Cell Therapeutics, Inc. Acquires New Class of Oral Anti-Angiogenic Drugs.

NEW YORK--(BW HealthWire)--Dec. 15, 1998--

Novel once-a-day therapy targets multiple pathways to

angiogenesis, providing a potential competitive lead

in the field of tumor angiogenesis suppression

Cell Therapeutics Inc.(cti)(Nasdaq:CTIC) in connection with a presentation at the ING Barings Health Care Conference announced today it has licensed the worldwide rights to a novel class of compounds which are inhibitors of tumor angiogenesis.

These synthetic small molecule compounds, termed aryl cyclams, have been shown to inhibit tumor blood vessel formation in a variety of standard preclinical animal models. The compounds are believed to exert their effect by binding extracellular copper and inhibiting a critical enzyme, lysyl oxidase, required for collagen cross-linking to allow new blood vessels to form in the tumor bed. Collagen cross-linking is one of the earliest steps in the formation of new blood vessels providing the framework upon which blood vessel cells grow. "Copper is a critical cofactor in several key steps in the formation of new blood vessels in tumors" noted Dr. Helene Sage, Professor of Biological Structure at the University of Washington, a noted expert on angiogenesis and a member of the team who, with Dr. Judah Folkman, first purified angiostatin. "Copper is essential to the function of several angiogenic growth factors including bFGF, PDGF and VEGF. By chelating copper, you are interfering with several major steps by which tumors stimulate new blood vessel formation. This is an exciting and novel approach to preventing this disease process" Dr. Sage added.

"The binding characteristics and high affinity for copper of one member in this family of compounds, termed SC-7, makes it an ideal lead candidate for this indication" said Dr. Robert Lewis, Chief Scientific Officer at Cell Therapeutics Inc. "In addition to focusing therapy on a single target that is involved in multiple pathways to angiogenesis, SC-7 appears to be orally active and possibly suitable for once a day dosing" he noted.

The majority of anti-angiogenic agents currently under development are biologic proteins or peptides targeting key growth factors involved in tumor blood vessel formation, such as antibodies against receptors for PDGF, bFGF, or VEGF. Other approaches are examining naturally occurring antagonists to blood vessel formation such as angiostatin or endostatin. Unlike synthetic small molecules, these therapies must be given by injection.

"This latest license is consistent with our focus on building a diversified late stage vertically integrated portfolio of products for treating cancer and its complications" said James A. Bianco, MD President and CEO of Cell Therapeutics Inc. "Anti-angiogenic treatments are an important, albeit crowded, therapeutic field. To get in the race we needed a novel approach that could compete not only on the scientific merits of hitting several key pathways through a single target but also on the basis of projected future costs for the product and the potential for patient ease of administration. This is especially true for a therapy that will likely need to be administered for long periods of time" Dr. Bianco noted.

Earlier this year cti announced that it had licensed PG-TXL, a novel water soluble and potentially more effective form of the well known cancer drug Taxol. PG-TXL is expected to enter clinical trials late next year. CT-2584 is currently in efficacy trials targeting patients with hormone refractory prostate cancer with trials in soft tissue sarcoma scheduled to get underway shortly. Lisofylline (LSF) is in several pivotal trials for the prevention of serious side effects associated with induction chemotherapy for acute myelogenous leukemia (AML) and bone marrow transplant (BMT). In addition to its oncology applications, LSF is under investigation in a pivotal trial sponsored by the National Heart, Lung and Blood Institute (NHLBI) as an agent to reduce the incidence of mortality associated with acute lung injury (ALI).

Cell Therapeutics, Inc. focuses on the discovery, development and commercialization of small molecule drugs that selectively regulate the metabolism of oxidized lipids and phospholipids relevant to the treatment of cancer and inflammatory and immune diseases. The company's web site is located at www.cticseattle.com.

This announcement includes forward-looking statements that involve a number of risks and uncertainties, the outcome of which could materially adversely affect actual future results. Specifically, the risks and uncertainties that could affect the development of cti's products under development include risks associated with pre-clinical and clinical developments in the biotechnology industry in general and of cti's products under development in particular (including, without limitation, the potential failure of CT-2584, lisofylline, PG-TXL, SC-7 and related compounds to prove safe and effective for treatment of disease), determinations by regulatory, patent, and administrative governmental authorities, competitive factors, technological developments, costs of developing, producing, and selling cti's products under development, and the risk factors listed or described from time to time in the company's filings with the Securities and Exchange Commission including, without limitation, the company's most recent registrations on Forms 10-K, 8-K, and 10-Q.