At least 19 companies are slated to report earnings this week. Four big biotechs - Alexion Pharmaceuticals Inc. (NASDAQ:ALXN), Amgen Inc. (NASDAQ:AMGN), Biogen Idec Inc. (NASDAQ:BIIB) and Celgene Corp. (NASDAQ:CELG) - are all expected to report earnings growth of more than 15% on strong top-line numbers. Alexion markets Soliris eculizumab for rare blood disorders and is anticipated to post a 34% increase in 4Q13 revenues to $430 million. Biogen Idec, which launched multiple sclerosis drug Tecfidera dimethyl fumarate in the U.S