Enanta Drops AbbVie Co-Development Of Hepatitis C Drugs

Enanta Pharmaceuticals has decided not to continue co-developing hepatitis C virus (HCV) drugs with AbbVie. The company announced its decision in a press release, stating that it leaves ABT-493, a protease inhibitor, in AbbVie’s capable hands while it focuses on other candidates. Enanta joins Bristol Myers Squibb (BMS) in the pharma giant’s own recent departure from one of its own HCV combo treatments. In October 2014, BMS withdrew its New Drug Application (NDA) for asunaprevir in combination treatment with daclatasvir for the treatment of HCV genotype 1b patients, citing the evolving HCV landscape in the U.S. In other words, Enanta and BMS are facing competition from drugs that provide a cure, such as Gilead’s Sovaldi. Enanta also said that it reached an agreement with AbbVie on sales royalties for ABT-450, a protease inhibitor.

Enanta and AbbVie Co-Development

Enanta states that it has decided not to exercise its co-development option for ABT-493. Jay R. Luly, PhD, President and CEO of Enanta, said, “At this time, we have decided it is better to use our financial resources generated by these partnered assets to advance our other internal proprietary candidates for HCV.” The two companies began their collaboration in 2006. Per that agreement, Enanta is due milestone payments based on regulatory approvals and royalties based on worldwide sales of ABT-493 and any ABT-493-containing regimens. Enanta has also come to an agreement with AbbVie regarding net sales allocations on royalty calculations for ABT-450-containing regimens. Enanta has provided a chart of the allocations in its press release.

Enanta’s EDP-239

Enanta states that it intends to focus its hepatitis C efforts on its newly reacquired NS5A program, which it regained from Novartis, who notified Enanta that it was discontinuing its HCV program. Enanta sold EDP-239, an NS5A inhibitor, to Novartis in 2012. Novartis is handing over proof-of-concept clinical studies and a combination study with EDP-239 and Alisporivir, a cyclophilin inhibitor licensed by Novartis from Debiopharm. EDP-239 is a non-structural (NS) viral protein inhibitor that has demonstrated activity against HCV genotypes. In combination with other HCV therapeutics, EDP-239 works additively or synergistically to reduce HCV replication.

Bicyclolides

Enanta also intends to focus on Bicyclolides, a new class of antibiotics. The company hopes to develop oral and intravenous agents for hospital and community MRSA (methicillin-resistant Staphylococcus aureus) infections. Its lead candidate is EDP-788, a prodrug that is inactive until conversion in the body turns it into an active compound.