Clinical Trial Promising Direct Antiviral Regimen in HCV Patients

INFORM-1 Clinical Trial Amended to Further Explore Promising Direct Antiviral Regimen in HCV Patients

- Non-responder and Null Responder HCV patients -

- Twice-Daily Dosing and Higher Doses of ITMN-191 (R7227) -

BRISBANE, Calif., April 21 /PRNewswire-FirstCall/ -- InterMune, Inc. (Nasdaq: ITMN) today announced that the innovative clinical study of protease inhibitor ITMN-191 (R7227) in combination with nucleoside polymerase inhibitor R7128 (Roche/Pharmasset), referred to as the INFORM-1 study, has been successfully amended to include additional cohorts to explore the combination in treatment-experienced and null responder HCV patients. In addition, the amended protocol now includes the administration of twice-daily and higher-dose regimens of ITMN-191 in combination with R7128 in treatment-naive patients. A description of the expanded study design can be viewed at . Dan Welch, Chairman, Chief Executive Officer and President of InterMune, said, "The first four cohorts of the INFORM-1 study successfully demonstrated that the novel combination of relatively low doses of two direct antiviral agents can be administered safely and, in the absence of interferon, result in robust antiviral activity in treatment-naive HCV patients. INFORM-1 has now been expanded to explore this novel regimen in treatment-experienced patients; both non-responder patients and so-called null responders, which together represent an important unmet medical need as their treatment options are currently very poor. The inclusion of twice-daily dosing of ITMN-191 at doses of up to 900mg, doses that were safely and effectively explored when combined with the current standard of care, is another important expansion of INFORM-1. We look forward to the results of these important new cohorts."

INFORM-1 Expanded Study Design

The expanded INFORM-1 design now includes three additional dosage cohorts, Cohorts E, F and G, as follows:

Cohort E evaluates the combination of twice-daily doses of ITMN-191 (600mg) and twice-daily R7128 (1000mg), or placebo, for 14 days in treatment-experienced patients with genotype 1 HCV infection who have been previously treated with pegylated interferon plus ribavirin, but did not achieve a sustained virologic response (SVR). Cohort F consists of null responder HCV patients with genotype 1 infection who have been treated with pegylated interferon plus ribavirin, but experienced a null response. Null response is defined as experiencing <2.0 log10 decline in HCV RNA at week 12, and/or <1.0 log10 decline at week 4. Patients will be administered twice-daily doses of ITMN-191 (900mg) and twice-daily R7128 (1000mg), or placebo, for a period of 14 days. Cohort G enrolls treatment-naive patients who will be administered twice-daily doses of ITMN-191 (900mg) and twice-daily R7128 (1000mg), or placebo, for a period of 14 days.

INFORM-1 Initial Study Design

The INFORM-1 study was initially designed to evaluate the safety and combined antiviral activity of ITMN-191 and R7128 in 14 days of combination therapy in treatment-naive patients chronically infected with HCV genotype 1. The original study protocol consisted of four dosage cohorts -- Cohorts A, B, C and D -- comprised of a total of six dosing groups:

-- Cohort A consists of two dosing groups, Group A and Group B. Patients in Group A receive 500mg BID of R7128 as monotherapy for three days, followed by four days of combination therapy comprised of the same dose of R7128 plus 100mg q8h of ITMN-191. Patients in Group B receive 100mg q8h of ITMN-191 as monotherapy for three days followed by four days of combination therapy comprised of the same dose of ITMN-191 plus 500mg BID of R7128.

-- Patients in Cohort B (Group C) receive the same doses of R7128 and ITMN-191 as in Cohort A, but for 14 days in combination.

-- Cohort C consists of two dosing groups, Group D and Group E. Patients in Group D receive 1000 mg BID of R7128 and 100mg q8h of ITMN-191 for 14 days. Patients in Group E receive 500 mg BID of R7128 and 200 mg q8h of ITMN-191 for 14 days.

-- Patients in Cohort D are dosed in one Group (Group F) and receive 1000 mg BID of R7128 and 200 mg of ITMN-191 q8h for 14 days.

About INFORM-1

The INFORM-1 clinical trial, being conducted in centers in Australia and New Zealand, is the first to investigate the combination of two oral direct-acting antiviral medicines in the absence of interferon. This initial study was designed to evaluate the safety and combined antiviral activity of R7227 (ITMN-191), a protease inhibitor, and R7128, a polymerase inhibitor, in 14 days of combination therapy. This direct-acting antiviral combination study represents an important first step in evaluating the therapeutic potential of an all-oral, interferon-free combination treatment for HCV. With InterMune, Roche is developing ITMN-191 (R7227), an HCV protease inhibitor compound to be used in combination with PEGASYS(R) (peginterferon alfa-2a) and COPEGUS(R) (ribavirin), the current standard of care. Concurrently with Pharmasset, Roche is developing R7128, an HCV RNA polymerase inhibitor, also for therapy in combination with PEGASYS(R) and COPEGUS(R). Both of these molecules have successfully completed Phase 1b monotherapy studies, have been dosed in combination with PEGASYS(R) and COPEGUS(R) and both have individually demonstrated safety and robust antiviral activity in HCV patients. Current standard of care for HCV comprises pegylated interferon plus ribavirin, for a duration that is dependent upon factors such as genotype of the virus. For the most difficult to treat genotype 1 virus, a 48-week treatment course generally results in sustained viral response in about 50% of patients. An abstract of interim results from the INFORM-1 study (Cohorts A and B) has been accepted for an oral late-breaker presentation at the 44th Annual Meeting of the European Association for the Study of the Liver (EASL), to be presented on Saturday, April 25 at the EASL meeting in Copenhagen, Denmark. The abstract can be viewed at www.easl.ch

About InterMune

InterMune is a biotechnology company focused on the research, development and commercialization of innovative therapies in pulmonology and hepatology. InterMune has an R&D portfolio addressing idiopathic pulmonary fibrosis (IPF) and hepatitis C virus (HCV) infections. The pulmonology portfolio includes pirfenidone for which a Phase 3 program in patients with IPF (CAPACITY) has been completed and the compound is currently in the pre-registration stage. The company also has a research program focused on a pirfenidone analog named ITMN-520. The hepatology portfolio includes the HCV protease inhibitor compound ITMN-191 (referred to as R7227 at Roche) expected to enter Phase 2b in the summer of 2009 and a second-generation HCV protease inhibitor research program. For additional information about InterMune and its R&D pipeline, please visit www.intermune.com.

Forward-Looking Statements

This news release contains forward-looking statements within the meaning of section 21E of the Securities Exchange Act of 1934, as amended, that reflect InterMune's judgment and involve risks and uncertainties as of the date of this release, including without limitation the statements related to anticipated product development timelines. All forward-looking statements and other information included in this press release are based on information available to InterMune as of the date hereof, and InterMune assumes no obligation to update any such forward-looking statements or information. InterMune's actual results could differ materially from those described in InterMune's forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in detail under the heading "Risk Factors" in InterMune's most recent annual report on Form 10-K filed with the SEC on March 16, 2009 (the "Form 10-K") and other periodic reports filed with the SEC, including the following: (i) risks related to the long, expensive and uncertain clinical development and regulatory process, including having no unexpected safety, toxicology, clinical or other issues or delays in anticipated timing of the regulatory approval process; (ii) risks related to failure to achieve the clinical trial results required to commercialize our product candidates; and (iii) risks related to timely patient enrollment and retention in clinical trials. The risks and other factors discussed above should be considered only in connection with the fully discussed risks and other factors discussed in detail in the Form 10-K and InterMune's other periodic reports filed with the SEC, all of which are available via InterMune's web site at www.intermune.com.

SOURCE InterMune, Inc. -0- 04/21/2009

CONTACT:

Jim Goff of InterMune, Inc.,
+1-415-466-2228, jgoff@intermune.com
Web Site: http://www.intermune.com