Appian Corp. /zigman2/quotes/203658597/composite APPN -2.24% shares dropped more than 11% in after-hours trading Thursday after the software company reduced its annual forecast. Appian reported first quarter losses of $17.5 million, or 27 cents a share, on sales of $59.6 million, up from $51.7 million a year ago. After adjusting for stock-based compensation, the company claimed losses of 16 cents a share, worse than a loss of 12 cents a share a year ago. Analysts on average expected a loss of 16 cents a share on sales of $59.7 million, according to FactSet. While the first quarter met expectations, the forecast was an issue. Appian projected larger second-quarter losses than analysts expected, and reduced its full-year forecast for earnings and revenue. Appian now expects total sales of $255 million to $258 million, after previously stating $258.5 million to $262.5 million, and adjusted losses of 50 cents to 55 cents a share, after previously projecting losses of 42 cents to 46 cents. The company, which went public two years ago at $12 a share, closed Thursday at $36.12, but dove to about $32 in the extended session.