Phase 3 Pivotal Trial Of TOCOSOL(R) Paclitaxel Does Not Meet Primary Endpoint

Sonus
Pharmaceuticals, Inc. (NASDAQ:SNUS) announced that its Phase 3
pivotal trial of TOCOSOL(R) Paclitaxel in women with metastatic breast
cancer did not meet its primary endpoint of non-inferiority on
objective response rate (ORR) when compared to the Taxol(R) control
arm. Trial results showed the ORR for TOCOSOL Paclitaxel was 37%
versus 45% for Taxol (p value = 0.085). The outcome of this trial does
not support the submission of a New Drug Application.



With regard to the safety profile, the rates of neutropenia and
febrile neutropenia in the TOCOSOL Paclitaxel arm were significantly
higher than the Taxol arm, which may be related to the higher dose of
TOCOSOL Paclitaxel used in the Phase 3 trial compared to Taxol.
Additionally, the study results did not demonstrate the expected
benefit in peripheral neuropathy, which was not statistically
different between the two arms.



Based on a risk/benefit analysis of these results, Sonus and Bayer
Schering Pharma AG, Germany are closing all clinical trials of TOCOSOL
Paclitaxel, including the Phase 3 study.



"We are profoundly surprised and disappointed that TOCOSOL
Paclitaxel did not achieve the primary endpoint of this pivotal trial,
particularly given the efficacy and safety results from previous
clinical studies of our drug," said Michael A. Martino, President and
Chief Executive Officer of Sonus. "Given these results, we expect
Bayer Schering will exercise its right to terminate our agreement. In
the coming weeks, Sonus will further evaluate the data and make
decisions about the future of TOCOSOL Paclitaxel and other programs.
Our primary goal remains to maximize shareholder value, and we are
actively evaluating all alternative ways to achieve that goal."



"We would like to take this opportunity to thank the patients and
investigators who have participated in the clinical development
program for TOCOSOL Paclitaxel," added Mr. Martino.



Conference Call Information



Sonus will sponsor a conference call at 5:00 A.M. PT/8:00 A.M. ET
today to discuss the Phase 3 results. The call will be web cast live
and archived at sonuspharma/events.html. A telephone replay
will be available on September 24 at 7:00 A.M. PT/10:00 A.M. ET for
one week at 800-405-2236 or 303-590-3000 for international calls; Pass
code: 11098211.



About Sonus Pharmaceuticals



Headquartered near Seattle, Washington, Sonus Pharmaceuticals,
Inc. is focused on the development of cancer drugs that are designed
to provide better efficacy, safety and tolerability, and are more
convenient to use. Sonus moved its second oncology product candidate,
TOCOSOL Camptothecin, into a Phase 1 clinical trial in September 2006.
For additional information on Sonus, including past news releases,
please visit sonuspharma.



Sonus Pharmaceuticals Safe Harbor



Certain statements made in this press release are forward-looking
such as those, among others, relating to the Company's further
evaluation of programs related to its therapeutic drugs and potential
applications for these products. As discussed in Sonus
Pharmaceuticals' filings with the Securities and Exchange Commission,
including its Annual Report on Form 10-K for 2006 and subsequent
Quarterly Reports on Form 10-Q, actual results could differ materially
from those projected in the forward-looking statements as a result of
the following factors, among others: the Company's products will
require continued pre-clinical evaluation and clinical testing and
approval by regulatory authorities; such activities are lengthy and
expensive and may never be successful; risks that the Phase 1 clinical
trial for TOCOSOL Camptothecin will not be successful; and risks that
the Company may not be successful in obtaining funding from third
parties or completing a financing necessary to support the costs and
expenses of other clinical studies as well as research and development
activities. The Company undertakes no obligation to update the
forward-looking statements contained herein or to reflect events or
circumstances occurring after the date hereof.

sonuspharma


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