Press Release
May 4, 2006

Sonus Pharmaceuticals, Inc. Raises $30.6 Million

BOSTON, May 4, 2006 — Sonus Pharmaceuticals, Inc. announced that it has raised $30.6 million through the sale of approximately 6.1 million shares in a registered direct offering led by Federated Kaufmann Funds. The company said that the financing will enable it to continue clinical trials of its Tocosol Paclitaxel treatment for metastatic breast cancer while simultaneously expanding efforts to develop other products. The lead placement agent in the offering was Needham & Company, LLC and Punk, Ziegel & Company and ThinkEquity Partners LLC acted as co-placement agents in the offering.

Mitchell S. Bloom, partner at Goodwin Procter, and James R. Kasinger and James W. Burns, associates at Goodwin Procter, represented the placement agents in this transaction.