The deal was underwritten so no doubt that it went through. Only question is if the over allotment was exercised. Based on the trading, my guess is that it was not exercised. Just taking some time for the shares to find strong hands.
"Onyx Pharmaceuticals, Inc. ( NASDAQ : ONXX ) today announced the pricing of an underwritten public offering of 4,400,000 shares of its common stock. The gross proceeds to Onyx from this offering are expected to be approximately $358,600,000, before underwriting discounts and commissions and other estimated offering expenses payable by Onyx. Onyx has also granted the underwriters a 30-day option to purchase up to an additional 660,000 shares of common stock offered in the public offering to cover overallotments, if any."