Chimerix Inc. and Omthera Pharmaceuticals Inc. have joined eight other biotechs with initial public offerings (IPO) filed and pending. IPO activity has been light in 2013 thus far, with just two companies pricing their first offerings. Once the ultimate aspirational goal for a start-up, the IPO has become almost an option of last resort in a public market that has run hot and cold on biotech for quite some time.