Phase III Results of INTRON A(R) and REBETOL(TM) Combination Therapy in Treatment-Naive Hepatitis C Patients Announced

Monday May 18, 8:52 am Eastern Time

Company Press Release

SOURCE: ICN Pharmaceuticals

NEW YORK, May 18 /PRNewswire/ — ICN Pharmaceuticals, Inc. (NYSE: ICN -news) today announced that it is encouraged with the results reported by its licensee Schering-Plough Corporation (NYSE: SGP – news), whose data, derived from two pivotal Phase III clinical studies, shows that INTRON(R) A (interferon alfa-2b, recombinant) injection and REBETOL(TM) (ribavirin, USP) capsules when used in combination therapy were significantly more active than INTRON A monotherapy in achieving sustained eradication of detectable {HCV-RNA (qPCR)- negative}* Hepatitis C virus in patients who had not received previous antiviral therapy (treatment-naive patients). Detailed data from these Phase III studies are being prepared for publication.

“We are pleased by the findings of our licensee Schering-Plough Corporation, and support the prompt submission of these data to regulatory authorities,” said Devron R. Averett, Ph.D., Senior Vice President of Research and Development at ICN Pharmaceuticals.

The Phase III studies evaluated the activity and tolerance of INTRON A and REBETOL combination therapy versus INTRON A alone in treatment-naive Hepatitis C patients. In two independent double-blind trials, a total of 1,744 patients were treated with subcutaneous injections of INTRON A 3 MIU three times a week and either oral REBETOL 1,000-1,200 mg daily or a matched placebo for either 24 or 48 weeks of treatment.

Patients were assessed for presence of Hepatitis C virus at the end of treatment and at six months following cessation of treatment. INTRON A and REBETOL therapy was significantly more active than INTRON A monotherapy in achieving loss of HCV-RNA at the end of treatment. Eradication of detectable Hepatitis C virus* six months post-treatment was achieved in 41 percent of patients treated with 48 weeks of therapy and in 33 percent of patients treated with 24 weeks of therapy in the INTRON A and REBETOL group versus 16 percent and 6 percent, respectively, in the INTRON A and placebo group. The increase in activity achieved when INTRON A and REBETOL combination therapy was extended from 24 weeks to 48 weeks was significant.

Patient tolerance of INTRON A and REBETOL therapy was good, with 9.5 percent of patients discontinuing therapy during the initial 24 weeks of treatment due to adverse events versus 6.8 percent of patients treated with INTRON A and placebo. A similar pattern (8.1 percent versus 7.4 percent, respectively) was seen in the second 24 weeks of treatment for patients treated for 48 weeks.

The types and frequency of adverse events reported with INTRON A and REBETOL combination therapy in clinical studies reflect the known safety profile of INTRON A monotherapy in conjunction with the known side effect profile of ribavirin. The most frequently reported adverse events were flu-like symptoms (headache, fatigue and myalgia), while the most frequent severe adverse events were fatigue and headache. A side effect associated with the addition of ribavirin to INTRON A monotherapy is a manageable and reversible hemolysis.

On May 4, the Antiviral Drug Advisory Committee to the U.S. Food and Drug Administration (FDA) unanimously concluded that INTRON A and REBETOL combination therapy is safe and effective for the treatment of chronic Hepatitis C in patients 18 years of age or older with compensated liver disease who have relapsed following alpha interferon therapy. The committee’s decision, although not binding, will be considered by FDA in its review of the New Drug Application (NDA) for the combination therapy submitted by Schering- Plough on Dec. 3, 1997. The NDA has been granted priority review status by FDA.

INTRON A is a recombinant version of naturally occurring alpha interferon, which has been shown to exert both antiviral and immunomodulatory effects. REBETOL is an oral formulation of ribavirin, a synthetic nucleoside analog with broad-spectrum antiviral activity. Schering-Plough has exclusive rights to market oral ribavirin for Hepatitis C in all major world markets through a licensing agreement with ICN, except in the European Union (EU), where both companies have the right to market oral ribavirin for Hepatitis C. ICN, which discovered ribavirin, currently markets the drug for aerosol use in the U.S. as VIRAZOLE(R) for treatment of hospitalized infants and young children with severe lower respiratory tract infection due to respiratory syncytial virus (RSV).

ICN manufactures and markets a broad range of prescription and non-prescription pharmaceuticals and biotechnology research products in over 90 countries. The Company employs over 15,700 people worldwide. ICN has operations in Eastern and Central Europe, North and Latin America, Western Europe, and the Pacific Rim. Additional information is available on the corporate website at  http://www.icnpharm.com.

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ACT OF 1995. This press release contains forward-looking statements that involve risks and uncertainties, including but not limited to, projections of future sales, operating income, returns on invested assets, regulatory approval processes, and other risks detailed from time to time in the Company’s Securities and Exchange Commission filings.

*[HCV-RNA (qPCR)-negative] is defined as less than 100 copies/ml of Hepatitis C viral RNA as measured by the National Genetics Institute assay.

SOURCE: ICN Pharmaceuticals