Valeant Pharmaceuticals Reports VISER2 Results for Viramidine(R); Company Initia

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Valeant Pharmaceuticals Reports VISER2 Results for Viramidine®;

Company Initiates Phase 2b Weight-Based Dose-Ranging Study

This is press release from Valent.

COSTA MESA, Calif.--(BUSINESS WIRE)--Sept. 12, 2006--Valeant

Pharmaceuticals International (NYSE:VRX) today reported summary

results of VISER2, the second of two Phase 3 pivotal trials, for

Viramidine®. The company is developing Viramidine (taribavirin

hydrochloride), a nucleoside (guanosine) analog prodrug of

ribavirin, in oral form, for administration in combination with a

pegylated interferon for the treatment of chronic hepatitis C in

treatment-naive patients. The VISER2 trial included two co-primary

endpoints: one for safety (superiority to ribavirin in the incidence

of anemia) and one for efficacy (non-inferiority to ribavirin in

sustained viral response, SVR).

The VISER2 study did not meet the non-inferiority efficacy endpoint

on an intent-to-treat (ITT) basis, with overall SVR rates of 40

percent versus 55 percent for the Viramidine and ribavirin arms,

respectively. However, consistent with the results seen in VISER1,

SVR rates in VISER2 trended higher among patients receiving

increased exposure on a mg/kg basis in the Viramidine arm without a

substantial increase in the anemia rate.

Consistent with results from the VISER1 trial released earlier in

the year, VISER2 confirmed the safety advantages of Viramidine.

Anemia rates (Hgb less than 10g/dL) during the treatment period were

significantly lower in patients treated with Viramidine than those

treated with ribavirin (6 percent versus 22 percent; p less than

0.001).

As a result of the combined VISER1 and VISER2 data, the company also

announced that it is initiating a Phase 2b program to evaluate the

efficacy of Viramidine at higher doses. The Phase 2b program is a

multi-center, randomized, parallel, open-label study in 240

treatment naive, genotype-one patients and will evaluate Viramidine

at 20 mg/kg, 25 mg/kg, and 30 mg/kg per day in combination with

pegylated interferon alpha-2b. There also will be a control group

comprised of ribavirin and pegylated interferon alpha-2b. Treatment

duration will be 48 weeks with a post-treatment follow-up period of

24 weeks. Based on a 12-week interim analysis of this study, the

company will decide whether to begin a third Phase 3 study at the

appropriate higher dose indicated by the Phase 2b study. The company

will seek to co-develop the product should it decide to pursue

another phase 3 registration trial next year.

C. Tyson, president and chief executive officer, said, " As

expected, VISER2 results were consistent with those seen in VISER1.

Although VISER1 and 2 did not meet non-inferiority efficacy

endpoints, Viramidine demonstrates meaningful clinical efficacy. Our

retrospective analyses of 750 patient plasma samples indicate that

Viramidine could be as effective as ribavirin at higher doses. These

analyses, coupled with feedback from the medical community that

there will continue to be a strong need for ribavirin or ribavirin

analogues in the treatment of hepatitis C, indicate that further

clinical testing is prudent. Our Phase 2b program should provide us

with sufficient information at little relative cost and time to

confirm the dose response, select an appropriate dose, test safety

at higher doses, establish the path for registration of the drug and

make a go/no-go decision. "

The company also announced the issuance of a U.S. patent for

Viramidine for use in the treatment of hepatitis C, which will not

expire until 2020.

The following table summarizes the anemia and SVR rates for both

VISER1 and VISER2:

VISER1 and VISER2: Safety and Efficacy

(Intent-to-Treat Analysis)

* Percent of Patients with Undetectable HCV RNA; NGI SuperQuant

Assay, sensitivity to 39 IU/mL (100 copies/mL)

Additional planned analyses of VISER1 and VISER2 data based on

weight (mg/kg) indicated that SVR was improved with increased mg/kg

concentrations while preserving the safety benefit as summarized

below:

VISER1 and VISER2: Viramidine Exposure Analysis

Percent of Patients with Undetectable HCV RNA

The majority of adverse events other than anemia and

gastrointestinal side effects were similar between treatment groups.

The anemia rate was lower in the Viramidine arm, while the

gastrointestinal rate was lower in the ribavirin arm. The most

common other adverse events associated with combination therapy

included fatigue, headache, insomnia, depression and myalgia.

VISER2 Trial Design

The VISER2 trial (VISER stands for VIramidine's Safety and Efficacy

vs. Ribavirin) evaluated a fixed 600 mg BID dose of Viramidine to a

weight-based 1,000/1,200 mg daily dose of ribavirin, both in

combination with peginterferon alfa 2a. The study, conducted in the

United States, Canada, Europe, Israel, Argentina and Australia,

enrolled 962 treatment-naive subjects with chronic HCV. Treatment

duration was based on genotype, with genotypes 2 and 3 receiving 24

weeks of treatment and genotype non 2, 3 receiving 48 weeks of

treatment, each with a post-treatment follow-up period of 24 weeks.

The study was stratified for genotype, weight and viral load.

Additional information regarding the Phase 3 trial will be furnished

by the company today with the Securities and Exchange Commission on

Form 8-K and is also available on the company's Web site at

www.valeant.com.

Viramidine is an investigational compound that has not been found by

the Food and Drug Administration (FDA) or any other regulatory

agency to be safe or effective in the diagnosis, mitigation,

treatment or cure of any disease or illness. It may not be sold or

promoted in the United States unless and until FDA has approved a

New Drug Application. Similar restrictions apply in other countries.