American Pharmaceutical Partners Adds to Its Broad Oncology Portfolio with the Approval of Mitoxantrone Injection, USP.

SCHAUMBURG, Ill. -- American Pharmaceutical Partners, Inc. (NASDAQ:APPX) (APP), a leading specialty injectable pharmaceutical company, today announced that it has received approval from the U.S. Food and Drug Administration (FDA) for its Abbreviated New Drug Application (ANDA) for Mitoxantrone Injection, USP (Concentrate), the generic equivalent of Serono Labs' Novantrone(R). According to IMS, sales in 2005 of mitoxantrone in the United States exceeded $76 million. APP expects to commence marketing mitoxantrone immediately. APP will sell mitoxantrone in AP-rated bar coded, latex-free vials with TALL man lettering.

Mitoxantrone Injection, USP in combination with corticosteroids is indicated as initial chemotherapy for the treatment of patients with pain related to advanced hormone-refractory prostate cancer. Mitoxantrone Injection, USP in combination with other approved drug(s) is indicated in the initial therapy of acute nonlymphocytic leukemia (ANLL) in adults. This category includes myelogenous, promyelocytic, monocytic, and erythroid acute leukemias.

This approval increases APP's oncology product offerings to seventeen and brings the total number of FDA approvals received by APP this year to eight. APP markets and manufactures one of the broadest portfolios of oncology products and, combined with the 23 ANDA's currently under review by the FDA, is positioned to be one of the largest manufacturers of injectable pharmaceutical products for the critically ill patient.

About American Pharmaceutical Partners, Inc.

American Pharmaceutical Partners, Inc. is a specialty drug company that develops, manufactures and markets injectable pharmaceutical products, focusing on the oncology, anti-infective and critical care markets. Abraxis(TM) Oncology, the proprietary division of APP, is devoted entirely to developing and promoting innovative, next-generation cancer therapies such as ABRAXANE(R) for Injectable Suspension (paclitaxel protein-bound particles for injectable suspension) (albumin-bound). At the close of the merger between American Pharmaceutical Partners (APP) and American BioScience (ABI) in the second quarter of this year, APP will become a division of Abraxis BioScience, a fully integrated global biopharmaceutical company. For more information, visit APP's website at www.appdrugs.com and www.abraxisoncology.com.

FORWARD-LOOKING STATEMENT

The statements contained in this press release that are not purely historical are forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements, whether expressed or implied, involve risks and uncertainties, There are important factors that could cause actual results to differ materially from those in the forward-looking statements. These factors include, without limitation, successfully commercializing mitoxantrone, the difficulty in predicting the timing or outcome of other product research and development efforts, potential product characteristics and indications, marketing approvals and launches of other products, the impact of pharmaceutical industry regulation, the impact of competitive products and pricing, the availability and pricing of ingredients used in the manufacture of pharmaceutical products, the ability to successfully manufacture products in a time-sensitive and cost effective manner, the acceptance and demand of new pharmaceutical products, the impact of patents and other proprietary rights held by competitors and other third parties. Additional relevant information concerning risks can be found in APP's Form 10-K for the year ended December 31, 2005, APP's information statement filed on March 13, 2006 and other documents it has filed with the Securities and Exchange Commission.

NOVANTRONE(R) is a registered trademark of Immunex Corporation. This product is now marketed by Serono, Inc.