In a continuing effort to expand tests...

In a continuing effort to expand tests of its ribavirin drug as a treatment for early-stage AIDS, a subsidiary of Costa Mesa-based ICN Pharmaceuticals Inc. has received approval from the Canadian government for a three-year clinical study of the drug that will involve 730 patients who have contracted the virus but show no other symptoms of the fatal disease. Viratek, the subsidiary, said the study will be conducted in 12 or more centers throughout Canada. In addition, it said it is negotiating with Australian health authorities to conduct a parallel test in that country. Since February, clinical tests of ribavirin on 130 early AIDS patients have been under way in Spain, and a similar but smaller study is being conducted in Britain. Meanwhile, three separate studies of ribavirin are being conducted in the United States under the auspices of the National Institutes of Health. Ribavirin is now marketed in the United States and Canada for the treatment of hospitalized infants and young children with severe respiratory tract virus infection.