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

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

Mitoxantrone Injection, USP in combination with corticosteroids isindicated as initial chemotherapy for the treatment of patients withpain 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 toseventeen and brings the total number of FDA approvals received by APPthis year to eight. APP markets and manufactures one of the broadestportfolios of oncology products and, combined with the 23 ANDA'scurrently under review by the FDA, is positioned to be one of thelargest manufacturers of injectable pharmaceutical products for thecritically ill patient.

About American Pharmaceutical Partners, Inc.

American Pharmaceutical Partners, Inc. is a specialty drug companythat develops, manufactures and markets injectable pharmaceuticalproducts, focusing on the oncology, anti-infective and critical caremarkets. Abraxis(TM) Oncology, the proprietary division of APP, isdevoted entirely to developing and promoting innovative,next-generation cancer therapies such as ABRAXANE(R) for InjectableSuspension (paclitaxel protein-bound particles for injectablesuspension) (albumin-bound). At the close of the merger betweenAmerican Pharmaceutical Partners (APP) and American BioScience (ABI)in the second quarter of this year, APP will become a division ofAbraxis BioScience, a fully integrated global biopharmaceuticalcompany. For more information, visit APP's website at www.appdrugs.comand www.abraxisoncology.com.

FORWARD-LOOKING STATEMENT

The statements contained in this press release that are not purelyhistorical are forward-looking statements within the meaning ofSection 21E of the Securities Exchange Act of 1934, as amended.Forward-looking statements, whether expressed or implied, involverisks and uncertainties, There are important factors that could causeactual results to differ materially from those in the forward-lookingstatements. These factors include, without limitation, successfullycommercializing mitoxantrone, the difficulty in predicting the timingor outcome of other product research and development efforts,potential product characteristics and indications, marketing approvalsand launches of other products, the impact of pharmaceutical industryregulation, the impact of competitive products and pricing, theavailability and pricing of ingredients used in the manufacture ofpharmaceutical products, the ability to successfully manufactureproducts in a time-sensitive and cost effective manner, the acceptanceand demand of new pharmaceutical products, the impact of patents andother proprietary rights held by competitors and other third parties.Additional relevant information concerning risks can be found in APP'sForm 10-K for the year ended December 31, 2005, APP's informationstatement filed on March 13, 2006 and other documents it has filedwith the Securities and Exchange Commission.

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