Moderna Inc. dropped its long-anticipated S-1 filing, allowing industry watchers to exhale. The Cambridge, Mass.-based company is seeking to raise $500 million, including overallotments – the same amount the company raised privately in February – in what many observers were calling biopharma's biggest IPO. Except that it's not, unless some qualifiers are used and provided that Moderna doesn't decide to upsize as the book-building begins.