Novartis exits hepatitis C market

Novartis called time on its efforts to develop a new therapy for hepatitis C virus (HCV), handing rights to its lead candidate EDP-239 back to partner Enanta Pharmaceuticals.

Novartis cut a $440m deal with Enanta back in 2012 for the drug - which acts as an NS5A inhibitor - with a $36m upfront license fee. The Swiss drugmaker had been developing EDP-239 alongside another in-licensed compound - Debiopharm's cyclophilin inhibitor alisporivir - but suffered a setback that same year after the latter drug was linked to pancreatitis which resulted in a clinical hold by the FDA.

Novartis' latest pipeline update suggests alisporivir remains in development, although Enanta indicated in a statement that its partner took the decision to return rights to EDP-239 because "HCV research would no longer be a strategic focus" for the company.

Enanta also received $11m from Novartis in January 2013 when EDP-239 entered Phase I clinical trials and was also due to receive another $15m on the start of the first Phase 3 study, although this milestone has not yet been reached. Enanta also received $1.8m per year in research funding.

Novartis confirmed that it would complete its current trials of alisporivir but would not pursue further development of the drug, which showed promise in a Phase 2a study reported in 2011, suggesting rights may be returned to Debiopharm.

For Enanta, Novartis' abandonment of EDP-239 is a minor consideration, given that the company is also partnered with AbbVie on its highly-anticipated interferon-free HCV regimen via ABT-450, a protease inhibitor discovered during their eight-year collaboration.

The agreement with AbbVie provides significant milestone payments to Enanta - $40m in the second quarter of this year for example - along with ongoing R&D funding.

A three-drug, fixed combination of ABT-450/ritonavir, ombitasvir (ABT-267) and dasabuvir could reach the market in Europe and the US early next year, and has been tipped to make almost $3bn in peak sales.

That would be a more-than-solid solid performance, even if it is eclipsed by the stellar success of Gilead Sciences' rival drug Sovaldi (sofosbuvir) which generated $5.75bn in the first six months of the year after being launched in December 2013.

The termination of Novartis' license results in "the transition of EDP-239 and the other NS5A inhibitor compounds developed under the collaboration back to Enanta, as well as completion or transition of specified proof-of-concept clinical studies currently underway involving EDP-239, and a combination study with EDP-239 and alisporivir," said the US firm in a Securities & Exchange Commission (SEC) filing.

Enanta also has a proprietary HCV portfolio which includes a cyclophilin inhibitor and nucleotide polymerase inhibitor programs, both of which are in preclinical development, and has also developed a new class of antibiotics called bicyclolides to treat multi-drug resistant bacteria.

"Enanta is now positioned with three wholly-owned HCV programmes from which future drug combinations can be explored," said the company's chief executive Jay Luly.