The Southwest Oncology Group will conduct a Phase III clinicalstudy of Ribi ImmunoChem Research Inc.'s Melacine to treatpatients with melanoma, the company said Tuesday.

The trial will test the ability of the melanoma theracine toprevent recurrence of disease in Stage II patients followingsurgical removal of primary melanoma tumors. Stage IIpatients have local lesions of a specified size.

About 30 percent of such patients have a recurrence of diseasewithin five years of the surgery, according to the Hamilton,Mont., company (NASDAQ:RIBI). Melacine incorporates Ribi'sDetox adjuvant with antigen derived from human melanomatumor cell lysates. The drug is designed to induce the body torecognize tumors systemically.

Ribi is conducting a Phase III trial of Melacine in late-stagemelanoma patients. In a Phase II trial, the median survival ofterminally ill Stage IV patients was 23 months, compared with12 months for patients receiving chemotherapy.

Melacine has orphan drug designation as a therapy for StageIII/IV melanoma.

Ribi shares were off 13 cents to $6.50.

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