INEX and Enzon Announce Marqibo to be Reviewed by FDA's Oncologic Drugs Advisory Committee.

VANCOUVER, British Columbia & BRIDGEWATER, N.J. -- Inex Pharmaceuticals Corporation ("INEX"; TSX: IEX) and Enzon Pharmaceuticals, Inc. ("Enzon"; NASDAQ: ENZN) announced today the United States Food and Drug Administration (FDA) will review Marqibo(R), (formerly referred to as Onco TCS), at its upcoming Oncologic Drugs Advisory Committee (ODAC) session scheduled for December 1, 2004. Marqibo(R) is being developed as a single-agent treatment for patients with relapsed aggressive non-Hodgkin's lymphoma (NHL) previously treated with at least two combination chemotherapy regimens.

The New Drug Application (NDA) for Marqibo(R) was submitted to the FDA on March 12, 2004 and accepted on May 21, 2004. The FDA has established a target date of January 15, 2005 for completion of its review of the NDA.

About Marqibo(R) (vincristine sulfate liposomes injection)

Marqibo(R) is a proprietary drug comprised of the widely used off-patent anticancer drug vincristine encapsulated in INEX's sphingosomal drug delivery technology. INEX's technology is designed to provide prolonged blood circulation, tumor accumulation and extended drug release at the cancer site. These characteristics are intended to increase the effectiveness and reduce the side effects of the encapsulated drug.

In the completed multi-center pivotal Phase 2/3 clinical trial, 119 patients with aggressive NHL who had not responded to their previous therapy or had responded and subsequently relapsed were treated with Marqibo(R). Prior to enrolment in this study, patients had received on average four other therapies. After treatment with Marqibo(R) as a single-agent, an overall response rate of 25% was attained. Currently, there is no standard treatment for patients with aggressive NHL who have not responded to or have relapsed following at least two prior treatment regimens.

The results of this pivotal trial were released in June 2003 and presented in December 2003 at the American Society of Hematology annual conference along with interim results from two ongoing Phase 2 trials in relapsed Hodgkin's disease and relapsed B-cell lymphoma.

In addition to the lead indication, relapsed aggressive NHL, Enzon and INEX intend to develop Marqibo(R) for use as a single-agent therapy or in combination therapy for several cancers in which vincristine is now used.

About ODAC

The Oncologic Drugs Advisory Committee (ODAC) is a committee formed by the FDA of external experts to advise the FDA in the evaluation of marketed and investigational drugs for use in the treatment of cancer. The Committee is comprised of a core of thirteen voting members from the fields of general oncology, pediatric oncology, hematologic oncology, immunologic oncology, biostatistics and other related professions.

About INEX

INEX is a Canadian biopharmaceutical company developing and commercializing proprietary drugs and drug delivery systems to improve the treatment of cancer.

About Enzon

Enzon Pharmaceuticals is a biopharmaceutical company dedicated to the discovery, development and commercialization of therapeutics to treat life-threatening diseases.

There are forward-looking statements contained herein that are not based on historical fact, including without limitation statements containing the words "believes," "may," "plans," "will," "estimate," "continue," "anticipates," "intends," "expects," and similar expressions. Such forward looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results, events or developments to be materially different from future results, events or developments described in the forward looking statements. Such factors include the risk that Marqibo(R) may not receive regulatory approval from the FDA under Subpart H of the Food and Drug Act for the lead indication and the fact that any such approval, if granted, will include post approval commitments, the risk that Inex and Enzon may not be successful in developing Marqibo(R) for other indications, as well as those risks described in Enzon's Form 10-K and Forms 10-Q on file with the SEC and INEX's publicly filed periodic reports. These factors should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. All information in this press release is as of September 27, 2004, and Enzon and INEX undertake no duty to update this information.

INEX's common shares are traded on the Toronto Stock Exchange under the trading symbol "IEX".

Enzon's common shares are traded on NASDAQ under the trading symbol "ENZN".