AbbVie joined BMS today in gaining Breakthrough Therapy designation for an investigational Hep C treatment. The three drug combo of ABT-450/r (protease inhibitor and ritonavir), ABT-267 (an NS5A inhibitor) and ABT-333 (a non-nucleoside polymerase inhibitor) treats patients with genotype 1 of the chronic disease.

FDA’s Breakthrough Therapy nod follows a promising Phase II clinical trial, named ‘Aviator’. In that trial, the three-drug combo saw 99% of patients hit the key benchmark of sustained viral response after 12 weeks of therapy. The combo will now move to Phase III trials.

John Leonard, SVP and Chief Scientific Officer, AbbVie, said in a release: “AbbVie is pleased that the FDA has granted Breakthrough Therapy designation to our 3-DAA combination with and without ribavirin. We feel it reflects the potential of this regimen to be important in the treatment of HCV.”

Five days ago, Gilead released data from its Phase II “Lonestar” study, in which the company tested a combination of sofosbuvir, which has been submitted for FDA approval, and ledipasvir. The Foster-City, California based drugmaker said the virus was undetectable in 19 out of 20 subjects after only eight weeks.