InterMune (being developed by Roche) – Danoprevir Hepatitis C Virus NS3/4 Protease Program
In 2002, we entered into a collaboration with InterMune for the discovery of novel small molecule inhibitors of the Hepatitis C Virus, or HCV, NS3/4A protease. Under the terms of Array's collaboration agreement with InterMune, InterMune funded certain drug discovery efforts, preclinical testing, process development and manufacturing in conformity with current Good Manufacturing Practices, or cGMP. InterMune will make milestone payments to us based on the selection and progress of clinical drug candidates, as well as royalties on sales of any products derived from the collaboration. To date, we have received $1.8 million in milestone payments and have the potential to earn an additional $9.0 million if all clinical and commercialization milestones are achieved under the agreement.

From 2002 to 2007, scientists from Array and InterMune collaborated on discovery activities that resulted in the joint discovery of danoprevir, which was acquired by Roche in October 2010 for $175 million. During 2008, InterMune advanced danoprevir in a Phase 1b multiple ascending dose clinical trial evaluating danoprevir in combination with standard of care therapies in treatment naive patients with chronic HCV genotype 1 infection. Results from the trial showed that danoprevir in combination with standard of care resulted in rapid and persistent reductions in HCV RNA in the patients. In addition, viral rebound was not observed in any patients receiving the treatment and danoprevir in combination with standard of care was safe and generally well-tolerated over 14 days.

During 2009, InterMune initiated a Phase 2b trial evaluating danoprevir in combination with standard of care therapies. In April 2010, InterMune announced top-line results from a planned interim analysis of the trial. Danoprevir was administered at either 300 mg three times daily, 600 mg twice daily or 900 mg twice daily for 12 weeks in combination with PEGASYS® (pegylated interferon alfa-2a) and COPEGUS® (ribavirin), compared with placebo for the same duration plus PEGASYS and COPEGUS. In November 2009, InterMune reported that due to a safety signal, dosing in the 900 mg group had been stopped. InterMune reported that results from the study indicate danoprevir plus PEGASYS and COPEGUS are capable of achieving complete early virologic response rates as high as 90% compared to 43% in the placebo group. In addition, InterMune completed a Phase 1b trial (INFORM-1) of danoprevir and a polymerase inhibitor, RG7128.

Development Status: Danoprevir is currently being tested in the following trials:

• Phase 2b trial with boosted danoprevir, PEGASYS and COPEGUS in genotype 1 +4, which enrolled 421 patients
• Phase 2b trial with boosted danoprevir in triple, quad and interferon-free combinations which expects to enroll 421 patients