AbbVie begins Phase IIb clinical trial of HCV drug candidate ABT-493

AbbVie, the development partner of Enanta Pharmaceuticals for protease inhibitors for hepatitis C virus (HCV), has started a Phase IIb clinical trial with Enanta's next-generation protease inhibitor ABT-493.

The trial is designed to assess the safety and efficacy of ABT-493 co-administered with ABT-530, AbbVie's next-generation NS5A inhibitor, to treat HCV patients.

ABT-493 is the second clinical-stage protease inhibitor candidate developed as part of the collaboration between Enanta and AbbVie.

Results from the Phase IIb trial are expected to be reported in 2015 and AbbVie plans to begin Phase III development of the combination next year.

Enanta Pharmaceuticals president and CEO Jay Luly said: "The goal of our collaboration's next-generation protease inhibitor programme is a pan-genotypic, ribavirin-free, once-daily dosing regimen for HCV patients."

The next-generation HCV NS3/4A protease inhibitor ABT-493 is designed to enable once-daily dosing without ritonavir and it is expected to be co-formulated with ABT-530.

Inhibition of the protease, which plays a major role in the viral lifecycle of HCV, prevents non-structural (NS) proteins from forming and prevents replication and survival of the HCV virus.

The two firms have entered into an agreement in 2006 to discover, develop and commercialise HCV NS3 and NS3/4A protease inhibitors and HCV-protease-inhibitor-containing drug combinations.

As part of that deal, AbbVie was responsible for all development and commercialisation activities for ABT-450, the collaboration's lead compound that has been submitted for approval in the US and the EU as part of a multi-drug regimen.

Enanta received $57m and is also eligible to receive payments for regulatory and reimbursement approval milestones, as well as tiered, double-digit royalties worldwide on any revenue allocable to the collaboration's protease inhibitors.