(Reuters) - Regeneron Pharmaceuticals Inc cut the top end of its full-year sales forecast for its blockbuster eye drug and reported a lower-than-expected adjusted quarterly profit, citing higher costs. The company's shares fell 7.6 percent to $365 in premarket trading on Tuesday. Regeneron said it expected full-year 2014 sales of Eylea, its eye injection drug, within a range of $1.7 billion to $1.74 billion. The company, more accustomed to raising its Eylea sales forecasts, cut the range from $1.7 billion to $1.8 billion. Eylea is a treatment for macular degeneration, a leading cause of blindness among the elderly. It is also used to treat macular edema, a build-up of fluid in the back of the eye, and a related condition called diabetic macular edema. Regeneron's net profit fell to $79.7 million, or 70 cents per share, in the third quarter ended Sept. 30 from $141.3 million, or $1.25 per share, a year earlier. Excluding special items, Regeneron earned $2.52 per share, below the average analyst estimate of $2.57 per share, according to Thomson Reuters I/B/E/S. Revenue rose 21.6 percent to $725.8 million and included collaboration payments from French drugmaker Sanofi SA and German partner Bayer AG. U.S. sales of Eylea rose 23 percent to $445 million, but Regeneron's quarterly earnings fell short of analysts' estimates due to significantly higher operating expenses.