For making a public offering biotech companies in most cases use good trial results to push the price higher. Once they get approval (SOMX, VNDA) they try to sell the drug to another big pharma and receive royalties. This way they get money without dilluite more.
From VNDA pr wuth deal with Novartis (http://www.reuters.com/finance/stocks/keyDevelopments?rpc=66&symbol=VNDA.O×tamp=20091012220000): "Under the agreement, Vanda will receive an upfront payment of $200 million and will be eligible for additional payments totaling up to $265 million upon the achievement of certain development and commercial milestones for Fanapt in the U.S. and Canada. Vanda will also receive royalties on the U.S. and Canadian net sales of Fanapt. The consummation of the transaction is expected by the end of 2009"