarter revenue that fell 16% to $9.5 billion. Sales of its best-selling asthma drug Advair fell 19% during the quarter on strong competition. Chief Executive Officer Sir Andrew Witty said the company expects that competition to continue, and GlaxoSmithKline will therefore be investing in six new medicines the company has launched within the last twelve months. TheStreet's Brittany Umar has details.