Hana Biosciences Completes Licensing of Three Targeted Cancer Drug Candidates from Inex Pharmaceuticals.

SOUTH SAN FRANCISCO, Calif. -- Hana Biosciences (NASDAQ:HNAB):

--Hana Plans to Initiate Pivotal Trials for Marqibo(R) (vincristine sulfate) Liposomes Injection in Hematological Malignancies in 2006.

--Sphingosome Encapsulated Vinorelbine Targeted to Start Clinical Trials in 2006, and Sphingosome Encapsulated Topotecan in 2007.

--Proprietary Sphingosomal Platform Doubles Hana's Oncology Pipeline to Six Clinical Stage Drugs.

Hana Biosciences (NASDAQ:HNAB), a biopharmaceutical company focused on advancing cancer care, completed its previously announced licensing transaction with Inex Pharmaceuticals Corporation (TSX:IEX). Under the terms of the transaction, Hana paid INEX a total of $11.5 million, consisting of cash and shares of Hana common stock. In addition, Hana will pay INEX up to $30.5 million in shares of Hana common stock, contingent upon achievement of specific clinical and regulatory milestones, as well as royalties on net sales. Canaccord Adams acted as the exclusive financial advisor to Hana in the transaction.

This licensing transaction doubled Hana's pipeline to six clinical-stage oncology compounds. The newly-licensed drug candidates are:

--Marqibo(R) (vincristine sulfate) Liposomes Injection, a sphingosome encapsulated vinorelbine, which has shown promising results in patients with non-Hodgkin's lymphoma (NHL) and acute lymphocytic leukemia (ALL) in completed and ongoing studies. After a Special Protocol Assessment (SPA) is completed with the FDA, Hana expects to commence pivotal trials in Marqibo(R) in 2006.

--Sphingosome encapsulated vinorelbine, for which a US Investigational New Drug (IND) application and Canadian Clinical Trials Application (CTA) have been accepted, is planned to enter clinical trials in 2006.

--Sphingosome encapsulated topotecan, based on a unique formulation which has shown significantly enhanced activity in pre-clinical models, is planned to enter clinical trials in 2007.

The intellectual property covering the three product candidates is protected worldwide until 2020 by issued and pending patents.

"This transaction enhances Hana's portfolio of novel anticancer compounds, underscoring our patient-focused commitment to developing and commercializing innovative oncology therapies. We look forward to working with the FDA to obtain an SPA to initiate pivotal trials for Marqibo(R) in 2006. Meanwhile, our current clinical programs continue on schedule," said Mark Ahn, PhD, Hana's President and CEO.

Timothy M. Ruane, President and CEO of INEX, stated: "The team at Hana has a strong track record in oncology drug development, and we believe our targeted chemotherapy products are a perfect fit in their pipeline. We will support their efforts as they move Marqibo(R) towards commercialization and continue the development of sphingosomal vinorelbine and sphingosomal topotecan."

"Vincristine is a cornerstone of combination chemotherapy in lymphoproliferative diseases. We believe that by raising the dose of this drug we can improve its clinical activity. The increased dose and promising activity of sphingosomal vincristine in patients with NHL and ALL support moving this drug into registrational trials", said Dr. Hagop Kantarjian, MD, Professor and Chairman of the Leukemia Department at the M.D. Anderson Cancer Center.

About Sphingosomal Targeted Drug Delivery 

Sphingosomal encapsulation is a new generation liposomal drug delivery platform, which is designed to significantly increase tumor targeting and duration of exposure for cell cycle-specific anticancer agents. Sphingosomal drug delivery consists of encapsulating an already approved cancer agent in a lipid envelope. The encapsulated agent is carried through the bloodstream and delivered to disease sites where it is released to carry out its therapeutic action. When used in unencapsulated form, chemotherapeutic drugs diffuse indiscriminately throughout the body, diluting drug effectiveness and causing toxic side effects in the patient's healthy tissues. The proprietary sphingosomal formulation technology permits the loading of a high concentration of therapeutic agent inside the lipid envelope, promotes accumulation of the drug in tumors and prolongs the release of the drug at disease sites. As a result, compared to unencapsulated drugs, agents encapsulated in sphingosomes have been shown in preclinical models to deliver more of the therapeutic agent to a targeted disease site over a longer period of time, thus potentially increasing the efficacy of the drug without increasing the toxicity in healthy, non-targeted tissues. The possible advantages of sphingosomal drug delivery include:

--Longer circulation time in plasma delivers more of the therapeutic agent to targeted tumor sites over a longer period of time. To stabilize the lipid bilayer walls and retain active drug within the aqueous interior, this new generation liposomal technology uses sphingomyelin, a safe, biologically inert macromolecule whose amide backbone is resistant to hydrolysis. The increased rigidity of the liposomal walls prolongs the circulating life of liposomes and significantly extends the duration of drug release.

--Sphingosomal drugs like Marqibo(R) readily extravasate through the pores of leaky tumor vessels created during angiogenesis and readily accumulate within the tumor. In normal tissues, a continuous endothelial lining constrains liposomes within capillaries, preventing accumulation of the drug in the interstitial space. In contrast, the immature neovasculature within tumors is created during angiogenesis and has numerous imperfections, pores and discontinuities up to 800 nm in size. With an average diameter of approximately 100 nm, sphingosomes readily extravasate through these pores and accumulate within the tumor. Once lodged within the interstitial space, these resilient sphingosomes slowly release the encapsulated drug. Slow release of the drug from extravasated sphingosomes increases drug levels within the tumor, extends drug exposure through multiple cell cycles, and significantly enhances tumor cell killing. Vincristine kills tumor cells as they pass through a sensitive phase of cell division, but fewer than 5% of a patient's tumor cells are in this sensitive phase at any point in time. We believe that the duration of drug exposure is therefore critical to increased clinical activity.

--Increased drug concentration at the tumor site is associated with increased clinical activity. The link between drug exposure and anti-tumor efficacy is especially pronounced for cell cycle-specific agents such as vincristine, vinorelbine and topotecan, which kill tumor cells by interfering with mitosis at a precise step during the cancer cell cycle. Thus, this proprietary sphingosomal drug delivery platform encapsulates approved anticancer agents within the aqueous interior of small liposomes to potentially enhance the therapeutic index of these existing anticancer treatments.

About Vincristine, Vinorelbine, and Topotecan

Sphingosomal products, such as Marqibo(R) (vincristine sulfate) Liposomes Injection, are loaded with active, cell cycle-specific anticancer agents that may benefit from increased targeting and long duration of drug exposure at the tumor site. Vincristine, vinorelbine and topotecan are approved cancer therapies which have been selected for sphingosomal formulation specifically for their ability to benefit from this novel encapsulation:

--Vincristine (Oncovin(R); Eli Lilly & Company), a microtubule inhibitor, is approved for ALL and is widely used as a single agent and in combination regimens for treatment for hematologic malignancies such as lymphomas and leukemias.

--Vinorelbine (Navelbine(R); GlaxoSmithKline), a microtubule inhibitor, is approved for use as a single agent or in combination with cisplatin for the first-line treatment of unresectable, advanced non-small cell lung cancer.

--Topotecan (Hycamtin(R); GlaxoSmithKline), a topoisomerase I inhibitor, is approved for use in relapsed small-cell lung cancer and in relapsed ovarian cancer.

About Non-Hodgkin's Lymphoma (NHL) and Acute Lymphocytic Leukemia (ALL)

NHL is a heterogeneous disease which results in approximately 50,000 new cases and almost 25,000 deaths annually in the United States. NHL usually originates in lymphoid tissues and can spread to other organs. The prognosis depends on the histologic type, stage, and treatment. The NHLs can be divided into 2 prognostic groups: indolent lymphomas and aggressive lymphomas. Indolent NHL types have a relatively good prognosis, with median survival as long as 10 years, but they usually are not curable in advanced clinical stages. The aggressive type of NHL has a shorter natural history, but a significant number of these patients can be cured with intensive combination chemotherapy regimens which include agents such as vincristine. With modern treatment, overall five-year survival of NHL patients is approximately 50% to 60%. Of patients with aggressive NHL, 30% to 60% can achieve durable remission. The vast majority of relapses occur in the first two years after therapy and new therapeutic options are needed.

ALL is a type of blood and bone marrow cancer -- the spongy tissue inside bones where blood cells are made. Acute leukemias progress rapidly and affect immature blood cells, rather than mature ones. Acute lymphocytic leukemia affects a group of white blood cells called lymphocytes, which fight infection. Normally, bone marrow produces immature cells (stem cells) in a controlled way, and they mature and specialize into the various types of blood cells, as needed. In people with ALL, this production process goes awry. Large numbers of immature, abnormal lymphocytes called lymphoblasts are produced and released into the bloodstream. These abnormal cells are not able to mature and perform their usual functions. Furthermore, they multiply rapidly and can crowd out healthy blood cells, leaving an adult or child with ALL vulnerable to infection or easy bleeding. Leukemic cells can also collect in certain areas of the body, including the central nervous system and spinal cord, which can cause serious problems. Almost 4,000 Americans are diagnosed with ALL each year. This form of cancer worsens quickly if not treated, but it usually responds well to initial treatment. Adults have a 20% to 40% cure rate, underscoring the need for new therapeutic options.

About Hana Biosciences, Inc.

Hana Biosciences, Inc. (NASDAQ:HNAB) is a South San Francisco, CA-based biopharmaceutical company that acquires, develops, and commercializes innovative products to advance cancer care. The company is committed to creating value by building a world-class team, accelerating the development of lead product candidates, expanding its pipeline by being the alliance partner of choice, and nurturing a unique company culture. Additional information on Hana Biosciences can be found at www.hanabiosciences.com.

About Inex Pharmaceuticals Corporation

Inex Pharmaceuticals Corporation is a Canadian biopharmaceutical company developing and commercializing proprietary drugs and drug delivery systems to improve the treatment of cancer. Since 1996, INEX common shares have been trading on the Toronto Stock Exchange under the symbol "IEX". Additional information on Inex Pharmaceuticals can be found at www.inexpharm.com.

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements involve risks and uncertainties that could cause Hana's actual results to differ materially from the anticipated results and expectations expressed in these forward-looking statements. These statements are often, but not always, made through the use of words or phrases such as "anticipates," "expects," "plans," "believes," "intends," and similar words or phrases. These statements are based on current expectations, forecasts and assumptions that are subject to risks and uncertainties, which could cause actual outcomes and results to differ materially from these statements. Among other things, there can be no assurances that any of Hana's development efforts relating to its product candidates, including those licensed from INEX, will be successful. Other risks that may affect forward-looking information contained in this press release include the possibility of being unable to obtain regulatory approval of Hana's product candidates, the risk that the results of clinical trials may not support Hana's claims, Hana's reliance on third-party researchers to develop its product candidates, and its lack of experience in developing and commercializing pharmaceutical products. Additional risks are described in the company's Annual Report on Form 10-K for the year ended December 31, 2005 filed with the Securities and Exchange Commission. Hana assumes no obligation to update these statements, except as required by law.