Maxim Pharmaceuticals Presents New Preclinical Results Showing Prevention of Liver Injury by Histamine.

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SAN DIEGO--(BUSINESS WIRE)--May 18, 2004

Data Presented as a Poster-of-Distinction at Digestive Disease

Week in New Orleans

Maxim Pharmaceuticals (Nasdaq: MAXM) (SSE: MAXM) today announced preclinical results demonstrating the ability of histamine to prevent lipopolysaccharide (LPS)-induced liver injury in a rodent model. In this model, presented as a liver disease poster-of-distinction at the annual Digestive Disease Week (DDW) meeting in New Orleans, the addition of histamine reduced pro-inflammatory cytokines and substantially increased survival in LPS induced liver injury after partial liver resection (hepatectomy).

Maxim scientists recently presented data at the 54th American Association for the Study of Liver Diseases (AASLD) last October showing the ability of histamine to accelerate liver regeneration after partial hepatectomy. This regenerative process was achieved by regulating cytokines despite the presence of LPS, which is inhibitory to regeneration at high doses. The current model is an extension of this work where a much higher dose of LPS was given two days after partial hepatectomy. This dose was lethal in LPS treated animals (0 % survival), but adding histamine proved highly protective showing 92 % survival. Histamine reduced serum transaminase (ALT, AST) levels four-fold and the pro-inflammatory cytokines, TNF-(alpha) and IL-6 levels five and eight-fold, respectively.

It has been previously reported that histamine inhibits the formation of reactive oxygen species and LPS-induced pro-inflammatory cytokines like TNF-(alpha) in circulating inflammatory cell types in blood. Similar cells in the liver called Kupffer cells, also mediate inflammation by releasing pro-inflammatory cytokines when stimulated by LPS. It is also been shown that this oxidative stress and inflammation are significant problems leading to disease progression in the livers of patients with chronic hepatitis C, alcoholic liver disease (ALD) and nonalcoholic steatohepatitis (NASH). "These are important data as we progress our oral form of this drug for possible use as a mono therapy in chronic liver disease applications such as ALD and NASH. Such protection is indicative of the important effect histamine has on reducing oxidative stress and inflammation in these lethal rodent models", says Dr. Kurt R. Gehlsen, Senior Vice President and Chief Scientific Officer.

Chronic liver diseases, including hepatitis, ALD and NASH, affect an estimated 25 million people in the U.S., approximately one in every ten. Hepatitis C is the leading blood-borne infection in the United States. The U.S. Center for Disease Control and Prevention estimates that over 4.5 million Americans are infected with the hepatitis C virus. The World Health Organization and other sources estimate that at least 200 million people are infected worldwide. Some experts estimate that without substantial improvements in treatment, deaths from hepatitis C will surpass those from HIV. Hepatitis C is the leading cause of liver cancer and the primary reason for liver transplantation in many countries. Even with recent advances, approximately half of patients still do not attain a sustained response with current therapies. NASH, non-alcoholic steatohepatitis, also called 'fatty liver,' is an inflammation of the liver associated with an increase of fat deposits in liver cells that may lead to severe liver damage and cirrhosis. NASH may occur in middle-aged, overweight, and often in diabetic patients who do not drink alcohol. ALD, caused by alcohol abuse, is one of the ten leading causes of death in the United States.

Overview of Histamine Therapy

Research has shown that oxygen free radicals released by certain immune cells can suppress the immune system and damage normal tissue, a process commonly referred to as oxidative stress. Oxidative stress, implicated in numerous diseases, is most pronounced in the liver and can damage or destroy liver tissue in patients with hepatitis and other chronic liver diseases. Histamine has been shown in preclinical testing to prevent the production and release of oxygen free radicals, thereby reducing oxidative stress. Accordingly, treatment with histamine has the potential to prevent or reverse damage induced by oxidative stress, thereby protecting critical cells and tissues, including the liver. Preclinical research, including results presented in 2003 at annual meeting of the American Association for the Study of Liver Diseases (AASLD) and published in the Inflammation (vol. 27 (5), p317-327), suggest that histamine can protect and promote the healing of the liver in models of ALD, NASH and partial surgical resection.

Research regarding histamine dihydrochloride has been the subject of more than 80 presentations at major scientific and clinical meetings, and has been published in more than 300 scientific and clinical articles. Ceplene(TM), Maxim's injectible form of histamine, has been tested in more than 2,000 patients in 17 trials, including hepatitis C patients. Maxim anticipates that any additional clinical testing of histamine for the treatment of chronic liver diseases will be with an oral formulation that has been recently tested in a phase 1A trial. A three-minute animation of the histamine mechanism of action in its injectible formulation as Ceplene(TM) can be viewed on the Company's website at www.maxim.com.

Maxim Overview

Maxim Pharmaceuticals is a global biopharmaceutical company with a diverse pipeline of therapeutic candidates for life-threatening cancers and liver diseases. Maxim's research and development programs are designed to offer hope to patients by developing safe and effective therapeutic candidates that have the potential to extend survival while maintaining quality of life.

Maxim's lead drug candidate Ceplene (subcutaneously delivered histamine dihydrochloride) is designed to prevent or inhibit oxidative stress, thereby reversing immune suppression and protecting critical immune cells. In November 2003, Maxim filed an application for market authorization in Europe for approval to market Ceplene for the treatment of advanced malignant melanoma. Ceplene is currently being tested in a Phase 3 cancer clinical trial for advanced malignant melanoma with liver metastasis. Phase 2 trials of Ceplene are also underway for the treatment of hepatitis C and advanced renal cell carcinoma.

In addition to Ceplene and oral-formulation histamine, Maxim is developing small-molecule inhibitors and activators of programmed cell death, also known as apoptosis, which may serve as drug candidates for cancer, cardiovascular disease and other degenerative diseases. Ceplene, the oral histamine formulation and the apoptosis inducers are investigational drugs and have not been approved by the U.S. Food and Drug Administration (FDA) or any international regulatory agency.

This news release contains certain forward-looking statements that involve risks and uncertainties. Such forward-looking statements include statements regarding the efficacy, safety and intended utilization of Ceplene, the oral histamine formulation and the apoptosis inducers, and the conduct, results and timelines associated with the Company's clinical trials. Such statements are only predictions and the Company's actual results may differ materially from those anticipated in these forward-looking statements. Factors that may cause such differences include the risk that products that appeared promising in early research and clinical trials do not demonstrate safety or efficacy in larger-scale clinical trials and the risk that the Company will not obtain approval to market its products. These factors and others are more fully discussed in the Company's periodic reports and other filings with the Securities and Exchange Commission.

Note: The Maxim logo is a trademark of the Company.

Editor's Note: This release is also available on the Internet at http://www.maxim.com.