Maxim Pharmaceuticals Reports Positive Results of Preclinical Studies in Oral Mucositis.

Business Editors/Health and Medical Writers

SAN DIEGO--(BW HealthWire)--Jan. 11, 2000

Maxim Pharmaceuticals (AMEX:MMP, SSE:MAXM) announced today results of two preclinical studies of the company's topical gel in the treatment of oral mucositis.

Both randomized studies demonstrated significant reductions in the duration and extent of ulcerative lesions when treated with the Maxim topical gel compared to a placebo control. The topical oral mucositis therapy is one of a series of drug candidates under development for the treatment of topical disorders based upon the company's MaxDerm(TM) technology.

The principal investigator in the study was Stephen T. Sonis, D.M.D., D.M.Sc., Department of Oral Medicine and Diagnostic Sciences, Harvard School of Dental Medicine and Brigham and Women's Hospital.

"These preclinical results are encouraging as they further support the potential benefit of using our gel in the treatment of oral mucositis, and are consistent with the results of the pilot human study we previously reported," said Kurt R. Gehlsen, Maxim's vice president, development and chief technical officer. "Oral mucositis is a serious side effect of certain cancer therapies, and these results suggest that administration of our topical gel may help to prevent the development of oral mucositis and reduce healing time once cells have been damaged by chemotherapy or radiation therapy."

Oral Mucositis

Oral mucositis (stomatitis) is a common and debilitating side effect of chemotherapy or head and neck radiation used in the treatment of cancer. There are possibly a million new cases each year in the U.S. and major international markets with no effective treatments yet available.

Mucositis includes the formation of canker sore-like lesions within the mouth that may extend to the tongue and throat and result in mild to severe discomfort and difficulty eating and drinking. The lesions may last 2 to 3 weeks, and in severe cases patients require hospitalization, morphine to alleviate pain, and limitations to their cancer treatment.

Study Design and Results

The company's topical therapy was tested using an accepted hamster cheek pouch model for oral mucositis. A total of 120 animals were studied in two separate experiments and randomized to receive one of four different dosage concentrations of Maxim's topical gel or a placebo control. All animals were irradiated on day zero and were monitored on a daily basis. Endpoints included an assessment of the severity of mucositis and weight gain.

Treatment with the optimal concentration of the Maxim gel resulted in a 43% reduction in mucositis days with scores of 3 or higher (a measurement of the severity of ulcerations) compared to the placebo controls (p=0.001). Animals treated with the optimal Maxim gel formulation also gained weight more rapidly than the placebo gel, a key endpoint due to the discomfort and difficulty eating and drinking mucositis patients often experience.

The company had previously reported the results of a small pilot human study in which nine patients with oral mucositis were randomized and treated with one of two dosage concentrations of the Maxim topical gel or a placebo. The patients treated with the Maxim gel experienced complete healing of lesions in a mean time of three to four days, depending upon the dosage. Patients treated with the placebo experienced no reduction in lesions during the treatment period. Patients treated with the Maxim gel also reported a reduction in the discomfort associated with eating and drinking.

Background

For millions of patients, topical disorders such as herpes labialis, herpes zoster, oral mucositis, canker sores, decubitus ulcers, and others result in prolonged pain, suffering, and slow healing times that can lead to an increased risk of secondary infection. The patient's immune response, localized inflammation and wound-healing status may contribute to the difficulty in treating many of these disorders.

The MaxDerm technology and pipeline of potential products are based on research on the active molecules underlying the Company's lead drug Maxamine(R). The MaxDerm discovery may be able to address the underlying mechanisms that cause many of the above disorders, and may enhance the cellular immune response, reduce inflammation, and enhance the wound healing process. This discovery is novel and differs from the anti-viral, pain relieving and anti-bacterial approaches underlying many existing and proposed treatments.

Small pilot, randomized, blinded, placebo-controlled trials have been conducted in more than 75 patients with oral mucositis, herpes labialis (cold sores), decubitus ulcers, shingles, burns, and conjunctivitis. Patients experienced improved healing times when treated with gels based on the MaxDerm technology compared to a placebo control.

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 3 cancer clinical trials in 12 countries for malignant melanoma and acute myelogenous leukemia. Maxim expects to file its NDA and report results for its U.S. Phase 3 study of Maxamine in the treatment of malignant melanoma in mid 2000.

Phase 2 trials of Maxamine Therapy are also underway for the treatment of hepatitis C and advanced renal cell carcinoma. Maxamine is designed to be safely administered by patients in their own homes, and more than 900 patients have been treated in completed and ongoing clinical trials.

The company is also developing MaxDerm, 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 for the year ended Sept. 30, 1999 and the company's Registration Statement of Form S-3 (File No. 333-91923), as filed with the Securities and Exchange Commission.

Note: Maxamine(R), Maxamine Therapy(TM), MaxDerm(TM), MaxVax(TM), and the Maxim logo are trademarks of the company. Editor's Note: This release is also available on the Internet at http://www.maxim.com.