AML Clinical Research Supports Maxamine Mechanism of Action; Results of Treatment in AML Patients Reported.

SAN DIEGO--(BW HealthWire)--Aug. 31, 1999--

Maxim Pharmaceuticals (AMEX:MMP, SSE:MAXM) announced today the first clinical data demonstrating that combination treatment with Maxamine(TM)(histamine) and interleukin-2 (IL-2) increased a key indicator of white blood cell function in patients with acute myelogenous leukemia (AML).

AML is the most common form of acute leukemia in adults.

Specifically, a team of researchers in the Department of Hematology, Karolinska University Hospital, Stockholm, Sweden showed that expression of a molecule (CD3 zeta), found to be suppressed in many AML patients prior to treatment, increased significantly after treatment with Maxamine and IL-2 in more than 80 percent of treatment courses evaluated. The CD3 zeta molecule is believed to be a surrogate indicator of the activity of two classes of key white blood cells, natural killer (NK) and T cells (CD4+ and CD8+), which are further believed to have protective effects against leukemic cells.

In December 1998, Maxim announced that Phase II studies of Maxamine and IL-2 in the treatment of patients with AML suggested a more than doubling of leukemia-free remission times and the prevention of relapse. "This recent data regarding CD3 zeta expression may explain the beneficial results that have been observed in AML patients treated with Maxamine and IL-2 to date," said Mats Brune, M.D., Ph.D., Department of Hematology, Sahlgrenska University Hospital, Gothenburg, Sweden, a co-author on the abstract. "The need for improved treatments for AML is significant as 75-80% of patients who achieve their first remission will relapse, and only about 5% of the relapsed patients survive long-term."

"The objective of Maxamine Therapy is to treat AML patients with the combination of Maxamine and low doses of IL-2 to prevent relapse and prolong leukemia-free survival, while maintaining a good quality of life for the patients during treatment," said Dr. Kurt Gehlsen, Maxim's Chief Technical Officer. Based on the results of the Phase II studies, the Company initiated a 360-patient Phase III trial of Maxamine Therapy in the treatment of AML patients that is currently underway in 12 countries, with clinical sites based in the U.S., Europe, Canada, Australia and Israel.

Additional Information Regarding CD3 Zeta Research

With many forms of cancer, the capacity of the patient's immune system to detect and destroy foreign cells is compromised. The rationale behind the combination therapy with Maxamine and cytokines such as IL-2 or interferon-alpha is to stimulate and protect NK cells and T cells, both of which are white blood cells with protective effects against leukemic cells.

In recent years, much interest in cancer research has been focused on an indicator marker of white blood cells, CD3 zeta. This molecule, which transduces activating signals to NK cells and T cells, is deficient in many cancer patients. The deficiency of CD3 zeta may explain why NK cells and T cells are frequently non-functional and cannot exert their protective effects in cancer patients.

As reported by the research team at the Karolinska Hospital and presented at the European Hematology Meeting, the purpose of the study was to determine the effect of Maxamine and IL-2 on the expression of CD3 zeta in white blood cells of AML patients. The CD3 zeta expression was monitored in a total of thirteen three-week courses of therapy with Maxamine and IL-2. In the study, the CD3 zeta expression in the NK cells and T cells of AML patients was examined before and up to 3 weeks after the beginning of therapy with Maxamine and IL-2.

Two important findings were reported by the research team at the Karolinska Hospital:

-- The CD3 zeta expression on NK cells and T cells was reduced

in a substantial portion of AML patients evaluated prior to

the commencement of Maxamine Therapy. This finding indicates

that the NK cells and T cells were non-functional.

-- In the AML patients with reduced CD3 zeta, the CD3 zeta

expression was rapidly and significantly up-regulated in

greater than 80% of courses of treatment with Maxamine and

IL-2. This up-regulation of CD3 zeta expression was observed

in NK cells as well as in T cells, including CD4 cells

("memory cells") and CD8 cells ("cytotoxic cells").

Company Overview

Maxim Pharmaceuticals is developing advanced drugs, therapies and vaccines for cancer and infectious diseases. The company's lead drug candidate, Maxamine, is currently being tested in three Phase III cancer clinical trials in 14 countries around the world for malignant melanoma and acute myelogenous leukemia. Maxim expects to file its NDA and report results for its U.S. Phase III study of Maxamine in the treatment of malignant melanoma by mid 2000. Phase II trials of Maxamine Therapy are also underway for the treatment of hepatitis C patients and advanced renal cell carcinoma patients. Maxamine is designed to be safely self-administered by patients in their own homes, and more than 750 patients have been treated in our completed and ongoing clinical trials. The Company is also developing MaxDerm(TM), a Maxamine-related drug for the treatment of medical conditions for which topical therapy is appropriate such as oral mucositis, herpes, decubitus ulcers, shingles, burns and related conditions. The company's third platform technology, MaxVax(TM), now in preclinical development, utilizes a needle-free mucosal vaccine carrier/adjuvant system for a broad range of infectious diseases. The company expects to commercialize its technologies through a combination of in-house development and collaborative agreements with pharmaceutical companies.

This news release contains certain forward-looking statements that involve risks and uncertainties. Such forward-looking statements include statements regarding the efficacy and intended utilization of Maxamine and 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 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 under "Risk Factors" and elsewhere in the company's Annual Report on Form 10-K/A for the year ended Sept. 30, 1998 and the company's Registration Statement on Form S-3 File No. 333-84711, as filed with the Securities and Exchange Commission.

Note: Maxamine(TM), Maxamine Therapy(TM), MaxDerm(TM), MaxVax(TM), and the Maxim logo are trademarks of the company.